Singleton (separate) message handler context in Javascript - Revision history

Marian at 06:54, 3 September 2024

2024-09-03T06:54:45Z

Marian at 06:50, 3 September 2024

2024-09-03T06:50:33Z

Marian at 13:55, 29 August 2024

2024-08-29T13:55:17Z

Marian at 13:50, 29 August 2024

2024-08-29T13:50:31Z

Marian at 13:49, 29 August 2024

2024-08-29T13:49:04Z

Marian at 13:47, 29 August 2024

2024-08-29T13:47:20Z

Marian: Created page with " Singleton message handlers should be used when application is expected to process a high number of messages and want to process it in a 'multithreaded' way. A regular messa..."

2024-08-29T13:21:55Z

Created page with " Singleton message handlers should be used when application is expected to process a high number of messages and want to process it in a 'multithreaded' way. A regular messa..."

New page

Singleton message handlers should be used when application is expected to process a high number of messages and want to process it in a 'multithreaded' way.

A regular message handler callback is called by javascript when script context is unlocked.<br/>
Script context is locked during message processing.

'''See also'''

* [[Javascript]]

@@ Line 9: / Line 9: @@
 The context is deleted after message is handled.<br/>
-Message singleton related functions (e.g. Message.installsingleton()) are not available:
+See [[Javascript Message|Message()]] for singleton functions availability.
-* When running in a singleton context.
-* When running a script configured with multiple instances
-* In routing script
-* In dynamic scripts (see ''javascript eval'' command)
@@ Line 126: / Line 122: @@
       Engine.output("Initializing module Sample Singleton Message Handler");
       if (first) {
   	if (!Message.installSingleton) {
   	    Engine.debug(Engine.DebugConf,"Refusing to start Sample Singleton Message Handler",

← Older revision		Revision as of 06:50, 3 September 2024
Line 12:		Line 12:
	* When running in a singleton context.		* When running in a singleton context.
	* When running a script configured with multiple instances		* When running a script configured with multiple instances
		+	* In routing script
		+	* In dynamic scripts (see ''javascript eval'' command)

@@ Line 25: / Line 25: @@
       // Increment some shared variable to be reported in status
       var perf = new Engine.SharedVars("handler_singleton_sample_perf");
-      var perf.inc("handled_" + context);
+      perf.inc("handled_" + context);
       if (!msg.called)
   	return false;
@@ Line 94: / Line 94: @@
       var str = "";
       var perf = new Engine.SharedVars("handler_singleton_sample_perf");
-      var perf = perf.getVars();
+      perf = perf.getVars();
       for (var name in perf)
   	str += "," + name + "=" + perf[name];

@@ Line 5: / Line 5: @@
 A singleton message handler may be used when application is expected to process a high number of messages and want to avoid contention due to javascript serialization.<br/>
-When a singleton message handler is installed the javascript module will build and initialize a separate context.<br/>
+When a singleton message handler is installed the javascript module will build and initialize a separate context each time a message is handled.<br/>
-Handle callback function is called in this context.<br/>
+Handler callback function is called in this context.<br/>
 The context is deleted after message is handled.<br/>

@@ Line 2: / Line 2: @@
 A regular message handler callback is called by javascript when script context is unlocked.<br/>
 Script context is locked during message processing.<br/>
-Script global data is available in message handler callback function.
+Script global data is available in message handler callback function.<br/>
-A singleton message handler may be used when application is expected to process a high number of messages and want to avoid contention due to javascript serialization.
+A singleton message handler may be used when application is expected to process a high number of messages and want to avoid contention due to javascript serialization.<br/>
 When a singleton message handler is installed the javascript module will build and initialize a separate context.<br/>
 Handle callback function is called in this context.<br/>
 The context is deleted after message is handled.<br/>
-Message singleton related functions (e.g. Message.installsingleton()) are not available in:
+Message singleton related functions (e.g. Message.installsingleton()) are not available:
 * When running in a singleton context.
 * When running a script configured with multiple instances

@@ Line 1: / Line 1: @@
-Singleton message handlers should be used when application is expected to process a high number of messages and want to process it in a 'multithreaded' way.
+A regular message handler callback is called by javascript when script context is unlocked.<br/>
 '''See also'''
 * [[Javascript]]