def killAllWorkers(self,wait = None):
        """ Kill all active workers.
            wait = seconds to wait until last worker ends
                   if None it waits forever.
        """
        
        self.countLock.acquire()
        self.killWorker(self.workers)
        self.countLock.release()
        self.allKilled.wait(wait)
 Kill all active workers.
            wait = seconds to wait until last worker ends
                   if None it waits forever.
        
recipes/Python/576910_Thread_pool_grows_on_demand/recipe-576910.py