tclmqmsgque

A library to connect things, run a server and integrate an application.

SYNOPSIS

The tclmqmsgque package is the implementation of the Programming-Language-Micro-Kernel (PLMK) into the target-language Tcl.

• package require tclmsgque::MqMsgque

The tclmqmsgque package is a composition of multiple classes defining the Programming-Language-Micro-Kernel (PLMK) :

object	description
tclmsgque::MqMsgque	the namespace with all tclmqmsgque specific definitions
tclmsgque::MqMsgque Attribute	the interface to access the package specific attribute
tclmsgque::MqMsgque::MqClassC Attribute	the interface to access the class specific attribute
$Instance Attribute	the interface to access the instance specific attribute

To access all features without tclmsgque::MqMsgque prefix use:

• namespace import tclmsgque::MqMsgque::*

Using the tclmqmsgque package ...

TCL package libraries

libtclmqmsgque.so	A shared library or shared object is a computer file that contains executable code designed to be used by multiple computer programs or other libraries at runtime.
libtclmqmsgque.la	A .la file is a text file used by the GNU libtools package to describe the files that make up the corresponding library.

> man n env

To access the tclmqmsgque package the environment variable TCLLIBPATH have to include the directory.

TCLLIBPATH
      If set, then it must contain a valid Tcl list giving directories to search during auto-load operations.
      Directories must be specified in Tcl format, using “/” as the path separator, regardless of platform.  
      This variable is only used when initializing the auto_path variable.

> man n pkg_create

::pkg::create is a utility procedure that is part of the standard Tcl library.
It is used to create an appropriate `package ifneeded` command for a given package specification.
It can be used to construct a `pkgIndex.tcl` file for use with the package mechanism.

> The syntax of the pkgIndex.tcl file is simple

package ifneeded tclmsgque::MqMsgque 9.0 [list load [file join $dir libtclmqmsgque.so]]

---

TABLE OF CONTENTS

BASICS

Index , Philosophy , ConfigFile

CLASS

MqMsgque PACKAGE , MqContextC , MqDumpC , MqFactoryC

CONTEXT

Class, Config, Link, Service, Send, Read, Route, Proxy, Slave, Storage, High, CallEnv, Error, Log

MISC

InstStor, Filter, Examples

INTRODUCTION

C-API: MQ_C_API - theLink - a API to link multiple package-items together to act as one application …

PHILOSOPHY

The theLink project is an infrastructure that allows multiple package-items to be linked together to act as one application.
To link, you need to distribute the work from one package-item to another package-item and wait for an answer or not.

Philosophy

Write Once → Run Everywhere

The package-item can be a thread, a separate local process that is started by fork or spawn, or even a network of multiple services on multiple hosts.

The package-item can be written in any language that is supported by the Programming-Language-Micro-Kernel (PLMK) support.
It even supports running multiple programming languages in a single piece of software.
Supported Languages are: (C,C++,C#,VB.NET,Java,Python,Ruby,Perl,PHP,Tcl or GO)

Strategy

It takes 4 years to write a programming-language, but it only takes 4 weeks to insert a micro-kernel.

The package-item is connected to one another via a pipe or a socket and is based on packages which are sent from one package-item to another package-item and back.

Conclusion

theLink is used to manage a network of multiple package-items using an API that is available in all major programming-languages.

PROGRAMMING

theLink is responsible for:

• establishing and managing the package-items, local or remote
• establishing and managing the connections between package-items
• establishing and managing the routing between package-items
• sending and receiving the package data, calling up a service
• reading and writing data from or into a data-package
• setup and maintain event-handling and scheduling
• interception, distribution and processing of error messages

The LibMsgque library is separted into three programming-layers:

1. The foundation-layer, used by theLink library programmer
2. The kernel-layer, used by the Programming-Language-Micro-Kernel programmer
3. The implementation-layer, used by the target-language programmer

foundation-layer

The foundation-layer implement the libmqmsgque library and is also responsible for the quality-target of the entire project.

• establishing and managing the package-items
• establishing and managing the connections
• memory-management and garbage-collection
• error-handling
• logging and debugging
• written in plain C

kernel-layer

The kernel-layer implement the Programming-Language-Micro-Kernel and is also responsible to generate and maintain the target-language-API source-code.

• implementation of the managed-object technology
• implementation of the token-stream-compiler technology
• written in plain C, TCL and the target-language-API

implementation-layer

The implementation-layer is the API used by the target-language-programmer.

• written in plain Target-Programming-Language (TPL)

Target

!! This documentation describe the implementation-layer and target the Tcl programmer. !!

CONFIG FILE

C-API: MqConfigS::cfg - add libconfig configuration file …

introduction

A config-file is used to add configuration-values to a libmqmsgque-application using a structured text-file.

supported

By default command-line-options; filter-pipline and slave-worker-setup is supported.

A service-callback and "programming" is not supported. To "programm and modify" something use a scripting language like tcl or python.

goal

The goal is to give the user of a compiled application the ability to provide a single place for common-configuration-values.

technology

libconfig is used to parse a config-file using the application … --config fileName … option.

syntax

The config-file syntax is defined at: http://hyperrealm.github.io/libconfig/libconfig_manual.html

The following restrictions apply to the --config option.

1. The config-file is parsed when the --config option is parsed
2. An application is identfied in the config-file by groupname : { ... } ( ":" or "=" is allowed )
3. The groupname is the return from MqClassIdentGet using hint from --ident-from prefix|factory
4. The groupname is modified with the --name string, --prefix string or --ident-from prefix|factory naming-options
5. The order of option-parsing is the order on the command-line
   MyClient … --XXX … --config YYY … --ZZZ …
   order MyClient : XXX < YYY < ZZZ
6. For a pipe the config-file from the client is added to the end of the server-options :
   MyClient --AAA … --config BBB --CCC … @ Filter3 --name otto --DDD … @ MyServer --EEE …
   

   application	groupname	option-parsing-order
   MyClient	MyClient	AAA < BBB < CCC
   Filter3	otto	DDD < BBB
   MyServer	MyServer	EEE < BBB

   This is required because the --name or --prefix option from DDD or EEE change the group read from the config-file
7. attention! on a client or a non-pipe server it is a difference if the naming-option is set before or after the --config option
8. All options set after the --config option overwrite the options from the config-file
9. The filter ( groupname : { … filter : [ … ] } ) config-file-option define the server to start in a pipe and have to be an array of strings starting with the application-executable OR the factory-identifer

examples

1. Example from MyClient.config → filter-pipeline with last server start in debug mode

 
# commandline OLD: MyClient @ Filter3 @ MyServer --debug 1
# commandline NEW: MyClient --config MyClient.config
 
version = "1.0"               ; // string : version of the configuration file reader
default = "MyClient"          ; // string : if the 'class' is unknown use 'default'
 
MyClient:
{
  config:
  {
  # name = "myName"             ; // string : displayname name of the 'context' (default: executable basename)
  # identFrom = "prefix"        ; // list   : select how to identify the application from remote: 'prefix' or 'factory' (default: prefix)
  # prefix = ""                 ; // string : set the 1'part of the visible displayname (default: "" = FactoryName)
  # postfix = ""                ; // string : set the 2'part of the visible displayname (default: "" = ConnectionName)
  # string = false              ; // bool   : (default: no)
  # startAs = "default"         ; // string : from list (ref… MqStartE): default, spawn, thread, fork (default: default)
  # daemon = "MyServer.pid"     ; // string : file for PID
  # timeout = 90                ; // int    : user defined timeout to terminate a blocking function call (default: 90 sec)
  # storage = "#memdb#"         ; // string : storage file for the database: #memdb#, #tmpdb# or filename (default: #memdb#)
 
  # runtime = {                   // struct (ref… MkRuntimeS) : runtime configuration (global)
    # debug = 1                 ; // int    : set the debug-level, Valid values are 0 <= debug <= 9 using 0 for "no" and 9 for "max". (default: 0)
    # silent = false            ; // bool   : write (no) or don't write (yes) any message to stdout or stderr (default: no)
    # logfile = "stderr"        ; // string : append to logfile, valid values are: stderr, stdout or a filename (default: stderr)
  # };
 
  # io = {                        // struct (ref… MqIoComE) : what kind of socket interface to use? (default: pipe)
 
    # buffersize = 4096           // int    : io buffersize (default: 4096)
    # pkgsize = 10240             // int    : io pkgsize (default: 10 * 1024)
 
    # pipe = true;                // struct (ref… MqIoPipeConfigS) → ONLY client (default: true)
    # init = false;               // struct (ref… MqIoInitConfigS) → ONLY server (default: false)
 
    # tcp = {                     // struct (ref… MqIoTcpConfigS)
      # port = "7777"           ; // string : port number or well known port name
      # host = "localhost"      ; // string : hostname / interfacename
      # myport = "1111"         ; // string : client MY port number or well known port name
      # myhost = "localhost"    ; // string : client MY hostname / interfacename
    # };
 
    # uds = {                     // struct (ref… MqIoUdsConfigS)
      # file = "filename"       ; // string : name of a uds-socket-file (default: null)
    # }
 
  # };
  };
 
  # start executable "Filter3" in a "@" pipe and change application-name (groupname) to "otto" 
  filter = [ "Filter3", "--name", "otto" ]        ; // array of string : filter pipeline name of "server"
};
 
# config section for "Filter3" start in the "pipe"
otto = {
  filter = [ "MyServer" ] ;
}
 
# final "MyServer" set option "debug" to "1"
MyServer = {
  config: { runtime: {debug = 1} }
  # 'config.runtime.debug = 1' is NOT supported.
}
 

2. Example from libconfig.test → filter-pipeline with last server connect by tcp/ip

            # OLD: MyClient @ Filter3 @ --tcp --port $PORT
            # NEW: MyClient --config configFile
            version: 1.0
            default = "MyClient"
            MyClient: {
              filter: [ "Filter3" ]
            }
            Filter3: {
              filter: [ "--tcp", "--port", "$PORT" ]
            }

---

MqMsgque PACKAGE

MqMsgque SETUP
		Cleanup	cleanup tclmqmsgque internal memory …
		Setup	setup tclmqmsgque internal memory …
MqMsgque ENUM
		enum MqWaitOnEventE	wait for an event? …
		enum MqStatusIsEF	Information about how the context was created.
		enum MqStartE	User preferences on HOWTO start a new entity.
		enum MqSlaveE	predefined slave-id for well known slaves …
		enum MqIdentE	identify the application using prefix (default) or factory …
MqMsgque HELP
		Help	write tclmqmsgque specific user-help to stderr
		HelpMsgque	return a page with the usage of all tclmqmsgque specific options
MqMsgque INIT
		InitGetArg0	get the process startup-prefix argument
		InitResetArg0	Reset the process-startup-prefix argument to an empty list …
		InitSetArg0	set the process startup-prefix argument to bfl
MqMsgque MAIN
		Main	Main entrypoint - start the application

MqMsgque DETAIL

C-API: MqMsgque_C_API - MqMsgque PACKAGE - the package is the toplevel structure of the tclmqmsgque …

The tclmqmsgque package is loaded with:

‍package require tclmsgque::MqMsgque

and is a composition of one or more package-item and exact one package-main.

The tclmqmsgque package add the following classes into MkObjectC_C_API :

Object	C-Short	Description
MqContextC	MQ_CTX	MqContextC - the class known as ctx or context is the application-handle of the application-server and also the main data-handle …
MqDumpC	MQ_DMP	MqDumpC - the class known as dmp or dump is used to export a tclmqmsgque data package as binary …
MqFactoryC	MQ_FCT	MqFactoryC - the class known as fct or factory is used to provide an interface to create one or more new MqContextC …

The tclmqmsgque package add the following types into MkObjectC_C_API :

ABSTRACT: MkTypeSTT (TypeTypeType = type of a TypeType)
|
|- ABSTRACT: MqCtxTypeC_TT (TypeType = type of a Type)
|  |
|  |- MqContextC_T
|
|- ABSTRACT: MkSuperTypeSTT (TypeType = type of a Type)
   |
   |- MqFactoryST, MqDumpST

---

MqMsgque SETUP

C-API: MqMsgque_Setup_C_API - MqMsgque PACKAGE - setup und cleanup the tclmqmsgque …

For details about MqSetup and MqCleanup usage refer to MkKernel_Setup_libmkkernel_C_API

(static) MqMsgque Cleanup

top cleanup tclmqmsgque internal memory … → API: tcl_mqmsgque_MqMsgque_Cleanup

MkCleanup can only be called once and will be ignored if not called in the same thread as MqSetup. after a call to MqSetup the call to MkCleanup is possible again.

Attention

during cleanup objects will be deleted too -> the language interpreter have to be active

(static) MqMsgque Setup

top setup tclmqmsgque internal memory … → API: tcl_mqmsgque_MqMsgque_Setup

MqSetup can only be called once, additional call's will be ignored until a MqCleanup is called.

MqMsgque ENUM

C-API: MqMsgque_Enum_C_API - MqMsgque PACKAGE - enum definition …

read more at: MkKernel_Enum_C_API

enum MqIdentE

top identify the application using prefix (default) or factory … → API: tcl_mqmsgque_Get_MqIdentE_FromObj

enum MqIdentE {
  MQ_IDENT_PREFIX     = 0   ,   
  MQ_IDENT_FACTORY    = 1       
};

See also

MqConfigGetIdentFrom, MqConfigSetIdentFrom, MqIdentE_ToString

(static) MqIdentE [MqMsgque IdentE_FromInt value:int32]

top return the MqIdentE from integer … → API: tcl_mqmsgque_MqMsgque_IdentE_FromInt

(static) int32 [MqMsgque IdentE_ToInt value:MqIdentE]

top return the MqIdentE as integer … → API: tcl_mqmsgque_MqMsgque_IdentE_ToInt

(static) string [MqMsgque IdentE_ToString value:MqIdentE]

top return the MqIdentE as string … → API: tcl_mqmsgque_MqMsgque_IdentE_ToString

enum MqSlaveE

top predefined slave-id for well known slaves … → API: tcl_mqmsgque_Get_MqSlaveE_FromObj

__parser__(enum-accept-integer=int32)
enum MqSlaveE {
  MQ_SLAVE_LOOPBACK =   0,      
  MQ_SLAVE_FILTER   =   1,      
  MQ_SLAVE_MASTER   =   1,      
  MQ_SLAVE_OTHER    =   1,      
  MQ_SLAVE_USER     =   10,     
 
  MQ_SLAVE_MAX      =   1024,
};

See also

MqServiceProxy, MqSlaveWorker, MqSlaveCreate, MqSlaveDelete, MqSlaveCheck, MqSlaveGet, MqSlaveGetProxy

(static) MqSlaveE [MqMsgque SlaveE_FromInt value:int32]

top return the MqSlaveE from integer … → API: tcl_mqmsgque_MqMsgque_SlaveE_FromInt

(static) int32 [MqMsgque SlaveE_ToInt value:MqSlaveE]

top return the MqSlaveE as integer … → API: tcl_mqmsgque_MqMsgque_SlaveE_ToInt

(static) string [MqMsgque SlaveE_ToString value:MqSlaveE]

top return the MqSlaveE as string … → API: tcl_mqmsgque_MqMsgque_SlaveE_ToString

enum MqStartE

top User preferences on HOWTO start a new entity. → API: tcl_mqmsgque_Get_MqStartE_FromObj

enum MqStartE {
  MQ_START_DEFAULT     = 0,         
  MQ_START_FORK        = 1,         
  MQ_START_THREAD      = 2,         
  MQ_START_SPAWN       = 3,         
};

See also

MqConfigSetStartAs, MqConfigCheckStartAs, MqConfigGetStartAs, MqStartE_ToString

(static) MqStartE [MqMsgque StartE_FromInt value:int32]

top return the MqStartE from integer … → API: tcl_mqmsgque_MqMsgque_StartE_FromInt

(static) int32 [MqMsgque StartE_ToInt value:MqStartE]

top return the MqStartE as integer … → API: tcl_mqmsgque_MqMsgque_StartE_ToInt

(static) string [MqMsgque StartE_ToString value:MqStartE]

top return the MqStartE as string … → API: tcl_mqmsgque_MqMsgque_StartE_ToString

enum MqStatusIsEF

top Information about how the context was created. → API: tcl_mqmsgque_Get_MqStatusIsEF_FromObj

__parser__(enum-is-flag)
enum MqStatusIsEF {
  MQ_STATUS_IS_INITIAL = 0,         
  MQ_STATUS_IS_DUP     = 1<<0,      
  MQ_STATUS_IS_THREAD  = 1<<1,      
  MQ_STATUS_IS_FORK    = 1<<2,      
  MQ_STATUS_IS_SPAWN   = 1<<3,      
};

See also

MqConfigGetStatusIs, MqStatusIsEF_ToString

(static) MqStatusIsEF [MqMsgque StatusIsEF_FromInt value:int32]

top return the MqStatusIsEF from integer … → API: tcl_mqmsgque_MqMsgque_StatusIsEF_FromInt

(static) int32 [MqMsgque StatusIsEF_ToInt value:MqStatusIsEF]

top return the MqStatusIsEF as integer … → API: tcl_mqmsgque_MqMsgque_StatusIsEF_ToInt

(static) string [MqMsgque StatusIsEF_ToString value:MqStatusIsEF]

top return the MqStatusIsEF as string … → API: tcl_mqmsgque_MqMsgque_StatusIsEF_ToString

enum MqWaitOnEventE

top wait for an event? … → API: tcl_mqmsgque_Get_MqWaitOnEventE_FromObj

enum MqWaitOnEventE {
  MQ_WAIT_NO      = 0,
  MQ_WAIT_ONCE    = 1,
  MQ_WAIT_OWN     = 2,
  MQ_WAIT_FOREVER = 3,
};

See also

MqProcessEvent

(static) MqWaitOnEventE [MqMsgque WaitOnEventE_FromInt value:int32]

top return the MqWaitOnEventE from integer … → API: tcl_mqmsgque_MqMsgque_WaitOnEventE_FromInt

(static) int32 [MqMsgque WaitOnEventE_ToInt value:MqWaitOnEventE]

top return the MqWaitOnEventE as integer … → API: tcl_mqmsgque_MqMsgque_WaitOnEventE_ToInt

(static) string [MqMsgque WaitOnEventE_ToString value:MqWaitOnEventE]

top return the MqWaitOnEventE as string … → API: tcl_mqmsgque_MqMsgque_WaitOnEventE_ToString

MqMsgque HELP

C-API: MqMsgque_Help_C_API - MqMsgque PACKAGE - access to a qualified help-message …

(static) string [MqMsgque Help tool:string]

top write tclmqmsgque specific user-help to stderr → API: tcl_mqmsgque_MqMsgque_Help

Parameters

tool	the name of the tool (e.g. argv[0]) or NULL.

Returns

the help messages as string

If tool != NULL, the function will display a header like:

 tool [ARGUMENT]... syntax:
   aclient [OPTION]... @ tool [OPTION]... @...

on the help page.

(static) string [MqMsgque HelpMsgque]

top return a page with the usage of all tclmqmsgque specific options → API: tcl_mqmsgque_MqMsgque_HelpMsgque

MqMsgque INIT

C-API: MqMsgque_Init_C_API - MqMsgque PACKAGE - initialize the MqContextC startup and/or external-object-link …

(static) MkBufferListC [MqMsgque InitGetArg0]

top get the process startup-prefix argument → API: tcl_mqmsgque_MqMsgque_InitGetArg0

Returns

a pointer to the initialization buffer (Only C-API)

Attention

if not set return a "MK_NULL" pointer

(static) MkBufferListC [MqMsgque InitResetArg0]

top Reset the process-startup-prefix argument to an empty list … → API: tcl_mqmsgque_MqMsgque_InitResetArg0

The startup-prefix have to be the name of the executable, found in the PATH environment variable, and additional arguments like the script name or the required startup options. The startup-prefix is used for two different purpose:

• To start a new entity using the MqStartAs "--spawn" command-line option.
• To replace the command-line-argument "... @ SELF ..." with "... @ startup-prefix ..." at LinkCreate.

Every use of this function will free the data of the previous startup-prefix. By default the startup-prefix is set during application startup by tclmqmsgque and have not to be initialized again.

Example from server.tcl → initialize the startup-prefix with the data read from service-args

  method Ot_INIT {} {
    my SendSTART
    tclmsgque::MqMsgque InitSetArg0 [my ReadALL]
    my SendRETURN
  }

See also

MqInitSetArg0 MqInitGetArg0

(static) MqMsgque InitSetArg0 ?bfl:MkBufferListC...="MK_NULL"?

top set the process startup-prefix argument to bfl → API: tcl_mqmsgque_MqMsgque_InitSetArg0

The startup-prefix is the argument(s) required to start the application… this is minimal the binary-path for binaries (same as as used on command-line) or the interpreter+scriptFile for scripts.

Parameters

[in]

bfl

the object will be merged into the startup-prefix, afterwords the bfl is empty and can be deleted

Example

Initialize the application startup command in C

MqInitSetArg0(MkBufferListCreateV("myExec", "myExecArgument_1")); 

MqMsgque MAIN

C-API: MqMsgque_Main_C_API - MqMsgque PACKAGE - the package-main is a single piece of code evaluated only once at application startup …

Example from MyServer.tcl → The package-main configure the factory and start the server.

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*
namespace import tclmsgque::MkKernel::*

# package-item
::oo::class create MyServer {
  superclass MqContextC

  # service to serve all incoming requests for token "HLWO"
  method myFirstService {} {
    my SendSTART
    my SendSTR "[my ReadSTR] World"
    my SendRETURN
  }

  # define a service as link between the token "HLWO" and the callback "MyFirstService"
  method serverSetup {} {
    my ServiceCreate "HLWO" myFirstService
  }

  # factory startup (constructor)
  constructor {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup serverSetup
  }
} 

# package-main
tclmsgque::MqMsgque Main {

  # setup commandline arguments for later use
  set args  [MkBufferListC CreateLA {*}$argv]

  # create "MyServer" factory... and make it to the default.
  set fct   [[MqFactoryC Add MyServer] Default]

  # inspect commandline-argument for the "factory" to choose... and create a object
  set fct   [MqFactoryC GetCalledL $args]
  set srv   [$fct New]

  try {
    $srv LinkCreate $args
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

(static) MqMsgque Main code:...

top Main entrypoint - start the application → API: MqMain

Tcl has a special requirement, for every new server-thread a new interpreter is created and
this interpreter source the toplevel file for initialization. This file is set on library startup and
can be changed with MqInitResetArg0. The problem is the server startup code from the toplevel. For internal
purpose this code should only be executed on application-startup (like the C main function)
and not for every thread again.

---

MqContextC

SUPER: MkObjectC, top

MqContextC CLASS
		Export	MqContextC - Export class functions …
		Introspection	MqContextC - Introspection class functions …
		Misc	MqContextC - Misc class functions …
MqContextC TOR
		Create	create and initialize the MqContextC ...
		new	create and initialize the MqContextC ...
		Delete	Destructor - delete a MqContextC instance …
MqContextC CLASS API			MqContextC - access data related to the factory-type of the object …
MqContextC CONFIG API
		Get	MqContextC - various function to 'get' the configuration-data from a context …
		Interface	MqContextC - various function to setup a interface for the context …
		Misc	MqContextC - various function to do 'misc' configuration …
		Set	MqContextC - various function to 'set' the configuration-data in a context …
MqContextC ENV API			MqContextC - protect and restore the service-environment …
MqContextC ERROR API			MqContextC - move and copy an error from a context …
MqContextC HIGH API			MqContextC - User friendly replacement for the MqContextC_SendApi_C_API and the MqContextC_ReadApi_C_API …
MqContextC LINK API			MqContextC - setup and manage a client-server-link …
MqContextC LOG API			MqContextC - log the output to a string or a MkLogFileC …
MqContextC MISC API			MqContextC - various functions to work on a context …
MqContextC PROXY API			MqContextC - copy data from the read-data-package of the sourceCtx to the send-data-package of the targetCtx
MqContextC READ API
		Atom	MqContextC - read a single-data-item outof a read-data-package …
		Block	MqContextC - read a block-of-data outof a read-data-package …
		Misc	MqContextC - various functions to work on a read-data-package …
MqContextC ROUTE API			MqContextC - setup and manage a routing-link …
MqContextC SEND API
		Atom	MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …
		Basics	MqContextC - finish the send-data-block and call synchronous/asynchronous a remote-service …
		Block	MqContextC - a wrapper to send a list-block or a transaction-block …
		Return	MqContextC - finish the send-data-block on the server and optional return the results. …
MqContextC SERVICE API			MqContextC - create and manage a service …
MqContextC SLAVE API			MqContextC - create and manage a slave context …
MqContextC STORAGE API			MqContextC - setup and manage a storage used to persist data-packages …

MqContextC DETAIL

C-API: MqContextC_C_API - MqContextC - the class known as ctx or context is the application-handle of the application-server and also the main data-handle …

The context is the package-item with the required features and created by the implementation-layer-programmer. The context can be a client or a server.

HOWTO client-context

The client-context-creation is triggerd by the software-workflow on demand. The client is calling the MqLinkCreate to create a connection to the server using the connection-arguments to specify the target.

The life-cycle of a client is:

ContextCreate	create and initialize the MqContextC ...
LinkCreate	make ctx to a parent-context and setup a new client-server-link …
SendTT	MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …
ReadTT	read a PRIMITIVE TYPE from the read-data-package …
LinkDelete	close the client-server-link …
ContextDelete	Destructor - delete a MqContextC instance …
Exit	delete the context and exit the current process or thread …

HOWTO server-context

The server-context-creation is always triggerd by the MqLinkCreate command of the client. The server is usually using a factory-constructor to call the MqContextCreate and finally to call the MqContextDelete.
The server-context is fully under control of the client.

The life-cycle of a server is:

SETUP	define a class and add the setup/cleanup code
IServerSetup	define the server-setup-interface (callback) used on startup …
ServiceCreate	create a link between a service-token and a service-callback …
IServerCleanup	define the server-cleanup-interface (callback) used on cleanup …
ServiceDelete	delete a service. …
STARTUP	define the factory and start the listener
FactoryAdd	add a new MqFactoryC identified by factory-identifier and defined by factory-constructor …
FactoryNew	create a new MqContextC from a MqFactoryC …
LinkCreate	make ctx to a parent-context and setup a new client-server-link …
ProcessEvent	enter the event-loop and wait for an incoming service-request. …
WORK	process the service-calls and exit on end
ReadTT	read a PRIMITIVE TYPE from the read-data-package …
SendTT	MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …
Exit	delete the context and exit the current process or thread …

MqContextC CTOR and DTOR

command	alias
(constructor,static) MqContextC [MqContextC Create ?tmpl:MqContextC="MK_NULL"?]	tclmsgque::MqContextC new ?tmpl:MqContextC=""?
(destructor) $ctx Delete	rename $ctx ""

MqContextC CLASS

NAVI: top, up

MqContextC CLASS EXPORT

		HandleResolve	Handle-Resolve-Slot - return a MqContextC from netHdl or "MK_NULL" if invalid…
		HandleGet	Handle-Get-Slot - returns a export-hdl to the MqContextC useable for external storage

MqContextC CLASS INTROSPECTION

		Instances	get head-instance from linked-list of MqContextS type …
		Next	get next instance from linked-list of MqContextS type
		Prev	get previous instance from linked-list of MqContextS type

MqContextC CLASS MISC

GetNull

Null-Slot - return a MqContextC typed NULL instance …

MqContextC CLASS DETAILS

C-API: MqContextC_Class_C_API - MqContextC - define the class …

MqContextC CLASS EXPORT

MqContextC - Export class functions …

(static) MqContextC [MqContextC HandleResolve netHdl:MK_HDL]

top Handle-Resolve-Slot - return a MqContextC from netHdl or "MK_NULL" if invalid… → API: tcl_mqmsgque_MqContextC_HandleResolve

The MqContextHandleResolve undo the MqContextHandleGet and is intended to export a unique identifer into external code not belonging to the Programming-Language-Micro-Kernel (PLMK).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	netHdl	handle former exported with MqContextHandleGet

Returns

the required handle or "MK_NULL" if netHdl is invalid

MK_HDL [$ctx HandleGet]

top Handle-Get-Slot - returns a export-hdl to the MqContextC useable for external storage → API: tcl_mkkernel_MkObjectC_HandleGet

The export-hdl is a reference to an instance that can be stored in software and converted back into an instance using the MqContextHandleResolve.

The export-hdl is only valid until the Programming-Language-Micro-Kernel (PLMK) ends.

example: The export-hdl is used in rpc to identify an object across the network.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Returns

the required export-hdl

MqContextC CLASS INTROSPECTION

MqContextC - Introspection class functions …

(static) MqContextC [MqContextC Instances]

top get head-instance from linked-list of MqContextS type … → API: tcl_mqmsgque_MqContextC_Instances

The head-instance is the last instance created.

MqContextC [$ctx Next]

top get next instance from linked-list of MqContextS type → API: tcl_mqmsgque_MqContextC_Next

MqContextC [$ctx Prev]

top get previous instance from linked-list of MqContextS type → API: tcl_mqmsgque_MqContextC_Prev

MqContextC CLASS MISC

MqContextC - Misc class functions …

(static) MqContextC [MqContextC GetNull]

top Null-Slot - return a MqContextC typed NULL instance … → API: tcl_mqmsgque_MqContextC_GetNull

MqContextC TOR

C-API: MqContextC_TOR_C_API - MqContextC - various functions to create, initialize and destroy a context …

(constructor,static) MqContextC [MqContextC Create ?tmpl:MqContextC="MK_NULL"?]

top create and initialize the MqContextC ... → API: tcl_mqmsgque_MqContextC_Create

This function is used to create a single new context… primary on the client. to create multiple new context on a server… a MqFactoryC is used.

The new instance belongs to the caller and may have to be released if necessary. A manual release using ContextDelete is always possible, but the instance can no longer be used afterwards.

Example from MyClient.tcl → create a context using the static tclmqmsgque CTOR

package require tclmsgque::MqMsgque

# create a context using the static tclmsgque CTOR method "Create"
set ctx [tclmsgque::MqMsgque::MqContextC Create]
try {
  $ctx ConfigSetName "MyClient"
  $ctx LinkCreate {*}$argv
  $ctx SendSTART
  $ctx SendSTR "Hello"
  $ctx SendEND_AND_WAIT "HLWO" 
  puts [$ctx ReadSTR]
} on error {} {
  $ctx ErrorCatch
} finally {
  # delete the context using the tclmsgque APPLICATION-DTOR method "Exit"
  $ctx Exit
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	type	type type of the object like MqContextC_T or a new type created with MkTypeDup2. (default: "MK_NULL", reuse the MkTypeSTT from tmpl or use MqContextC_T if tmpl = "MK_NULL")
[in]	tmpl	an other context-data-structure used as template to initialize the configuration data. This template is used for a child to get the configuration data from the parent. (default: "MK_NULL", create an initial context)

Returns

The newly created MqContextC instance, the instance is owned by the caller

See also

MqContextDelete, MqExit

(constructor,static) MqContextC [MqContextC new ?tmpl:MqContextC="MK_NULL"?]

top create and initialize the MqContextC ... → API: tcl_mqmsgque_MqContextC_new

This function is used to create a single new context… primary on the client. to create multiple new context on a server… a MqFactoryC is used.

The new instance belongs to the caller and may have to be released if necessary. A manual release using ContextDelete is always possible, but the instance can no longer be used afterwards.

Example from MyClient.tcl → create a context using the static tclmqmsgque CTOR

package require tclmsgque::MqMsgque

# create a context using the static tclmsgque CTOR method "Create"
set ctx [tclmsgque::MqMsgque::MqContextC Create]
try {
  $ctx ConfigSetName "MyClient"
  $ctx LinkCreate {*}$argv
  $ctx SendSTART
  $ctx SendSTR "Hello"
  $ctx SendEND_AND_WAIT "HLWO" 
  puts [$ctx ReadSTR]
} on error {} {
  $ctx ErrorCatch
} finally {
  # delete the context using the tclmsgque APPLICATION-DTOR method "Exit"
  $ctx Exit
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	type	type type of the object like MqContextC_T or a new type created with MkTypeDup2. (default: "MK_NULL", reuse the MkTypeSTT from tmpl or use MqContextC_T if tmpl = "MK_NULL")
[in]	tmpl	an other context-data-structure used as template to initialize the configuration data. This template is used for a child to get the configuration data from the parent. (default: "MK_NULL", create an initial context)

Returns

The newly created MqContextC instance, the instance is owned by the caller

See also

MqContextDelete, MqExit

(destructor) $ctx Delete

top Destructor - delete a MqContextC instance … → API: MqContextDelete_RT

Shutdown the client-server-link, free the memory and set the ctx to "MK_NULL". The context can not be reused.

Example from MyClient2.tcl → delete a application-context using the tclmqmsgque DTOR

package require tclmsgque::MqMsgque
 
# create a context using the default CTOR method "new"
set ctx [tclmsgque::MqMsgque::MqContextC new]
try {
  $ctx ConfigSetName "MyClient"
  $ctx LinkCreate {*}$argv
  $ctx SendSTART
  $ctx SendSTR Hello
  $ctx SendEND_AND_WAIT "HLWO" 
  puts [$ctx ReadSTR]
} on error {} {
  $ctx ErrorCatch
} finally {
  # delete context using the DTOR method "Delete"
  $ctx Delete
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

See also

MqContextCreate

MqContextC CLASS API

NAVI: top, up

		ClassFactoryGet	get the MqFactoryC used by the MqContextC
		ClassFactorySet	link the MqContextC to a new MqFactoryC
		ClassIdentGet	get the application-identification …
		ClassIdentSet	link the MqContextC to a new MqFactoryC identified by ident
		ClassOriginalIdentGet	get the MqFactoryS::originalIdent from the MqContextC

MqContextC CLASS API DETAILS

C-API: MqContextC_ClassApi_C_API - MqContextC - access data related to the factory-type of the object …

The type of an object is related to the MqFactoryC. The factory decide which class a new created object has. The factory has two identifiers:

• the current name MqClassIdentGet
• the original name MqClassOriginalIdentGet

The relevance of the MqContextC CLASS API based type system, provided by MqFactoryC, decreased with the rise of the MANAGED OBJECT technology.
The MqContextC CLASS API based type system has more influence for target-languages without reflection, like C or C++.
The factory is something like a constructor but only support the application-context MqContextC .
The MqContextC ROUTE API using the MqClassIdentGet from MqFactoryC to identify an application from remote.

MqFactoryC [$ctx ClassFactoryGet]

top get the MqFactoryC used by the MqContextC → API: tcl_mqmsgque_MqContextC_ClassFactoryGet

Parameters

[in]

ctx

the MqContextC to extract the MqFactoryC from

Returns

the MqFactoryC

$ctx ClassFactorySet item:MqFactoryC

top link the MqContextC to a new MqFactoryC → API: tcl_mqmsgque_MqContextC_ClassFactorySet

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextC to be linked with the MqFactoryC
[in]	item	the MqFactoryC to link with

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

string [$ctx ClassIdentGet]

top get the application-identification … → API: tcl_mqmsgque_MqContextC_ClassIdentGet

Parameters

[in]

ctx

the MqContextC to extract the ident from

Returns

the identifer or an empty string if ident was not set

An application has TWO possible names:

1. The name from the context the application was configured with.
2. The name from the factory the application was created with.

The --ident-from prefix|factory value decide which on is used.

The application-identification is defined by MqConfigS::identFrom :

MqFactoryS::originalIdent	if ident == MQ_IDENT_FACTORY
MqConfigS::prefix	if ident == MQ_IDENT_PREFIX (default)

The MqFactoryS::originalIdent is the official name of the MqFactoryC and is defined by the application-programmer with MqFactoryAdd or MqFactoryDup2.

The MqConfigS::prefix is the official name of the MqContextC that startet first, usually the server-name, and is set by the application-user with --prefix string at startup or with the MqConfigSetPrefix at setup.

When the server starts, the MqClassIdentGet value is send from the server to the client and the client initializes the MqLinkS::targetIdent with this value. This value identifes the server from remote and is used by the MqContextC ROUTE API to select which server receive the routing-package.

The client usually get the factory and the idenfication from the: MqFactoryInitial.

Example: Change the factory-identifier of MqFactoryInitial to the value "TestClient" with:

C#	MqFactoryC.Get("initial").Dup2("TestClient").Initial()
TCL	[[tclmsgque::MqFactoryC Get "initial"] Dup2 "TestClient"] Initial

Note

After the link-start, the MqLinkS::targetIdent is no longer changed.

Attention

The string is owned by tclmqmsgque -> do not free !!

$ctx ClassIdentSet ident:string

top link the MqContextC to a new MqFactoryC identified by ident → API: tcl_mqmsgque_MqContextC_ClassIdentSet

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextC to set the ident
[in]	ident	the MqFactoryS::originalIdent to link with

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

this function does not replace the ident of the current factory linked to context… this function replace the entire factory with a new factory identified by name. if the factory is not found or the link is already connected… an error is retured.

string [$ctx ClassOriginalIdentGet]

top get the MqFactoryS::originalIdent from the MqContextC → API: tcl_mqmsgque_MqContextC_ClassOriginalIdentGet

Parameters

[in]

ctx

the MqContextC to extract the original-ident from

Returns

the identifer or an empty string if no factory is available

Attention

the string is owned by tclmqmsgque -> do not free !!

MqContextC CONFIG API

NAVI: top, up

MqContextC CONFIG API GET

		ConfigGetBuffersize	get the minimum of the read/send buffersize of the socket
		ConfigGetIdentFrom	get the MqConfigS::identFrom
		ConfigGetIoPipe	return the MqIoPipeConfigS
		ConfigGetIoTcp	get the configuration-data of the tcp-client-server-link …
		ConfigGetIoTcpL	get the configuration-data of the tcp-client-server-link as MkBufferListC …
		ConfigGetIoUds	return the MqIoUdsConfigS
		ConfigGetIsParent	does the context object is a parent ? An objext is a parent id the MqConfigS::parent attribute is "MK_NULL"
		ConfigGetIsServer	does the context object is a server ?
		ConfigGetIsString	does the context object is using the string-mode ?
		ConfigGetName	get the name of the context object
		ConfigGetPkgsize	get the maximun size of a BDY package
		ConfigGetPostfix	get the MqConfigS::postfix
		ConfigGetPrefix	get the MqConfigS::prefix
		ConfigGetStartAs	return the MqConfigS::startAs value
		ConfigGetStatusIs	return the MqContextS::statusIs value
		ConfigGetStorage	get the storage of the context object
		ConfigGetTimeout	get the timeout value of the context object
		ConfigSetConfigFile	set the config-file and parse for well-known config-items

MqContextC CONFIG API INTERFACE

		ConfigSetBgError	set the MqSetupS::BgError
		ConfigSetEvent	set the MqSetupS::Event
		ConfigSetServerCleanup	set the MqSetupS::ServerCleanup
		ConfigSetServerSetup	set the MqSetupS::ServerSetup

MqContextC CONFIG API MISC

ConfigReset

clean the MqContextS::config data

MqContextC CONFIG API SET

		ConfigCheckStartAs	check if MqConfigS::startAs can be set to data
		ConfigSetAllDebug	set the MkRuntimeS::debug value
		ConfigSetAllTimeout	set the MqIoConfigS::timeout value
		ConfigSetBuffersize	set the MqIoConfigS::buffersize value
		ConfigSetDaemon	start the server-context as daemon …
		ConfigSetIdentFrom	set the MqConfigS::identFrom value
		ConfigSetIgnoreExit	set the MqSetupS::ignoreExit value
		ConfigSetIoPipe	set the pipe configuration data …
		ConfigSetIoTcp	configure a context to use a tcp-client-server-link …
		ConfigSetIoTcpL	configure a context to use a tcp-client-server-link …
		ConfigSetIoUds	configure a context to use a uds-client-server-link …
		ConfigSetIsServer	set the MqSetupS::isServer value
		ConfigSetIsString	set the MqConfigS::native value 'S'string or 'L'owEndian or 'B'igEndian
		ConfigSetName	set the MqConfigS::dispname value and cleanup old value
		ConfigSetPkgsize	set the MqIoConfigS::pkgsize value
		ConfigSetPostfix	set the client-part (2) of the application-identifer MqConfigS::dispname …
		ConfigSetPrefix	set the server-part (1) of the application-identifer MqConfigS::dispname …
		ConfigSetStartAs	set the MqConfigS::startAs value
		ConfigSetStartAsString	set the MqConfigS::startAs value using string default, thread, fork or spawn
		ConfigSetStorage	set the Storage value and cleanup old value
		ConfigSetTimeout	set the MqIoConfigS::timeout value

MqContextC CONFIG API DETAILS

C-API: MqContextC_ConfigApi_C_API - MqContextC - various functions to config a context …

The configuration is done persistent using config-api functions or on link-setup using command-line-arguments.

Options API

Naming Options

--config fileName, --name string, --prefix string, --postfix string, --ident-from prefix|factory

Startup Options

--tcp --host string --port int --myhost string --myport int, --uds --file fileName, --pipe, --thread --spawn --fork, --daemon pidfile

Runtime Options

--logfile fileName, --silent, --debug

Misc Options

--buffersize int, --pkgsize int, --timeout int, --string

Interface API

interface: $ctx ConfigSetServerSetup ?callback:callable="MK_NULL"?
interface: $ctx ConfigSetServerCleanup ?callback:callable="MK_NULL"?
interface: $ctx ConfigSetBgError ?callback:callable="MK_NULL"?
interface: $ctx ConfigSetEvent ?callback:callable="MK_NULL"?

Function API

CONFIG OPTION DETAILS

CONFIG NAMING OPTIONS DETAILS

--config fileName

set: $ctx ConfigSetConfigFile filename:string

add libconfig configuration file …

introduction

A config-file is used to add configuration-values to a libmqmsgque-application using a structured text-file.

supported

By default command-line-options; filter-pipline and slave-worker-setup is supported.

A service-callback and "programming" is not supported. To "programm and modify" something use a scripting language like tcl or python.

goal

The goal is to give the user of a compiled application the ability to provide a single place for common-configuration-values.

technology

libconfig is used to parse a config-file using the application … --config fileName … option.

syntax

The config-file syntax is defined at: http://hyperrealm.github.io/libconfig/libconfig_manual.html

The following restrictions apply to the --config option.

1. The config-file is parsed when the --config option is parsed
2. An application is identfied in the config-file by groupname : { ... } ( ":" or "=" is allowed )
3. The groupname is the return from MqClassIdentGet using hint from --ident-from prefix|factory
4. The groupname is modified with the --name string, --prefix string or --ident-from prefix|factory naming-options
5. The order of option-parsing is the order on the command-line
   MyClient … --XXX … --config YYY … --ZZZ …
   order MyClient : XXX < YYY < ZZZ
6. For a pipe the config-file from the client is added to the end of the server-options :
   MyClient --AAA … --config BBB --CCC … @ Filter3 --name otto --DDD … @ MyServer --EEE …
   

   application	groupname	option-parsing-order
   MyClient	MyClient	AAA < BBB < CCC
   Filter3	otto	DDD < BBB
   MyServer	MyServer	EEE < BBB

   This is required because the --name or --prefix option from DDD or EEE change the group read from the config-file
7. attention! on a client or a non-pipe server it is a difference if the naming-option is set before or after the --config option
8. All options set after the --config option overwrite the options from the config-file
9. The filter ( groupname : { … filter : [ … ] } ) config-file-option define the server to start in a pipe and have to be an array of strings starting with the application-executable OR the factory-identifer

examples

1. Example from MyClient.config → filter-pipeline with last server start in debug mode

 
# commandline OLD: MyClient @ Filter3 @ MyServer --debug 1
# commandline NEW: MyClient --config MyClient.config
 
version = "1.0"               ; // string : version of the configuration file reader
default = "MyClient"          ; // string : if the 'class' is unknown use 'default'
 
MyClient:
{
  config:
  {
  # name = "myName"             ; // string : displayname name of the 'context' (default: executable basename)
  # identFrom = "prefix"        ; // list   : select how to identify the application from remote: 'prefix' or 'factory' (default: prefix)
  # prefix = ""                 ; // string : set the 1'part of the visible displayname (default: "" = FactoryName)
  # postfix = ""                ; // string : set the 2'part of the visible displayname (default: "" = ConnectionName)
  # string = false              ; // bool   : (default: no)
  # startAs = "default"         ; // string : from list (ref… MqStartE): default, spawn, thread, fork (default: default)
  # daemon = "MyServer.pid"     ; // string : file for PID
  # timeout = 90                ; // int    : user defined timeout to terminate a blocking function call (default: 90 sec)
  # storage = "#memdb#"         ; // string : storage file for the database: #memdb#, #tmpdb# or filename (default: #memdb#)
 
  # runtime = {                   // struct (ref… MkRuntimeS) : runtime configuration (global)
    # debug = 1                 ; // int    : set the debug-level, Valid values are 0 <= debug <= 9 using 0 for "no" and 9 for "max". (default: 0)
    # silent = false            ; // bool   : write (no) or don't write (yes) any message to stdout or stderr (default: no)
    # logfile = "stderr"        ; // string : append to logfile, valid values are: stderr, stdout or a filename (default: stderr)
  # };
 
  # io = {                        // struct (ref… MqIoComE) : what kind of socket interface to use? (default: pipe)
 
    # buffersize = 4096           // int    : io buffersize (default: 4096)
    # pkgsize = 10240             // int    : io pkgsize (default: 10 * 1024)
 
    # pipe = true;                // struct (ref… MqIoPipeConfigS) → ONLY client (default: true)
    # init = false;               // struct (ref… MqIoInitConfigS) → ONLY server (default: false)
 
    # tcp = {                     // struct (ref… MqIoTcpConfigS)
      # port = "7777"           ; // string : port number or well known port name
      # host = "localhost"      ; // string : hostname / interfacename
      # myport = "1111"         ; // string : client MY port number or well known port name
      # myhost = "localhost"    ; // string : client MY hostname / interfacename
    # };
 
    # uds = {                     // struct (ref… MqIoUdsConfigS)
      # file = "filename"       ; // string : name of a uds-socket-file (default: null)
    # }
 
  # };
  };
 
  # start executable "Filter3" in a "@" pipe and change application-name (groupname) to "otto" 
  filter = [ "Filter3", "--name", "otto" ]        ; // array of string : filter pipeline name of "server"
};
 
# config section for "Filter3" start in the "pipe"
otto = {
  filter = [ "MyServer" ] ;
}
 
# final "MyServer" set option "debug" to "1"
MyServer = {
  config: { runtime: {debug = 1} }
  # 'config.runtime.debug = 1' is NOT supported.
}
 

2. Example from libconfig.test → filter-pipeline with last server connect by tcp/ip

            # OLD: MyClient @ Filter3 @ --tcp --port $PORT
            # NEW: MyClient --config configFile
            version: 1.0
            default = "MyClient"
            MyClient: {
              filter: [ "Filter3" ]
            }
            Filter3: {
              filter: [ "--tcp", "--port", "$PORT" ]
            }

--name string

attribute: MqConfigS::dispname, getter: MqContextC_ConfigGetName, setter: MqContextC_ConfigSetName
set the display-name of the context …

The display-name is used as:

• A prefix in the local debug/error/log output:
  • C> (dispname) [2009-01-12:16-22-27] [4-0-sIoCheckArg]: option: io->com = PIPE

The dispname is initialized with:

• the MqConfigS::prefix and MqConfigS::postfix value
• the $ctx ConfigSetName data:string, $ctx ConfigSetPrefix data:string, $ctx ConfigSetPostfix data:string function
• the --name string OR with --prefix string and --postfix string value

Example

use MqConfigS::prefix and MqConfigS::postfix to set the MqConfigS::dispname :

• prefix	postfix	dispname
  client	-1-1	client-1-1

Attention

• the memory of MqConfigS::dispname is owned by tclmqmsgque -> do not free.
• if the dispname is NOT set the value is initialized from MqConfigS::prefix
• to initialize the dispname by yourself use: $ctx ConfigSetName data:string or --name string
• if the --name string is explicitly set, then --prefix string and --postfix string have no effect

--prefix string

attribute: MqConfigS::prefix, getter: MqContextC_ConfigGetPrefix, setter: MqContextC_ConfigSetPrefix
set the server-part (1) of the application-identifer MqConfigS::dispname …

The prefix is used for:

1. MqConfigS::dispname initialization
2. application-identifer if --ident-from prefix|factory is set to prefix (default)
3. groupname in --config fileName is used as application-identifer

The prefix is initialize with:

1. the basename of the executable if NO factory is used
2. the MqFactoryS::originalIdent
3. the $ctx ConfigSetPrefix data:string or the $ctx ConfigSetName data:string function
4. the --name string OR the --prefix string option

Attention

if the --name string is explicitly set, then --prefix string and --postfix string have no effect

--postfix string

attribute: MqConfigS::postfix, getter: MqContextC_ConfigGetPostfix, setter: MqContextC_ConfigSetPostfix
set the client-part (2) of the application-identifer MqConfigS::dispname …

The postfix is used for:

1. MqConfigS::dispname initialization

The postfix is initialize with:

1. an empty string
2. the $ctx ConfigSetPostfix data:string function
3. the client postfix at server-startup
4. the --postfix string option

Attention

if the --name string is explicitly set, then --prefix string and --postfix string have no effect

--storage fileName

attribute: MqConfigS::storage, getter: MqContextC_ConfigGetStorage, setter: MqContextC_ConfigSetStorage

--ident-from prefix|factory

attribute: MqConfigS::identFrom, getter: MqContextC_ConfigGetIdentFrom, setter: MqContextC_ConfigSetIdentFrom
select how to identify the application from remote …

An application has TWO possible names:

1. The name from the context the application was configured with.
2. The name from the factory the application was created with.

The --ident-from prefix|factory value decide which on is used.

The application-identification is defined by MqConfigS::identFrom :

MqFactoryS::originalIdent	if ident == MQ_IDENT_FACTORY
MqConfigS::prefix	if ident == MQ_IDENT_PREFIX (default)

The MqFactoryS::originalIdent is the official name of the MqFactoryC and is defined by the application-programmer with MqFactoryAdd or MqFactoryDup2.

The MqConfigS::prefix is the official name of the MqContextC that startet first, usually the server-name, and is set by the application-user with --prefix string at startup or with the MqConfigSetPrefix at setup.

When the server starts, the MqClassIdentGet value is send from the server to the client and the client initializes the MqLinkS::targetIdent with this value. This value identifes the server from remote and is used by the MqContextC ROUTE API to select which server receive the routing-package.

The client usually get the factory and the idenfication from the: MqFactoryInitial.

Example: Change the factory-identifier of MqFactoryInitial to the value "TestClient" with:

C#	MqFactoryC.Get("initial").Dup2("TestClient").Initial()
TCL	[[tclmsgque::MqFactoryC Get "initial"] Dup2 "TestClient"] Initial

Note

After the link-start, the MqLinkS::targetIdent is no longer changed.

CONFIG STARTUP OPTIONS DETAILS

--tcp --host string --port int --myhost string --myport int

attribute: MqIoTcpConfigS, getter: MqContextC_ConfigGetIoTcp, setter: MqContextC_ConfigSetIoTcp
configure a context to use a tcp-client-server-link …

Parameters

[in]	host	client: name of the remote interface (default: localhost) server: name of the local interface (default: listen on all interfaces)
[in]	port	client: name of the remote port server: name of the local port
[in]	myhost	client: name of the local interface
[in]	myport	client: name of the local port

--uds --file fileName

attribute: MqIoUdsConfigS, getter: MqContextC_ConfigGetIoUds, setter: MqContextC_ConfigSetIoUds
configure a context to use a uds-client-server-link …

The uds-socket (http://en.wikipedia.org/wiki/Unix_domain_socket) is usually 50% faster than a local tcp communication but only available on UNIX.

Parameters

[in]

file

name of a uds-socket-file (default: "MK_NULL")

--pipe

attribute: MqIoPipeConfigS, getter: MqContextC_ConfigGetIoPipe, setter: MqContextC_ConfigSetIoPipe
configure a context to use a pipe-client-server-link …

The socket option is special because it is used only for internal purpose to submit the socket from the client to the server started as pipe by the client.

Parameters

[in]

hdl

the file-descriptor-number (default: not set)

--thread --spawn --fork

attribute: MqConfigS::startAs, getter: MqContextC_ConfigGetStartAs, setter: MqContextC_ConfigSetStartAs
create a new application-context as thread, spawn or fork …

A new application-context is created if:

• a tcp-uds-server listen on socket and get a connection-request from a client.
  This require: MqFactoryC and IServerSetup .
• a filter-context create a new filter-object
• a server-context create a new worker-context using MqSlaveWorker
• a server-context start a new client-server-link using SELF as executable-name using MqLinkCreate

The allowed integer values for MqConfigS::startAs are:

• MQ_START_DEFAULT = 0, use application-context default entity creation
• MQ_START_FORK = 1, create entity as fork
• MQ_START_THREAD = 2, create entity as thread
• MQ_START_SPAWN = 3, create entity as spawn process

(default: do not create a new application-context)

--daemon pidfile

set: $ctx ConfigSetDaemon pidfile:string

This option is not available for tclmqmsgque.

CONFIG RUNTIME OPTIONS DETAILS

--logfile fileName

attribute: MkRuntimeS::logfile, getter: MkRuntimeC_GetLogfile, setter: MkRuntimeC_SetLogfile

--silent

attribute: MkRuntimeS::isSilent, getter: MkRuntimeC_GetIsSilent, setter: MkRuntimeC_SetIsSilent

--debug

attribute: MkRuntimeS::debug, getter: MkRuntimeC_GetDebug, setter: MkRuntimeC_SetDebug

CONFIG MISC OPTIONS DETAILS

--buffersize int

attribute: MqIoConfigS::buffersize, getter: MqContextC_ConfigGetBuffersize, setter: MqContextC_ConfigSetBuffersize
set the OS specific value for the socket-operation-buffer (default: OS specific)

--pkgsize int

attribute: MqIoConfigS::pkgsize, getter: MqContextC_ConfigGetPkgsize, setter: MqContextC_ConfigSetPkgsize
set maximum package size (default: 10 KiB)

--timeout int

attribute: MqIoConfigS::timeout, getter: MqContextC_ConfigGetTimeout, setter: MqContextC_ConfigSetTimeout
user defined timeout to terminate a blocking function call (default: 90 sec)

--string

attribute: MqConfigS::native, getter: MqContextC_ConfigGetIsString, setter: MqContextC_ConfigSetIsString
define if data is string or little or big endian …

CONFIG INTERFACE API

• IServerSetup, IServerCleanup
• IBgError, IEvent

interface: $ctx ConfigSetServerSetup ?callback:callable="MK_NULL"?

define the server-setup-interface (callback) used on startup …

This interface is used to configure a new server-context-link, like a constructor, and is called at the end of MqLinkCreate or MqLinkCreateChild. This interface is called for every new incoming connection request and is used to define context specific services using MqServiceCreate or to initialize context-specific variables. As side-effect this interface set MqSetupS::isServer to true.

IServerSetup : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

Read more about how to define a service-callback in theLink .

interface: $ctx ConfigSetServerCleanup ?callback:callable="MK_NULL"?

define the server-cleanup-interface (callback) used on cleanup …

This interface is used to cleanup an old server-context-link, like a destructor, and is called at the beginning of MqLinkDelete to free context-specific variables. As side-effect this interface set MqSetupS::isServer to true.

IServerCleanup : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

Read more about how to define a service-callback in theLink .

interface: $ctx ConfigSetBgError ?callback:callable="MK_NULL"?

define the background-error-interface …

A background error is an error without a link to an application-context and happen if an MqSendEND call fails or if an other asynchronous task fails. if the interface is not defined the error is printed to stderr and the application continue to work. if the interface is defined the context is set to error and the callback is called to process this error. Inside the callback the error is available using ErrorGetNum and ErrorGetText and can be cleared using ErrorReset.

IBgError : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

Read more about how to define a service-callback in theLink .

interface: $ctx ConfigSetEvent ?callback:callable="MK_NULL"?

Create a link to the calling tool event-handling queue …

Event-Handling is used to process tasks in the background to give the tool-user the feeling of a non-blocking application. For example Tcl using the event-handling to update the Tk user-interface while the application is waiting for data. The event handling function is called on idle-time and is designed for a very short function execution time. Do only one action per function call. This function will be called with a ~10000 usec interval to guarantee a parallel like execution.

Attention

1. The Event-Handler is used to start background processing during idel-time.
2. If MqSetupS::ignoreExit is set… and the process/thread is already on shutdown… the process/thread will continue to work as long as background tasks are available.
3. The process will only exit if all Event-Handler return ErrorSetCONTINUE to signal that no other background tasks are available.
example: example/LANG/Filter4.EXT

IEvent : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

Read more about how to define a service-callback in theLink .

MqContextC CONFIG API GET

C-API: MqContextC_ConfigApi_Get_C_API - MqContextC - various function to 'get' the configuration-data from a context …

int32 [$ctx ConfigGetBuffersize]

top get the minimum of the read/send buffersize of the socket → API: tcl_mqmsgque_MqContextC_ConfigGetBuffersize

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.buffersize(R/S) value

MqIdentE [$ctx ConfigGetIdentFrom]

top get the MqConfigS::identFrom → API: tcl_mqmsgque_MqContextC_ConfigGetIdentFrom

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

prefix or factory

int32 [$ctx ConfigGetIoPipe]

top return the MqIoPipeConfigS → API: tcl_mqmsgque_MqContextC_ConfigGetIoPipe

Parameters

[in]

ctx

the MqContextS instance to work on

{host:string port:string myhost:string myport:string} [$ctx ConfigGetIoTcp]

top get the configuration-data of the tcp-client-server-link … → API: tcl_mqmsgque_MqContextC_ConfigGetIoTcp

Parameters

[in]	ctx	the MqContextS instance to work on
[out]	host_out	client: name of the remote interface (default: localhost) server: name of the local interface (default: listen on all interfaces)
[out]	port_out	client: name of the remote port server: name of the local port
[out]	myhost_out	client: name of the local interface
[out]	myport_out	client: name of the local port

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

• if the config-value is not defined… the out-value will be set to "MK_NULL"
• if the the out-value is "MK_NULL" … nothing will be done

MkBufferListC [$ctx ConfigGetIoTcpL]

top get the configuration-data of the tcp-client-server-link as MkBufferListC … → API: tcl_mqmsgque_MqContextC_ConfigGetIoTcpL

host	client name of the remote interface (default: localhost) server name of the local interface (default: listen on all interfaces
port	client name of the remote port server name of the local port
myhost	name of the local interface
myport	name of the local port

Parameters

[in]	ctx	the MqContextS instance to work on
[out]	vals_out	the contain host, port, myhost and myport data

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

the vals_out is owned by tclmqmsgque ... do not free !

string [$ctx ConfigGetIoUds]

top return the MqIoUdsConfigS → API: tcl_mqmsgque_MqContextC_ConfigGetIoUds

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.io.uds.file value

bool [$ctx ConfigGetIsParent]

top does the context object is a parent ? An objext is a parent id the MqConfigS::parent attribute is "MK_NULL" → API: tcl_mqmsgque_MqContextC_ConfigGetIsParent

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the (ctx->config.parent == NULL) value

bool [$ctx ConfigGetIsServer]

top does the context object is a server ? → API: tcl_mqmsgque_MqContextC_ConfigGetIsServer

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the (ctx->setup.isServer == true) value

bool [$ctx ConfigGetIsString]

top does the context object is using the string-mode ? → API: tcl_mqmsgque_MqContextC_ConfigGetIsString

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the (ctx->config.native == 'S') value

string [$ctx ConfigGetName]

top get the name of the context object → API: tcl_mqmsgque_MqContextC_ConfigGetName

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.name value

Attention

the string is owned by tclmqmsgque -> do not free !!

int32 [$ctx ConfigGetPkgsize]

top get the maximun size of a BDY package → API: tcl_mqmsgque_MqContextC_ConfigGetPkgsize

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.pkgsize(R/S) value

string [$ctx ConfigGetPostfix]

top get the MqConfigS::postfix → API: tcl_mqmsgque_MqContextC_ConfigGetPostfix

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the value requested

Attention

the string is owned by tclmqmsgque -> do not free !!

string [$ctx ConfigGetPrefix]

top get the MqConfigS::prefix → API: tcl_mqmsgque_MqContextC_ConfigGetPrefix

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the value requested

Attention

the string is owned by tclmqmsgque -> do not free !!

MqStartE [$ctx ConfigGetStartAs]

top return the MqConfigS::startAs value → API: tcl_mqmsgque_MqContextC_ConfigGetStartAs

MqStatusIsEF [$ctx ConfigGetStatusIs]

top return the MqContextS::statusIs value → API: tcl_mqmsgque_MqContextC_ConfigGetStatusIs

string [$ctx ConfigGetStorage]

top get the storage of the context object → API: tcl_mqmsgque_MqContextC_ConfigGetStorage

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.storage value

Attention

the string is owned by tclmqmsgque -> do not free !!

MkTimeoutE|int32 [$ctx ConfigGetTimeout]

top get the timeout value of the context object → API: tcl_mqmsgque_MqContextC_ConfigGetTimeout

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the context.config.timeout value

$ctx ConfigSetConfigFile filename:string

top set the config-file and parse for well-known config-items → API: tcl_mqmsgque_MqContextC_ConfigSetConfigFile

Read more at MqConfigS::cfg

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	filename	name of the config-file for input

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC CONFIG API INTERFACE

C-API: MqContextC_ConfigApi_Interface_C_API - MqContextC - various function to setup a interface for the context …

The "Setup"-Callback is special because this callback have to be callable by the server child and/or the slave context.

To distinguish the server child and slave the following functions are used:

• using a "if" clause and the child/parent check
  • MqConfigGetIsParent == true -> check for parent
  • MqConfigGetIsParent == false -> check for child
• using a "if" clause and the master/slave check
  • MqSlaveIs == false -> check for master
  • MqSlaveIs == true -> check for slave
• using a "if" clause and the server/child check
  • MqConfigGetIsServer == true -> check for master as server
  • MqConfigGetIsServer == false -> check for slave as client

$ctx ConfigSetBgError ?callback:callable="MK_NULL"?

top set the MqSetupS::BgError → API: tcl_mqmsgque_MqContextC_ConfigSetBgError

define the background-error-interface …

A background error is an error without a link to an application-context and happen if an MqSendEND call fails or if an other asynchronous task fails. if the interface is not defined the error is printed to stderr and the application continue to work. if the interface is defined the context is set to error and the callback is called to process this error. Inside the callback the error is available using ErrorGetNum and ErrorGetText and can be cleared using ErrorReset.

IBgError : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

This function register a callback and is used to configure the application for a specific task.

• The implementation depends on the Target-Programming-Language (TPL) and uses either a interface or a function for this purpose.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fCall	function called with callback as argument to work on an specific task.
[in]	callback	argument for fCall, for a target-language this is the target-language-callback-hdl.
[in]	fFree	cleanup the callback, called at the destruction of ctx.
[in]	fCopy	copy-constructor of the callback, used if the ctx is used to initialize an other newctx.

$ctx ConfigSetEvent ?callback:callable="MK_NULL"?

top set the MqSetupS::Event → API: tcl_mqmsgque_MqContextC_ConfigSetEvent

Create a link to the calling tool event-handling queue …

Event-Handling is used to process tasks in the background to give the tool-user the feeling of a non-blocking application. For example Tcl using the event-handling to update the Tk user-interface while the application is waiting for data. The event handling function is called on idle-time and is designed for a very short function execution time. Do only one action per function call. This function will be called with a ~10000 usec interval to guarantee a parallel like execution.

Attention

1. The Event-Handler is used to start background processing during idel-time.
2. If MqSetupS::ignoreExit is set… and the process/thread is already on shutdown… the process/thread will continue to work as long as background tasks are available.
3. The process will only exit if all Event-Handler return ErrorSetCONTINUE to signal that no other background tasks are available.
example: example/LANG/Filter4.EXT

IEvent : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

This function register a callback and is used to configure the application for a specific task.

• The implementation depends on the Target-Programming-Language (TPL) and uses either a interface or a function for this purpose.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fCall	function called with callback as argument to work on an specific task.
[in]	callback	argument for fCall, for a target-language this is the target-language-callback-hdl.
[in]	fFree	cleanup the callback, called at the destruction of ctx.
[in]	fCopy	copy-constructor of the callback, used if the ctx is used to initialize an other newctx.

Attention

• the MqSetupS::Event will only active if MqSetupS::isServer is true
• use this configuration after MqSetupS::ServerSetup to avoid unused MqSetupS::Event setup

$ctx ConfigSetServerCleanup ?callback:callable="MK_NULL"?

top set the MqSetupS::ServerCleanup → API: tcl_mqmsgque_MqContextC_ConfigSetServerCleanup

define the server-cleanup-interface (callback) used on cleanup …

This interface is used to cleanup an old server-context-link, like a destructor, and is called at the beginning of MqLinkDelete to free context-specific variables. As side-effect this interface set MqSetupS::isServer to true.

IServerCleanup : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

This function register a callback and is used to configure the application for a specific task.

• The implementation depends on the Target-Programming-Language (TPL) and uses either a interface or a function for this purpose.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fCall	function called with callback as argument to work on an specific task.
[in]	callback	argument for fCall, for a target-language this is the target-language-callback-hdl.
[in]	fFree	cleanup the callback, called at the destruction of ctx.
[in]	fCopy	copy-constructor of the callback, used if the ctx is used to initialize an other newctx.

$ctx ConfigSetServerSetup ?callback:callable="MK_NULL"?

top set the MqSetupS::ServerSetup → API: tcl_mqmsgque_MqContextC_ConfigSetServerSetup

define the server-cleanup-interface (callback) used on cleanup …

This interface is used to cleanup an old server-context-link, like a destructor, and is called at the beginning of MqLinkDelete to free context-specific variables. As side-effect this interface set MqSetupS::isServer to true.

IServerCleanup : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

This function register a callback and is used to configure the application for a specific task.

• The implementation depends on the Target-Programming-Language (TPL) and uses either a interface or a function for this purpose.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fCall	function called with callback as argument to work on an specific task.
[in]	callback	argument for fCall, for a target-language this is the target-language-callback-hdl.
[in]	fFree	cleanup the callback, called at the destruction of ctx.
[in]	fCopy	copy-constructor of the callback, used if the ctx is used to initialize an other newctx.

MqContextC CONFIG API MISC

C-API: MqContextC_ConfigApi_Misc_C_API - MqContextC - various function to do 'misc' configuration …

$ctx ConfigReset

top clean the MqContextS::config data → API: tcl_mqmsgque_MqContextC_ConfigReset

MqContextC CONFIG API SET

C-API: MqContextC_ConfigApi_Set_C_API - MqContextC - various function to 'set' the configuration-data in a context …

bool [$ctx ConfigCheckStartAs data:MqStartE]

top check if MqConfigS::startAs can be set to data → API: tcl_mqmsgque_MqContextC_ConfigCheckStartAs

$ctx ConfigSetAllDebug data:int32

top set the MkRuntimeS::debug value → API: tcl_mqmsgque_MqContextC_ConfigSetAllDebug

set all childs and all slaves and the link target parter… too

$ctx ConfigSetAllTimeout data:MkTimeoutE|int32

top set the MqIoConfigS::timeout value → API: tcl_mqmsgque_MqContextC_ConfigSetAllTimeout

set all childs and all slaves too

$ctx ConfigSetBuffersize data:int32

top set the MqIoConfigS::buffersize value → API: tcl_mqmsgque_MqContextC_ConfigSetBuffersize

$ctx ConfigSetDaemon pidfile:string

top start the server-context as daemon … → API: tcl_mqmsgque_MqContextC_ConfigSetDaemon

A daemon is a server-process without any link to the parent-process. A daemon-process has closed all default IO (e.g stdout, stdin, stderr) and forked into the background. (default: no daemon)

enum MkErrorE
MqConfigSetDaemon_RT (
  MK_RT_ARGS
  MQ_CTX const ctx,
  MK_STRN pidfile
) {
  MK_RT_ATTR_HDL_CHECK(ctx);
  MK_RT_ATTR_CHECK_RUNTIME_XN(ctx);
  if (MQ_IS_SERVER(ctx)) {
    if (MqContextCT_X(ctx)->ignoreFork == true) {
      return MkErrorDbV_1_XS (MK_ERROR_OPTION_FORBIDDEN, "--daemon", "current");
    } else {
      MkErrorCheck (MkSysDaemonize(MkOBJ(ctx), pidfile));
      MkRuntimeSetIsSilent (true);
    }
  } else {
    return MkErrorDbV_1_XS (MK_ERROR_OPTION_FORBIDDEN, "--daemon", "client");
  }
  return MK_OK;
error:
  return MkErrorStack_1X(ctx);
}

Attention

this option require the fork system-call and is not compatible with threads.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	pidfile	write the PID of the daemon into this file (default: NULL, do not start as daemon)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ConfigSetIdentFrom data:MqIdentE

top set the MqConfigS::identFrom value → API: tcl_mqmsgque_MqContextC_ConfigSetIdentFrom

$ctx ConfigSetIgnoreExit data:bool

top set the MqSetupS::ignoreExit value → API: tcl_mqmsgque_MqContextC_ConfigSetIgnoreExit

$ctx ConfigSetIoPipe fh:int32

top set the pipe configuration data … → API: tcl_mqmsgque_MqContextC_ConfigSetIoPipe

This is configuration option is only useful for a (x)inetd setup to use the stdin (socket=0) as send/recv communication socket

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fh	the name of the known socket

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ConfigSetIoTcp ?host:string="NULL"? ?port:string="NULL"? ?myhost:string="NULL"? ?myport:string="NULL"?

top configure a context to use a tcp-client-server-link … → API: tcl_mqmsgque_MqContextC_ConfigSetIoTcp

Parameters

[in]	host	client: name of the remote interface (default: localhost) server: name of the local interface (default: listen on all interfaces)
[in]	port	client: name of the remote port server: name of the local port
[in]	myhost	client: name of the local interface
[in]	myport	client: name of the local port
[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ConfigSetIoTcpL vals:MkBufferListC

top configure a context to use a tcp-client-server-link … → API: tcl_mqmsgque_MqContextC_ConfigSetIoTcpL

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	vals	a list with host, port, myhost, myport

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ConfigSetIoUds file:string

top configure a context to use a uds-client-server-link … → API: tcl_mqmsgque_MqContextC_ConfigSetIoUds

The uds-socket (http://en.wikipedia.org/wiki/Unix_domain_socket) is usually 50% faster than a local tcp communication but only available on UNIX.

Parameters

[in]	file	name of a uds-socket-file (default: "MK_NULL")
[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ConfigSetIsServer data:bool

top set the MqSetupS::isServer value → API: tcl_mqmsgque_MqContextC_ConfigSetIsServer

$ctx ConfigSetIsString data:bool

top set the MqConfigS::native value 'S'string or 'L'owEndian or 'B'igEndian → API: tcl_mqmsgque_MqContextC_ConfigSetIsString

Attention

only the client can set this option... the server get this option from the client and using this function is ignored.

$ctx ConfigSetName data:string

top set the MqConfigS::dispname value and cleanup old value → API: tcl_mqmsgque_MqContextC_ConfigSetName

$ctx ConfigSetPkgsize data:int32

top set the MqIoConfigS::pkgsize value → API: tcl_mqmsgque_MqContextC_ConfigSetPkgsize

$ctx ConfigSetPostfix data:string

top set the client-part (2) of the application-identifer MqConfigS::dispname … → API: tcl_mqmsgque_MqContextC_ConfigSetPostfix

The postfix is used for:

1. MqConfigS::dispname initialization

The postfix is initialize with:

1. an empty string
2. the $ctx ConfigSetPostfix data:string function
3. the client postfix at server-startup
4. the --postfix string option

Attention

if the --name string is explicitly set, then --prefix string and --postfix string have no effect

$ctx ConfigSetPrefix data:string

top set the server-part (1) of the application-identifer MqConfigS::dispname … → API: tcl_mqmsgque_MqContextC_ConfigSetPrefix

The prefix is used for:

1. MqConfigS::dispname initialization
2. application-identifer if --ident-from prefix|factory is set to prefix (default)
3. groupname in --config fileName is used as application-identifer

The prefix is initialize with:

1. the basename of the executable if NO factory is used
2. the MqFactoryS::originalIdent
3. the $ctx ConfigSetPrefix data:string or the $ctx ConfigSetName data:string function
4. the --name string OR the --prefix string option

Attention

if the --name string is explicitly set, then --prefix string and --postfix string have no effect

$ctx ConfigSetStartAs data:MqStartE

top set the MqConfigS::startAs value → API: tcl_mqmsgque_MqContextC_ConfigSetStartAs

$ctx ConfigSetStartAsString data:string

top set the MqConfigS::startAs value using string default, thread, fork or spawn → API: tcl_mqmsgque_MqContextC_ConfigSetStartAsString

$ctx ConfigSetStorage data:string

top set the Storage value and cleanup old value → API: tcl_mqmsgque_MqContextC_ConfigSetStorage

$ctx ConfigSetTimeout data:MkTimeoutE|int32

top set the MqIoConfigS::timeout value → API: tcl_mqmsgque_MqContextC_ConfigSetTimeout

MqContextC ENV API

NAVI: top, up

		EnvProtect	protect the service-environment
		EnvRestore	restore the service-environment

MqContextC ENV API DETAILS

C-API: MqContextC_EnvApi_C_API - MqContextC - protect and restore the service-environment …

The "Env" style functions are used to secure the service-environment (defined in MqEnvS)
and is required.. under special conditions... to proper answer the original service call at the
end of the service-processing.
By default tclmqmsgque guarantee the proper management of the environment on behalf of the user.
Under normal conditions the user don't need these functions.

The folllowing design-goals were defined:

• normal condition...
  • Every tclmqmsgque function does protect the original service-environment by default
  • esay goal to remember: come-in == come-out
• special condition...
  • After loading the read-data-package...
    • from the database (with MqStorageImport)
    • from the dump file (with MqDumpImport)
  • the service-environment must be in the same condition as when the read-data-package was saved.

The two design-goals from above are in conflict and the both functions MqEnvProtect and MqEnvRestore are used to solve this conflict.

Example from server.tcl → protect the environment and import from database

        # PROTECT the original service-call
        my EnvProtect
        # OVERWRITE the original service-call with data from the database
        $dump Import [self]
        set ret [my ReadALL]
        # RESTORE the original service-call
        my EnvRestore
        # ANSWER the original service-call
        my Send "R" "L" $ret

$ctx EnvProtect

top protect the service-environment → API: tcl_mqmsgque_MqContextC_EnvProtect

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

$ctx EnvRestore

top restore the service-environment → API: tcl_mqmsgque_MqContextC_EnvRestore

Parameters

[in]

ctx

the MqContextS instance to work on

MqContextC ERROR API

NAVI: top, up

		ErrorCopy	copy a MkErrorS from the sourceCtx to the targetCtx …
		ErrorFORMAT	helper used to access MkErrorDEFAULT from MqContextC
		ErrorMove	move a MkErrorS from the sourceCtx to the targetCtx …

MqContextC ERROR API DETAILS

C-API: MqContextC_ErrorApi_C_API - MqContextC - move and copy an error from a context …

MkErrorE [$targetCtx ErrorCopy sourceCtx:MqContextC]

top copy a MkErrorS from the sourceCtx to the targetCtx … → API: tcl_mqmsgque_MqContextC_ErrorCopy

In tclmqmsgque the a MkRuntimeC is only one error-object per thread but this error-object has also addiitional attributes to identify the source of the error. In addition the tclmqmsgque has also an extended-error-object MqErrorS which also has error-specific-attributes. The MqContextErrorCopy is used to copy an error frome sourceCtx to targetCtx and keep the additional attributes in sync.

Note

• by default… every error set in a slave is also set in the master.
• by default… the error is only copied if sourceCtx and targetCtx are different.
• by default… the error is not copied if targetCtx MqConfigS::master of sourceCtx.
• by default… the copy only happen if sourceCtx has an error.
• on copy… the error of sourceCtx will be reset.

See also

MqContextErrorMove

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
	targetCtx	the MqContextC object and the target of the error
	sourceCtx	the MqContextC object and the source of the error

MkErrorC [$fmtobj ErrorFORMAT]

top helper used to access MkErrorDEFAULT from MqContextC → API: tcl_mqmsgque_MqContextC_ErrorFORMAT

MkErrorE [$targetCtx ErrorMove sourceCtx:MqContextC]

top move a MkErrorS from the sourceCtx to the targetCtx … → API: tcl_mqmsgque_MqContextC_ErrorMove

Note

• by default… every error set in a slave is also set in the master.
• by default… the error is only copied if sourceCtx and targetCtx are different.
• by default… the error is not copied if targetCtx MqConfigS::master of sourceCtx.
• by default… the copy only happen if sourceCtx has an error.
• on copy… the error of sourceCtx will be reset.

See also

MqContextErrorCopy

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
	targetCtx	the MqContextC object and the target of the error
	sourceCtx	the MqContextC object and the source of the error and cleared

MqContextC HIGH API

NAVI: top, up

Send

user friendly replacement for the MqContextC_SendApi_C_API …

MqContextC HIGH API DETAILS

C-API: MqContextC_HighApi_C_API - MqContextC - User friendly replacement for the MqContextC_SendApi_C_API and the MqContextC_ReadApi_C_API …

User Friendly mean, replacing many lines of code by a single line of code.
The basic idea is, to use a format-signature to identify the additional command-line-arguments (args…).

The pseudo syntax is:

MqSend( "CALL-SIGNATUR",call-args …,"TOKEN-SIGNATURE",send-args …,read-args …);
 
CALL-SIGNATUR     = "[E|W|C|S|T|R|t|r]" or ?call-args?
 
  E               =   MqSendEND                           ?t-arg = 0?
  W               =   MqSendEND_AND_WAIT,                 ?t-arg = MK_TIMEOUT_DEFAULT?
  C               =   MqSendEND_AND_CALLBACK,     c-arg,  ?t-arg = MK_TIMEOUT_DEFAULT?
  S               =   MqSendEND_AND_SUB,          c-arg,  ?t-arg = MK_TIMEOUT_DEFAULT?
  T               =   MqSendEND_AND_TRANSACTION,  i-arg,  ?t-arg = MK_TIMEOUT_DEFAULT?
  R               =   MqSendRETURN
 
  t               =   expect timeout value as t-arg in call-arg
  r               =   switch 'rpc-flag' on to enable 'rpc' style parsing of the TOKEN-SIGNATURE 
 
  call-args       =   ?c-arg?, ?i-arg?, ?t-arg?
    ?c-arg?       =     callback ... function, service
    ?i-arg?       =     ident ...... MQ_TOK service-identifer to receive the result
    ?t-arg?       =     timeout .... MK_TIME_T in seconds
 
TOKEN-SIGNATUR    = "service-ident:send-signature@read-signature"
 
  service-ident   =   MQ_TOK service identifier to call a remote service
  send-signature  =   ?(…)? or multiple [Y|O|S|I|F|W|D|G|C|B|U|L] or […]
    ?(…)?         =     only as FIRST arg, only for MqSendEND_AND_TRANSACTION
      (           =       MqSendT_START
      )           =       MqSendT_END
    [             =     MqSendL_START
    ]             =     MqSendL_END
    Y             =     MqSendI8
    O             =     MqSendBOL
    S             =     MqSendI16
    I             =     MqSendI32
    F             =     MqSendFLT
    W             =     MqSendI64
    D             =     MqSendDBL
    G             =     MqSendLONG
    C             =     MqSendSTR
    B             =     MqSendBIN
    U             =     MqSendBUF
    L             =     MqSendBFL
  read-signature  =   multiple [Y|O|S|I|F|W|D|G|C|B|U|L] or . or * or […]
    .             =     MqReadBUF
    *             =     MqReadALL
    [             =     MqReadL_START
    ]             =     MqReadL_END
    Y             =     MqReadI8
    O             =     MqReadBOL
    S             =     MqReadI16
    I             =     MqReadI32
    F             =     MqReadFLT
    W             =     MqReadI64
    D             =     MqReadDBL
    G             =     MqReadLONG
    C             =     MqReadSTR
    B             =     MqReadBIN
    U             =     MqReadBUF
    L             =     MqReadBFL

The following parts from the MqContextC_SendApi_C_API will be replaced by the MqContextC_HighApi_C_API

API Function	Usage
MqSendSTART	-> start a service call or a answer
SendATOM	-> write a single argument into the data-package
SendEND	-> send the service-call to the receiver
ReadATOM	-> read a single argument from the data-package
SendRETURN	-> answer a service call

The replacement is defined by two parts, a High_CALL_SIGNATURE and a High_TOKEN_SIGNATURE. Both parts are strings and descripe a type or an action of a vararg argument.

Example: a typical code replacement in C looks like

MkErrorCheck( MqSend( ctx, "Wt", 15, "SUBI:IDC@D", 5, 6.3, "HALLO", &doubleVal ) );

and replaces the following commands...

MkErrorCheck( MqSendSTART( ctx ) );
MkErrorCheck( MqSendI32( ctx, 5 ) );
MkErrorCheck( MqSendDBL( ctx, 6.3 ) );
MkErrorCheck( MqSendSTR( ctx, "HALLO" ) );
MkErrorCheck( MqSendEND_AND_WAIT( ctx, "SUBI", 15 ) );
MkErrorCheck( MqReadDBL( ctx, &doubleVal ) );

High_CALL_SIGNATURE

The Call-Signature is a string of call-signature-char (CFC) starting with "E", "W", "C", "S" or "R" followed optional with "t"

CFC	Required	Reference	call-args	Default	Usage
E	yes	once	no	yes	MqSendEND
W	yes	once	no	no	MqSendEND_AND_WAIT
C	yes	once	function or service	no	MqSendEND_AND_CALLBACK
S	yes	once	function or service	no	MqSendEND_AND_SUB
T	yes	once	service-ident	no	MqSendEND_AND_TRANSACTION
R	yes	once	no	no	MqSendRETURN
t	no	W,S,T	seconds	MK_TIMEOUT_USER	set the TIMEOUT

High_TOKEN_SIGNATURE

1. The token-signature has the usage "service-ident : send-signature @ read-signature" and is used to identify the target-service and the required arguments.
2. The service-ident is identified by the MQ_TOK item followed by a [:] and the send-signature.
3. The send-signature has one type-identifer for every send-argument. The send-argument is identified by a arg-signature-char (ASC) and is defined in MkTypeE.
4. The MkTypeE is used in the MkBufferU and descripe the type of a vararg argument or action.

ASC	MkTypeE	Usage	Number of arguments required
"Y"	MK_I8	MkBufferAtomU.I8	1
"O"	MK_BOL	MkBufferAtomU.BOL	1
"S"	MK_I16	MkBufferAtomU.I16	1
"I"	MK_I32	MkBufferAtomU.I32	1
"F"	MK_FLT	MkBufferAtomU.FLT	1
"W"	MK_I64	MkBufferAtomU.I64	1
"D"	MK_DBL	MkBufferAtomU.DBL	1
"G"	MK_LONG	32bit=I, 64bit=W	1
"B"	MK_BIN	MkBufferU.B	1 -> MkBinaryR reference
"C"	MK_STR	MkBufferU.C	1
"U"	MK_BUF	MkBufferC .	1 -> typeless Buffer able to hold every kind of data
"L"	MK_BFL	MkBufferListC .	1 -> list of MkBufferC .
"."	MK_BUF	MkBufferC .	1 -> READ ONLY - like 'U' but return the Buffer-Value and not the MkBufferC .
"*"	MK_BFL	MkBufferListC .	1 -> READ ONLY - like 'L' but collect ALL remaining data as ONE MkBufferListC .
"["		MqSendL_START	0 -> Start of List
"]"		MqSendL_END	0 -> End of List
"("		MqSendT_START	0 -> Start of Transaction Object, only as FIRST parameter
")"		MqSendT_END	0 -> End of Transaction Object, only ONE supported
":"		END of SERVICE-IDENT	* -> next SEND_SIGNATURE
"@"		END of SEND-SIGN.	* -> next READ-SIGNATURE

Example from server.tcl → in a service-call send the server-configuratien back to the client

  method Ot_CNFG {} {
    my SendSTART
    my SendBOL [my ConfigGetIsServer]
    my SendBOL [my LinkIsParent]
    my SendBOL [my SlaveIs]
    my SendBOL [my ConfigGetIsString]
    my SendBOL [MkRuntimeC GetIsSilent]
    my SendBOL [my LinkIsConnected]
    my SendSTR [my ConfigGetName]
    my SendI32 [MkRuntimeC GetDebug]
    my SendI32 [my LinkGetCtxId]
    my SendSTR [my ServiceTokenGet]
    my SendRETURN
  }

$ctx Send cstr:string args:args...

top user friendly replacement for the MqContextC_SendApi_C_API … → API: MqSend_RT

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	cstr	the High_CALL_SIGNATURE

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqSendVL2

MqContextC LINK API

NAVI: top, up

		LinkConnect	re-connect a client-server-link after a server crash or a network downtime …
		LinkCreate	make ctx to a parent-context and setup a new client-server-link …
		LinkCreateChild	make a context to a child-context on-top of an existing parent-client-server-link …
		LinkDelete	close the client-server-link …
		LinkGetCtxId	get an identifier which is unique per parent-or-child-context …
		LinkGetParent	get the initial parent-context from a client/server link …
		LinkGetTargetIdent	get the ident of the link-target …
		LinkIsConnected	is the context connected? …
		LinkIsParent	is the context a parent-context? …
		LinkShutdown	shutdown the communication with a server

MqContextC LINK API DETAILS

C-API: MqContextC_LinkApi_C_API - MqContextC - setup and manage a client-server-link …

The client-server-link connect two context, a client-parent-context and a server-parent-context. The link can be local (connect two context on the same host) or can be remote (connect two context on different hosts). On-Top the parent-context multiple child-context are allowed.

  !on remote host!                                  !on local host!

      server1---------x                     x----------server2
         |            |                     |             |
         |     child-context-1       child-context-2      |
         |            |                     |             |                      server
 parent-context-1-----x                     x-----parent-context-2
         |                                                |
 (MqConfigS::server)                 (example: MqConfigS::server --fork --uds … --file …)
         |                                                |
 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
         |                                                |
      (--tcp)                                  (--pipe, --uds, --tcp)
         |                                                |
 parent-context-1-----x                     x-----parent-context-2
         |            |                     |             |                      client
         |     child-context-1       child-context-2      |
         |            |                     |             |
         x------------x--------client-------x-------------x

                           !on local host!

Definition of a "client-context"

• every new client-parent-context create a new client-server-link and perform the connect system-call.
• every new client-server-link start a new server-object and creating a new server-parent-context
• every deletion of the client-parent-context stop the previous started server-object and delete the server-parent-context
• the client-context get all the error/warning/info messages from the server-context

Definition of a "server-context"

• every new server-parent-context is created by request from the client-parent-context:
• in remote mode every new server-parent-context wait for a tcp or uds connection request using the accept system-call.

client --tcp --host REMOTE_HOST --port REMOTE_PORT ...    or
client --uds --file MYFILE ...

• in local mode new server-parent-context is started by the client-parent-context as pipe:

  client @ server

  • a server-context have to implement the IServerSetup and the MqFactoryC interface.
  • a server-context have to enter the event-loop and wait for incoming service-request using MqProcessEvent together with the MQ_WAIT_FOREVER.

Definition of a "parent-context"

• the parent is the first context created and is created with MqLinkCreate
• every new parent-context on the client create a new communication to a server.
• every new parent-context on the client connect to a new parent-context on the server
• every new parent-context on the server create a new thread or process.
• the parent-context control the socket communication interface

Definition of a "child-context"

• the child-context is the second or more context and is created with MqLinkCreateChild.
• every new child-context on the client create a new child-context on the server.
• every new child-context is totally independent from the parent-context setup and is able to serve its own services.
• the child-context is using the parent-context as a tunnel.
• the child-context is using the the thread or process of the parent-context.
• the parent of a child-context can be a parent-context or an other child-context. A tree like structure is created.
• the child-context is using the communication interface from the parent-context.
• if a context is deleted (parent or child) the depending context (parent or child) is deleted too.

$ctx LinkConnect

top re-connect a client-server-link after a server crash or a network downtime … → API: tcl_mqmsgque_MqContextC_LinkConnect

Do nothing if the client-server-link is already connected. This function is only useful in an event-function (IEvent) if the link-disconnect (ErrorIsEXIT) is ignored (ErrorReset). Read more from the: /example/tcl/Filter4.tcl example.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx LinkCreate ?args:MkBufferListC...="MK_NULL"?

top make ctx to a parent-context and setup a new client-server-link … → API: tcl_mqmsgque_MqContextC_LinkCreate

The goal of the MqLinkCreate is to setup a link to a new server-context on the SERVER.

• SERVICE CALL

The link is created with MqIoComE to a server started with MqStartE.

• EXAMPLES

The argument args is a list of command-line-arguments to configure the client-server-link including the @ item to add server-command-line-arguments.

The following special-keyword as first argument after @ is recognized:

factory-name

A known factory previous added with MqFactoryAdd.

MqFactoryAdd_1("myFeature");
...
MqLinkCreate(ctx,...,"@",myFeature,...);

SELF

Recognized as the initial-factory-name. (e.g. MqFactoryInitial)
The startup with "@ SELF arg1…" will be "@ executable factory-name arg1…"

WORKER

Recognized as the own executable name.
The startup from "@ WORKER arg1…" will be "@ executable arg1…"
If the ctx is not the server-context… (e.g MqSetupS::isServer == true) the default-factory (e.g. MqFactoryDefault) will be used.

The executable is defined by (static) MqMsgque InitSetArg0 ?bfl:MkBufferListC...="MK_NULL"? and will be automatical set for a non C / C++ language.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	args	command-line-arguments to configure the client-server-link

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx LinkCreateChild parent:MqContextC ?args:MkBufferListC...="MK_NULL"?

top make a context to a child-context on-top of an existing parent-client-server-link … → API: tcl_mqmsgque_MqContextC_LinkCreateChild

A child is using the same process or thread as the parent but a different namespace. With a different namespace a child is able to act on different services on the shared server.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	parent	the parent-context defined with MqLinkCreate
[in]	args	command-line-arguments to configure the client-server-link without the "@" item.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx LinkDelete

top close the client-server-link … → API: tcl_mqmsgque_MqContextC_LinkDelete

On a client the context will be set to not-connected and the function MqLinkIsConnected will return false. On a server the context will be deleted but only if MqSetupS::ignoreExit is not set to true. If the link is already not-connected nothing will happen.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

int32 [$ctx LinkGetCtxId]

top get an identifier which is unique per parent-or-child-context … → API: tcl_mqmsgque_MqContextC_LinkGetCtxId

The context-identifier is a number and is used in the protocol to link a data-package to a context-pointer. This is necessary because the communication interface is shared between the parent-context and the child-context. This number is unique.

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the identifier as number

MqContextC [$ctx LinkGetParent]

top get the initial parent-context from a client/server link … → API: tcl_mqmsgque_MqContextC_LinkGetParent

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the parent-context or "MK_NULL" if ctx is "MK_NULL"

string [$ctx LinkGetTargetIdent]

top get the ident of the link-target … → API: tcl_mqmsgque_MqContextC_LinkGetTargetIdent

This function is only useful if the link is up and running.

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

get the ident of the link-target or "MK_NULL" if not connected

bool [$ctx LinkIsConnected]

top is the context connected? … → API: tcl_mqmsgque_MqContextC_LinkIsConnected

A context is connected if the MqLinkCreate command was successful. A context is not connected if:

• the context has just been created and not connected
• the link was deleted with MqLinkDelete

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

a boolean value, true or false

bool [$ctx LinkIsParent]

top is the context a parent-context? … → API: tcl_mqmsgque_MqContextC_LinkIsParent

A context is a parent-context if it was created with MqLinkCreate

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

a boolean value, true or false

$ctx LinkShutdown

top shutdown the communication with a server → API: tcl_mqmsgque_MqContextC_LinkShutdown

The following tasks are performend:

• shutdown all childs
• shutdown all slaves
• client send the shutdown-sequence to the server
• server answer the shutdown-sequence from the client
• if parant … shutdown the communication infrastructure

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC LOG API

NAVI: top, up

		Log	log the MqContextC …
		LogConfig	log the MqContextC part MqConfigS …
		LogEnv	log the MqContextC part MqEnvS …
		LogLink	log the MqContextC part MqLinkS …
		LogSetup	log the MqContextC part MqSetupS …
		LogShort	log the MqContextC with less info then MqContextLog …
		LogType	log the MqContextC part MkTypeS …
		LogParentOrChild	is ctx a PARENT or a CHILD ? …
		LogServerOrClient	is ctx a SERVER or a CLIENT ? …

MqContextC LOG API DETAILS

C-API: MqContextC_LogApi_C_API - MqContextC - log the output to a string or a MkLogFileC …

Logging is an important part of the debugging and validation task.

The logging target is set with MkRuntimeSetLogfile wich accepts a filename or the special token stdout or stderr.

Many logging functions have common parameters:

Parameters

[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)

$ctx Log ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC … → API: tcl_mqmsgque_MqContextC_Log

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

See also

MqContextC_C_API MqContextLogShort

$ctx LogConfig ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC part MqConfigS … → API: tcl_mqmsgque_MqContextC_LogConfig

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

$ctx LogEnv ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC part MqEnvS … → API: tcl_mqmsgque_MqContextC_LogEnv

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

See also

MqContextC_EnvApi_C_API

$ctx LogLink ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC part MqLinkS … → API: tcl_mqmsgque_MqContextC_LogLink

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

$ctx LogSetup ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC part MqSetupS … → API: tcl_mqmsgque_MqContextC_LogSetup

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

$ctx LogShort ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0? ?label:string="NULL"?

top log the MqContextC with less info then MqContextLog … → API: tcl_mqmsgque_MqContextC_LogShort

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	label	a string to identify a task or object
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

See also

MqContextC_C_API MqContextLog

$ctx LogType ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqContextC part MkTypeS … → API: tcl_mqmsgque_MqContextC_LogType

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

See also

MqContextC_C_API MqContextLog

string [$ctx LogParentOrChild]

top is ctx a PARENT or a CHILD ? … → API: tcl_mqmsgque_MqContextC_LogParentOrChild

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the string PARENT or CHILD

string [$ctx LogServerOrClient]

top is ctx a SERVER or a CLIENT ? … → API: tcl_mqmsgque_MqContextC_LogServerOrClient

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the string SERVER or CLIENT

MqContextC MISC API

NAVI: top, up

		GetBuffer	get the MqContextS::ctxbuf object
		ToString	String-Slot - returns the string representation of the inst …
		Exit	delete the context and exit the current process or thread …
		GetRoot	get the Root (toplevel initial context)
		ProcessEvent	enter the event-loop and wait for an incoming service-request. …

MqContextC MISC API DETAILS

C-API: MqContextC_MiscApi_C_API - MqContextC - various functions to work on a context …

MkBufferC [$ctx GetBuffer]

top get the MqContextS::ctxbuf object → API: tcl_mqmsgque_MqContextC_GetBuffer

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Returns

the context->ctxbuf object

Attention

(do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.

string [$ctx ToString]

top String-Slot - returns the string representation of the inst … → API: tcl_mqmsgque_MqContextC_ToString

The string is a human-readable form of the data stored in the object.

See also

slot: every class should provide a ToString function by default.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Returns

the requested string or "MK_NULL" on error

Note

(do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.

$ctx Exit ?callfunc:string="MK_NULL"? ?callfile:string="MK_NULL"? ?callline:int32=-1?

top delete the context and exit the current process or thread … → API: tcl_mqmsgque_MqContextC_Exit

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	callfile	the name of the file the call take place (e.g. FILE)
[in]	callline	the number of the line the call take place (e.g. LINE)

To delete an application is a difficult task because the link-target have to be informed. This information is send as shutdown-event and finally as socket-exit after application-exit. This library tries to perform this two steps even if the default exit function is called. This is no problem because the second step (socket-exit) is enough to signal a link-down. It is not secure to depend only on socket-exit for application exit because sometimes the sockets stop working or the link-target does not get a socket-exit. For example the pipe-link on windows. The client can not exit and create a socket-exit error on the server because the server is still running without receiving a shutdown-event. A second argument for using the MqExit function is, that it can be used for process and thread exit. A thread, started by tclmqmsgque, does exit but the process continue to work. To make it short use MqExit to exit your application.

The following steps are performed:

• delete the client-server-link using: MqLinkDelete
• if available call the context-specific-exit-handler: MqCtxTypeS::fProcessExit
• or call application-default-exit-handler
• it is a panic-error to call MqExit twice for the same object

Attention

It is a bad practice to call MqExit from inside a service.

• To trigger an exit in a service use the MkErrorSetEXIT exception.
• The MkErrorSetEXIT is an attribute of the MkErrorC class.
• The MkErrorC class is available with:
  1. MkErrorFORMAT from MkErrorC
  2. MqContextErrorFORMAT from MqContextC

potential problems

1. If you call MqExit on a service in a c++ (p)thread on linux … an SIGABRT is raised… ??? this problem is related with the "internal thread cleanup"… call ErrorSetEXIT to exit from a service handle

MqContextC [$ctx GetRoot]

top get the Root (toplevel initial context) → API: tcl_mqmsgque_MqContextC_GetRoot

$ctx ProcessEvent ?wait:MqWaitOnEventE=NO? ?timeout:MkTimeoutE|int32=DEFAULT?

top enter the event-loop and wait for an incoming service-request. … → API: tcl_mqmsgque_MqContextC_ProcessEvent

This function is used to enter the event-loop and start listen on open file-handles and to call IEvent on idle.
This function is mostly used on a server to enter the event-loop and wait for an incoming service request or on a client/server with all functions which exchange data like MqContextC SEND API, MqLinkConnect etc.

Attention

Be aware that the read-data-package is only valid until the event-loop is entered. During event-loop new data may be available for the ctx and the read-data-package will be overwritten.

See also

MqRouteTraverse

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	wait	the operation-mode used to define the behaviour, possible values are: MQ_WAIT_NO 0 Check for one event but do not wait … If an event is available process the event, but only one. If no event is available return with MK_CONTINUE. This is the default. MQ_WAIT_ONCE 1 Wait maximum timeout seconds for one new event, doesn't matter which context the event belongs to or raise an timeout-error … attention: During serving an event and this event uses the MqContextC SEND API or an other MqProcessEvent … an additional event could be served as well. error: An asynchronous error (_ERR) always belong to the parent-context of the socket connection if $ctx ConfigSetBgError ?callback:callable="MK_NULL"? is set.. the current context returns MK_OK. if $ctx ConfigSetBgError ?callback:callable="MK_NULL"? is not set.. the current context the returns MK_ERROR and an error is raised. MQ_WAIT_OWN 2 Wait maximum timeout seconds for one new event that belongs to the current context or raise an timeout-error … error: An asynchronous error (_ERR) always belong to the parent-context of the socket connection if $ctx ConfigSetBgError ?callback:callable="MK_NULL"? is set.. the current context will not return and continue working. if $ctx ConfigSetBgError ?callback:callable="MK_NULL"? is not set.. the current context returns MK_ERROR and an error is raised. MQ_WAIT_FOREVER 3 Wait maximum timeout seconds for an event or raise an timeout-error … If an event was found process the event. If an event was not found, raise a timeout-error. After the event was processed continue to listen for a the new event. This function will only come back on error or on exit.
[in]	timeout	in seconds until a timeout-error is raised, possible values are: integer >0 use this value as number of seconds. MK_TIMEOUT_DEFAULT -1 MK_TIMEOUT_USER for MQ_WAIT_ONCE or MK_TIMEOUT_MAX for MQ_WAIT_FOREVER. - request the default timeout value MK_TIMEOUT_USER -2 request the user defined timeout value from MqIoConfigS::timeout MK_TIMEOUT_MAX -3 request the maximum possible (infinite) timeout value

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC PROXY API

NAVI: top, up

		ProxyForward	send the entire read-data-package-data to the link-target …
		ProxyItem	Copy a single-data-item from the sourceCtx to the targetCtx.

MqContextC PROXY API DETAILS

C-API: MqContextC_ProxyApi_C_API - MqContextC - copy data from the read-data-package of the sourceCtx to the send-data-package of the targetCtx

The proxy-feature is used in a filter-setup to process-and-forward incoming data.

See also

MqDumpC

Example: A typical proxy-setup in pseudo C++ code

void myService () {
  MqContextC *ftr = SlaveGetFilter();     // get the "slave" with id "1" (the filter)
  ...
  ftr->SendSTART();                       // start the FORWARD
  while (ReadItemExists()) {              // read ALL data from the ORIGINAL service-call
    ProxyItem(ftr);                       // forward a SINGEL item from "this" to "ftr"
  }
  ...
  ftr->SendEND_AND_WAIT("MYTK");          // send the data.package to "ftr"
  ...
  SendSTART();                            // start the ANSWER
  while (ftr->ReadItemExists()) {         // read ALL data from the "MYTK" service-call
    ftr->ProxyItem(this);                 // forward a SINGEL item from "ftr" to "this"
  }
  SendRETURN();                           // answer the ORIGINAL service call
}

$sourceCtx ProxyForward targetCtx:MqContextC ?dump:MqDumpC="MK_NULL"? ?timeout:MkTimeoutE|int32=DEFAULT?

top send the entire read-data-package-data to the link-target … → API: tcl_mqmsgque_MqContextC_ProxyForward

The goal of this function is to link two context, typically a master and a slave (filter). This function is typically used in a service or and event callback to send the entire package and wait for the answer.

Example of a typical usage in pseudo c++

void myService () {
  MqContextC *ftr = SlaveGetFilter();    // get the "slave" with id "1" (the filter)
  ...
  ProxyForward(ftr);              // forward AND send the entire ENTIRE package from "this" to "ftr"
  ...
  SendRETURN();                   // answer the ORIGINAL service call
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	sourceCtx	the source of the copy
[in,out]	targetCtx	the target of the copy
[in]	dump	if not "MK_NULL", the value is the source of the copy, dump is the return from MqDumpExport,
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=MK_TIMEOUT_USER)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqProxyItem MqServiceProxy MqServiceProxyCtx

$sourceCtx ProxyItem targetCtx:MqContextC

top Copy a single-data-item from the sourceCtx to the targetCtx. → API: tcl_mqmsgque_MqContextC_ProxyItem

MqContextC - copy data from the read-data-package of the sourceCtx to the send-data-package of the targetCtx

The proxy-feature is used in a filter-setup to process-and-forward incoming data.

See also

MqDumpC

Example: A typical proxy-setup in pseudo C++ code

void myService () {
  MqContextC *ftr = SlaveGetFilter();     // get the "slave" with id "1" (the filter)
  ...
  ftr->SendSTART();                       // start the FORWARD
  while (ReadItemExists()) {              // read ALL data from the ORIGINAL service-call
    ProxyItem(ftr);                       // forward a SINGEL item from "this" to "ftr"
  }
  ...
  ftr->SendEND_AND_WAIT("MYTK");          // send the data.package to "ftr"
  ...
  SendSTART();                            // start the ANSWER
  while (ftr->ReadItemExists()) {         // read ALL data from the "MYTK" service-call
    ftr->ProxyItem(this);                 // forward a SINGEL item from "ftr" to "this"
  }
  SendRETURN();                           // answer the ORIGINAL service call
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	sourceCtx	the source of the copy
[in,out]	targetCtx	the target of the copy

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqProxyForward MqServiceProxy MqServiceProxyCtx

MqContextC READ API

NAVI: top, up

MqContextC READ API ATOM

		ReadTT	read a PRIMITIVE TYPE from the read-data-package …
		ReadALL	get a temporary MkBufferListC from all data in the read-data-package …
		ReadBFL	get a temporary MkBufferListC from next list-item in the read-data-package …
		ReadBinaryR	read a MkBinaryR from the read-data-package …
		ReadBUF	get a temporary MkBufferC from the read-data-package …
		ReadHDL	read the handle from the read-data-package
		ReadLIST	get all arguments as native list …
		ReadLONG	read the long native object from the read-data-package
		ReadNEXT	get the next argument as native object …
		ReadStringR	read a MkStringR from the read-data-package …

MqContextC READ API BLOCK

		ReadL_END	finish to extract a list-items from the read-data-package. …
		ReadL_START	start to extract a list-items from the read-data-package. …
		ReadT_END	finish to extract a longterm-transaction-item from the read-data-package. …
		ReadT_START	start to extract a longterm-transaction-item from the read-data-package. …

MqContextC READ API MISC

		ReadGetNextType	get the type (MkTypeE) of the next Item in the read-data-buffer or "0" if not available
		ReadGetNumItems	get the number of items left in the read-data-package …
		ReadItemExists	check if an item exists in the read-data-package …
		ReadUndo	undo the last MqContextC READ API function call …

MqContextC READ API DETAILS

C-API: MqContextC_ReadApi_C_API - MqContextC - extract data from an incoming read-data-package …

A data-package is read in two different scenarios:

• on a server to serve an incoming service-call from the client
• on a client to process the return-data from a previous service-call

Reading data is a passive-task and the opposite of sending data, which is an active-task. Passive means that the reading process is triggered by an incoming-data-package and not by the software workflow or by the user.
There is a read function and some help functions for each basic type defined in MkBufferC .

Read-Safe

Each service-call has a private read-data-package. This means that during a service-call that is in progress, another service-call can be served without damaging the read-data-package of the current service-call.

Type-Safe

A data-item in a read-data-package is type safe, this mean that every read of a data-item have to match the data-type of the previous write. One exception is available, the cast from and to the string data-type (TYPE=C) is allowed.

Example from server.tcl → read-safety: Make a nested service-call

  method Ot_CSV1 {} {

    # read the input-data from the CSV1-service-call
    # client → server
    set inI   [my ReadI32]
    incr inI

    # call the CSV2-service at the client, wait 10sec for timeout
    # server → client → server
    set retI  [my Send "Wt" 10 "CSV2:I@I" $inI]
    incr retI

    # answer the CSV1-service-call with the result from the CSV2-service-call
    # server → client
    my Send "R" "I" $retI
  }

MqContextC READ API ATOM

C-API: MqContextC_ReadApi_Atom_C_API - MqContextC - read a single-data-item outof a read-data-package …

MkBufferListC [$ctx ReadALL ?val_inout:MkBufferListC="MK_NULL"?]

top get a temporary MkBufferListC from all data in the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadALL

If the val_inout is "MK_NULL" than a temporary MkBufferListC is returned. If the val_inout is not "MK_NULL" than the memory of the val_inout is reused.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_inout	the MkBufferListC - the storage of the input is reused

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqReadBFL

Attention

(do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.

MkBufferListC [$ctx ReadBFL]

top get a temporary MkBufferListC from next list-item in the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadBFL

If the next item in the read-data-package is a list-item, (created with MqReadL_START and $ctx ReadL_END), only return this item. If the next item in the read-data-package is not a list-item than return an error. If you require all data in the read-data-package returned as single MkBufferListC than use MqReadALL.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the MkBufferListC as return-value

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqReadALL

Attention

(do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.

binary [$ctx ReadBinaryR]

top read a MkBinaryR from the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadBinaryR

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the MkBinaryR to return

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqSendSTR

MkBufferC [$ctx ReadBUF]

top get a temporary MkBufferC from the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadBUF

Return a temporary-data-item from the read-data-package. The lifetime of the MkBufferC is only the current callback up to the next read operation in the same parent-context. This object is owned by TclMqMsgque and must not be freed.

Example from server.tcl → read and update a MkBufferC

        # START - ReadBUF - Example, read a buffer-object and append a string
        set buf [my ReadBUF]
        $buf AppendSTR "- a really log text to overwrite the already allocated space"
        my SendBUF $buf
        set i   [my ReadI32]
        my SendI32 [expr {$i+1}]
        rename $buf ""

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	The out-value of type MkBufferC. 1) It is an error if the out-value is "MK_NULL", 2. If there is an error, the out-value remains unchanged.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Error Messages

1. if ctx is "MK_NULL"
2. if ctx is not connected
3. if val_out is null
4. if are no items to return
5. if the data-package is corrupt

Attention

(do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.

MK_HDL [$ctx ReadHDL]

top read the handle from the read-data-package → API: tcl_mqmsgque_MqContextC_ReadHDL

See also

MqSendHDL, MK_HDL

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the handle-object to read

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

this is NON portable

[list...] [$ctx ReadLIST]

top get all arguments as native list … → API: MqReadLIST_RT

The MqReadLIST is a function what interacts with the Target-Programming-Language (TPL) list-object.

There is no guarantee that a list-object will be available. Therefore, this function is an add-on and will only be implemented when possible.

Example from example/tcl/server.tcl → start a WORKER using all arguments from the service-call.

        # start worker with arguments from the service-call using the current executable
        my SlaveWorker $id "WORKER" {*}[my ReadLIST] --name wk-cl-$id @ --name wk-sv-$id

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the native list as return

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqReadBFL MqReadNEXT

long [$ctx ReadLONG]

top read the long native object from the read-data-package → API: tcl_mqmsgque_MqContextC_ReadLONG

on 64bit use a MqReadI64 and on 32bit use a MqReadI32

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the native long object to read

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

this is NON portable

obj [$ctx ReadNEXT]

top get the next argument as native object … → API: MqReadNEXT_RT

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the native object as return

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqReadLIST MqReadBUF

string [$ctx ReadStringR]

top read a MkStringR from the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadStringR

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the MkStringR to return

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqSendSTR

[$ctx ReadTT]

top

The ReadTT provide a single function for every PRIMITIVE TYPE

attribute	return	command	C-API :
	int8	[$ctx ReadI8]	MqReadI8_RT
	int16	[$ctx ReadI16]	MqReadI16_RT
	int32	[$ctx ReadI32]	MqReadI32_RT
	int64	[$ctx ReadI64]	MqReadI64_RT
	string	[$ctx ReadSTR]	MqReadSTR_RT
	binary	[$ctx ReadBIN]	MqReadBIN_RT
	bool	[$ctx ReadBOL]	MqReadBOL_RT
	float	[$ctx ReadFLT]	MqReadFLT_RT
	double	[$ctx ReadDBL]	MqReadDBL_RT

read a PRIMITIVE TYPE from the read-data-package …

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	val_out	the value to read

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC READ API BLOCK

C-API: MqContextC_ReadApi_Block_C_API - MqContextC - read a block-of-data outof a read-data-package …

$ctx ReadL_END

top finish to extract a list-items from the read-data-package. … → API: tcl_mqmsgque_MqContextC_ReadL_END

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ReadL_START ?buf:MkBufferC="MK_NULL"?

top start to extract a list-items from the read-data-package. … → API: tcl_mqmsgque_MqContextC_ReadL_START

Initialize the read with the current body-item or an optional MkBufferC. This command requires a final $ctx ReadL_END to finish the read.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	buf	an optional MkBufferC as result from a previous RMqReadBUF call or "MK_NULL" to use the next item from the read-data-package.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ReadT_END

top finish to extract a longterm-transaction-item from the read-data-package. … → API: tcl_mqmsgque_MqContextC_ReadT_END

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ReadT_START

top start to extract a longterm-transaction-item from the read-data-package. … → API: tcl_mqmsgque_MqContextC_ReadT_START

Initialize the read with the current-item or an optional MkBufferC. The current-item have to be the first item in the read-data-package. This command requires a final $ctx ReadL_END to finish the read.

Example from server.tcl → read the results from a service-call with transaction-support

  method Ot_TRN2 {} {
    my variable i j
    my ReadT_START
    set i [my ReadI32]
    my ReadT_END
    set j [my ReadI32]
  }

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC READ API MISC

C-API: MqContextC_ReadApi_Misc_C_API - MqContextC - various functions to work on a read-data-package …

MkTypeE [$ctx ReadGetNextType]

top get the type (MkTypeE) of the next Item in the read-data-buffer or "0" if not available → API: tcl_mqmsgque_MqContextC_ReadGetNextType

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the type

int32 [$ctx ReadGetNumItems]

top get the number of items left in the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadGetNumItems

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the number of items as integer

bool [$ctx ReadItemExists]

top check if an item exists in the read-data-package … → API: tcl_mqmsgque_MqContextC_ReadItemExists

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

boolean, true or false

$ctx ReadUndo

top undo the last MqContextC READ API function call … → API: tcl_mqmsgque_MqContextC_ReadUndo

Put the internal position-pointer to the start of the last read body-item. The next read function call will extract the same item again. Only one undo level is supported.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC ROUTE API

NAVI: top, up

		RouteCreate	create/delete a routing-link between context an a service using route
		RouteDelete	delete a routing-link created with MqRouteCreate
		RouteGetPath	return the absolut route-connection-string up to the current ctx …
		RouteGetTree	create an overview about all available routing-target and services …
		RouteResolve	return a list of all context belonging to ident …
		RouteTraverse	traverse a tree down and call service if available.

MqContextC ROUTE API DETAILS

C-API: MqContextC_RouteApi_C_API - MqContextC - setup and manage a routing-link …

A routing-link is the connection of two context, the route-source and the route-target, with a unspecifiend number of hub-context in between using a specific service-token.

A single context is identified by the context-identifier as returned by MqClassIdentGet.

A routing-link can be created using Service-Level-Routing or Package-Level-Routing.

• The Service-Level-Routing is using a round-robin-proxy-service on the hub-context to forward an incoming package to the routing-target.
• The Package-Level-Routing is using a routing-database to route the data on the package-level without a service involved.

The difference between Service-Level-Routing and Package-Level-Routing is the public versa private behaviour.

• The Service-Level-Routing route EVERY package send to the hub-context using the service-token to the routing-target, this behaviour is called public.
• The Package-Level-Routing route ONLY the package(s) from the creator (owner) of the route, this behaviour is called private.

Summary:

• The routing-link connect two context, a source-context and a target-context using multiple hub-context in between.
• The routing-link is created with the command $ctx RouteCreate route:string service:string ?overwrite:bool=false? using a route-connection-string and a service-token.
• The route-connection-string has a syntax like a UNIX-path, understand an application as a tree with the initial client as the root and multiple server and slave server as directories and subdirectories with the final service as the file-data wanted.
• The Service-Level-Routing is an extension of the already available MqServiceProxyRoundRobin and MqServiceProxyCtx feature.

TCP/IP layer model

The TCP/IP model define the following layers (from: https://www.geeksforgeeks.org/tcp-ip-model/) :

Network Access Layer

This layer corresponds to the combination of Data Link Layer and Physical Layer of the OSI model. It looks out for hardware addressing and the protocols present in this layer allows for the physical transmission of data.

Internet Layer

This layer parallels the functions of OSI’s Network layer. It defines the protocols which are responsible for logical transmission of data over the entire network
The main protocols residing at this layer are :

1. IP – stands for Internet Protocol and it is responsible for delivering packages from the source host to the destination host by looking at the IP addresses in the package headers. IP has 2 versions: IPv4 and IPv6. IPv4 is the one that most of the websites are using currently. But IPv6 is growing as the number of IPv4 addresses are limited in number when compared to the number of users.
2. ICMP – stands for Internet Control Message Protocol. It is encapsulated within IP datagrams and is responsible for providing hosts with information about network problems.
3. ARP – stands for Address Resolution Protocol. Its job is to find the hardware address of a host from a known IP address. ARP has several types: Reverse ARP, Proxy ARP, Gratuitous ARP and Inverse ARP.

Host-to-Host Layer

This layer is analogous to the transport layer of the OSI model. It is responsible for end-to-end communication and error-free delivery of data. It shields the upper-layer applications from the complexities of data.
The two main protocols present in this layer are :

1. Transmission Control Protocol (TCP) – It is known to provide reliable and error-free communication between end systems. It performs sequencing and segmentation of data. It also has acknowledgment feature and controls the flow of the data through flow control mechanism. It is a very effective protocol but has a lot of overhead due to such features. Increased overhead leads to increased cost.
2. User Datagram Protocol (UDP) – On the other hand does not provide any such features. It is the go-to protocol if your application does not require reliable transport as it is very cost-effective. Unlike TCP, which is connection-oriented protocol, UDP is connectionless.

Application Layer

This layer performs the functions of top three layers of the OSI model: Application, Presentation and Session Layer. It is responsible for node-to-node communication and controls user-interface specifications. Some of the protocols present in this layer are: HTTP, HTTPS, FTP, TFTP, Telnet, SSH, SMTP, SNMP, NTP, DNS, DHCP, NFS, X Window, LPD. Have a look at Protocols in Application Layer for some information about these protocols.
Protocols other than those present in the linked article are :

1. HTTP and HTTPS – HTTP stands for Hypertext transfer protocol. It is used by the World Wide Web to manage communications between web browsers and servers. HTTPS stands for HTTP-Secure. It is a combination of HTTP with SSL(Secure Socket Layer). It is efficient in cases where the browser need to fill out forms, sign in, authenticate and carry out bank transactions.
2. SSH – SSH stands for Secure Shell. It is a terminal emulations software similar to Telnet. The reason SSH is more preferred is because of its ability to maintain the encrypted connection. It sets up a secure session over a TCP/IP connection.
3. NTP – NTP stands for Network Time Protocol. It is used to synchronize the clocks on our computer to one standard time source. It is very useful in situations like bank transactions. Assume the following situation without the presence of NTP. Suppose you carry out a transaction, where your computer reads the time at 2:30 PM while the server records it at 2:28 PM. The server can crash very badly if it’s out of sync.

LibMqMsgque layer model

The libmqmsgque layer model is an extension to the TCP/IP layer model.

TCP/IP Application Layer

This layer is used for the libmqmsgque protocol - The protocol is the "language" of the libmqmsgque
library. The layer is defined as protocol-message-format and as protocol-flow-format.

1. protocol-message-format - Example from protocoll_mq.h → this is the "syntax" of the protocol.

    
   struct HdrS {
       MK_STRB         ID[4]             ;   
       MK_STRB         native            ;   
       MK_STRB         charA             ;   
       union HdrIU     ctxId             ;   
       MK_STRB         charS             ;   
       union HdrIU     bdySize           ;   
       MK_STRB         charO             ;   
       MK_STRB         tok[HDR_TOK_LEN]  ;   
       MK_STRB         charT             ;   
       union HdrIU     transSId          ;   
       MK_STRB         charR             ;   
       union HdrIU     routeId           ;   
       MK_STRB         charC             ;   
       MK_STRB         hs                ;   
       MK_STRB         charE             ;   
       MK_STRB         tt                ;   
       MK_STRB         charF             ;   
   };
    
   struct BdyS {
       MK_STRB         ID[4]   ;   
       //MK_STRB       charN   ;   ///< <TT>size: 1 .............. -> total: 4 .. -> character .. -> "+"</TT>
       union HdrIU     numItems;   
       MK_STRB         charE   ;   
   };
    
   struct LtrS {
       MK_STRB   ID[4]                 ;   
       //MK_STRB   charN                 ;   ///< <TT>size: 1 .............. -> total: 4 .. -> character .. -> "+"</TT>
       MK_BINB   ltrP[HDR_ID_SIZE]     ;   
       MK_STRB   charE                 ;   
   };
   #define LTR_SIZE  (3 + 1 + HDR_ID_SIZE + 1)
    
   struct RouS {
       MK_STRB   ID[4]                 ;   
       //MK_STRB   charN                 ;   ///< <TT>size: 1 .............. -> total: 4 .. -> character .. -> "+"</TT>
       MK_BINB   rouP[HDR_ID_SIZE]     ;   
       MK_STRB   charE                 ;   
   };
   #define ROU_SIZE  (3 + 1 + HDR_ID_SIZE + 1)
    
   struct PackageS {
       struct HdrS     hdr     ;   
       struct BdyS     bdy     ;   
   };
    

2. protocol-flow-format - this is the "grammatic" of the protocol.

LibMqMsgque Service Layer

This layer provide the MqContextC-ServiceApi ontop of the Application Layer.

The master-slave-link is used to create a mesh of nodes defined by different parent-context. The master control the slave.

The master-slave-link is used to perform the following tasks:

• report error messages from the slave-context to the master-context
• to create a slave-child-context if a master-child-context is created
• to delete a slave-context if a master-context is deleted

In difference to the client-server-link the master-slave-link connect two independent parent-context in the same process or thread (e.g. node). This leads to the restriction that only the master-context can be a server-context because only one server-context per node is possible.

   node-0   |           node-1/2        |   node-3/4/5
===================================================================

| <- client/server link -> | <- client/server link -> |

             | <-- master/slave link --> |

                           |- client1-0 -|- server3 ...
             |-  server1  -|
             |             |- client1-1 -|- server4 ...
  client0-0 -|
             |-  server2  -|- client1-2 -|- server5 ...

Definition of the "master-context"

• the master-context is a parent-context without a child-context available.
• the master-context is a client-context or a server-context.
• the link between the master-context and the slave-context is done using MqSlaveWorker or MqSlaveCreate

Definition of the "slave-context"

• the slave-context is a parent-context without a child-context available.
• the slave-context is a client-context.
• the slave-context lifetime is controlled by the master-context.
• the slave-context report all error-messages to the master-context.
• the slave-context is identified by a unique-slave-id starting with 0.
• a special form of a slave-context is a worker-context

Definition of the "worker-context"

• the worker-context is a slave-context using the image of the master-context self.
• the master-context can be a server-context or a client-context.
• the worker-context is created using MqSlaveWorker
• the worker-context is identified by a unique-slave-id starting with 0.

Definition of the "slave-id"

• the slave-id is defined at enum MqSlaveE
• a slave is identified in his master-context by a slave-id
• the slave-id work like a defined well-known-port-number in /etc/services
• the slave-id is an integer value with valid values > 0
• it is a good practice to plan the usage of your slave-id(s)
• slave

  slave-id	value	definition
  MQ_SLAVE_MAX	1024	internal: the maximum slave-id … .
  MQ_SLAVE_USER	10	internal: start of user-defined-slave-id .
  MQ_SLAVE_LOOPBACK	0	internal: the loopback-slave-id, (call my own services) .
  MQ_SLAVE_FILTER	1	internal: the filter-slave-id, (on a master get the filter-slave) .
  MQ_SLAVE_MASTER	1	internal: the master-slave-id, (on a slave get the master) .
  MQ_SLAVE_OTHER	1	internal: on the master-ctx get the slave-ctx and on the slave-ctx get the master-ctx .

• range

  range	definition
  0 <= slave-id < MQ_SLAVE_MAX	range of valid slave-id's
  0 <= slave-id < MQ_SLAVE_USER	internale usage
  MQ_SLAVE_USER <= slave-id < MQ_SLAVE_MAX	external usage

Definition of the "LOOPBACK" (0) slave

•    client   |           server            |
  ===========================================
  
  | <--- client/server --->  | <-- loop --> |
  
              | <------ master/slave -----> |
  
    client -- | -- server -- | -- client -- #
                     ==             ==      #
                   server -- | -- client -- #

• the loopback has always the slave-id = 0 .
• the loopback has the same class as the parent, if reflection is not available the MqFactoryInitial is used.
• the loopback is used to call a service on the same process or thread.
• the loopback is a special filter without an additional process or thread to be started.
• the loopback is only internal accessible
• the service called by the loopback need the same attention as the service called by the filter, the context of the service is the loopback-context.
• the loopback can call MqServiceCreate to create a new link between a service-token and a service-method, by default all services from the master-context (the owner of the loopback) are also accessible by the loopback.
• in the service use MqSlaveGetMaster to get the master-context from the loopback-context.
• Example from MyLoopServer.tcl → create a new loop-server

  package require tclmsgque::MqMsgque
  namespace import tclmsgque::MqMsgque::*
  
  ::oo::class create MyLoopServer {
    superclass MqContextC
    export variable
  
    # factory startup
    constructor {{tmpl ""}} {
      my variable mydata;
      next $tmpl
      my ConfigSetServerSetup ServerSetup
      # set the "mydata" attribute to the master-context
      set mydata  "Hello World";
    }
  
    # service to serve all EXTERNAL requests for token "HLWO"
    method HLWO_srv {} {
      # get the "loopback" context
      set loop  [my SlaveGet LOOPBACK]
      # call the LOOP service on the SAME server
      $loop Send "W" "LOOP"
      # answer HLWO with string-return from LOOP
      my Send "R" "C" [$loop ReadSTR]
    }
  
    # service to serve all INTERNAL requests for token "LOOP"
    method LOOP_srv {} {
      # get the "master" context
      set master  [my SlaveGetMaster]
      # answer LOOP with data from MASTER->mydata attribute
      $master variable mydata
      my Send "R" "C" $mydata
    }
  
    # setup a server-context - called for every new server-context
    method ServerSetup {} {
      # EXTERNAL: link the "HLWO" service with "HLWO_srv"
      my ServiceCreate "HLWO" HLWO_srv
      # INTERNAL: link the "LOOP" service with "LOOP_srv"
      [my SlaveGet MQ_SLAVE_LOOPBACK] ServiceCreate "LOOP" LOOP_srv
    }
  }
  
  tclmsgque::MqMsgque Main {
  
    # create "MyLoopServer" factory... and the instance
    set srv   [[MqFactoryC Add MyLoopServer] New]
  
    try {
      $srv LinkCreate $argv
      $srv ProcessEvent MQ_WAIT_FOREVER
    } on error {} {
      $srv ErrorCatch
    } finally {
      $srv Exit
    }
  }
  

Performance analyse

The performance-test is created with:

• pipe
  • Nhi1Exec perfclient.c --parent --wrk ? @ perfserver.c
• spawn, fork, thread
  • Nhi1Exec -r=uds perfserver.c --spawn|fork|thread
  • Nhi1Exec -r=uds perfclient.c --parent --wrk ?
• the number of workers are set with the –wrk option
• the cpu is a xeon with 4/8
• the performance is calculated as worker-context-created / time-in-sec with a ~2sec (default) measurement period.

performance-test code:

• The test-setup is done as:

    perfclient                                worker                            perfserver
    ==========                                ======                            ==========
    |
    |- loop --wrk x
      |- MqSlaveWorker(...)               ->  worker[1] 
      |- MqSend(worker[1],"E","STR0..")   ->  PerfWorker_I160(...)
                                              |- loop endless
                                                |- MqContextCreate(...)
                                                |- MqLinkCreate(...)      <->   MqContextCreate(...)
                                                |- MqContextDelete(...)   <->   MqContextDelete(...)
    |- sleep x sec
    |- loop --wrk x
      |- MqSend(worker[1],"C"..,"END0")   ->  PerfWorker_END0(...)
      |                                       |- stop loop
      |- "callback" - add number to all   <-  |- return #context 

• Using the worker-code:

  // asynchronous call
  static enum MkErrorE PerfWorker_STR0( MQ_SERVICE_CALL_ARGS ) {
    MK_BFL largv = NULL;
    MK_BFL pargv = NULL;
    MK_I32 num   = MqReadI32_e(mqctx);
           pargv = MkBufferListDup(MqReadBFL_e(mqctx));
    enum MkErrorE ret = MK_OK;
   
    if (num == -1) num = 999999;  // endless
   
    // start test until "doNext" is "false" or "num" exceeds
    for (int i=0; doNext && i<num; i++) {
      // CREATE the context
      MQ_CTX ctx = MqContextCreate(NULL, mqctx);
      largv = MkBufferListDup(pargv);
      MqLinkCreate_C (ctx, largv) {
        MqContextErrorMove(mqctx,ctx);
        MqContextDelete(ctx);
        goto error;
      }
   
  //MqSend(ctx,"E","MARK:C","start");
   
      MkBufferListDelete(largv);
   
      // DELETE the context
      MqContextDelete(ctx);
   
      // count the loops
      worker_count++;
   
      // give PerfWorker_END0 time to update "doNext"
      MqProcessEvent(mqctx, MQ_WAIT_NO, MK_TIMEOUT_DEFAULT);
    }
   
  end:
  //printV("ret=%i, Delete=%p\n", ret, largv)
    MkBufferListDelete(largv);
    MkBufferListDelete(pargv);
   
    if (doNext == true) {
      // finish the test WITHOUT "END0" -> test on --num, answer required.
      MqSend_E(mqctx, "R", "I", worker_count);
    }
    return ret;
   
  error:
    if (doNext == true) {
      ret = MkErrorStack_1X(mqctx);
    } else {
      ret = MkErrorReset_1X(mqctx);
    }
    goto end;
  }

performance-test results:

• results generated using the debug environment

  setup	–wrk	# worker-context	performance	info
  pipe	1	2500	1000	the pipe start a new worker-context with spawn
  spawn	1	2500	<1000	same as pipe but use network-protocoll
  fork	1	3800	4000	the fork is faster than spawn
  thread	1	16500	9000	the thread is faster than fork
  pipe	4	8000	4500	the worker scale linear up to number of processors
  spawn	4	7600	<4500	-
  fork	4	23200	11500	-
  thread	4	55500	27500	-
  pipe	8	10000	5500	the additional scaling up to the max hyper-threading does not really help
  spawn	8	9100	<5500	-
  fork	8	23200	11500	-
  thread	8	55500	27500	-

example (C++ syntax)

Route-Connection-String

A client-server connection is defined with the route-connection-string as a composition of "identifier" and is build like a UNIX directory tree with the initial client as root.

Example: GUI/Data Frontend

*
 
               |-header
         |-GUI-|
frontend-|     |-footer
         |
         |-DB
 
*

With --ident-from prefix|factory the identifier is defined as prefix-identifier or factory-identifer.

A route-connection-string is the path between TWO locations in the tree using the UNIX syntax:

short	syntax	direction
dot	.	current-context
double-dot	..	previous-context
slash	/	root-context (the client)
"string"	xxx	next-context with name xxx

path between "DB" and "header"

• relative: ctx.RouteCreate("../GUI/header",service)
• absolute: ctx.RouteCreate("/frontend/GUI/header",service)

path between "footer" and "DB"

• relative: ctx.RouteCreate("../../DB",service)
• absolute: ctx.RouteCreate("/frontend/DB",service)

path between "frontend" and "footer"

• relative: ctx.RouteCreate("GUI/footer",service)
• absolute: ctx.RouteCreate("/frontend/GUI/footer",service)

Service-Layer-Routing

The LibMqMsgque-Service-Layer-Routing create proxy-services (MqServiceProxyRoundRobin ...) between frontend and footer. (example c++)

// 1. on "frontend" create a route to the service "MYSV" on the "footer" passing "GUI"
DOING: frontendCtx.RouteCreate("GUI/footer", "MYSV");
 
// 2. on "frontend" call the route using the "loopback" slave
DOING: frontendCtx.SlaveGet(MQ_SLAVE_LOOPBACK).Send("W", "MYSV:..@..", ..);
 
// 3. on "frontend/GUI" proxy "footer"
INTERNAL: frontendCtx.ServiceProxyRoundRobin("MYSV", GUICtx);
INTERNAL: GUICtx.ServiceProxyRoundRobin("MYSV", footerCtx);
 
// 4. on "footer" call the service "MYSV"
SETUP: footerCtx.ServiceCreate("MYSV", ...);

The MqRouteCreate will take the following action:

1. create a round-robin-proxy on frontend and on GUI using service MYSV
2. check if service MYSV is available on footer

Attention:

1. With the proxy on frontend/GUI no other service with the name MYSV on frontend/GUI is possible and every service-call to frontend or GUI using the service MYSV will be redirected to the service MYSV on footer.
2. The live-time of the Service-Layer-Routing is up to the next MqRouteDelete call using the same arguments. If the proxy-to-footer becomes invalid on a the GUI-context the routing-link will be recreated.
3. The MqRouteCreate can be used multiple times with the same Route-Connection-String and service-token and overwrite=true to guarantee that a route is available.

Package-Layer-Routing

...

$ctx RouteCreate route:string service:string ?overwrite:bool=false?

top create/delete a routing-link between context an a service using route → API: tcl_mqmsgque_MqContextC_RouteCreate

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	route	the absolute or relative path to the target-context, if NULL or '\0' the current context is returned.
[in]	service	the service token on the target context
[in]	overwrite	if overwrite=false an error is raised if the service already exists.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqRouteCreate, MqRouteDelete

$ctx RouteDelete route:string service:string ?overwrite:bool=false?

top delete a routing-link created with MqRouteCreate → API: tcl_mqmsgque_MqContextC_RouteDelete

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	route	the absolute or relative path to the target-context, if NULL or '\0' the current context is returned.
[in]	service	the service token on the target context
[in]	overwrite	if overwrite=false an error is raised if the service already exists.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqRouteCreate, MqRouteDelete

string [$ctx RouteGetPath]

top return the absolut route-connection-string up to the current ctx … → API: tcl_mqmsgque_MqContextC_RouteGetPath

The absolut route-connection-string is the route starting at root (e.g. "/").

Attention

• The path_out returned is owned by the loopback-slave -> do not free.
• The path_out returned is only valid until the next call to the loopback-slave.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	path_out	the return path or "MK_NULL" on error

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqRouteGetTree

MkBufferListC [$ctx RouteGetTree]

top create an overview about all available routing-target and services … → API: tcl_mqmsgque_MqContextC_RouteGetTree

The data returned is a list of "ROUTE|IDENT|SERVICE,..." string items.

• The ROUTE is the route-connection-string used in $ctx RouteCreate route:string service:string ?overwrite:bool=false?.
• The IDENT is the MqClassIdentGet and usually the final part of the route-connection-string.
• The SERVICE is the list of services available at IDENT.

Example from MyWorker.tcl → get the "Tree" as service

    void TREE () {
      Send("R", "L", RouteGetTree());
    }

Example from tests/route2.test -> route2-1-0

• Get a list of all services on all servers reachable by test-context.

 /cl-0/sv-0/svWO2-11/svWO3-11|svWO3-11-0-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-11|svWO3-11-1-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-11|svWO3-11-2-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-12|svWO3-12-0-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-12|svWO3-12-1-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-12|svWO3-12-2-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11|svWO2-11-0-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11|svWO2-11-1-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11|svWO2-11-2-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-11|svWO3-11-0-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-11|svWO3-11-1-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-11|svWO3-11-2-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-12|svWO3-12-0-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-12|svWO3-12-1-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12/svWO3-12|svWO3-12-2-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12|svWO2-12-0-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12|svWO2-12-1-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-12|svWO2-12-2-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0|sv-0-0-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0|sv-0-1-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0|sv-0-2-2|FOID,HLWO,HLWS,PATH,TREE
 /cl-0|cl-0-0-2|HLWO,HLWS
 /cl-0|cl-0-1-2|HLWO,HLWS
 /cl-0|cl-0-2-2|HLWO,HLWS
 /cl-0/sv-0/svWO2-11/svWO3-11|svWO3-11-0-2|FINL,FOID,HLWO,HLWS,PATH,TREE
 /cl-0/sv-0/svWO2-11/svWO3-11|svWO3-11-1-2|FINL,FOID,HLWO,HLWS,PATH,TREE

The following information is available:

• root is cl-0
• multiple other clients, parallel to cl-0, are reachable: cl-0-....
• multiple servers involved: sv...
• multiple services reachable: FINL,FOID,HLWO,HLWS,PATH,TREE

Attention

• The list-object returned is owned by MqRouteGetTree and is only valid until the next call to MqRouteGetTree.
  
• On error the list-object will be empty.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	treeP_out	the tree-object with the results…

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqRouteGetPath

[MqContextC...] [$ctx RouteResolve ident:string ?retnum:int32=-1?]

top return a list of all context belonging to ident … → API: tcl_mqmsgque_MqContextC_RouteResolve

This api-proc is used to return all context with MqLinkS::targetIdent == ident .

• The MqLinkS::targetIdent is the value returned by MqClassIdentGet from the remote-context based on the configuration value of --ident-from prefix|factory.
• The MqConfigS::prefix is initialized with MqFactoryS::originalIdent and can be modified with MqConfigSetPrefix.
• The MqFactoryS::originalIdent is set by MqFactoryAdd at factory setup.

In addition the following special ident are recognized:

• EMPTY or "MK_NULL" or DOT=. or ClassIdentGet -> The loopback-slave
• DOUBLE-DOT=.. -> On the server the server-context and on the slave the master-context

Example from server.tcl → in a service call return all connected targets

        foreach myctx [my RouteResolve [my ReadSTR]] {
          my SendSTR [$myctx LinkGetTargetIdent]
        }

See also

MqRouteTraverse

Attention

1. (do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
For details on the out/return value, see: MkKernel_Storage_C_API.
2. The maximun number of items in the return-array is MQ_ROUTE_CTX_MAX .
3. (C-API) The last item in the return-array is always a "MK_NULL".

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	ident	The identifer to search the context for
[in]	retnum	The maximum number-of-items accepted in the result-array, if <0 than MQ_ROUTE_CTX_MAX is used.

Returns

An array of MqContextC, the last item is a "MK_NULL".

$ctx RouteTraverse service:string ?args:MkBufferListC...="MK_NULL"?

top traverse a tree down and call service if available. → API: tcl_mqmsgque_MqContextC_RouteTraverse

The MqRouteTraverse is intended to call a service on all-routes "*" starting from ctx.

This is a tool to be used to do maintenance work, sometimes a service is changed (e.g MqRouteCreate) or an internal status need to be reset.

Note

- Internal the service is called using the loopback-slave context, be aware to call MqSlaveGetMaster first to start on the master-context.

- It is not an error if a service does not exists on a specific route starting from ctx.

The following internal tasks are performed ( C notation ) :

1. Call MqSendEND_AND_WAIT on the MQ_SLAVE_LOOPBACK if the service exists.

       if (MqServiceTokenExists(ctx,service)) {
         MQ_CTX loop = MqSlaveGet_e(ctx,MQ_SLAVE_LOOPBACK);
         MqSendSTART_E(loop);
         MqSendL_FLAT_E(loop,args);
         MqSendEND_AND_WAIT_E(loop,service,MK_TIMEOUT_DEFAULT);
       }

2. Call MqRouteResolve with "*" to get all routes starting from the ctx up to MQ_ROUTE_CTX_MAX routes :

       int flag[MQ_ROUTE_CTX_MAX] = {0};
       MQ_CTX_A rr = MqRouteResolve(ctx, "*", -1);

3. Call MqRouteTraverse on every route from rr with :

       // call for a "routing" setup/check using all rrctx from "rr->list"  in parallel.
       // -> use "flag" to check if a callback was called.
       for (int i=0; i<rr.size; i++) {
         MQ_CTX rrctx = rr.data[i];
         if (MQ_IS_LOOPBACK(rrctx)) continue;
         if (MQ_IS_SERVER(rrctx) && ctx == rrctx) continue;
         MqSendSTART_E(rrctx);
         MqSendSTR_E(rrctx,service);
         MqSendBFL_E(rrctx,args);
         if (MkErrorCheckI(MqSendEND_AND_CALLBACK(rrctx,"_RTR",sRouteTool_CB,&flag[i],NULL,MK_TIMEOUT_DEFAULT))) {
           pContextErrorCopy ( ctx,rrctx);
           goto error;
         }
       }

   The sRouteTool_CB set the flag[i] to 1 to signal done.
4. Call MqProcessEvent to wait for an answer and check on error with timeout MK_TIMEOUT_DEFAULT.

       // wait to finish all "calls" from obove - using "flag" to check if wait is still required.
       for (int i=0; i<rr.size; i++) {
         MQ_CTX rrctx = rr.data[i];
         if (MQ_IS_LOOPBACK(rrctx)) continue;
         if (MQ_IS_SERVER(rrctx) && ctx == rrctx) continue;
         while (flag[i] == 0) {   // just be shure the CB is still "open=0"
           if (MkErrorCheckI(MqProcessEvent(rrctx, MQ_WAIT_OWN, MK_TIMEOUT_DEFAULT))) {
             MqContextErrorCopy (ctx,rrctx);
             goto error;
           }
         }
       }

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	service	the service token to be called
[in]	args	command-line-arguments passed as arguments to the service call

MqContextC SEND API

NAVI: top, up

MqContextC SEND API ATOM

		SendTT	MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …
		SendBFL	append a MkBufferListC object to the send-data-package object …
		SendBinaryR	append a MkBinaryR object to the send-data-package. …
		SendBUF	append a MkBufferC object to the send-data-package object …
		SendBUS_FLAT	append a MkBufferStreamC object to the send-data-package object …
		SendHDL	send the handle to the send-data-package
		SendL_FLAT	append a MkBufferListC object as flat list of items to the send-data-package object …
		SendLONG	send the long native object to the send-data-package
		SendStringR	MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …

MqContextC SEND API BASICS

		SendEND	MqContextC - finish the send-data-block and call synchronous/asynchronous a remote-service …
		SendEND_AND_CALLBACK	finish the send-data-block, call the remote service, do not-wait for the result but expect the result on a callback …
		SendEND_AND_SUB	finish the send-data-block, call the remote service, do wait for the result and expect multiple sub-results on a callback …
		SendEND_AND_TRANSACTION	finish the send-data-block, call the remote service to do a longterm-transaction-call …
		SendEND_AND_WAIT	finish the send-data-block, call the remote service and wait for result…
		SendSTART	initialize the send-data-package. …
		SendSYNC	garantee that all pending asynchronous-service-calls are processed. …

MqContextC SEND API BLOCK

		SendL_END	finish to append an embedded body-list-item to the send-data-package. …
		SendL_START	start to append an embedded body-list-item to the send-data-package. …
		SendT_END	closed a longterm-transaction-item …
		SendT_START	open a longterm-transaction-item …

MqContextC SEND API RETURN

		SendERROR	send the data from the MkErrorC to the link target . …
		SendRETURN	MqContextC - finish the send-data-block on the server and optional return the results. …
		SendRETURN_SUB	return Sub-Data-Blocks required by MqSendEND_AND_SUB …

MqContextC SEND API DETAILS

C-API: MqContextC_SendApi_C_API - MqContextC - construct an outgoing send-data-package …

A data-package is send in two different scenarios:

1. on a client to call a service on the server
2. on a server to answer a service call from the client

Sending data is an active task and the opposite of reading data, which is a passive task. Active means that the send process is triggered by the software workflow or by the user.
For each basic type defined in MkBufferC, there is a send function and some help functions.

Send-Safe

Sending data is an atomic task and must not be interrupted between MqSendSTART and MqSendEND. The MqContextC HIGH API is uninterruptible by design.
Basic rule: process first and send all data last.

If timeout != 0 is used, the application enters the event loop and waits in the current process or thread for timeout seconds until the service call is finished.
While waiting for a result, the application can continue to work on other events that are in the same or in a different process or thread.

Recursion-Safe

If another-service-call arrives while waiting for a response from a previous-service-call, the previous-service-call will NOT end until processing of the other-service-call is complete.

Example-1: a service call, send and read a data-package

On a client: perform a service call

send the service-call	MqSendSTART → SendTT... → MqSendEND_AND_WAIT
read the result package	ReadTT... → ...

on a server: answer a service call

read the service-call	ReadTT... → ...
send the result package	MqSendSTART → SendTT... → MqSendRETURN

Important in the code from above is the last command MqSendEND_AND_WAIT because this is just one of five possibilities:

command	synchron	database	result
MqSendEND	no	no	no
MqSendEND_AND_WAIT	yes	no	single return data
MqSendEND_AND_SUB	yes	no	multiple return data
MqSendEND_AND_CALLBACK	no	no	single return data
MqSendEND_AND_TRANSACTION	no	yes	two return data

To send a data-package is one task, to send it to the right receiver is an other one. The right receiver is identified using the token parameter argument. This parameter have to be a 4 character string. You'll probably ask "why 4?" the answer is that this string should be "human" readable and easy to "compare". As solution this string is mapped to a 4 byte integer used to find the proper key/value entry in the service-hash-table on the server. (in short: to search an integer is much faster as to search a string)

Example-2: (in C) At the client, calling the service and wait for an answer

...
enum MkErrorE MyServiceCall(MQ_CTX const ctx) {
  // ... do some work
    MqSendSTART_E(ctx);                     // init the Send-Buffer object
    MqSendI32_E(ctx,int_value);               // 1. argument: a MK_I32 value
    MqSendSTR_E(ctx,"num:01");                // 2. argument: a MK_STRN value
    MqSendBIN_E(ctx,mypicture,size);          // 3. argument: a MK_BIN picture of size length
    MqSendEND_AND_WAIT_E(ctx,"SRV1",60);    // call service "SRV1" and wait max 60sec for the results
  // ... get the results
    MK_I32 retI = MqReadI32_e(ctx);           // expect ONE integer as result
  // ... do some work
    return MK_OK;
  error:                                    // default error-handler
    return MkErrorStack_1X(ctx);              // on error, build up the error-stack
}

... or using the MqContextC HIGH API

...
enum MkErrorE MyServiceCall(MQ_CTX const ctx) {
  // ... do some work
    MqSend_E(ctx, "W", "SRV1:ICB", int_value, "num:01", mypicture, size);
  // ... get the results
    MK_I32 retI = MqReadI32_e(ctx);           // expect ONE integer as result
  // ... do some work
    return MK_OK;
  error:                                    // default error-handler
    return MkErrorStack_1X(ctx);              // on error, build up the error-stack
}

Example-3: (in C) At the server, answer the service call

...
static MkErrorE SRV1(MQ_CTX const ctx, MK_PTR data) {   // the name "SRV1" can be free chosen
  // ... do some work
    MK_I32 myInt = MqReadI32_e(ctx);          // read a MK_I32 value
    MK_STRN myStr = MqReadSTR_e(ctx);          // read a MK_STR value
    MK_BUF myPic = MqReadBUF_e(ctx);          // read a MkBuffer64S object to store the picture data
  // ... do some work
    MqSendSTART_E(ctx);                     // init the Send-Buffer object
    MqSendI32_E(ctx,int_ret);                 // return argument: a MK_I32 value
  error:                                    // something is wrong, error back
    return MqSendRETURN(ctx);                   // send the package as an answer of a previous service-call
}

... or using the MqContextC HIGH API

...
static MkErrorE SRV1(MQ_CTX const ctx, MK_PTR data) {   // the name "SRV1" can be free chosen
  // ... do some work
    MK_I32 myInt = MqReadI32_e(ctx);          // read a MK_I32 value
    MK_STRN myStr = MqReadSTR_e(ctx);          // read a MK_STR value
    MK_BUF myPic = MqReadBUF_e(ctx);          // read a MkBuffer64S object to store the picture data
  // ... do some work
  error:
    return MqSend(ctx, "R", "I", int_ret);  // send the package as an answer of a previous service-call
}

MqContextC SEND API ATOM

C-API: MqContextC_SendApi_Atom_C_API - MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the value to appending

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendBFL val:MkBufferListC

top append a MkBufferListC object to the send-data-package object … → API: tcl_mqmsgque_MqContextC_SendBFL

The items of the list are send as list using MqSendL_START and MqSendL_END.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the pointer to an MkBufferListC object to send

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

If val == NULL an empty binary (size=0) will be send.

See also

MqSendL_FLAT

$ctx SendBinaryR val:binary

top append a MkBinaryR object to the send-data-package. … → API: tcl_mqmsgque_MqContextC_SendBinaryR

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the value to appending

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

If val == NULL an empty byte-array ([]) will be send.

$ctx SendBUF val:MkBufferC

top append a MkBufferC object to the send-data-package object … → API: tcl_mqmsgque_MqContextC_SendBUF

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the value to appending

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

If val == NULL an error is raised.

$ctx SendBUS_FLAT val:MkBufferStreamC

top append a MkBufferStreamC object to the send-data-package object … → API: tcl_mqmsgque_MqContextC_SendBUS_FLAT

The items of the stream are send flast as the stream is appended to the send-data-package.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the pointer to an MkBufferStreamC object to send

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

If val == NULL an empty binary (size=0) will be send.

See also

MqSendL_FLAT

$ctx SendHDL val:MK_HDL

top send the handle to the send-data-package → API: tcl_mqmsgque_MqContextC_SendHDL

See also

MqReadHDL, MK_HDL

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the handle-object to send

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

this is NON portable

$ctx SendL_FLAT val:MkBufferListC

top append a MkBufferListC object as flat list of items to the send-data-package object … → API: tcl_mqmsgque_MqContextC_SendL_FLAT

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the pointer to an MkBufferListC object to send

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqSendBFL

$ctx SendLONG val:long

top send the long native object to the send-data-package → API: tcl_mqmsgque_MqContextC_SendLONG

on 64bit use a MqSendI64 and on 32bit use a MqSendI32

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the native long object to send

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

this is NON portable

See also

MqReadLONG

$ctx SendStringR val:string

top MqContextC - append a native PRIMITIVE TYPE value to the send-data-package … → API: tcl_mqmsgque_MqContextC_SendStringR

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the value to appending

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

If val == NULL the string "MK_NULL" will be send.

See also

MqReadSTR

$ctx SendTT val:int8

top

The SendTT provide a single function for every PRIMITIVE TYPE

attribute	return	command	C-API :
		$ctx SendI8 val:int8	MqSendI8_RT
		$ctx SendI16 val:int16	MqSendI16_RT
		$ctx SendI32 val:int32	MqSendI32_RT
		$ctx SendI64 val:int64	MqSendI64_RT
		$ctx SendSTR val:string	MqSendSTR_RT
		$ctx SendBIN val:binary	MqSendBIN_RT
		$ctx SendBOL val:bool	MqSendBOL_RT
		$ctx SendFLT val:float	MqSendFLT_RT
		$ctx SendDBL val:double	MqSendDBL_RT

MqContextC - append a native PRIMITIVE TYPE value to the send-data-package …

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	val	the value to appending

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC SEND API BASICS

C-API: MqContextC_SendApi_Basics_C_API - MqContextC - finish the send-data-block and call synchronous/asynchronous a remote-service …

calling a remote service and wait timeout seconds for an result. If timeout == 0 it is an asynchronous-service-call and if the timeout > 0 it is a synchronous-service-call.

service-call	blocking	timeout
synchronous	yes	timeout > 0
asynchronous	no	timeout == 0

blocking mean waiting max timeout seconds to finishing the service-call:

• If the service-call is finished in less than timeout seconds… the results are available and can be processed.
• If the service-call is NOT finished in timeout seconds… an timeout-error is created and the transaction will be canceled.

If an error was raised on the server during the service-processing… the following error-handling will be available

1. on a synchronous-service-call the error will be the result of the service-call
2. on a asynchronous-service-call with callback the error will be the result of the callback
3. on a asynchronous-service-call without callback the error will be send asynchronous from the server to the client . On the client the error will be raised on the NEXT event-handlng-command or as background-error if the MqSetupS::BgError function was defined.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=0)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqSendSYNC

$ctx SendEND token:string[4] ?timeout:MkTimeoutE|int32=DEFAULT?

top MqContextC - finish the send-data-block and call synchronous/asynchronous a remote-service … → API: tcl_mqmsgque_MqContextC_SendEND

calling a remote service and wait timeout seconds for an result. If timeout == 0 it is an asynchronous-service-call and if the timeout > 0 it is a synchronous-service-call.

service-call	blocking	timeout
synchronous	yes	timeout > 0
asynchronous	no	timeout == 0

blocking mean waiting max timeout seconds to finishing the service-call:

• If the service-call is finished in less than timeout seconds… the results are available and can be processed.
• If the service-call is NOT finished in timeout seconds… an timeout-error is created and the transaction will be canceled.

If an error was raised on the server during the service-processing… the following error-handling will be available

1. on a synchronous-service-call the error will be the result of the service-call
2. on a asynchronous-service-call with callback the error will be the result of the callback
3. on a asynchronous-service-call without callback the error will be send asynchronous from the server to the client . On the client the error will be raised on the NEXT event-handlng-command or as background-error if the MqSetupS::BgError function was defined.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=0)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqSendSYNC

$ctx SendEND_AND_CALLBACK token:string[4] callback:callable ?timeout:MkTimeoutE|int32=DEFAULT?

top finish the send-data-block, call the remote service, do not-wait for the result but expect the result on a callback … → API: tcl_mqmsgque_MqContextC_SendEND_AND_CALLBACK

This function will never block and return immediately. Usually multiple MqSendEND_AND_CALLBACK are send and finally multiple MqProcessEvent are called to wait for the results.

Example from route_mq.c → (C) call a service using a callback

    int i;
    int flag[MQ_ROUTE_CTX_MAX] = {0};
    // call for a "routing" setup/check using all rrctx from "rr->list" in parallel.
    // -> use "flag" to check if a callback was called.
    for (i=0; i<rr->num; i++) {
     MQ_CTX rrctx = rr->list[i];
      MqSendSTART_E(rrctx);
      MqSendSTR_E(rrctx,routeCUR);
      MqSendSTR_E(rrctx,service);
      MqSendBOL_E(rrctx,isCreate);
      MqSendBOL_E(rrctx,overwrite);
      if (MkErrorCheckI(MqSendEND_AND_CALLBACK(rrctx,"_ROU",sRouteTool_CB,&flag[i],NULL,MK_TIMEOUT_DEFAULT))) {
        MqContextErrorCopy ( ctx,rrctx);
        goto error;
      }
    }
    // wait to finish all "calls" from obove - using "flag" to check if wait is still required.
    for (i=0; i<rr->num; i++) {
      MQ_CTX rrctx = rr->list[i];
      while (flag[i] == 0) {   // just be shure the CB is still "open=0"
        if (MkErrorCheckI(MqProcessEvent(rrctx, MQ_WAIT_OWN, MK_TIMEOUT_DEFAULT))) {
          MqContextErrorCopy ( ctx,rrctx);
          goto error;
        }
      }
    }

Be aware of the followig limitatitions if multiple MqSendEND_AND_CALLBACK are called with different ctx:

• If no error is available the callback is called with the ctx of the previous call to MqSendEND_AND_CALLBACK.
• If an error is available the error is raised as result from the call to MqProcessEvent and NOT as result th the previous call to MqSendEND_AND_CALLBACK. The error-context is the context of the call to MqProcessEvent and not the context of the previous call to MqSendEND_AND_CALLBACK.

See also

MqRouteTraverse

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	fCall	the function to process the service-call results
[in]	callback	a user defined additional data-argument for the callback function (C-API only)
[in]	fFree	the function to free the data-argument after use (C-API only)
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT= 0)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Note

It is a good-practice to protect a bulk of asyncrone-service-calls with a MqSendSYNC or with a MqProcessEvent and MQ_WAIT_OWN .

MqSendEND_AND_CALLBACK : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

$ctx SendEND_AND_SUB token:string[4] callback:callable ?timeout:MkTimeoutE|int32=DEFAULT?

top finish the send-data-block, call the remote service, do wait for the result and expect multiple sub-results on a callback … → API: tcl_mqmsgque_MqContextC_SendEND_AND_SUB

The goal of this service-call is, to split a big data-block into multiple pieces. A typical solution would be a database-application doing a select and sending EVERY row as a $ctx SendRETURN_SUB. At the end ONE final and EMPTY $ctx SendRETURN is used to delete the open transaction and finish the service call.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	fCall	the function to process the service-call results
[in]	callback	a user defined additional data-argument for the callback function (C-API only)
[in]	fFree	the function to free the data-argument after use (C-API only)
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=MK_TIMEOUT_USER)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

By default, the callback for the last packet ( $ctx SendRETURN) is only called if the packet contains a data-item or on an error. If the packet is empty, only the transaction is closed.

See also

MqSendEND_AND_WAIT MqSendEND_AND_CALLBACK MqSendRETURN_SUB MqSendRETURN

MqSendEND_AND_SUB : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

$ctx SendEND_AND_TRANSACTION token:string[4] callback:string[4] ?timeout:MkTimeoutE|int32=DEFAULT?

top finish the send-data-block, call the remote service to do a longterm-transaction-call … → API: tcl_mqmsgque_MqContextC_SendEND_AND_TRANSACTION

A longterm-transaction is a service-call with guaranteed delivery. guaranteed mean that the transaction is using the MqContextC STORAGE API to keep every step persistent being able to recover a step if something unexpected happen.

To link the result with the calling-environment a private transaction-item is used to save the calling-environment to the local-storage. If the local-storage is persistent, the calling-environment will even survive an application restart.
If the result from the public service-call arrives, the transaction-item will be extracted from the result and the private calling-environment will be initialized from the local-storage.

To create a persistent-transaction the MqContextC STORAGE API have to be setup as persistent. By default, an in-memory MqContextC STORAGE API is used.

The longterm-transaction-call has TWO results…

• the FIRST result is a acknowledge that the longterm-transaction was stored in the remote database
• the SECOND result is the result of the service-call

In difference to MqSendEND_AND_WAIT and MqSendEND_AND_CALLBACK a longterm-transaction-call have to survive an application restart. To achieve this goal… two features have to be available to process the results:

• a transaction-callback as a service created with MqServiceCreate
• a transaction-item as a environment created with MqSendT_START … MqSendT_END and stored into an internal database.

transaction-item

The transaction-item is the entry-id from the local internal database and is the public handle of the private data. If the transaction-item-private-data should be persistent (survive an application restart) the internal database have to be persistent using the Storage option.
The transaction-item-private-data requires a MqSendT_START … MqSendT_END at the beginning of the send-data-package.
The list of data-items in the transaction-item-private-data have to be provided by the programmer and is used to initialise the environment in the callback (for example an external database-entry-id).
In the transaction-callback the transaction-item-private-data have to be extracted with MqReadT_START … MqReadT_END at the beginning of the read-data-package.

transaction-callback

The transaction-callback have to be a MqContextC_ServiceApi_Identifer defined with MqServiceCreate in the application setup code (like IServerSetup) and have to be available after an application restart.

If an error is raised on the server during the database-insert the function will return this error immediately. During waiting for the return the event-loop is used to process other events. Use IEvent to add your tasks into the event loop.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	callback	the MqContextC_ServiceApi_Identifer of the MqContextC_ServiceApi_Callback
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=MK_TIMEOUT_USER)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Example from MyTransaction.tcl → make a logterm-transaction-call using the LOW and the HIGH api

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*
namespace import tclmsgque::MkKernel::*

proc callback {ctx} {
  $ctx ReadT_START
  set myPrivateHandle [$ctx ReadSTR]
  $ctx ReadT_END
  set myServiceResult [$ctx ReadI32]

  puts "myPrivateHandle=$myPrivateHandle, myServiceResult=$myServiceResult"
}

# setup the client-context
set ctx [MqContextC new]

try {

  $ctx ConfigSetName "MyTransaction"

  # setup commandline arguments used for parsing
  set args [MkBufferListC CreateLA {*}$argv]

  # check if the '--token' option is available, default "SRVC"
  set token [$args CheckOptionSTR "--token" "SRVC"]
   
  # connect to the server
  $ctx LinkCreate $args
   
  # register callback
  $ctx ServiceCreate CLB1 callback
   
  # send block using the LOW-Api
  $ctx SendSTART
  $ctx SendT_START
  $ctx SendSTR "Privat_Data_1"
  $ctx SendT_END
  $ctx SendI32 11111
  $ctx SendEND_AND_TRANSACTION $token CLB1
   
  # send block using the HIGN-Api -> same as above, but shorter
  $ctx Send "T" CLB1 "$token:(C)I" "Privat_Data_2" 22222
   
  # now we wait for exact ONE result of the $ctx
  $ctx ProcessEvent MQ_WAIT_OWN

} on error {} {
  $ctx ErrorCatch
} finally {
  $ctx Exit
}

$ctx SendEND_AND_WAIT token:string[4] ?timeout:MkTimeoutE|int32=DEFAULT?

top finish the send-data-block, call the remote service and wait for result… → API: tcl_mqmsgque_MqContextC_SendEND_AND_WAIT

If an error is raised on the server during the service-processing the function will return this error immediately. During waiting for the return the event-loop is used to process other events. Use IEvent to add your tasks into the event loop.

See also

MqRouteTraverse

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	timeout	in seconds until a timeout-error is raised (possible values like ProcessEvent) (MK_TIMEOUT_DEFAULT=MK_TIMEOUT_USER)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendSTART

top initialize the send-data-package. … → API: tcl_mqmsgque_MqContextC_SendSTART

This function must be the first statement in a send-data-block.

If the socket is closed or failed, the connection is established with a MqLinkConnect.
Note that during MqLinkConnect the event-loop is called and your read-data-package may be invalid.

‍It is recommended to perform all READ operations first and then all SEND operations.

From MqSendSTART to MqSendEND is a send-data-block and no event-loop action is allowed between them.

‍The event-loop could modify the already started send-data-package and corrupt the data.

Note

• There is only one send-data-package per context.
• You should assume that any meta-function-call can enter the event-loop.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendSYNC

top garantee that all pending asynchronous-service-calls are processed. … → API: tcl_mqmsgque_MqContextC_SendSYNC

The asynchronous-service-call is defined at: MqContextC_ServiceApi_C_API.

All service-calls to a specific ctx are queued in a service-call-pipeleine. The synchronous-service-call is blocking the service-call-pipeleine until the synchronous-service-call is finished. The asynchronous-service-call does NOT blocking the pipeline and so all asynchronous-service-call are processed in parallel. The MqSendSYNC is used if multiple asynchronous-service-calls are done to a single ctx and this ctx should be blocked until all asynchronous-service-calls are finished. The MqSendSYNC is just an normal blocking synchronous-service-call which is only finished after all asynchronous-service-calls are finished.

Example from perfclient.c → sending a bulk of asynchronous-sevice-requests

    StatTimerSP itemT = StatCreate (mqctx,sec,num);
    {
      StatCtxSP stat = StatCtxCreate (mqctx, "--send");
 
      // init
      PerfSendPackageStart(mqctx,9999);
      MqSendEND_E (mqctx, "RDUL", 0);
      MqSendSYNC_E (mqctx);
 
      // test 
      StatInit (itemT);
        // TEST: start as many as possible asyncron-service-calles in "itemT" intervall.
        while (StatCheck(itemT)) {
          PerfSendPackageStart(mqctx, StatCount(itemT));
          MqSendEND_E (mqctx, "RDUL", 0);
        }
        // just sync with the server
        MqSendSYNC_E (mqctx);
      StatCtxCalc (stat, itemT, -1);
      StatCtxPrint (stat);
      StatCtxDelete (&stat);
    }

The last MqSendSYNC garantee the all previous asynchronous-service-calls are finished.

MqContextC SEND API BLOCK

C-API: MqContextC_SendApi_Block_C_API - MqContextC - a wrapper to send a list-block or a transaction-block …

start to append an embedded body-list-item to the send-data-package. …

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Example

Create a body-list-item in C

MqSendL_START(send);      // start a list-item
MqSendI32(send,myInt);          // first list-sub-item
MqSendSTR(send,"myString");     // second list- sub-item
// ... do additional MqSend?
MqSendL_END(send);                // finish a list-item

$ctx SendL_END

top finish to append an embedded body-list-item to the send-data-package. … → API: tcl_mqmsgque_MqContextC_SendL_END

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendL_START

top start to append an embedded body-list-item to the send-data-package. … → API: tcl_mqmsgque_MqContextC_SendL_START

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Example

Create a body-list-item in C

MqSendL_START(send);      // start a list-item
MqSendI32(send,myInt);          // first list-sub-item
MqSendSTR(send,"myString");     // second list- sub-item
// ... do additional MqSend?
MqSendL_END(send);                // finish a list-item

$ctx SendT_END

top closed a longterm-transaction-item … → API: tcl_mqmsgque_MqContextC_SendT_END

finish a setup-block started with MqSendT_START. read more at MqSendEND_AND_TRANSACTION.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendT_START

top open a longterm-transaction-item … → API: tcl_mqmsgque_MqContextC_SendT_START

Every longterm-transaction-item have to be closed with MqSendT_END. Between MqSendT_START and MqSendT_END, a non specified number of other items can be added. These items are saved in a local database (in-memory or file-based) and the rowid is send as transaction-id to the link-target. By Default only the in-memory-database is used. To switch to a file-based database use the MqStorageOpen function.

Example from server.tcl → make a service-call with transaction-support

  method Ot_TRNS {} {
    my variable i j
    my Send "T" TRN2 "ECOI:(I)I" 9876 [my ReadI32]
    my ProcessEvent MQ_WAIT_ONCE
    my Send "R" "II" $i $j
  }

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC SEND API RETURN

C-API: MqContextC_SendApi_Return_C_API - MqContextC - finish the send-data-block on the server and optional return the results. …

Every service-handler have to use this function at the end to return the results or the error. If an error is returned the local MkErrorC is reset. The following behaviour is used:

• if a shortterm transaction is ongoing this function return the data or the error to the link target
• if the answer does not return any data no previous MqSendSTART is required.
• if no transaction is ongoing this function does just return. If an error is available report an asynchronous error to the link target.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendERROR

top send the data from the MkErrorC to the link target . … → API: tcl_mqmsgque_MqContextC_SendERROR

If an error is available the error-number and the error-text is send to the link target. After send the error is reset. This function only raise an error if the sending self fails or the MkErrorDEFAULT is set and the ctx is a client-context.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendRETURN

top MqContextC - finish the send-data-block on the server and optional return the results. … → API: tcl_mqmsgque_MqContextC_SendRETURN

Every service-handler have to use this function at the end to return the results or the error. If an error is returned the local MkErrorC is reset. The following behaviour is used:

• if a shortterm transaction is ongoing this function return the data or the error to the link target
• if the answer does not return any data no previous MqSendSTART is required.
• if no transaction is ongoing this function does just return. If an error is available report an asynchronous error to the link target.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx SendRETURN_SUB

top return Sub-Data-Blocks required by MqSendEND_AND_SUB … → API: tcl_mqmsgque_MqContextC_SendRETURN_SUB

Every service-handler CAN use this function at the end of a data block if the caller used MqSendEND_AND_SUB to initiate the service call. MqSendEND_AND_SUB will block until ithe final $ctx SendRETURN was send.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC SERVICE API

NAVI: top, up

		ServiceCreate	create a link between a service-token and a service-callback …
		ServiceDelete	delete a service. …
		ServiceIsTransaction	check if the ongoing-service-call belongs to a transaction …
		ServiceProxy	create a service to link a master-context with a slave-context. …
		ServiceProxyCtx	same as MqServiceProxy but use an MqContextC as input.
		ServiceProxyCtxExists	check if service who belongs to token is a proxy-service
		ServiceProxyRoundRobin	create a proxy-service using Round-Robin as load-balancer …
		ServiceStorage	setup a service listen on a MqContextC_ServiceApi_Identifer and save all read-data-package into the STORAGE …
		ServiceTokenCheck	in an ongoing-service-call check if the current MqContextC_ServiceApi_Identifer is token …
		ServiceTokenExists	check if the MqContextC_ServiceApi_Identifer token is defined as ctx service …
		ServiceTokenGet	in an ongoing-service-call get the current MqContextC_ServiceApi_Identifer …

MqContextC SERVICE API DETAILS

C-API: MqContextC_ServiceApi_C_API - MqContextC - create and manage a service …

To provide a service is the main purpose of a server and the main-purpose of a client/server connection is to call a service and to process the result.
A service can be defined on the server or on the client. On the server a service can be initial setup with IServerSetup method and finally cleanup with IServerCleanup.

‍A service is created with the MqServiceCreate and deleted with the MqServiceDelete.

A service can be created and deleted during the entire life-cycle of the server or the client. If the server/client-context is deleted all services of the are deleted also.

‍A MqServiceDelete is not required.

Creating or deleting a service is like granting or revoking the right to access a single feature.

eventloop

To receive a data-package on a service the event-loop have to be active. The event-loop ia always active on an synchronous-service-call . On a server the event-loop is started with MqProcessEvent at startup.

synchronous-service-call

A synchronous-service-call always block and enter the event-loop to wait for an answer

asynchronous-service-call

A asynchronous-service-call always return immediately and the possible result is received on a callback

callback

A callback is the function called by a service and required to receive data from remote.
A callback is created with MqServiceCreate or is part of the service-call.
A callback can be a service-identifer or a service-callback.

service-call with callback

SendEND_AND_CALLBACK, SendEND_AND_SUB, SendEND_AND_TRANSACTION

service-call without callback

SendEND, SendEND_AND_WAIT

Example from MyServer.tcl → define the service SRV1 on the server-link-setup

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*
namespace import tclmsgque::MkKernel::*

# package-item
::oo::class create MyServer {
  superclass MqContextC

  # service to serve all incoming requests for token "HLWO"
  method myFirstService {} {
    my SendSTART
    my SendSTR "[my ReadSTR] World"
    my SendRETURN
  }

  # define a service as link between the token "HLWO" and the callback "MyFirstService"
  method serverSetup {} {
    my ServiceCreate "HLWO" myFirstService
  }

  # factory startup (constructor)
  constructor {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup serverSetup
  }
} 

# package-main
tclmsgque::MqMsgque Main {

  # setup commandline arguments for later use
  set args  [MkBufferListC CreateLA {*}$argv]

  # create "MyServer" factory... and make it to the default.
  set fct   [[MqFactoryC Add MyServer] Default]

  # inspect commandline-argument for the "factory" to choose... and create a object
  set fct   [MqFactoryC GetCalledL $args]
  set srv   [$fct New]

  try {
    $srv LinkCreate $args
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

$ctx ServiceCreate token:string[4] callback:callable

top create a link between a service-token and a service-callback … → API: tcl_mqmsgque_MqContextC_ServiceCreate

The servive-token (e.g. MqContextC_ServiceApi_Identifer) have to be unique but the service-callback (e.g. MqServiceCallbackF) not. If a service-callback is not unique than this is called an alias, use string[4] [$ctx ServiceTokenGet] to get the current token for an incoming-service-call.

The service-callback have to be callable by the server and/or by the child and/or the slave context. A static-callback is a good choice to achive this goal.

The filter, a slave-context, is setup with the initial factory using the initial-class (MqContextC) usually different from the server-class (MyServer…). The filter need the service-callback, usually shared with the server, to report a filter-message to the server.
To distinguish the server and the filter the following functions are used
(all function cann be called as either server or filter context):

• master and slave
  • MqSlaveGetMaster get the master as server
  • MqSlaveGetFilter get the filter as client
• MqSlaveGet - (using pseudo-code)
  • ctx.SlaveGet(MASTER) for the server
  • ctx.SlaveGet(FILTER) for the filter
  • more info at: MqContextC_SlaveApi_C_API
• using a "if" clause and the server check
  • MqConfigGetIsServer == true -> the master is always a server
  • MqConfigGetIsServer == false -> the slave is always a client
• using a "if" clause and the slave check
  • MqSlaveIs == false -> the server is always a master
  • MqSlaveIs == true -> the client is always a slave

Example from Filter6.tcl → setup the services for server and filter

  method FilterSetup {} {
    set ftr [my SlaveGetFilter]
    my variable FH
    set FH ""
    my ServiceCreate    "LOGF" LOGF
    my ServiceCreate    "EXIT" EXIT
    my ServiceCreate    "SOEX" SOEX
    my ServiceCreate    "ERR1" ERR1
    my ServiceStorage   "PRNT"
    my ServiceStorage   "PRN2"
    my ServiceCreate    "+ALL" FilterIn
    $ftr ServiceCreate  "WRIT" WRIT
    my ServiceCreate    "WRIT" WRIT
    $ftr ServiceProxy   "WRT2" MASTER
  }

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	fCall	the C-function to process the incoming service-request (C-API only)
[in]	callback	the user defined callback as data-argument for the C-function fCall
[in]	fFree	the function to free the data-argument after use (C-API only)
[in]	fMark	the function to mark the data-argument during garbage-collection (C-API only)

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

the link-setup (MqLinkCreate or MqLinkCreateChild) have to done before using this function

MqServiceCreate : callback signature

  1. The *service-ctx* is the *context* for which the service was defined.
  2. If the *callback* is **not** an instance of the calling *context*, the *service-ctx* is added as an argument.
 
  callback-args := service-ctx:MqContextC[in]
  [static]   proc callback { callback-args ?additional-args...? } ...
  [own]      ::oo::class create XXX {
               superclass MqContextC
               method callback { ?additional-args...? } ...
  [instance] ::oo::class create YYY {
               method callback { callback-args ?additional-args...? } ...
  [class]    ::oo::class create ZZZ {
               self method callback { callback-args ?additional-args...? } ...

read more at: Callback signature

$ctx ServiceDelete token:string[4]

top delete a service. … → API: tcl_mqmsgque_MqContextC_ServiceDelete

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

bool [$ctx ServiceIsTransaction]

top check if the ongoing-service-call belongs to a transaction … → API: tcl_mqmsgque_MqContextC_ServiceIsTransaction

A service-call can be with-transaction (return true if the package was send with MqSendEND_AND_WAIT or MqSendEND_AND_CALLBACK) or can be without-transaction (return false if the package was send with MqSendEND)

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

a boolean value, true or false

$ctx ServiceProxy token:string[4] ?id:MqSlaveE|int32=MQ_SLAVE_OTHER?

top create a service to link a master-context with a slave-context. … → API: tcl_mqmsgque_MqContextC_ServiceProxy

This function is used to create a proxy-service to forward the body-data from the read-data-package of the master to the send-data-package of the slave. The data is not changed. This function support the reverse-operation also. If the ctx is a master-context than the data is send to slave identified by id. If the ctx is a slave-context than the data is send to the master of the slave.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ServiceProxyCtx token:string[4] target:MqContextC

top same as MqServiceProxy but use an MqContextC as input. → API: tcl_mqmsgque_MqContextC_ServiceProxyCtx

See also

MqServiceProxy

bool [$ctx ServiceProxyCtxExists token:string[4] target:MqContextC]

top check if service who belongs to token is a proxy-service → API: tcl_mqmsgque_MqContextC_ServiceProxyCtxExists

This is used for route (MqRouteDelete) to identify the service-usage

See also

MqServiceProxy

$ctx ServiceProxyRoundRobin token:string[4] ident:string

top create a proxy-service using Round-Robin as load-balancer … → API: tcl_mqmsgque_MqContextC_ServiceProxyRoundRobin

This function is used to create a proxy-service to forward the body-data from the read-data-package of the master-context to the send-data-package of the slave-context. The data is not changed. This function support the reverse-operation also. If the ctx is a master-context than the data is send to one of the slave-context identified by ident. If the ctx is a slave-context than the data is send to the master-context of the slave.

The Round-Robin-Load-Balancer is only used for the direction from the master-context to the slave-context if the name-resolution return multiple target-context for the single ident.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service
[in]	ident	the targetIdent used to select a list slave-Context for the Round-Robin

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx ServiceStorage token:string[4]

top setup a service listen on a MqContextC_ServiceApi_Identifer and save all read-data-package into the STORAGE … → API: tcl_mqmsgque_MqContextC_ServiceStorage

In a shortterm-transaction-synchronous-service-call the service will return an empty data package. In a longterm-transaction-synchronous-service-call the data will return as normal.

Example from Filter6.tcl → using MqServiceStorage to store all packages from service PRNT and PRN2 into database

  method FilterSetup {} {
    set ftr [my SlaveGetFilter]
    my variable FH
    set FH ""
    my ServiceCreate    "LOGF" LOGF
    my ServiceCreate    "EXIT" EXIT
    my ServiceCreate    "SOEX" SOEX
    my ServiceCreate    "ERR1" ERR1
    my ServiceStorage   "PRNT"
    my ServiceStorage   "PRN2"
    my ServiceCreate    "+ALL" FilterIn
    $ftr ServiceCreate  "WRIT" WRIT
    my ServiceCreate    "WRIT" WRIT
    $ftr ServiceProxy   "WRT2" MASTER
  }

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

bool [$ctx ServiceTokenCheck token:string[4]]

top in an ongoing-service-call check if the current MqContextC_ServiceApi_Identifer is token … → API: tcl_mqmsgque_MqContextC_ServiceTokenCheck

See also

MqServiceTokenGet

Parameters

[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service

Returns

a boolean value, true or false

bool [$ctx ServiceTokenExists token:string[4]]

top check if the MqContextC_ServiceApi_Identifer token is defined as ctx service … → API: tcl_mqmsgque_MqContextC_ServiceTokenExists

This code is used to detect if a service with identifer token exists.

See also

MqRouteTraverse

Parameters

[in]	ctx	the MqContextS instance to work on
[in]	token	the MqContextC SERVICE API to identify the service

Returns

a boolean value, true or false

string[4] [$ctx ServiceTokenGet]

top in an ongoing-service-call get the current MqContextC_ServiceApi_Identifer … → API: tcl_mqmsgque_MqContextC_ServiceTokenGet

This function is needed on the server to process a service-request defined as +ALL or as an alias to extract the current MqContextC_ServiceApi_Identifer.

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

the MqContextC_ServiceApi_Identifer

MqContextC SLAVE API

NAVI: top, up

		SlaveCheck	check if slave-id is valid
		SlaveCreate	create a master/slave link between the master-parent-context and the slave-parent-context …
		SlaveDelete	Delete a slave object from a master/slave link identified by id. …
		SlaveGet	get the slave-context from a master-context …
		SlaveGetFilter	get the filter-ctx or the master-ctx …
		SlaveGetMaster	opposite function of MqSlaveGetFilter
		SlaveGetProxy	on slave return the master and on master return the slave identified by id.
		SlaveIs	is the context a slave-context ? …
		SlaveWorker	create a master/slave link using the image of the ctx object self. …

MqContextC SLAVE API DETAILS

C-API: MqContextC_SlaveApi_C_API - MqContextC - create and manage a slave context …

The master-slave-link is used to create a mesh of nodes defined by different parent-context. The master control the slave.

The master-slave-link is used to perform the following tasks:

• report error messages from the slave-context to the master-context
• to create a slave-child-context if a master-child-context is created
• to delete a slave-context if a master-context is deleted

In difference to the client-server-link the master-slave-link connect two independent parent-context in the same process or thread (e.g. node). This leads to the restriction that only the master-context can be a server-context because only one server-context per node is possible.

   node-0   |           node-1/2        |   node-3/4/5
===================================================================

| <- client/server link -> | <- client/server link -> |

             | <-- master/slave link --> |

                           |- client1-0 -|- server3 ...
             |-  server1  -|
             |             |- client1-1 -|- server4 ...
  client0-0 -|
             |-  server2  -|- client1-2 -|- server5 ...

Definition of the "master-context"

• the master-context is a parent-context without a child-context available.
• the master-context is a client-context or a server-context.
• the link between the master-context and the slave-context is done using MqSlaveWorker or MqSlaveCreate

Definition of the "slave-context"

• the slave-context is a parent-context without a child-context available.
• the slave-context is a client-context.
• the slave-context lifetime is controlled by the master-context.
• the slave-context report all error-messages to the master-context.
• the slave-context is identified by a unique-slave-id starting with 0.
• a special form of a slave-context is a worker-context

Definition of the "worker-context"

• the worker-context is a slave-context using the image of the master-context self.
• the master-context can be a server-context or a client-context.
• the worker-context is created using MqSlaveWorker
• the worker-context is identified by a unique-slave-id starting with 0.

Definition of the "slave-id"

• the slave-id is defined at enum MqSlaveE
• a slave is identified in his master-context by a slave-id
• the slave-id work like a defined well-known-port-number in /etc/services
• the slave-id is an integer value with valid values > 0
• it is a good practice to plan the usage of your slave-id(s)
• slave

  slave-id	value	definition
  MQ_SLAVE_MAX	1024	internal: the maximum slave-id … .
  MQ_SLAVE_USER	10	internal: start of user-defined-slave-id .
  MQ_SLAVE_LOOPBACK	0	internal: the loopback-slave-id, (call my own services) .
  MQ_SLAVE_FILTER	1	internal: the filter-slave-id, (on a master get the filter-slave) .
  MQ_SLAVE_MASTER	1	internal: the master-slave-id, (on a slave get the master) .
  MQ_SLAVE_OTHER	1	internal: on the master-ctx get the slave-ctx and on the slave-ctx get the master-ctx .

• range

  range	definition
  0 <= slave-id < MQ_SLAVE_MAX	range of valid slave-id's
  0 <= slave-id < MQ_SLAVE_USER	internale usage
  MQ_SLAVE_USER <= slave-id < MQ_SLAVE_MAX	external usage

Definition of the "LOOPBACK" (0) slave

•    client   |           server            |
  ===========================================
  
  | <--- client/server --->  | <-- loop --> |
  
              | <------ master/slave -----> |
  
    client -- | -- server -- | -- client -- #
                     ==             ==      #
                   server -- | -- client -- #

• the loopback has always the slave-id = 0 .
• the loopback has the same class as the parent, if reflection is not available the MqFactoryInitial is used.
• the loopback is used to call a service on the same process or thread.
• the loopback is a special filter without an additional process or thread to be started.
• the loopback is only internal accessible
• the service called by the loopback need the same attention as the service called by the filter, the context of the service is the loopback-context.
• the loopback can call MqServiceCreate to create a new link between a service-token and a service-method, by default all services from the master-context (the owner of the loopback) are also accessible by the loopback.
• in the service use MqSlaveGetMaster to get the master-context from the loopback-context.
• Example from MyLoopServer.tcl → create a new loop-server

  package require tclmsgque::MqMsgque
  namespace import tclmsgque::MqMsgque::*
  
  ::oo::class create MyLoopServer {
    superclass MqContextC
    export variable
  
    # factory startup
    constructor {{tmpl ""}} {
      my variable mydata;
      next $tmpl
      my ConfigSetServerSetup ServerSetup
      # set the "mydata" attribute to the master-context
      set mydata  "Hello World";
    }
  
    # service to serve all EXTERNAL requests for token "HLWO"
    method HLWO_srv {} {
      # get the "loopback" context
      set loop  [my SlaveGet LOOPBACK]
      # call the LOOP service on the SAME server
      $loop Send "W" "LOOP"
      # answer HLWO with string-return from LOOP
      my Send "R" "C" [$loop ReadSTR]
    }
  
    # service to serve all INTERNAL requests for token "LOOP"
    method LOOP_srv {} {
      # get the "master" context
      set master  [my SlaveGetMaster]
      # answer LOOP with data from MASTER->mydata attribute
      $master variable mydata
      my Send "R" "C" $mydata
    }
  
    # setup a server-context - called for every new server-context
    method ServerSetup {} {
      # EXTERNAL: link the "HLWO" service with "HLWO_srv"
      my ServiceCreate "HLWO" HLWO_srv
      # INTERNAL: link the "LOOP" service with "LOOP_srv"
      [my SlaveGet MQ_SLAVE_LOOPBACK] ServiceCreate "LOOP" LOOP_srv
    }
  }
  
  tclmsgque::MqMsgque Main {
  
    # create "MyLoopServer" factory... and the instance
    set srv   [[MqFactoryC Add MyLoopServer] New]
  
    try {
      $srv LinkCreate $argv
      $srv ProcessEvent MQ_WAIT_FOREVER
    } on error {} {
      $srv ErrorCatch
    } finally {
      $srv Exit
    }
  }
  

Performance analyse

The performance-test is created with:

• pipe
  • Nhi1Exec perfclient.c --parent --wrk ? @ perfserver.c
• spawn, fork, thread
  • Nhi1Exec -r=uds perfserver.c --spawn|fork|thread
  • Nhi1Exec -r=uds perfclient.c --parent --wrk ?
• the number of workers are set with the –wrk option
• the cpu is a xeon with 4/8
• the performance is calculated as worker-context-created / time-in-sec with a ~2sec (default) measurement period.

performance-test code:

• The test-setup is done as:

    perfclient                                worker                            perfserver
    ==========                                ======                            ==========
    |
    |- loop --wrk x
      |- MqSlaveWorker(...)               ->  worker[1] 
      |- MqSend(worker[1],"E","STR0..")   ->  PerfWorker_I160(...)
                                              |- loop endless
                                                |- MqContextCreate(...)
                                                |- MqLinkCreate(...)      <->   MqContextCreate(...)
                                                |- MqContextDelete(...)   <->   MqContextDelete(...)
    |- sleep x sec
    |- loop --wrk x
      |- MqSend(worker[1],"C"..,"END0")   ->  PerfWorker_END0(...)
      |                                       |- stop loop
      |- "callback" - add number to all   <-  |- return #context 

• Using the worker-code:

  // asynchronous call
  static enum MkErrorE PerfWorker_STR0( MQ_SERVICE_CALL_ARGS ) {
    MK_BFL largv = NULL;
    MK_BFL pargv = NULL;
    MK_I32 num   = MqReadI32_e(mqctx);
           pargv = MkBufferListDup(MqReadBFL_e(mqctx));
    enum MkErrorE ret = MK_OK;
   
    if (num == -1) num = 999999;  // endless
   
    // start test until "doNext" is "false" or "num" exceeds
    for (int i=0; doNext && i<num; i++) {
      // CREATE the context
      MQ_CTX ctx = MqContextCreate(NULL, mqctx);
      largv = MkBufferListDup(pargv);
      MqLinkCreate_C (ctx, largv) {
        MqContextErrorMove(mqctx,ctx);
        MqContextDelete(ctx);
        goto error;
      }
   
  //MqSend(ctx,"E","MARK:C","start");
   
      MkBufferListDelete(largv);
   
      // DELETE the context
      MqContextDelete(ctx);
   
      // count the loops
      worker_count++;
   
      // give PerfWorker_END0 time to update "doNext"
      MqProcessEvent(mqctx, MQ_WAIT_NO, MK_TIMEOUT_DEFAULT);
    }
   
  end:
  //printV("ret=%i, Delete=%p\n", ret, largv)
    MkBufferListDelete(largv);
    MkBufferListDelete(pargv);
   
    if (doNext == true) {
      // finish the test WITHOUT "END0" -> test on --num, answer required.
      MqSend_E(mqctx, "R", "I", worker_count);
    }
    return ret;
   
  error:
    if (doNext == true) {
      ret = MkErrorStack_1X(mqctx);
    } else {
      ret = MkErrorReset_1X(mqctx);
    }
    goto end;
  }

performance-test results:

• results generated using the debug environment

  setup	–wrk	# worker-context	performance	info
  pipe	1	2500	1000	the pipe start a new worker-context with spawn
  spawn	1	2500	<1000	same as pipe but use network-protocoll
  fork	1	3800	4000	the fork is faster than spawn
  thread	1	16500	9000	the thread is faster than fork
  pipe	4	8000	4500	the worker scale linear up to number of processors
  spawn	4	7600	<4500	-
  fork	4	23200	11500	-
  thread	4	55500	27500	-
  pipe	8	10000	5500	the additional scaling up to the max hyper-threading does not really help
  spawn	8	9100	<5500	-
  fork	8	23200	11500	-
  thread	8	55500	27500	-

bool [$ctx SlaveCheck id:MqSlaveE|int32]

top check if slave-id is valid → API: tcl_mqmsgque_MqContextC_SlaveCheck

Parameters

[in]	ctx	the master-context as PARENT or CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.

Returns

boolean true = valid or false = invalid

$ctx SlaveCreate id:MqSlaveE|int32 slave:MqContextC

top create a master/slave link between the master-parent-context and the slave-parent-context … → API: tcl_mqmsgque_MqContextC_SlaveCreate

The slave-context have to be a sub-class of MqContextC and is owned by the master-context. Owned mean that no other external references should be used.
The slave-context will be deleted if the master-context is deleted and the slave-context will create a child-context if the master-context create a child context.

Example from server.cs → with reflection support... only the class is required :

          Client clt = new Client();
          clt.LinkCreate(ConfigGetStartAs());
          SlaveCreate (id, clt);

Example from server.cc → without reflection support... the factory is required :

  MqFactoryCT<Client>::Add("client");

and the factory is used to create the object :

            Client *clt = MqFactoryCT<Client>::Get("client")->New();
            clt->LinkCreate(ConfigGetStartAs());
            SlaveCreate (id, clt);

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the master context object as PARENT without a CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.
[in]	slave	the slave context object as CLIENT-PARENT without a CHILD

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqSlaveGet

$ctx SlaveDelete id:MqSlaveE|int32

top Delete a slave object from a master/slave link identified by id. … → API: tcl_mqmsgque_MqContextC_SlaveDelete

By default the slave-context object will be deleted if the master-context is deleted. Use this function to delete the parent-slave-context explicit and brake the master/slave link. If id is invalid nothing will happen. It is an error to delete a child-slave-context.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the master context object as PARENT without a CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

it is still possible to delete a child-slave-context using MqLinkDelete but this will break the internal master/slave order.

MqContextC [$ctx SlaveGet id:MqSlaveE|int32]

top get the slave-context from a master-context … → API: tcl_mqmsgque_MqContextC_SlaveGet

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the master-context as PARENT or CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.
[out]	ctx_out	the slave-context or "MK_NULL" on error

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

an error is raised if id is not valid or ctx is not a master-context.

MqContextC [$ctx SlaveGetFilter]

top get the filter-ctx or the master-ctx … → API: tcl_mqmsgque_MqContextC_SlaveGetFilter

The functions MqSlaveGetFilter, MqSlaveGetMaster and MqSlaveGetProxy have the same purpose. A filter-pipeline has two ctx, one on the left and one on the right. The left-ctx is linked with the master-ctx and the right-ctx is linked to the slave-ctx. This function return the ctx wanted or an error if NOT available. The search is done using the following order:

1. return ctx if ctx is the wanted ctx
2. return master-ctx or filter-ctx
3. return a "context not available" error

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	ctx_out	the ctx or "MK_NULL" on error

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

MqContextC [$ctx SlaveGetMaster]

top opposite function of MqSlaveGetFilter → API: tcl_mqmsgque_MqContextC_SlaveGetMaster

Attention

if no master is available, a "MK_NULL" is returned

MqContextC [$ctx SlaveGetProxy id:MqSlaveE|int32]

top on slave return the master and on master return the slave identified by id. → API: tcl_mqmsgque_MqContextC_SlaveGetProxy

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the master or slave-context as PARENT or CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.
[out]	ctx_out	the other-context or "MK_NULL" on error

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

an error is raised if id is not valid

bool [$ctx SlaveIs]

top is the context a slave-context ? … → API: tcl_mqmsgque_MqContextC_SlaveIs

Parameters

[in]

ctx

the MqContextS instance to work on

Returns

a boolean value, true or false

$ctx SlaveWorker id:MqSlaveE|int32 ?fct:string="WORKER"? ?args:MkBufferListC...="MK_NULL"?

top create a master/slave link using the image of the ctx object self. … → API: tcl_mqmsgque_MqContextC_SlaveWorker

The slave-context is started as an independent process or thread based on the StartAs argument.

The start of a "worker" can be done at:

• context-creation in the Factory or the class-constructor
• link-creation in the IServerSetup method
• service-call in the client-service-request (starting worker one-the-fly)

Example from server.tcl → create a worker in a service-callback reading arguments from the service

        # start worker with arguments from the service-call using the current executable
        my SlaveWorker $id "WORKER" {*}[my ReadLIST] --name wk-cl-$id @ --name wk-sv-$id

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the master context object as PARENT without a CHILD
[in]	id	the SlaveId to unique identify the master/slave link, the id < MQ_SLAVE_USER is internal.
[in]	fct	the MqFactoryS::originalIdent or "MK_NULL" or '\0' or "WORKER". if ident is "MK_NULL" or '\0' or WORKER the factory of ctx will be used if ident is MqFactoryS::originalIdent the factory defined will be used
[in]	args	command-line arguments passed to the worker-client or the worker-server. all arguments prior the first @ token are added to the worker-client and the other arguments to the worker-server. example: --debug 5 --name hello @ --name myserver

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

- A slave-worker can only be created in a parent-context.

• The args MkBufferListC is comsumed by the MqSlaveWorker and is EPMTY afterwords.
  

MqContextC STORAGE API

NAVI: top, up

		StorageClose	close the storage. …
		StorageCount	count the number of storage-rows …
		StorageDecrRef	decrease the internal refCount lock of the database-entry
		StorageDelete	delete the storage-row identified by the transLIdP_inout …
		StorageErrCnt	increment and return the database row-error-count for the row defined with transLId
		StorageExport	export the read-data-package into the STORAGE …
		StorageImport	import the storage-package into the read-data-package …
		StorageIncrRef	increase the internal refCount lock of the database-entry
		StorageLog	log the storage the status of the open transactions
		StorageOpen	switch to a file-based-transaction-database …
		StorageResolve	extract the context->link.protect.rmtTransLId entry from the database

MqContextC STORAGE API DETAILS

C-API: MqContextC_StorageApi_C_API - MqContextC - setup and manage a storage used to persist data-packages …

The storage is divided into: INTERNAL and EXTERNAL storage. Only the read-data-package can be stored or dumped into the storage.

The read-data-package is saved into the storage using:

ServiceStorage	setup a service listen on a MqContextC_ServiceApi_Identifer and save all read-data-package into the STORAGE …
StorageExport	export the read-data-package into the STORAGE …

The read-data-package is restored from the storage using:

StorageImport	import the storage-package into the read-data-package …
ProxyForward	send the entire read-data-package-data to the link-target …
All this usually happen in an Event Handler

Some important facts of the storage-feature:

• The internal-storage depends on SQLite.
• The package-storage can be used to save all kind of package-data.
• The longterm-transaction-package-data is allways saved into storage.
• By default only an in-memory storage is in use, but this can be changed with MqStorageOpen or Storage
• An entire service-call can be saved with MqServiceStorage

The following internal storages are supported:

default

The default-storage is set with the configuration parameter --storage fileName and defaults to "#memdb#". If a package have to be saved into the storage and the storage is not open the default-storage id used. The open will always be performed. If an explicit storage is required the default can be changed or a storage can explicit be opened with MqStorageOpen. Keep in mind that the default-storage is a per-context configuration but only one storage per process or thread is currently supported.

memdb

This is the default storage and can be set explicitly with MqStorageOpen using the "#memdb#" parameter.

tmpdb

This storage is like an in-memory-storage but export data to the TEMPORARY filesystem if the application run out of memory. This storage can explicit be set with MqStorageOpen with the parameter "#tmpdb#".

filedb

This storage always work on files. Only this storage is persistent and can explicit be set with MqStorageOpen with the storageFile parameter.

Performance analyse:

• The performance is tested with: Nhi1Exec perfclient.c --all --storage VALUE @ perfserver.c.
• The parameter VALUE is set to #memdb#, #tmpdb# or a filedb file.
• If –storage is not set the filedb database is used together with an internal file-name.

database	performance	host crash	application crash	info
memdb	30.000	data lost	data lost	non persistent
tempdb	< 30.000	data lost	data lost	uses memory and/or temporary file
filedb (mem)	10.000	data lost	data safe	in memory filesystem
filedb (disc)	50	data safe	data safe	disc-speed is the key factor

$ctx StorageClose

top close the storage. … → API: tcl_mqmsgque_MqContextC_StorageClose

the next storage request will open the storage again with the location from Storage

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

int32 [$ctx StorageCount]

top count the number of storage-rows … → API: tcl_mqmsgque_MqContextC_StorageCount

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	cnt_out	number of rows, OLL if nothing is available

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

$ctx StorageDecrRef transLId:int32

top decrease the internal refCount lock of the database-entry → API: tcl_mqmsgque_MqContextC_StorageDecrRef

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	transLId	storage-id … return from MqStorageImport

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqStorageImport, MqStorageIncrRef

int32 [$ctx StorageDelete ?*transLIdP_inout:int32=0?]

top delete the storage-row identified by the transLIdP_inout … → API: tcl_mqmsgque_MqContextC_StorageDelete

The transLIdP_inout is the value returned by a previous MqStorageImport. If transLIdP_inout is "MK_NULL" than OLL is used. MqStorageImport and MqStorageDelete work together link an transaction and every successfull transcation have to delete the transLIdP_inout out of the storage. After sucessfull delete the transLIdP_inout is set to 0LL, on error the initial value is unchanged.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in,out]	transLIdP_inout	pointer to storage-id to delete, will be 0LL on success

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

int32 [$ctx StorageErrCnt transLId:int32]

top increment and return the database row-error-count for the row defined with transLId → API: tcl_mqmsgque_MqContextC_StorageErrCnt

The storage is typical used in the following workflow:

<----- AT CALLING CLIENT ----->|<----- AT RECEIVING SERVER ----->
                               |
    *setup transaction         |
    make service-request      -->    *start service-handler
                               |     save request into storage
    wait for confirmation     <--    confirm data receiving
                               |     *stop service-handler

  ====================  enter event loop  =====================

                               |     *start event-handler
                               |     load reqest from storage
                               |     process data
    *start transaction        <--    send result-data
    process result-data        |     *stop event-handler
    *stop transaction          |

Example Filter6 - store incoming packages into storage

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	transLId	storage-id … return from MqStorageImport
[out]	cnt_out	the new value or -1 on error

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

int32 [$ctx StorageExport]

top export the read-data-package into the STORAGE … → API: tcl_mqmsgque_MqContextC_StorageExport

The export include all data required to setup a read-data-package later again. After import with MqStorageImport the read-data-package and the environment will be set as it was on MqStorageExport

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	ltid_out	if ltid_out != NULL return the storage-id

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqDumpExport, MqStorageImport

int32 [$ctx StorageImport ?*transLIdP_inout:int32=0?]

top import the storage-package into the read-data-package … → API: tcl_mqmsgque_MqContextC_StorageImport

Select the read-data-package from the database using the transLIdP. Only a package with refCount = 0 will be selected.
After selection the refCount is incremented and the next call to MqStorageImport using the same transLId will fail.
MqStorageImport is used together with MqStorageDelete or MqStorageDecrRef to delete the selected package from database or to undo the select.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in,out]	transLIdP_inout	storage-id or "MK_NULL" or 0 … return from MqStorageExport *transLIdP > 0 return the read-data-package identified with the storage-id. *transLIdP == 0 return the top-most (FIFO) read-data-package and set the transLIdP to the storage-id. *transLIdP < 0 return an error transLIdP == NULL like transLIdP == 0 *transLIdP invalid like transLIdP < 0

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

Read MqProcessEvent for the dependency with the event-loop.

There is no guarantee that a package will be read FIFO.
In principle, the first free package (refCount=0) with the smallest transLId is read.
However, if the package hangs in subsequent processing and the refCount is not reset or the package is not deleted, then the package remains locked and a subsequent call to MqStorageImport will read the next free package.

• This approach protects a server or router from blocking after an unpredictable failure.

See also

MqDumpExport, MqStorageExport, MqStorageDelete, MqStorageDecrRef, MqStorageIncrRef

$ctx StorageIncrRef transLId:int32

top increase the internal refCount lock of the database-entry → API: tcl_mqmsgque_MqContextC_StorageIncrRef

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	transLId	storage-id … return from MqStorageImport

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqStorageImport, MqStorageDecrRef

$ctx StorageLog ?callfunc:string="MK_NULL"?

top log the storage the status of the open transactions → API: tcl_mqmsgque_MqContextC_StorageLog

$ctx StorageOpen storageFile:string

top switch to a file-based-transaction-database … → API: tcl_mqmsgque_MqContextC_StorageOpen

the value can also be set using the --storage commandline option.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[in]	storageFile	the file used to create the transaction-database. Allowed values are: "#memdb#" for a in-memory-database (default) "#tmpdb#" for a temporary-database-file filename for a persistent-database-file

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

{otherCtxP:MqContextC otherLIdP:int32} [$ctx StorageResolve]

top extract the context->link.protect.rmtTransLId entry from the database → API: tcl_mqmsgque_MqContextC_StorageResolve

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the MqContextS instance to work on
[out]	otherCtxP_out	the ctx of the resolve
[out]	otherLIdP_out	the transLId of the resolve

---

INSTANCE STORAGE API

SUPER: MqContextC, top

tclmqmsgque is using a class-attribute as instance-storage. …

introduction

• https://wiki.tcl-lang.org/page/Variables+in+TclOO

The instance-storage is defined using the variable keyword:

package require tclmsgque::MkKernel
namespace import tclmsgque::MkKernel::*
 
# package-item
::oo::class create MyClass {
  superclass MkBufferC
  variable my_data
 
  constructor {val} {
    set my_data $val
  }
}

---

MqDumpC

SUPER: MkObjectC, top

MqDumpC CLASS
		Export	MqDumpC - Export class functions …
		Introspection	MqDumpC - Introspection class functions …
		Misc	MqDumpC - Misc class functions …
MqDumpC TOR
		Export	create a MqDumpC as export of the ctx-read-data-package …
		BinSet	create an MqDumpS object from binary data
		Error	export the context->error into the dump-package …
		new	create a MqDumpC as export of the ctx-read-data-package …
		Delete	Destructor - delete a MqDumpC instance …
		BinGet	export the binary data from an MqDumpS object
		Import	import the dump-package into the ctx-read-data-package …
MqDumpC MISC
		Log	log the MqDumpC …
		SizeGet	report the binary data size from an MqDumpS object
		TokenGet	return the MqContextC_ServiceApi_Identifer …

MqDumpC DETAIL

C-API: MqDumpC_C_API - MqDumpC - the class known as dmp or dump is used to export a tclmqmsgque data package as binary …

The dump is used to exchange data with external counterparts such as a database or a user-specific infrastructure.

There are 3 different function that deal with a dump:

1. The MqDumpExport export the read-data-package from the calling context to a dump.
2. The MqDumpImport imports the dump into the read-data-package of the calling context. All MqContextC READ API functions can be used to read the data from the read-data-package.
3. The MqProxyForward imports the dump into the send-data-package of the calling context. All MqContextC SEND API functions can be used to write the data into the send-data-package

See also

MqContextC PROXY API

MqDumpC CLASS

NAVI: top, up

MqDumpC CLASS EXPORT

		HandleResolve	Handle-Resolve-Slot - return a MqDumpC from netHdl or "MK_NULL" if invalid…
		HandleGet	Handle-Get-Slot - returns a export-hdl to the MqDumpC useable for external storage

MqDumpC CLASS INTROSPECTION

		Instances	get head-instance from linked-list of MqDumpS type …
		Next	get next instance from linked-list of MqDumpS type
		Prev	get previous instance from linked-list of MqDumpS type

MqDumpC CLASS MISC

GetNull

Null-Slot - return a MqDumpC typed NULL instance …

MqDumpC CLASS DETAILS

C-API: MqDumpC_Class_C_API - MqDumpC - define the class …

MqDumpC CLASS EXPORT

MqDumpC - Export class functions …

(static) MqDumpC [MqDumpC HandleResolve netHdl:MK_HDL]

top Handle-Resolve-Slot - return a MqDumpC from netHdl or "MK_NULL" if invalid… → API: tcl_mqmsgque_MqDumpC_HandleResolve

The MqDumpHandleResolve undo the MqDumpHandleGet and is intended to export a unique identifer into external code not belonging to the Programming-Language-Micro-Kernel (PLMK).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	netHdl	handle former exported with MqDumpHandleGet

Returns

the required handle or "MK_NULL" if netHdl is invalid

MK_HDL [$dmp HandleGet]

top Handle-Get-Slot - returns a export-hdl to the MqDumpC useable for external storage → API: tcl_mkkernel_MkObjectC_HandleGet

The export-hdl is a reference to an instance that can be stored in software and converted back into an instance using the MqDumpHandleResolve.

The export-hdl is only valid until the Programming-Language-Micro-Kernel (PLMK) ends.

example: The export-hdl is used in rpc to identify an object across the network.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	dmp	the MqDumpS instance to work on

Returns

the required export-hdl

MqDumpC CLASS INTROSPECTION

MqDumpC - Introspection class functions …

(static) MqDumpC [MqDumpC Instances]

top get head-instance from linked-list of MqDumpS type … → API: tcl_mqmsgque_MqDumpC_Instances

The head-instance is the last instance created.

MqDumpC [$dmp Next]

top get next instance from linked-list of MqDumpS type → API: tcl_mqmsgque_MqDumpC_Next

MqDumpC [$dmp Prev]

top get previous instance from linked-list of MqDumpS type → API: tcl_mqmsgque_MqDumpC_Prev

MqDumpC CLASS MISC

MqDumpC - Misc class functions …

(static) MqDumpC [MqDumpC GetNull]

top Null-Slot - return a MqDumpC typed NULL instance … → API: tcl_mqmsgque_MqDumpC_GetNull

MqDumpC TOR

C-API: MqDumpC_TOR_C_API - MqDumpC - various functions to create, initialize and destroy a dump …

(constructor,static) MqDumpC [MqDumpC Export ctx:MqContextC ?dumpP_inout:MqDumpC="MK_NULL"?]

top create a MqDumpC as export of the ctx-read-data-package … → API: tcl_mqmsgque_MqDumpC_Export

The new instance belongs to the caller and may have to be released if necessary. A manual release using DumpDelete is always possible, but the instance can no longer be used afterwards.

The export include all data required to setup a read-data-package again later. After import with MqDumpImport the read-data-package and the environment will be set as it was on MqDumpExport The export can be saved into an external storage or be used in a network-tunnel (example: the aguard tool).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the context to be exported into the dump-package-data
[in,out]	dumpP_inout	returns

Returns

The newly created MqDumpC instance, the instance is owned by the caller

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqStorageExport, MqDumpImport, MqDumpError

Attention

1. The goal of this function is to create a dump to be loaded in the context later. If the context is not the original context… propably additional work is necessary.
2. The MqDumpExport is using realloc to allocate space. The value of *value should be initialized with either "MK_NULL" or a result of a previous MqDumpExport or MqDumpError.
3. Garbage is detected using MqDumpC_SIGNATURE… there is a MINIMAL chance (1 to 4.294.967.295) that the gargabe is NOT detected… to be save… always initialize the dump.
4. If the dump was initialized with "MK_NULL" or garbage … new memory will be allocated… If the dump memory will NOT be reused… free the memory with (6.)
5. If the dump was initialized with an previous dump … the memory will be reused… and extended with realloc if required.
6. Free the memory with MqDumpDelete.
7. On error… the dump is unchanged.
8. In case of TLS memory returned read more at MkKernel_Storage_C_API.

(constructor,static) MqDumpC [MqDumpC BinSet data:binary]

top create an MqDumpS object from binary data → API: tcl_mqmsgque_MqDumpC_BinSet

Check the MqDumpC_SIGNATURE and set the refCount to 0

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	data	the binary data
[out]	dmp_out	the new MqDumpC

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

The MqDumpS object is an pointer object… this mean the original data is still required and must NOT be freed.

enum MkErrorE MqDumpBinSet_RT (
  MK_RT_ARGS
  MkBinaryR  bin,
  MQ_DMP  *dmp_out
) {
  MK_RT_ATTR_HDL_CHECK(bin.data);
  MkRtSetup_NULL_RT;
  assert(dmp_out!=NULL);
 
  MQ_DMP dump = (MQ_DMP) bin.data;
  if (!__MkCheckX(MqDumpC,dump)) {
    return MkErrorDbV_2_M(MK_ERROR_PRINT,MK_ERROR_VALUE_INVALID, "signature", "MqDumpS");
  } else {
    MkOBJ_R(dump).refCount = 0;
  }
  *dmp_out = dump;
  return MK_OK;
}

(constructor,static) MqDumpC [MqDumpC Error error:MqContextC ?dumpP_inout:MqDumpC="MK_NULL"?]

top export the context->error into the dump-package … → API: tcl_mqmsgque_MqDumpC_Error

The export include all data required to setup a read-data-package later again. After import with MqDumpImport the read-data-package and the environment will be set as it was on MqDumpExport The export can be saved into an external storage or be used in a network-tunnel (example: the agurad tool).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	error	the error-context to be exported into the dump-package-data
[in,out]	dumpP_inout	the dump-error-package-data to save

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

1. use remarks from MqDumpExport
2. MqDumpError using the send-data-package to create the dump-package.. to use the send-data-package afterwords a MqSendSTART is required

See also

MqStorageExport, MqDumpImport, MqDumpExport

(constructor,static) MqDumpC [MqDumpC new ctx:MqContextC ?dumpP_inout:MqDumpC="MK_NULL"?]

top create a MqDumpC as export of the ctx-read-data-package … → API: tcl_mqmsgque_MqDumpC_new

The new instance belongs to the caller and may have to be released if necessary. A manual release using DumpDelete is always possible, but the instance can no longer be used afterwards.

The export include all data required to setup a read-data-package again later. After import with MqDumpImport the read-data-package and the environment will be set as it was on MqDumpExport The export can be saved into an external storage or be used in a network-tunnel (example: the aguard tool).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	ctx	the context to be exported into the dump-package-data
[in,out]	dumpP_inout	returns

Returns

The newly created MqDumpC instance, the instance is owned by the caller

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

See also

MqStorageExport, MqDumpImport, MqDumpError

Attention

1. The goal of this function is to create a dump to be loaded in the context later. If the context is not the original context… propably additional work is necessary.
2. The MqDumpExport is using realloc to allocate space. The value of *value should be initialized with either "MK_NULL" or a result of a previous MqDumpExport or MqDumpError.
3. Garbage is detected using MqDumpC_SIGNATURE… there is a MINIMAL chance (1 to 4.294.967.295) that the gargabe is NOT detected… to be save… always initialize the dump.
4. If the dump was initialized with "MK_NULL" or garbage … new memory will be allocated… If the dump memory will NOT be reused… free the memory with (6.)
5. If the dump was initialized with an previous dump … the memory will be reused… and extended with realloc if required.
6. Free the memory with MqDumpDelete.
7. On error… the dump is unchanged.
8. In case of TLS memory returned read more at MkKernel_Storage_C_API.

(destructor) $dmp Delete

top Destructor - delete a MqDumpC instance … → API: MqDumpDelete_RT

See also

MqDumpExport MqDumpError MkObjectDelete

binary [$dump BinGet]

top export the binary data from an MqDumpS object → API: tcl_mqmsgque_MqDumpC_BinGet

Parameters

[in]

dump

the source object

Returns

The required MkBinaryR

Attention

The data still belongs to the MqDumpS object… do NOT free.

MkBinaryR MqDumpBinGet (
  MQ_DMPN const   dump
) {
  MK_ATTR_HDL_CHECK(dump);
  return (MkBinaryR) {dump->size, (MK_BIN)dump};
}

$dump Import ctx:MqContextC

top import the dump-package into the ctx-read-data-package … → API: tcl_mqmsgque_MqDumpC_Import

The dump is the result of a previous MqDumpExport function call. After the load an package is suitable for all kind of MqContextC READ API function. To just forward the package use the MqProxyForward function.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	dump	the dump-package to be imported
[in]	ctx	the context in wich the dump-package is imported

Exceptions

MkExceptionC

→ The default-exception from the Programming-Language-Micro-Kernel (PLMK)

Attention

- The memory is dynamic-allocated and can be reused for the next MqDumpExport.

• (do not free) The memory of the out/return value belongs to the called TclMqMsgque function and therefore never becomes "MK_NULL" for a non-error result.
  For details on the out/return value, see: MkKernel_Storage_C_API.

See also

MqStorageExport, MqDumpExport, MqDumpError

MqDumpC MISC

C-API: MqDumpC_Misc_C_API - MqDumpC - various functions to work on a dump …

$dmp Log ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqDumpC … → API: tcl_mqmsgque_MqDumpC_Log

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	dmp	the MqDumpS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

long [$dump SizeGet]

top report the binary data size from an MqDumpS object → API: tcl_mqmsgque_MqDumpC_SizeGet

Parameters

[in]

dump

the source object

Returns

the size of the dump

MK_SIZE MqDumpSizeGet (
  MQ_DMPN const dump
) {
  MK_ATTR_HDL_CHECK(dump);
  return dump->size;
}

string [$dump TokenGet]

top return the MqContextC_ServiceApi_Identifer … → API: tcl_mqmsgque_MqDumpC_TokenGet

MK_STRN MqDumpTokenGet (
  MQ_DMPN const dump
) {
  MK_ATTR_HDL_CHECK(dump);
  return dump->hdr.tok;
}

---

MqFactoryC

SUPER: MkObjectC, top

MqFactoryC CLASS
		Export	MqFactoryC - Export class functions …
		Introspection	MqFactoryC - Introspection class functions …
		Misc	MqFactoryC - Misc class functions …
MqFactoryC TOR
		Add	add a new MqFactoryC identified by factory-identifier and defined by factory-constructor …
		new	add a new MqFactoryC identified by factory-identifier and defined by factory-constructor …
		Delete	Destructor - delete a MqFactoryC instance …
		Dup2	create a duplicate of the singleton object MqFactoryC using a new factory-identifer
MqFactoryC GET
		Get	return the MqFactoryC
		GetCalled	returns the MqFactoryC identified by ident …
		GetCalledL	returns the MqFactoryC identified as first argument in the largs MkBufferListC …
		GetOriginalIdent	helper function to return MqFactoryS::originalIdent
MqFactoryC MISC
		DefaultIdent	return the factory-identifier of the default MqFactoryC
		InitialIdent	return the factory-identifier of the initial MqFactoryC
		LogAll	log all "factories" to stderr
		Default	set the default-attribute to the factory …
		Initial	set the initial-attribut to fct …
		Log	log the MqFactoryC …
		New	create a new MqContextC from a MqFactoryC …

MqFactoryC DETAIL

C-API: MqFactoryC_C_API - MqFactoryC - the class known as fct or factory is used to provide an interface to create one or more new MqContextC …

The factory is an important part of the object management and has the following basic features:

1. create/delete a MqContextC defined by a MqFactoryC
2. infrastructure to host multiple MqFactoryC in a single executable
3. provide an identifier used for factory-lookup and as an unique-application-name
4. identification of a client and a server in an application-link

Without a factory only the pipe-feature without the child-feature is guaranteed to work. Other features may work, this depends of the "flexibility" of the programming-language.

The link between the MqFactoryS-identifier and the MqFactoryC is important for the future development of tclmqmsgque. Message-Routing, Service-Location and Persistent-Transactions depend on this feature.

The relationship between the MqFactoryC and the MqContextC is the same as the relationship between a type (MqFactoryS) and an object (MqContextS) of a regular programming language. The MqFactoryC define the type of the server and the MqContextC define a single object of the server process or thread.

                                     Application
|-------------------------------------------------------------------------------------|
|--------------- physical host 1 -----------------------|------ physical host 2 ------|
|-------- process-1 --------|-------- process-2 --------|-- process-3 --|---- … ------|
 thread-1     thread-2…      thread-1…     thread-2…      thread-1…       thread-…
  factory-A     factory-X     factory-Y…    factory-Z…
   object-1     object-1   object-…    …
   object-2     object-2   …
   object-3     object-3
   …              …

A server has a single MqFactoryC object per thread or process but multiple MqFactoryC objects per application. Decreasing the size and the complexity of a MqContextC object will improve the server performance. In future more fields, defined in the MqSetupS attribute of the the MqContextC object, will move into MqFactoryC object.

Thread Support and 'tclmsgque Main'

Description: a tclmsgque SERVER listen on a port and start for every incoming connetion a NEW sub-server. If a thread sub-server was choosen... with the --thread commandline-option... a new thread is created. To setup a new thread the INITIAL tcl-file is READ again and PROCS and VARIABLES are initialized. The NEW thread has it's own MqMain-Loop and so... the original MqMain-Loop is skipped. If a Factory command is used OUTSIDE of the MqMain-Loop... the initial MqFactoryS would be created TWICE. The creation of multiple MqFactoryS objects... with the SAME name... is an ERROR.

MqFactoryC CLASS

NAVI: top, up

MqFactoryC CLASS EXPORT

		HandleResolve	Handle-Resolve-Slot - return a MqFactoryC from netHdl or "MK_NULL" if invalid…
		HandleGet	Handle-Get-Slot - returns a export-hdl to the MqFactoryC useable for external storage

MqFactoryC CLASS INTROSPECTION

		Instances	get head-instance from linked-list of MqFactoryS type …
		Next	get next instance from linked-list of MqFactoryS type
		Prev	get previous instance from linked-list of MqFactoryS type

MqFactoryC CLASS MISC

GetNull

Null-Slot - return a MqFactoryC typed NULL instance …

MqFactoryC CLASS DETAILS

C-API: MqFactoryC_Class_C_API - MqFactoryC - define the class …

MqFactoryC CLASS EXPORT

MqFactoryC - Export class functions …

(static) MqFactoryC [MqFactoryC HandleResolve netHdl:MK_HDL]

top Handle-Resolve-Slot - return a MqFactoryC from netHdl or "MK_NULL" if invalid… → API: tcl_mqmsgque_MqFactoryC_HandleResolve

The MqFactoryHandleResolve undo the MqFactoryHandleGet and is intended to export a unique identifer into external code not belonging to the Programming-Language-Micro-Kernel (PLMK).

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	netHdl	handle former exported with MqFactoryHandleGet

Returns

the required handle or "MK_NULL" if netHdl is invalid

MK_HDL [$fct HandleGet]

top Handle-Get-Slot - returns a export-hdl to the MqFactoryC useable for external storage → API: tcl_mkkernel_MkObjectC_HandleGet

The export-hdl is a reference to an instance that can be stored in software and converted back into an instance using the MqFactoryHandleResolve.

The export-hdl is only valid until the Programming-Language-Micro-Kernel (PLMK) ends.

example: The export-hdl is used in rpc to identify an object across the network.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	fct	the MqFactoryS instance to work on

Returns

the required export-hdl

MqFactoryC CLASS INTROSPECTION

MqFactoryC - Introspection class functions …

(static) MqFactoryC [MqFactoryC Instances]

top get head-instance from linked-list of MqFactoryS type … → API: tcl_mqmsgque_MqFactoryC_Instances

The head-instance is the last instance created.

MqFactoryC [$fct Next]

top get next instance from linked-list of MqFactoryS type → API: tcl_mqmsgque_MqFactoryC_Next

MqFactoryC [$fct Prev]

top get previous instance from linked-list of MqFactoryS type → API: tcl_mqmsgque_MqFactoryC_Prev

MqFactoryC CLASS MISC

MqFactoryC - Misc class functions …

(static) MqFactoryC [MqFactoryC GetNull]

top Null-Slot - return a MqFactoryC typed NULL instance … → API: tcl_mqmsgque_MqFactoryC_GetNull

MqFactoryC TOR

C-API: MqFactoryC_TOR_C_API - MqFactoryC - various functions to create, initialize and destroy a factory …

(constructor,static) MqFactoryC [MqFactoryC Add constructor:class ?ident:string="MK_NULL"?]

top add a new MqFactoryC identified by factory-identifier and defined by factory-constructor … → API: tcl_mqmsgque_MqFactoryC_Add

The factory is required to get all tclmqmsgque features.

The context is a instance from a subclass of MqContextC …

The constructor require a tmpl argument with default "MK_NULL"

Example from example_code.tcl → setup a server called MyServer with one service MYTO

::oo::class create MyServer {
  superclass MqContextC
  ...
  <constructor> {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup serverSetup
    ...
  }
  method serverSetup {} {
    my ServiceCreate "MYTO" myService
    ...
  }
  ...
}

# package-main
tclmsgque::MqMsgque Main {
  ...
  # create "MyServer" factory... and make it to the default.
  set fct   [[MqFactoryC Add MyServer] Default]
  ...
}

Example from Filter5.tcl → create a new context using factory F1; F2 or F3 read from the commandline

tclmsgque::MqMsgque Main {

  # create buffer-list of the application arguments
  set largs [MkBufferListC CreateLA {*}$argv]

  # add factories
  MqFactoryC Add F1
  MqFactoryC Add F2
  MqFactoryC Add F3

  # call factory using the !first! application argument
  set srv [[MqFactoryC GetCalledL $largs] New]
  try {
    # configure and start the server
    $srv LinkCreate $largs

    # start event-loop and wait forever
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {

    # set the libmqmsgque error from the tcl error
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	error	(C-API) flag to signal how to report an error. valid values are: MK_ERROR_PANIC, MK_ERROR_PRINT, MK_ERROR_IGNORE or an other MqContextC
[in]	ident	the factory-identifier, if "MK_NULL" or EMPTY the class-name is used. The ident is the public identifier (name) of the factory and is used in logging-output (MqLog...) , name-resolution (MqFactoryGet...) and an first parameter in the executable-call: myserver ident ....
[in]	createCallF	(C-API) object constructor function
[in]	constructor	object (class) constructor data
[in]	createDataFreeF	(C-API) object constructor data free function
[in]	createDataCopyF	(C-API) object copy-constructor data free function
[in]	deleteCallF	(C-API) object destructor function
[in]	destructor	object (class) destructor data
[in]	deleteDataFreeF	(C-API) object destructor data free function
[in]	deleteDataCopyF	(C-API) object copy-constructor data free function

Returns

the new MqFactoryC or "MK_NULL" on error

See also

MqFactoryTypeAdd

(constructor,static) MqFactoryC [MqFactoryC new constructor:class ?ident:string="MK_NULL"?]

top add a new MqFactoryC identified by factory-identifier and defined by factory-constructor … → API: tcl_mqmsgque_MqFactoryC_new

The factory is required to get all tclmqmsgque features.

The context is a instance from a subclass of MqContextC …

The constructor require a tmpl argument with default "MK_NULL"

Example from example_code.tcl → setup a server called MyServer with one service MYTO

::oo::class create MyServer {
  superclass MqContextC
  ...
  <constructor> {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup serverSetup
    ...
  }
  method serverSetup {} {
    my ServiceCreate "MYTO" myService
    ...
  }
  ...
}

# package-main
tclmsgque::MqMsgque Main {
  ...
  # create "MyServer" factory... and make it to the default.
  set fct   [[MqFactoryC Add MyServer] Default]
  ...
}

Example from Filter5.tcl → create a new context using factory F1; F2 or F3 read from the commandline

tclmsgque::MqMsgque Main {

  # create buffer-list of the application arguments
  set largs [MkBufferListC CreateLA {*}$argv]

  # add factories
  MqFactoryC Add F1
  MqFactoryC Add F2
  MqFactoryC Add F3

  # call factory using the !first! application argument
  set srv [[MqFactoryC GetCalledL $largs] New]
  try {
    # configure and start the server
    $srv LinkCreate $largs

    # start event-loop and wait forever
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {

    # set the libmqmsgque error from the tcl error
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	error	(C-API) flag to signal how to report an error. valid values are: MK_ERROR_PANIC, MK_ERROR_PRINT, MK_ERROR_IGNORE or an other MqContextC
[in]	ident	the factory-identifier, if "MK_NULL" or EMPTY the class-name is used. The ident is the public identifier (name) of the factory and is used in logging-output (MqLog...) , name-resolution (MqFactoryGet...) and an first parameter in the executable-call: myserver ident ....
[in]	createCallF	(C-API) object constructor function
[in]	constructor	object (class) constructor data
[in]	createDataFreeF	(C-API) object constructor data free function
[in]	createDataCopyF	(C-API) object copy-constructor data free function
[in]	deleteCallF	(C-API) object destructor function
[in]	destructor	object (class) destructor data
[in]	deleteDataFreeF	(C-API) object destructor data free function
[in]	deleteDataCopyF	(C-API) object copy-constructor data free function

Returns

the new MqFactoryC or "MK_NULL" on error

See also

MqFactoryTypeAdd

(destructor) $fct Delete

top Destructor - delete a MqFactoryC instance … → API: MqFactoryDelete_RT

The factory-delete is more a pseudo-delete because a factory is always in-duty:

1. The context has a link to a factory (MqSetupS::factory) → this link is not protected by the refCount.
   1. The factory-delete will modify the environment of an existing context.
2. The factory is a singelton (like a type) → there are very "few" factories at all.
3. The factory is shared between threads → a modification would risk a race-condition.
   1. the factory can not be modify after creation

See also

MkRefDecr MqFactoryFree

(constructor) MqFactoryC [$fct Dup2 ident:string]

top create a duplicate of the singleton object MqFactoryC using a new factory-identifer → API: tcl_mqmsgque_MqFactoryC_Dup2

MqFactoryC GET

C-API: MqFactoryC_Get_C_API - MqFactoryC - various functions to 'get' data out of a factory …

(static) MqFactoryC [MqFactoryC Get ?ident:string=""?]

top return the MqFactoryC → API: tcl_mqmsgque_MqFactoryC_Get

The ident is the factory-name used with MqFactoryAdd - usually the class-name.

The following ident are also supported:

"initial"	belongs to the factory with MqFactoryInitial
"default" or ""	belongs to the factory with MqFactoryDefault

Parameters

[in]

ident

the factory-identifier to search for

Returns

the MqFactoryC or "MK_NULL" if ident was not found

(static) MqFactoryC [MqFactoryC GetCalled ?ident:string=""?]

top returns the MqFactoryC identified by ident … → API: tcl_mqmsgque_MqFactoryC_GetCalled

If multiple factories (MqFactoryAdd) are available the startup code have to choose which factory to use.
The selection is done by the factory-identifer and is taken from the ident or from the first argument of the commandline-arguments-list.

Parameters

[in]

ident

the factory-identifier or "" for the default MqFactoryC

Returns

the MqFactoryC or "MK_NULL" if nothing was found

See also

MqFactoryGetCalledL

(static) MqFactoryC [MqFactoryC GetCalledL largs:MkBufferListC]

top returns the MqFactoryC identified as first argument in the largs MkBufferListC … → API: tcl_mqmsgque_MqFactoryC_GetCalledL

Like MqFactoryGetCalled but the ident is taken from the MkBufferListC object that was created from the commandline-arguments-list.

Command-Line-Arguments-List

The Commandline-Argumentis-List begins with the first argument after the executable and/or the script file.

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	largs	the command-line-args or "" for the default MqFactoryC

Returns

the MqFactoryC or "MK_NULL" if nothing was found

See also

MqFactoryGetCalled

string [$fct GetOriginalIdent]

top helper function to return MqFactoryS::originalIdent → API: tcl_mqmsgque_MqFactoryC_GetOriginalIdent

Attention

The MK_STRN returned belongs to tclmqmsgque… do not free the data.

MqFactoryC MISC

C-API: MqFactoryC_Misc_C_API - MqFactoryC - various functions to work on a factory …

(static) string [MqFactoryC DefaultIdent]

top return the factory-identifier of the default MqFactoryC → API: tcl_mqmsgque_MqFactoryC_DefaultIdent

(static) string [MqFactoryC InitialIdent]

top return the factory-identifier of the initial MqFactoryC → API: tcl_mqmsgque_MqFactoryC_InitialIdent

(static) MqFactoryC LogAll ?callfunc:string="MK_NULL"?

top log all "factories" to stderr → API: tcl_mqmsgque_MqFactoryC_LogAll

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)

MqFactoryC [$fct Default]

top set the default-attribute to the factory … → API: tcl_mqmsgque_MqFactoryC_Default

The default-factory is used to create an MqFactoryC if MqFactoryGetCalled was not able to find a specific factory object. This is designed for a scenario with multiple factories included into a single binary and the first commandline parameter after the executable name… (position 0=executable, position 1=factory-selector)… is not related to a factory-ident… added with MqFactoryAdd.

Parameters

[in]

fct

the new default MqFactoryC

Returns

the input fct

Example: from example/tcl/server.cs

    static void Main(string[] argv) {
      var largv = new MkBufferListC(argv);
 
      MqFactoryCT<Server>.Add("server").Default();
      MqFactoryCT<Client>.Add("client");
 
      // "ctx" get the "Default" factory "server" ... or ... the factory "client" ... 
      // if string "client" is on the FIRST position in "argv"
      MqContextC ctx = MqFactoryCT<MqContextC>.GetCalled(largv).New();
 
      try {
        ctx.LinkCreate(largv);
        ctx.LogC("this is the log test\n",1,"test");
        ctx.ProcessEvent(MqWaitOnEventE.FOREVER);
      } catch (Exception ex) {
        ctx.ErrorCatch (ex);
      } finally {
        ctx.Exit();
      }
    }

MqFactoryC [$fct Initial]

top set the initial-attribut to fct … → API: tcl_mqmsgque_MqFactoryC_Initial

The factory with "Initial"-attribute is always used for an object that should only be created with the MqContextC base class, but for which no other factory has been specified.
Use this attribute with care because you are firmly linking a factory. In a programming language with class-support, such as C++ or C#, this class is used for every new MqContextC object.
Where "Reflection" is available, this attribute has less meaning since the class is primarily determined from the parent object by means of "Reflection".
The "Initial" attribute is otherwise used for the "Loopback" and the "Filter" capability.

Example from Filter4.tcl → set Initial attribute to a Factory

tclmsgque::MqMsgque Main {
  # !!ATTENTION!! if you put the "MqFactoryC Add" outsite of "tclmsgque::MqMsgque Main"
  # you get a error like: "...factory identifer already in use..."
  # because in a "thread" startup... you try to create a factory with SAME NAME again.
  [MqFactoryC Add Filter4 ] Initial
  set srv [Filter4 new]

  try {
    $srv LinkCreate {*}$argv
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Parameters

[in]

fct

the new initial MqFactoryC

Returns

the input fct

$fct Log ?fmtobj:MkObjectC="MK_NULL"? ?debug:int32=0? ?callfunc:string="MK_NULL"? ?lvl:int32=0?

top log the MqFactoryC … → API: tcl_mqmsgque_MqFactoryC_Log

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	fct	the MqFactoryS instance to work on
[in]	fmtobj	managed object used to format the log-message (default="MK_NULL" → use default-format)
[in]	debug	the debug level from MkRuntimeS::debug, use 0 <= debug <= 9 (default=0)
[in]	callfunc	a user-defined postfix to identify the calling function or the environment (default=name-of-function)
[in]	lvl	a user-defined prefix starting with "" for lvl=0 and increase with " " for lvl+1 (default=0)

See also

MqFactoryC

MqContextC [$fct New]

top create a new MqContextC from a MqFactoryC … → API: tcl_mqmsgque_MqFactoryC_New

this create only the initial-server-object… all other server-objects will be created on behalf of the client-request.

Example from MyServer.tcl → create a new server context

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*
namespace import tclmsgque::MkKernel::*

# package-item
::oo::class create MyServer {
  superclass MqContextC

  # service to serve all incoming requests for token "HLWO"
  method myFirstService {} {
    my SendSTART
    my SendSTR "[my ReadSTR] World"
    my SendRETURN
  }

  # define a service as link between the token "HLWO" and the callback "MyFirstService"
  method serverSetup {} {
    my ServiceCreate "HLWO" myFirstService
  }

  # factory startup (constructor)
  constructor {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup serverSetup
  }
} 

# package-main
tclmsgque::MqMsgque Main {

  # setup commandline arguments for later use
  set args  [MkBufferListC CreateLA {*}$argv]

  # create "MyServer" factory... and make it to the default.
  set fct   [[MqFactoryC Add MyServer] Default]

  # inspect commandline-argument for the "factory" to choose... and create a object
  set fct   [MqFactoryC GetCalledL $args]
  set srv   [$fct New]

  try {
    $srv LinkCreate $args
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Parameters

[in]	mkrt	the MkRuntimeS instance to work on - the runtime argument, used by MK_RT_CALL (C-only)
[in]	fct	a MqFactoryC used to create a MqContextC
[in]	tmpl	(C-API only) template for context intialization
[out]	val_out	the new context object as return or "MK_NULL" on error

Returns

the new MqContextC or NULL on error

Attention

(C-API only)

the programmer have-to check the return value on "MK_NULL" pointer

(non C-API only)

this is no hard constructor because the factory create the object and the self pointer is already available. ObjNew is used to extract the self pointer from the object

---

FILTER MODE

C-API: MqContextC_FilterApi_C_API - MqContextC - modify the data using the filter-technology …

The filter mode is related to a special usage of the tclmqmsgque software called a command pipeline. To define a filter create a server with:

• MqSetupS::isServer or IServerSetup and add a factory:
• MqFactoryC

Every filter has two context one belongs to the left command and one belongs to the right command:

 <-- left cmd --> <------- filter -------> <-- right cmd -->

                  <-- left --><- right -->
                  <- server -><- client ->
                  <- master -><- slave -->
                  <-context1-><-context2->

  ... command1   @         filter         @   command2 ...

The left context is created on application startup and the right context is created as slave of the left context.

• if the @ argument is followed by an normal command (server) a local pipeline is created:

  client @ filter @ server
  

• if the @ argument is followed by an option a non-local pipeline is created:

  <------------ host-1 -------------> <-- network --> <---------- host-2 ----------->
         <---- client arguments ---->                       <--- server arguments -->
                  <-- filter arg. -->
                    <--- options --->
  
  client @ filter @ --tcp --port 7777   ...........   server --tcp --port 7777 --fork
  

BI-DIRECTIONAL FILTER

A bi-directional filter allow a data-flow in both directions and is used in a classical client/server application:

    client ... <--> ... server

as a feature enhancement like a protocol-tunnelling:

    client @ mq2tunnel ... <--> ... tunnel2mq @ server

or to convert the protocol into an other protocol:

    client @ mq2soap ... <--> ... soap-server

To define a bi-directional filter a couple of commands provide support:

• MqServiceCreate
  • use the token +ALL to add a listener for all services. This feature is used for a tunnel to modify the body at all. (example: aguard)
• MqServiceProxy
  • use this function to link the left context with the right context identified with the slave-identifier id (default: 0). No data manipulation is performed.
• MqSlaveGetFilter, MqSlaveGetMaster, MqSlaveGetProxy
  • in a filter service the current context is used to read the data. To send the data an other context, belonging to the other site of the communication, have to be used. This function return the context of the other site.
• MqServiceTokenGet
  • if the token +ALL is used in ServiceCreate to add a generic service handler the current token is not known. This function return the current token.
• MqServiceIsTransaction
  • if the token +ALL is used in ServiceCreate to add a generic service handler the current transaction-status is not known. This function return the transaction-status as boolean with true (with-transaction) or false (without-transaction).
  • with-transaction: the package was send with MqSendEND_AND_WAIT or MqSendEND_AND_CALLBACK
  • without-transaction: the package was send with MqSendEND
• MqDumpExport
  • read and return the read-data-package as MqDumpC. Use this dump to apply a transformation to the data, like encryption (example: aguard), or to save the body in a persistent storage for later use MqDumpImport.
• MqDumpImport
  • load the MqDumpC into the read-data-package
• MqProxyForward
  • send the read-buffer or a MqDumpC, as returned by MqDumpExport, to the filter target.

ONE-DIRECTIONAL FILTER

A one-directional filter is a special form of a bi-directional filter and allow a data-flow from the left to the right.
This filter is well known from the unix shell to link different commands together:

    command1 | command2 | command3

A tclmqmsgque command pipeline is created with the special character "@" instead of "|" :

    msgcmd1 @ msgcmd2 @ msgcmd3

To define a tclmqmsgque filter... create a service handle with MqServiceCreate or MqServiceProxy ... using the token +FTR and +EOF

token	description
+FTR	required to act on filter data rows. Every filter input data is a list of filter data rows and every row is a list of filter data columns. Every row is send to the following filter-command as +FTR service request
+EOF	required to act on End-Of-Filter data and is called after all +FTR data was send. Sometimes the filter data can not be served as +FTR data (example: sorting of the input rows need to read all rows before the data can be send to the next filter command) and the+EOF token is used to continue send +FTR data rows.

and send every data item with MqSendEND_AND_WAIT .

PORTABILITY ISSUES

This library is actively developed and tested on x86_64 Linux (opensuse), older versions have also been successful tested on FreeBSD, WindowsXP/7, MacOSX and Solaris using x86_64, i686, ppc and sparc processor.

---

EXAMPLES

1. simple client/server application

• The simple client/server application to provide the external "MMUL" service to multiplicate 2 double values
• The client and the server application is using the low-level MqContextC SEND API and MqContextC READ API.

a) server to provide the "MMUL" service

Example from mulserver.tcl →

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*

::oo::class create MulServer {
  superclass MqContextC
  constructor {{tmpl ""}} {
    next $tmpl
    my ConfigSetServerSetup ServerSetup
  }
  method MMUL {} {
    my SendSTART
    my SendDBL [expr {[my ReadDBL] * [my ReadDBL]}]
    my SendRETURN
  }
  method ServerSetup {} {
    my ServiceCreate "MMUL" MMUL
  }
}

tclmsgque::MqMsgque Main {
  set srv [[MqFactoryC Add MulServer "mulserver"] New]
  try {
    $srv LinkCreate {*}$argv
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Start mulserver.tcl using TCP port 7777 and spawn a new session for every incoming connection

> tclsh mulserver.tcl --tcp --port 7777 --spawn

b) client to call the "MMUL" service

Example from mulclient.tcl →

package require tclmsgque::MqMsgque
tclmsgque::MqMsgque::MqContextC create ctx
ctx LinkCreate --name "MyMul" {*}$argv
ctx SendSTART
ctx SendDBL 3.67 
ctx SendDBL 22.3 
ctx SendEND_AND_WAIT "MMUL" 
puts [ctx ReadDBL]
ctx Exit

Use mulclient.tcl to connect to mulserver.tcl using TCP port 7777:

> tclsh mulclient.tcl --tcp --port 7777

2. advanced client/server application

• The advanced client/server application to provide the external "HLWO" and the internal "LOOP" service.
• The external "HLWO" service is calling the internal "LOOP" service.
• The internal "LOOP" service is using a instance-attribute to return data.
• The server is using the MqContextC HIGH API to simplify service-usage.

a) server to provide the "HLWO" service

Example from MyLoopServer.tcl →

package require tclmsgque::MqMsgque
namespace import tclmsgque::MqMsgque::*

::oo::class create MyLoopServer {
  superclass MqContextC
  export variable

  # factory startup
  constructor {{tmpl ""}} {
    my variable mydata;
    next $tmpl
    my ConfigSetServerSetup ServerSetup
    # set the "mydata" attribute to the master-context
    set mydata  "Hello World";
  }

  # service to serve all EXTERNAL requests for token "HLWO"
  method HLWO_srv {} {
    # get the "loopback" context
    set loop  [my SlaveGet LOOPBACK]
    # call the LOOP service on the SAME server
    $loop Send "W" "LOOP"
    # answer HLWO with string-return from LOOP
    my Send "R" "C" [$loop ReadSTR]
  }

  # service to serve all INTERNAL requests for token "LOOP"
  method LOOP_srv {} {
    # get the "master" context
    set master  [my SlaveGetMaster]
    # answer LOOP with data from MASTER->mydata attribute
    $master variable mydata
    my Send "R" "C" $mydata
  }

  # setup a server-context - called for every new server-context
  method ServerSetup {} {
    # EXTERNAL: link the "HLWO" service with "HLWO_srv"
    my ServiceCreate "HLWO" HLWO_srv
    # INTERNAL: link the "LOOP" service with "LOOP_srv"
    [my SlaveGet MQ_SLAVE_LOOPBACK] ServiceCreate "LOOP" LOOP_srv
  }
}

tclmsgque::MqMsgque Main {

  # create "MyLoopServer" factory... and the instance
  set srv   [[MqFactoryC Add MyLoopServer] New]

  try {
    $srv LinkCreate $argv
    $srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    $srv ErrorCatch
  } finally {
    $srv Exit
  }
}

Start MyLoopServer.tcl using UDS file /var/loop-server.uds and thread a new session for every incoming connection

> tclsh MyLoopServer.tcl --uds --file /var/loop-server.uds --thread

b) client to call the "HLWO" service

Example from MyClient.tcl →

package require tclmsgque::MqMsgque

# create a context using the static tclmsgque CTOR method "Create"
set ctx [tclmsgque::MqMsgque::MqContextC Create]
try {
  $ctx ConfigSetName "MyClient"
  $ctx LinkCreate {*}$argv
  $ctx SendSTART
  $ctx SendSTR "Hello"
  $ctx SendEND_AND_WAIT "HLWO" 
  puts [$ctx ReadSTR]
} on error {} {
  $ctx ErrorCatch
} finally {
  # delete the context using the tclmsgque APPLICATION-DTOR method "Exit"
  $ctx Exit
}

Use MyClient.tcl to connect to mulserver.tcl using UDS file /var/loop-server.uds:

> tclsh MyClient.tcl --uds --file /var/loop-server.uds

3. create a filter to wrap every column in a '<>' pair

Example from manfilter.tcl →

package require tclmsgque::MqMsgque

proc FTRcmd {ctx} {
  set ftr [$ctx SlaveGetFilter]
  $ftr SendSTART
  while {[$ctx ReadItemExists]} {
    $ftr SendSTR "<[$ctx ReadSTR]>"
  }
  $ftr SendEND_AND_WAIT "+FTR"
  $ctx SendRETURN
}

tclmsgque::MqMsgque Main {
  tclmsgque::MqMsgque::MqContextC create srv
  srv ConfigSetIsServer yes
  srv ConfigSetName "filter"

  try {
    srv LinkCreate {*}$argv
    srv ServiceCreate "+FTR" FTRcmd
    srv ServiceProxy  "+EOF"
    srv ProcessEvent MQ_WAIT_FOREVER
  } on error {} {
    srv ErrorCatch
  } finally {
    srv Exit
  }
}

Use manfilter.tcl in a tclmqmsgque command pipeline:

> echo -e "1:2:3\na:b:c" | atool split -d : @ tclsh manfilter.tcl @ atool join -d :

---

SEE ALSO

libmqmsgque, ccmqmsgque, csmqmsgque, javamqmsgque, gomqmsgque, pymqmsgque, rbmqmsgque, tclmqmsgque, perlmqmsgque, phpmqmsgque

KEYWORDS

Tcl, unix, socket, message, msgque