Adding a Message Pattern Callback

To add a callback routine to your pattern, use the tt_pattern_callback_add function.

Callbacks are called in reverse order of registration (for example, the most recently added callback is called first).

When the ToolTalk service matches a message, it automatically calls your callback routine to examine the message and take appropriate actions. When a message that matches a pattern with a callback is delivered to you, it is processed through the callback routine. When the routine is finished, it returns TT_CALLBACK_PROCESSED and the API objects involved in the operation are freed. You can then use tt_message_destroy to destroy the message, which frees the storage used by the message, as illustrated in the following code sample.

Tt_callback_action
sample_msg_callback(Tt_message m, Tt_pattern p)
{
	... process the reply msg ...

	tt_message_destroy(m);
	return TT_CALLBACK_PROCESSED;
}