满足条件时终止多处理进程 [英] Killing a multiprocessing process when condition is met
问题描述
我试图运行的想法是这样的:
The idea im trying to run is this:
RUN 3 个进程做计算一旦 3 个进程之一完成任务立即杀死其他人并继续主要任务,我不能让它再运行了
RUN 3 Processes doing calculation ONCE one of the 3 processes finishes the task KILL others imediatly and continue with the main task, i can't let it run any second longer
我尝试过的事情是:通过 multiprocessing.manager 放置全局变量,但这仍然让进程完成它们的循环.引发异常
The things i've tried was: Putting the global variable through multiprocessing.manager, but that still lets processes finish their loops. Raising an exception
操作系统:Windows蟒蛇:2.7
OS: Windows PYTHON: 2.7
def f(name):
Doing = True
try:
while Doing:
print 'DOING',name
somecodethatmarksDoingAsFalse()
except Exception as error:
print 'bye'
print error
Doing = False
return True
if __name__ == '__main__':
p = multiprocessing.Process(target=f, args=('bob',))
p2 = multiprocessing.Process(target=f, args=('tom',))
p.start()
p2.start()
p.join()
p2.join()
raise Exception('I know Python!')
sys.exit()
当我将执行标记为 false、引发异常或以任何方式对其中一个进程进行计算时,我希望能够杀死所有进程
I expect to be able to kill all processes when i mark doing as false, raise an exception or any way when calculation is done on ONE of the processes
EDIT:它不是重复的,因为它仍然执行完代码,例如Requests模块仍然发送数据
EDIT: It's not a duplicate, because it still finishes executing code, for example Requests module still sends data
推荐答案
如果你需要即时杀戮,你可以使用 multiprocessing.Event
通知父进程满足条件并让它立即杀死工作进程.管理器进程对于这种需要的少量同步来说太重了.
If you need instant kills, you can use a multiprocessing.Event
to inform the parent-process about the condition met and let it kill the worker processes immediately. A manager-process would be too heavyweight for this little synchronization needed.
import os
from datetime import datetime
from multiprocessing import Process, Event
def worker(range_, target, found_event):
print('{} | pid: {} started'.format(datetime.now(), os.getpid()))
for x in range_:
if x == target:
print('{} | pid: {} found target'.format(
datetime.now(), os.getpid())
)
found_event.set()
if __name__ == "__main__":
N_WORKERS = 4
step = int(200e6)
ranges = [range(x, x + step) # change `range` to `xrange` for Python 2
for x in range(0, N_WORKERS * step, step)]
# range(0, 200000000), ..., range(800000000, 1000000000)]
target = int(150e6) # <-- worker finding this value triggers massacre
found_event = Event()
pool = [Process(target=worker, args=(range_, target, found_event))
for range_ in ranges]
for p in pool:
p.start()
found_event.wait() # <- blocks until condition met
print('{} | terminating processes'.format(datetime.now()))
for p in pool:
p.terminate()
for p in pool:
p.join()
print('{} | all processes joined'.format(datetime.now()))
示例输出:
2019-01-17 01:55:33.781884 | pid: 28376 started
2019-01-17 01:55:33.782333 | pid: 28377 started
2019-01-17 01:55:33.782851 | pid: 28378 started
2019-01-17 01:55:33.783484 | pid: 28379 started
2019-01-17 01:55:54.715425 | pid: 28376 found target
2019-01-17 01:55:54.715613 | terminating processes
2019-01-17 01:55:54.716326 | all processes joined
Process finished with exit code 0
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