function onmessage(event)
	{
		var uuid = event.data.uuid;

		if (self.tasks[uuid] !== undefined)
		{
			var task = self.tasks[uuid];
			task.callback(event.data.data);
			delete self.tasks[uuid];
		}
		else
		{
			throw new Error("Unknown worker task " + uuid);
		}
	}
Create workers for this pool.

@method createWorkers