my $tcount :shared = 0;

	while( $message = $msgQueue->poll()){
		if($tcount < 4){
			Logger::log(3, "Number of active threads : ".$tcount." processing incomming message");
			threads->create(processData,$message,createMsgId());
		} else {
			Logger::log(2, "Maximum number of threads reached. Waiting");
			sleep 1 until $tcount < 4);
			threads->create(processData,$message,createMsgId());
		}
	}

	sub processData {
		$tcount++;
		# do something
		$tcount--;
		threads->exit();
	}