Python多线程-2（线程共享全局变量）

 

 

例子：

from threading import Thread,Lock
from time import sleep, ctime 
 
global_num = []
 
def func1():
    global global_num
    for i in range(5):
        sleep(1)  #假设是最耗时的主过程
        lock.acquire()#两个线程会最开始抢这个锁，拿到锁就会处于关锁，执行后面的程序，其他线程执行处于监听状态，等待这个线程开锁，再抢锁
        global_num.append(1)
        print('-----%s---func1----:global_num=%s--------\n'%(ctime(),global_num))
        lock.release()
 
def func2():
    global global_num
    for i in range(3):
        sleep(1)
        lock.acquire()
        global_num.append(2)
        print('-----%s---func2-----:global_num=%s========\n'%(ctime(),global_num))
        lock.release()

print('global_num=',global_num)
 
lock = Lock()
 
t1 = Thread(target=func1)
t1.start()
 
t2 = Thread(target=func2)
t2.start()

t1.join()
t2.join()
print('global_num=%s\n'%global_num)