(PECL gearman >= 0.5.0)
Register and add callback function
public bool GearmanWorker::addFunction ( string $function_name, callable $function [, mixed &$context [, int $timeout ]] )
Registers a function name with the job server and specifies a callback corresponding to that function. Optionally specify extra application context data to be used when the callback is called and a timeout.
Parameters: