我想使用 multiprocessing.Pool ,但 multiprocessing.Pool 无法在超时后中止任务。我找到了 solution并进行一些修改。
from multiprocessing import util, Pool, TimeoutError
from multiprocessing.dummy import Pool as ThreadPool
import threading
import sys
from functools import partial
import time
def worker(y):
print("worker sleep {} sec, thread: {}".format(y, threading.current_thread()))
start = time.time()
while True:
if time.time() - start >= y:
break
time.sleep(0.5)
# show work progress
print(y)
return y
def collect_my_result(result):
print("Got result {}".format(result))
def abortable_worker(func, *args, **kwargs):
timeout = kwargs.get('timeout', None)
p = ThreadPool(1)
res = p.apply_async(func, args=args)
try:
# Wait timeout seconds for func to complete.
out = res.get(timeout)
except TimeoutError:
print("Aborting due to timeout {}".format(args[1]))
# kill worker itself when get TimeoutError
sys.exit(1)
else:
return out
def empty_func():
pass
if __name__ == "__main__":
TIMEOUT = 4
util.log_to_stderr(util.DEBUG)
pool = Pool(processes=4)
# k - time to job sleep
featureClass = [(k,) for k in range(20, 0, -1)] # list of arguments
for f in featureClass:
# check available worker
pool.apply(empty_func)
# run job with timeout
abortable_func = partial(abortable_worker, worker, timeout=TIMEOUT)
pool.apply_async(abortable_func, args=f, callback=collect_my_result)
time.sleep(TIMEOUT)
pool.terminate()
print("exit")
主要修改 - 使用 sys.exit(1) 退出工作进程。它是杀死工作进程和杀死工作线程,但我不确定这个解决方案是否好。当进程因运行作业而自行终止时,我会遇到哪些潜在问题?
请您参考如下方法:
停止正在运行的作业没有隐含的风险,操作系统将负责正确终止进程。
如果您的工作是在文件上写入,您最终可能会在磁盘上看到大量被截断的文件。
如果您在数据库上写入或连接到某个远程进程,也可能会出现一些小问题。
然而,Python 标准 Pool 不支持在任务超时时终止 worker。突然终止进程可能会导致您的应用程序出现奇怪的行为。
Pebble处理池确实支持超时任务。
from pebble import ProcessPool
from concurrent.futures import TimeoutError
TIMEOUT_SECONDS = 5
def function(one, two):
return one + two
with ProcessPool() as pool:
future = pool.schedule(function, args=(1, 2), timeout=TIMEOUT_SECONDS)
try:
result = future.result()
except TimeoutError:
print("Future: %s took more than 5 seconds to complete" % future)
