python_多線程加鎖

 

python3多線程可以不加鎖，每個多線程就自帶鎖

python2多線程必須加鎖，多線程本身不帶鎖

 

加鎖有兩種方式，一種如下圖： 

import time, threading
count=0 #聲明全局變量
lock=threading.Lock() #申請一把鎖
def lajifenlei():
    global count #引用全局變量
    lock.acquire()  #加鎖
    count+=1
    lock.release() #釋放鎖
    time.sleep(1)
    print(count)

for i in range(10):
    th = threading.Thread(target=lajifenlei,) #聲明線程數
    th.start() #啟動線程
while threading.activeCount()!=1:
    pass

C:\Users\zhaow\AppData\Local\Programs\Python\Python37\python.exe D:/study/python/atp/lib/t.py
10
1010
101010
10

10

1010

另一種類似打開和關閉文件的with方法，自動開關鎖

import time, threading
count=0 #聲明全局變量
lock=threading.Lock() #申請一把鎖
def lajifenlei():
    global count #引用全局變量

    with lock: #with模塊自動加鎖及解鎖
     count+=1

    time.sleep(1)
    print(count)

for i in range(10):
    th = threading.Thread(target=lajifenlei,) #聲明線程數
    th.start() #啟動線程
while threading.activeCount()!=1:
    pass