execute_void

Make this execute the func function with the arg argument (along with a Error which is not error) in the sub thread managed by this.

To execute a function which returns some pointer, use execute.

This method returns immediately. Calling fetch_result is not necessary as func does not return any result. However, it may be necessary to call iterate to give this a chance to execute the arg_destroy_func function if not null (note that iterate is called by fetch_result itself).

Once func's execution is finished, if arg is not null, the arg_destroy_func destruction function is called on arg. This call occurs in the thread calling fetch_result.

If an error occurred in this function, then the arg_destroy_func function is not called to free arg.

Parameters:

this	a ThreadWrapper object
func	the function to execute, not null
arg	argument to pass to func
arg_destroy_func	function to be called when the execution has finished, to destroy arg, or null

Returns:

the job ID, or 0 if an error occurred