Python 条件变量同步(Condition):
有一类线程需要满足条件之后才能继续执行,Python提供了threading..Condition。对象用于条件变量线程的支持。它除了能提供RLock()或 Lock()的方法外,还提苍了wait(),notify(),notifyAll()方法
lock_con = threading.Condition([Lock/Rlock]),锁是可选选项,不传入锁,对象自动创建一个RLock()
- wait() : 条件不满足时调用,线程会释放锁并进入等待阻塞。
- notify(): 条件创造后调用,通知 等待池激活一个线程。
- notifyA(): 条件创造后调用,通知等待池激活所有线程。
import threading,time from random import randint class Producer(threading.Thread): def run(self): global L while True: val = randint(0,100) print('生产者',self.name,':Append' + str(val),L) if lock_con.acquire(): L.append(val) lock_con.notify() lock_con.release() time.sleep(3) class Consumer(threading.Thread): def run(self): global L while True: lock_con.acquire() if len(L) == 0: lock_con.wait() print('消费者',self.name,":Delete" + str(L(0)),L) del L[0] lock_con.release() time.sleep(0.001) if __name__ == "__main__": L = [] lock_con = threading.Condition() threads = [] for i in range(5): threads.append(Producer()) for t in threads: t.start() for t in threads: t.join() print('========================')