ASYNC Module

Daniel-Constantin Mierla

Edited by

Daniel-Constantin Mierla


Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. workers (int)
4. Functions
4.1. async_route(routename, seconds)
4.2. async_sleep(seconds)

List of Examples

1.1. Set workers parameter
1.2. async_sleep usage
1.3. async_sleep usage

Chapter 1. Admin Guide

1. Overview

This module provides asynchornous operations for handling SIP requests in configuration file.

It uses t_suspend() and t_continue() from TM module.

Note that after invoking the an asyncronous operation, the processing will continue later, in another application process. Therefore, do not rely on variables stored in private memory, used shared memory if you want to get values after the processing is resumend (e.g., $avp(...), $xavp(...), $shv(...), htable $sht(...)).

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

  • tm - transaction management.

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • None

3. Parameters

3.1. workers (int)

Number of worker processes to be started to handle the asynchornous tasks.

Default value is 1.

Example 1.1. Set workers parameter

...
modparam("async", "workers", 2)
...

4. Functions

4.1.  async_route(routename, seconds)

Simulate a sleep of 'seconds' and then continue the processing of SIP request with the route[routename]. In case of internal errors, the function returns false, otherwise the function exits the execution of config at that moment (return 0 behaviour).

The routename parameter can be a static string or a dynamic string value with config variables.

The sleep parameter represent the number of seconds to suppend the processing of SIP request. Maximum value is 100. The parameter can be a static integer or a varaible holding an integer.

Since the SIP request handling is resumed in another process, practically the config file execution state is lost. Therefore beware that the execution of config after resume will end once the route[routename] is finished.

This function can be used from REQUEST_ROUTE.

Example 1.2. async_sleep usage

...
async_route("RESUME", "4");
...
route[RESUME] {
   send_reply("404", "Not found");
   exit;
}
...

4.2.  async_sleep(seconds)

Simulate a sleep of 'seconds' and then continue the processing of SIP request with the next action. In case of internal errors, the function returns false, otherwise the function exits the execution of config at that moment (return 0 behaviour).

The sleep parameter represent the number of seconds to suppend the processing of SIP request. Maximum value is 100. The parameter can be a static integer or a varaible holding an integer.

Since the SIP request handling is resumed in another process, practically the config file execution state is lost. Therefore beware that the execution of config after resume will end once the route block where async_sleep() is called is finished.

This function can be used from REQUEST_ROUTE.

Example 1.3. async_sleep usage

...
async_sleep("4");
send_reply("404", "Not found");
exit;
...