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Python's Queue module provides synchronous, thread-safe queue classes, including FIFO (first in first out) queue Queue, LIFO (last in first out) queue LifoQueue, and priority queue PriorityQueue . These queues implement lock primitives and can be used directly in multi-threads. Queues can be used to achieve synchronization between threads.
Commonly used methods in the Queue module:
1.Queue.qsize() returns the size of the queue
2.Queue.empty() If the queue is empty, returns True , Otherwise False
3.Queue.full() If the queue is full, return True, otherwise False
4.Queue.full corresponds to the maxsize size
5.Queue .get([block[, timeout]]) gets the queue, timeout waiting time
6.Queue.get_nowait() is equivalent to Queue.get(False)
7.Queue.put(item ) Write to the queue, timeout waiting time
8.Queue.put_nowait(item) is equivalent to Queue.put(item, False)
9.Queue.task_done() after completing a job , the Queue.task_done() function sends a signal to the queue where the task has been completed
10.Queue.join() actually means waiting until the queue is empty before performing other operations
#!/usr/bin/python # -*- coding: UTF-8 -*- import Queue import threading import time exitFlag = 0 class myThread (threading.Thread): def __init__(self, threadID, name, q): threading.Thread.__init__(self) self.threadID = threadID self.name = name self.q = q def run(self): print "Starting " + self.name process_data(self.name, self.q) print "Exiting " + self.name def process_data(threadName, q): while not exitFlag: queueLock.acquire() if not workQueue.empty(): data = q.get() queueLock.release() print "%s processing %s" % (threadName, data) else:queueLock.release() time.sleep(1) threadList = ["Thread-1", "Thread-2", "Thread-3"] nameList = ["One", "Two", "Three", "Four", "Five"] queueLock = threading.Lock() workQueue = Queue.Queue(10) threads = [] threadID = 1 # 创建新线程 for tName in threadList: thread = myThread(threadID, tName, workQueue) thread.start() threads.append(thread) threadID += 1 # 填充队列 queueLock.acquire() for word in nameList: workQueue.put(word) queueLock.release() # 等待队列清空 while not workQueue.empty(): pass # 通知线程是时候退出 exitFlag = 1 # 等待所有线程完成 for t in threads: t.join() print "Exiting Main Thread"
The execution result of the above program:
Starting Thread-1 Starting Thread-2 Starting Thread-3 Thread-1 processing One Thread-2 processing Two Thread-3 processing Three Thread-1 processing Four Thread-2 processing Five Exiting Thread-3 Exiting Thread-1 Exiting Thread-2 Exiting Main Thread
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