我正在構建一個運行另一個

Python程序的監(jiān)視程序計時器,如果它無法從任何線程中找到簽入,則關閉整個程序.這樣,它最終將能夠控制所需的通信端口.計時器的代碼如下：

from multiprocessing import Process, Queue

from time import sleep

from copy import deepcopy

PATH_TO_FILE = r'.\test_program.py'

WATCHDOG_TIMEOUT = 2

class Watchdog:

def __init__(self, filepath, timeout):

self.filepath = filepath

self.timeout = timeout

self.threadIdQ = Queue()

self.knownThreads = {}

def start(self):

threadIdQ = self.threadIdQ

process = Process(target = self._executeFile)

process.start()

try:

while True:

unaccountedThreads = deepcopy(self.knownThreads)

# Empty queue since last wake. Add new thread IDs to knownThreads, and account for all known thread IDs

# in queue

while not threadIdQ.empty():

threadId = threadIdQ.get()

if threadId in self.knownThreads:

unaccountedThreads.pop(threadId, None)

else:

print('New threadId < {} > discovered'.format(threadId))

self.knownThreads[threadId] = False

# If there is a known thread that is unaccounted for, then it has either hung or crashed.

# Shut everything down.

if len(unaccountedThreads) > 0:

print('The following threads are unaccounted for:\n')

for threadId in unaccountedThreads:

print(threadId)

print('\nShutting down!!!')

break

else:

print('No unaccounted threads...')

sleep(self.timeout)

# Account for any exceptions thrown in the watchdog timer itself

except:

process.terminate()

raise

process.terminate()

def _executeFile(self):

with open(self.filepath, 'r') as f:

exec(f.read(), {'wdQueue' : self.threadIdQ})

if __name__ == '__main__':

wd = Watchdog(PATH_TO_FILE, WATCHDOG_TIMEOUT)

wd.start()

我還有一個小程序來測試看門狗功能

from time import sleep

from threading import Thread

from queue import SimpleQueue

Q_TO_Q_DELAY = 0.013

class QToQ:

def __init__(self, processQueue, threadQueue):

self.processQueue = processQueue

self.threadQueue = threadQueue

Thread(name='queueToQueue', target=self._run).start()

def _run(self):

pQ = self.processQueue

tQ = self.threadQueue

while True:

while not tQ.empty():

sleep(Q_TO_Q_DELAY)

pQ.put(tQ.get())

def fastThread(q):

while True:

print('Fast thread, checking in!')

q.put('fastID')

sleep(0.5)

def slowThread(q):

while True:

print('Slow thread, checking in...')

q.put('slowID')

sleep(1.5)

def hangThread(q):

print('Hanging thread, checked in')

q.put('hangID')

while True:

pass

print('Hello! I am a program that spawns threads!\n\n')

threadQ = SimpleQueue()

Thread(name='fastThread', target=fastThread, args=(threadQ,)).start()

Thread(name='slowThread', target=slowThread, args=(threadQ,)).start()

Thread(name='hangThread', target=hangThread, args=(threadQ,)).start()

QToQ(wdQueue, threadQ)

正如您所看到的,我需要將線程放入queue.Queue,而單獨的對象會慢慢將queue.Queue的輸出提供給多處理隊列.相反,如果我將線程直接放入多處理隊列中,或者在put之間沒有QToQ對象休眠,則多處理隊列將鎖定,并且在看門狗端看起來總是為空.

現(xiàn)在,由于多處理隊列應該是線程和進程安全的,我只能假設我在實現(xiàn)中搞砸了一些東西.我的解決方案似乎有效,但也覺得hacky足夠我覺得我應該解決它.

我正在使用Python 3.7.2,如果重要的話.

總結

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