这种Python生产者-消费者无锁方法是线程安全的吗?

方法。因此,如果我的物品有

不过,不用费心使用这个。你最终会在毫无意义的轮询周期中耗尽CPU,而且它并不比使用带锁的队列快,因为Python已经有了全局锁。

真的 QUEUE_ITEM 在消费者消费之前,消费者可以消费 队列项 两次。正如你提到的,你对此没问题,但大多数人都不这么认为。

QUEUE = []

# this is executed in one threading.Thread object
def producer():
    global QUEUE
    while True:
        i = produce_item()
        QUEUE.append(i)

# this is executed in another threading.Thread object
def consumer():
    global QUEUE
    while True:
        try:
            i = QUEUE.pop(0)
        except IndexError:
            # queue is empty
            continue

        consume_item(i)

在下面这样的类作用域中,您甚至可以清除队列。

class Atomic(object):
    def __init__(self):
        self.queue = []

    # this is executed in one threading.Thread object
    def producer(self):
        while True:
            i = produce_item()
            self.queue.append(i)

    # this is executed in another threading.Thread object
    def consumer(self):
        while True:
            try:
                i = self.queue.pop(0)
            except IndexError:
                # queue is empty
                continue

            consume_item(i)

    # There's the possibility producer is still working on it's current item.
    def clear_queue(self):
        self.queue = []

__del__ QUEUE_ITEM

increase the reference counter on the old object
assign a new one to `QUEUE_ITEM`
decrease the reference counter on the old object