How to lock queue for one thread?

Question

I have a queue that has several producer and consumer threads adding and removing items. Every once in a while, another thread needs to lock the queue, remove and process every item in the queue, and then release the queue back to the rest of the threads. How can I keep blocking other threads between successive calls of queue.get().

Answer 1

Thanks to martineau, who has a couple of good approaches to the solution in the comments. Here is an example class that locks the queue while processing all items in the queue:

import queue
from threading import Thread


class PriorityConsumer(Thread):

    def __init__(self, q):
        super(PriorityConsumer, self).__init__()
        self.q = q
    
    def process(self, x):
        pass

    def run(self):
        with self.q.mutex:
            while self.q.queue:
                x = self.q.queue.popleft()
                self.process(x)


q = queue.Queue()
p_consumer = PriorityConsumer(q)
p_consumer.start()