Multiprocessing & Multithreading

2024-06-26 11:08| 来源: 网络整理| 查看: 265

本文主要介绍可以综合使用哪些方法来监测相应子进程/线程的状态，该方法在嵌套循环的场景下尤其重要。 Last Modified: 2022/1/22

Multiprocessing / Multithreading | 子进程/线程状态的监测 Multiprocessing & Multithreading示例子进程子线程参考链接源码&官方docQ&A

示例

此处给出2个示例，分别针对子进程和子线程的状态校验。

子进程 import multiprocessing import time, os def Subpro(n): for i in range(n): print(multiprocessing.current_process.__name__, 'is going to sleep', i, 's.') time.sleep(i) def _get_status(subprocess=None): ''' dict = { 'initlal': { subprocess._popen: None, subprocess.is_alive(): False, }, 'started': { subprocess._popen: is not None, subprocess.is_alive(): True, subprocess._popen.poll: is not None }, 'stopped': { subprocess._popen: is not None, subprocess.is_alive(): False, subprocess._popen.poll: 0 # if exit as expected }, 'closed': { subprocess._closed: True } } ''' if subprocess._closed: return 'closed' if subprocess._popen is None: if not subprocess.is_alive(): return 'initial' else: exitcode = subprocess._popen.poll() if exitcode is not None: exitcode = multiprocessing.process._exitcode_to_name.get(exitcode, exitcode) return 'stopped' else: if subprocess._parent_pid != os.getpid(): return 'unknown' else: return 'started' if __name__=='__main__': pro = multiprocessing.Process(target=Subpro, args=(3, ), name='ChildProcess') print('initial', _get_status(subprocess=pro)) pro.start() print('start', _get_status(subprocess=pro)) pro.join() print('join', _get_status(subprocess=pro)) pro.close() print('close', _get_status(subprocess=pro)) ######################################################### /Applications/Multiprocessing/Status.py initial initial start started current_process is going to sleep 0 s. current_process is going to sleep 1 s. current_process is going to sleep 2 s. join stopped close closed Process finished with exit code 0 子线程 import threading import time, os def Subthread(n): for i in range(n): print('is going to sleep', i, 's.') time.sleep(i) def _get_status(thread=None): ''' dict = { 'initlal': { thread.is_alive(): False, thread._ident: None,# type thread._started.is_set(): False, thread._is_stopped: False }, 'started': { thread.is_alive(): True, thread._ident: is not None, thread._started.is_set(): True, thread._is_stopped: False }, 'stopped': { thread.is_alive(): False, thread._ident: is not None, thread._started.is_set(): True, thread._is_stopped: True } } ''' if not thread.is_alive(): if thread._is_stopped: return 'stopped' else: return 'initial' else: if thread._started.is_set(): return 'started' if __name__=='__main__': subthread = threading.Thread(target=Subthread, args=(3, ), name='Childthread') print('initial', _get_status(thread=subthread)) subthread.start() print('start', _get_status(thread=subthread)) subthread.join() print('join', _get_status(thread=subthread)) ######################################################### /Applications/Multithreading/Status.py initial initial is going to sleep 0 s. start started is going to sleep 1 s. is going to sleep 2 s. join stopped Process finished with exit code 0 参考链接

写本文时有参考以下链接：

multi-processing-threading/Multiprocessing/Status.py multi-processing-threading/Multithreading/Status.py

源码&官方doc

cpython/Lib/multiprocessing/ multiprocessing — Process-based parallelism cpython/Lib/threading.py threading — Thread-based parallelism

Q&A

how to extract the status of a subprocess

【本文地址】

公司简介

联系我们