Python-线程技巧

def test(x,y):
    t= threading.currentThread()
    # 这里的参数相当于是线程的一个属性
    while getattr(t, "flag", True):
        print(x)
        time.sleep(1)

if __name__ == "__main__":        
    x = 1
    y = 2
    # args的值最好后面添加一个逗号
    t = threading.Thread(target=test, args=(x,y,))
    t.start()
    
    time.sleep(5)
    
    t.flag = Flase

1、可以使用线程锁完成不同线程间公共资源的互斥访问，如下程序所示。这里的t就是锁，相当于是一个mutex资源，不同线程之间进行PV操作。

2、也可以使用t.join()来让不同线程之间线性执行，不过这种方式就和只有一个进程的效果一样，不好使。可以看下面join()的说明

import threading
import time

def doit(a, data):
    global t
    t.acquire()
    while True:
        a[0] = data
        print(a)
        # t.release()


if __name__ == "__main__":
    tmp = [0]
    t = threading.Lock()
    t1 = threading.Thread(target=doit, args=(tmp, 1,))
    t1.start()

    t2 = threading.Thread(target=doit, args=(tmp, 2,))
    t2.start()

    while True:
        pass

1、join()用来阻塞进程，只有在两个线程都执行完以后才执行主进程

import threading
import time

def doit(a, data):
    a[0] = data
    print(a)
    time.sleep(2)

if __name__ == "__main__":
    tmp = [0]
    # t = threading.Lock()
    t = []
    t1 = threading.Thread(target=doit, args=(tmp, 1,))
    t.append(t1)

    t2 = threading.Thread(target=doit, args=(tmp, 2,))
    t.append(t2)

    for each in t:
        each.start()
    for each in t:
        each.join()

    print(4)
    while True:
        pass

2、用来阻塞其他线程

import threading
import time

def doit(a, data):
    a[0] = data
    print(a)
    time.sleep(2)

if __name__ == "__main__":
    tmp = [0]
    # t = threading.Lock()
    t = []
    t1 = threading.Thread(target=doit, args=(tmp, 1,))
    t.append(t1)

    t2 = threading.Thread(target=doit, args=(tmp, 2,))
    t.append(t2)

    for each in t:
        each.start()
        each.join()
        
    print(4)
    while True:
        pass