python - 如何在 Python 中暂停多处理进程？

Question

我希望用户能够在启动后的任何给定时间暂停多处理的执行。如何实现？

我的代码是:

# -*- coding: utf-8 -*-
from PySide import QtCore, QtGui
from Ui_MainWindow import Ui_MainWindow
from queue import Queue
import sys
import multiprocessing, os, time

def do_work():
    print ('Work Started: %d' % os.getpid())
    time.sleep(1)
    return 'Success'

def manual_function(job_queue, result_queue):
    while not job_queue.empty():
        try:
            job = job_queue.get(block=False)
            result_queue.put(do_work())
        except Queue.Empty:
            pass

class Worker(QtCore.QThread):
    def __init__(self,name):
        QtCore.QThread.__init__(self)
        self.name = name
        self.pause = False

    def run(self):
        job_queue = multiprocessing.Queue()
        result_queue = multiprocessing.Queue()

        for i in range(1000):
            job_queue.put(None)

        self.workers = []
        for i in range(6):
            tmp = multiprocessing.Process(target=manual_function, args=(job_queue, result_queue))
            tmp.start()
            self.workers.append(tmp)

    def paused(self):
        '''
        pause / resumme ?????????????????????????
        '''

    def stop(self):
       for worker in self.workers:
           print ("end")
           worker.terminate()
           worker.join()


class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.connect(self.ui.actionStart, QtCore.SIGNAL('triggered()'),self.start)
        self.connect(self.ui.actionStop, QtCore.SIGNAL('triggered()'),self.stop)
        self.connect(self.ui.actionPause, QtCore.SIGNAL('triggered()'),self.pause)

    def pause(self):
        self.work.paused()

    def stop(self):
        self.work.stop()

    def start(self):
        self.threads = []
        for tName in range(1):
            self.work = Worker("Thread-%s"%tName)
            self.threads.append(self.work)
            self.work.start()

if __name__ == "__main__":
    app = QtGui.QApplication (sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

如何在 Python 中暂停按钮单击多处理进程？

Answer 1

使用一个简单的标志作为共享内存，以确定生成的进程是否运行。看一个小例子。

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from multiprocessing import Process, Value
from time import sleep

def do_work():
    print("Working...")
    sleep(1)

def worker(run):
    while True:
        if run.value:
            do_work()

if __name__ == "__main__":
    run = Value("i", 1)
    p = Process(target=worker, args=(run,))
    p.start()
    while True:
        raw_input()
        run.value = not run.value

我分享了一个 Value 的实例进程之间。按 Enter 暂停或恢复生成的进程。

这适用于 Python 2，您应该指出您正在运行哪个版本。

希望能帮助到你。