python线程同步

#!/usr/bin/python
 
import threading
import time
 
class myThread (threading.Thread):
    def __init__(self,threadID,name,counter):
        threading.Thread.__init__(self)
        self.threadID = threadID
        self.name = name
        self.counter = counter
    def run(self):
        print "Starting " + self.name
        # Get lock to synchronize threads
        threadLock.acquire()
        print_time(self.name,self.counter,3)
        # Free lock to release next thread
        threadLock.release()
 
def print_time(threadName,delay,counter):
    while counter:
        time.sleep(delay)
        print "%s: %s" % (threadName,time.ctime(time.time()))
        counter -= 1
 
threadLock = threading.Lock()
threads = []
 
# Create new threads
thread1 = myThread(1,"Thread-1",1)
thread2 = myThread(2,"Thread-2",2)
 
# Start new Threads
thread1.start()
thread2.start()
 
# Add threads to thread list
threads.append(thread1)
threads.append(thread2)
 
# Wait for all threads to complete
for t in threads:
    t.join()
print "Exiting Main Thread"
 

Starting Thread-1
Starting Thread-2
Thread-1: Thu Mar 21 09:11:28 2013
Thread-1: Thu Mar 21 09:11:29 2013
Thread-1: Thu Mar 21 09:11:30 2013
Thread-2: Thu Mar 21 09:11:32 2013
Thread-2: Thu Mar 21 09:11:34 2013
Thread-2: Thu Mar 21 09:11:36 2013
Exiting Main Thread