Thread-Safe priority queue based on event implementation (Python implementation)

Event events are a great thread-synchronization and thread-communication mechanism, and many of the Python source code is based on the event to implement a lot of thread-safe, support for concurrent, thread-communication libraries

For the heap implementation of the priority queue, see "Python implementation two fork heap and heap sorting", Python event see <python Lock, Semaphore, event implementation thread synchronization, in fact, the main attention to the use of several methods of the event, As well as the logical order of the program under multi-threaded access, there are several ways to put the event in the relevant code snippet. It's not hard to understand yourself. Look at the source bar:

ImportHEAPQImportThreading#Import TimeclassItem:def __init__(self, name): Self.name=namedef __repr__(self):return 'Item ({!r})'. Format (self.name)classPriorityqueue:def __init__(self): Self._queue=[] Self._index=0 self._event=Threading. Event ()defpush (self, item, priority):ifLen (self._queue)! =0:self._event.clear () while  notSelf._event.is_set (): Self._event.set () Heapq.heappush (Self._queue, (-priority, Self._index, item))#In a ternary group, the default is to construct a small top heapSelf._index + = 1#Self._event.set ()    defpop (self):ifLen (self._queue)! =0:self._event.set () whileSelf._event.is_set (): Self._event.wait () x= Heapq.heappop (Self._queue) [-1]#Reverse Outputself._event.clear ()returnxdeftest1 (P, item, index): forIinchRange (3): P.push (item), index)deftest2 (p): forIinchRange (3):        Print(P.pop ())if __name__=='__main__': P=priorityqueue () T1= Threading. Thread (Target=test1, args= (p,'Foo', 1)) T3= Threading. Thread (Target=test1, args= (p,'Bar', 2)) T4= Threading. Thread (Target=test1, args= (p,'Ryan', 28)) T2= Threading. Thread (Target=test2, args=(P,)) T5= Threading. Thread (Target=test2, args=(P,)) T6= Threading. Thread (Target=test2, args=(P,)) T1.start () T2.start () T1.join () T2.join () T3.start () T5.start () T3.join () T5.join () t 4.start () T6.start () T4.join () T6.join ( )

Suggested to see Python socket source code and queue.py and other source of these are related to multi-threaded access to the library are based on these thread synchronization mechanism to achieve, you can write down, after all, people write more professional.

Thread-Safe priority queue based on event implementation (Python implementation)