互斥锁

互斥锁保证每个进程内的“任务”都会执行完，再执行其他进程，保证了数据的一致性，但降低了效率

from multiprocessing import Process,Lock
import time
def task(name,mutex):
    mutex.acquire()
    print('%s start'%name)
    time.sleep(1)
    print('%s end'%name)
    mutex.release()
if __name__ == '__main__':
    mutex = Lock()
    p1 = Process(target=task,args=(1,mutex))
    p2 = Process(target=task,args=(2,mutex))
    p3 = Process(target=task,args=(3,mutex))
    p1.start()
    p2.start()
    p3.start()
    p1.join()
    p2.join()
    p3.join()
    print('main')

#1 start
#1 end
#2 start
#2 end
#3 start
#3 end
#main