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在线程类python中控制循环

multithreading python

Masoud Rahimi Chris · 技术社区 · 9 年前

我想在python3中创建一个线程类。我想在一个类函数中控制一个无限循环。我想在类外的主函数中启动或停止这个循环。假设此代码:

import threading
from time import sleep
class my_thread(threading.Thread):
    """Thread class with a stop() method. The thread itself has to check
    regularly for the stopped() condition."""

    def __init__(self):
        super(my_thread, self).__init__()
        self._stop_event = threading.Event()

    def stop(self):
        print("stopping the thread")
        self._stop_event.set()

    def stopped(self):
        return(self._stop_event.is_set())

    def run(self):
        print("running the thread")
        print("start function startt()")
        self._stop_event.clear()
        self.startt()

    def startt(self):
        print("it is going to wait forever")
        while not self.stopped():
            #wait forever, this part is going to run again and again
            pass
        print("This line never executes")


if __name__+'__main__':
    thr=my_thread()
    thr.start()
    sleep(5)
    print("stopping the thread")
    thr.stop()
    # I cant start the thread and relative while loop again
    #thr.start()   
    print("Exiting the whole program")

stop() 和 startt() 在我的主要例行程序中需要时,可以多次执行功能。谢谢

1 回复 | 直到 9 年前

Kallz 9 年前

首先,在my_thread类中使用Queue来管理由线程完成或调用的任务(方法)

detail

其次,添加一个类方法,以便可以将新方法或任务添加到队列中

from queue import Queue
# or
# from multiprocessing import Queue
class my_thread(threading.Thread):
    queue = Queue()

    @classmethod
    def add_task(cls,callable_task):
        cls.queue.put(callable_task)

    def startt(self):
        print("it is going to wait forever")
        while not self.stopped():
            #wait forever, this part is going to run again and again
            if not  self.queue.empty():
                  _m = self.queue.get()
                 # do what ever you want to do with _m

        print("This line never executes")

 Class my_thread(Threading.Thread)
     stop_event = threading.Event()

     @classmethod
     def stop_thread(cls)
         cls.stop_event.set()

     def startt(self):
         print("it is going to wait forever")
         cls = self.__class__
         while not cls.stop_event.is_set():
             #wait forever, this part is going to run again and again
             if not  self.queue.empty():
                 _m = self.queue.get()
                 # do what ever you want to do with _m

         print("This line never executes")

现在呼吁停止therad

  my_thread.stop_thread()

import threading
import time
class my_thread(threading.Thread):
    stop_event = threading.Event()

    @classmethod
    def stop_thread(cls):
        cls.stop_event.set()

    def run(self):
        print("running the thread")
        print("start function startt()")
        self.__class__.stop_event.clear()
        self.startt()

    def startt(self):
        print("it is going to wait forever")
        cls = self.__class__
        print cls.stop_event.is_set()
        while not cls.stop_event.is_set():
            pass

        print("This line never executes")

a = my_thread()
a.start()
time.sleep(0.5)
my_thread.stop_thread()
print "\n\n\n"
b = my_thread()
b.start()
time.sleep(0.5)
my_thread.stop_thread()