我希望使用KeyboardInterrupt停止异步多处理作业。但有时候在呼叫终止时会发生挂起。
from multiprocessing.pool import ThreadPool
import multiprocessing
import time
import queue
import inspect
def worker(index):
print('{}: start'.format(index))
for i in range(5):
time.sleep(1)
print('{}: stop'.format(index))
return index, True
def wrapper(index, stopEvent, qResult):
if stopEvent.is_set() is True:
return index, False
try:
result = worker(index)
except:
print('*' * 50)
return index, False
else:
if result[1] == True:
qResult.put(result)
return result
def watcher(qResult, stopEvent):
cntQ = 0
while True:
try:
result = qResult.get(timeout=10)
qResult.task_done()
except queue.Empty:
if stopEvent.is_set() is True:
break
except KeyboardInterrupt:
stopEvent.set()
else:
cntQ += 1
print(result)
qResult.join()
qResult.close()
print('qResult count:', cntQ)
def main():
stopEvent = multiprocessing.Event()
qResult = multiprocessing.JoinableQueue()
qResult.cancel_join_thread()
watch = multiprocessing.Process(target=watcher, args=(qResult, stopEvent))
watch.start()
pool = ThreadPool()
lsRet = []
for i in range(100000):
try:
ret = pool.apply_async(wrapper, args=(i, stopEvent, qResult))
lsRet.append(ret)
except KeyboardInterrupt:
stopEvent.set()
time.sleep(1)
break
if i+1 % 10 == 0:
time.sleep(2)
cntTotal = len(lsRet)
cntRet = 0
for ret in lsRet:
if stopEvent.is_set():
break
try:
ret.get()
except KeyboardInterrupt:
stopEvent.set()
time.sleep(1)
else:
cntRet += 1
if stopEvent.is_set() is False:
stopEvent.set()
print(inspect.stack()[0][1:4])
if watch.is_alive() is True:
watch.join()
print(inspect.stack()[0][1:4])
pool.terminate() # Why hang??????????
print(inspect.stack()[0][1:4])
pool.join()
print(cntTotal, cntRet)
if __name__ == '__main__':
main()
main()使用watcher()异步调用wrapper()个线程和许多multiprocessing.pool.Threadpool个线程。
wrapper()调用worker()并将其结果置于队列中。
watcher()监视结果排队。
如果按 ctrl - c ，则设置stopEvent。
设置stopEvent后，wrapper()停止调用worker()，Watcher()表示queue.Empty和stopEvent并退出循环。
最后main()调用池terminate()。
有时流程做得很好，但有时会挂起。每次都不一样。