python - 如何同步python线程？

Question

我想同步两个线程:一个追加，另一个从列表中弹出:

import threading


class Pop(threading.Thread):
    def __init__(self, name, alist):
        threading.Thread.__init__(self)
        self.alist = alist
        self.name = name

    def run(self):
        print "Starting " + self.name
        self.pop_from_alist(self.alist)
        print "Exiting " + self.name

    def pop_from_alist(self, alist):
        alist.pop(0)


def main():
    alist = [1, 2]
    # Create new thread
    thread = Pop("Pop thread", alist)
    for x in range(2):
        alist.append(alist[-1]+1)
    thread.start()
    print "Exiting Main Thread"
    print alist
main()

我该怎么做，我应该使用 Lock 还是使用 join 方法？找不到任何适合初学者的同步教程

Answer 1

两个线程需要共享同一个锁。这样他们就可以知道另一个线程何时锁定了它。您需要在主线程中定义锁并在初始化时将其传递给您的线程:

# Create a lock
lock = threading.Lock()

# Create new threads
thread1 = Append("Append thread", alist, lock)
thread2 = Pop("Pop thread", alist, lock)

# Start new Threads
thread1.start()
thread2.start()

在线程中，您可以像以前那样处理它，但跳过锁创建:

class Append(threading.Thread):
    def __init__(self, name, alist, lock):
        threading.Thread.__init__(self)
        self.alist = alist
        self.name = name
        self.lock = lock

def append_to_list(self, alist, counter):
    while counter:
        with self.lock:
            alist.append(alist[-1]+1)
            counter -= 1