Condition synchronization and condition variable synchronization similar meaning, just short of lock function, because the conditions are not synchronous design to access a shared resource environment conditions. event = threading.Event (): target environment conditions, the initial value of False
event.isSet (): returns the event status value;
event.wait (): if event.isSet () == False the blocked thread;
event.set (): Set event state value is True, all blocked thread pools activating a ready state, waiting for the operating system scheduling;
the Event.CLEAR (): recovery event state is False.
