Python-threading多线程进阶

# 线程锁套线程锁，即为递归锁

import threading
def run1():
    print("grab the first part data")
    lock.acquire()
    global num
    num += 1
    lock.release()
    return num

def run2():
    print("grab the second part data")
    lock.acquire()
    global num2
    num2 += 1
    lock.release()
    return num2

def run3():
    lock.acquire()
    res= run1()
    print("----between run1 and run2----")
    res2 = run2()
    lock.release()
    print(res, res2)

num, num2 = 0, 0
# 递归锁,使用RLock(), 使用Lock()会进入无限死循环
lock = threading.RLock()
for i in range(1):
    t = threading.Thread(target=run3)
    t.start()
while threading.active_count() != 1:
    print("当前活跃的线程数:", threading.active_count())
else:
    print("--all  threads done---")
    print("打印num和num2:", num, num2)

信号量：控制线程一次运行的个数

import threading
semaphore = threading.BoundedSemaphore(5)

def run(n):
    semaphore.acquire()
    time.sleep(1)
    print("run the thread:%s\n" % n)
    semaphore.release()

if __name__ == '__main__':
    for i in range(22):
        t = threading.Thread(target=run, args=(i,))
        t.start()

Event事件

import threading
event = threading.Event()

# event.set()  设置标识   event.clear() 清除标志位  event.is_set() 判断是否存在标志位  event.wait() 等待的时长
def lighter():
    count = 0
    event.set()  # 刚开始的标识位先设置绿灯
    while True:
        if 5 < count < 10:  # 改成红灯
            event.clear()  # 把标志位清了
            print("\033[41;1mred light is on....\033[0m")
        elif count > 10:
            event.set()  # 变绿灯
            count = 0
        else:
            print("\033[42;1mgreen light is on....\033[0m")
        time.sleep(1)
        count += 1

def car(name):
    while True:
        if event.is_set():  # 代表绿灯
            print("[%s] running..." % name)
            time.sleep(1)
        else:
            print("[%s] sees red light , waiting...." % name)
            event.wait()
            print("\033[34;1m[%s] green light is on, start going...\033[0m" % name)

light = threading.Thread(target=lighter, )
light.start()
car1 = threading.Thread(target=car, args=("Tesla",))
car1.start()