Python多进程

 1 from multiprocessing import Process
 2 import os
 3 import time
 4 
 5 def task_process(delay):
 6     num = 0
 7     for i in range(delay*100000000):
 8         num += 1
 9     print(f"进程pid为{os.getpid()},执行完成")
10 
11 if __name__ == '__main__':
12     print(f"父进程pid为:{os.getpid()}")
13     t0 = time.time()
14     task_process(3)
15     task_process(3)
16     t1 = time.time()
17     print(f"顺序执行耗时{t1-t0}")
18     p0 = Process(target=task_process,args=(3,))
19     p1 = Process(target=task_process, args=(3,))
20     t2 = time.time()
21     p0.start();p1.start()
22     p0.join();p1.join()
23     t3 = time.time()
24     print(f"多进程并发执行耗时{t3-t2}")

 1 from multiprocessing import Process
 2 import os
 3 import time
 4 
 5 class MyProcess(Process):
 6     def __init__(self,delay):
 7         self.delay = delay
 8         super().__init__()
 9     def run(self):
10         num = 0
11         for i in range(self.delay * 100000000):
12             num += 1
13         print(f"进程pid为{os.getpid()},执行皮完成")
14 
15 if __name__ == '__main__':
16     print(f"父进程pid为:{os.getpid()}")
17     p0 = MyProcess(3)
18     p1 = MyProcess(3)
19     t0 = time.time()
20     p0.start();p1.start()
21     p0.join();p1.join()
22     t1 = time.time()
23     print(f"多进程并发执行耗时{t1-t0}")

 1 import multiprocessing,time
 2 def worker(s,i):
 3     s.acquire()
 4     print(time.strftime('%H:%M:%S'),multiprocessing.current_process().name+" 获得运行锁")
 5     time.sleep(i)
 6     print(time.strftime('%H:%M:%S'), multiprocessing.current_process().name + " 释放运行锁")
 7     s.release()
 8 
 9 if __name__ == "__main__":
10     s = multiprocessing.Semaphore(2) #同一时刻只有两个进程在执行操作
11     for i in range(6):
12         p = multiprocessing.Process(target=worker,args=(s,2))
13         p.start()

 1 import multiprocessing,time
 2 def task1():
 3     n = 5
 4     while n > 1:
 5         print(f"{time.strftime('%H:%M:%S')} task1 输出信息")
 6         time.sleep(1)
 7         n -= 1
 8 
 9 def task2():
10     n = 5
11     while n > 1:
12         print(f"{time.strftime('%H:%M:%S')} task2 输出信息")
13         time.sleep(1)
14         n -= 1
15 
16 def task3():
17     n = 5
18     while n > 1:
19         print(f"{time.strftime('%H:%M:%S')} task3 输出信息")
20         time.sleep(1)
21         n -= 1
22 
23 if __name__ == "__main__":
24     p1 = multiprocessing.Process(target=task1)
25     p2 = multiprocessing.Process(target=task2)
26     p3 = multiprocessing.Process(target=task3)
27     p1.start()
28     p2.start()
29     p3.start()

 1 import multiprocessing,time
 2 def task1(lock):
 3     with lock: #和下文的lock.acquire()同样
 4         n = 5
 5         while n > 1:
 6             print(f"{time.strftime('%H:%M:%S')} task1 输出信息")
 7             time.sleep(1)
 8             n -= 1
 9 
10 def task2(lock):
11     lock.acquire()
12     n = 5
13     while n > 1:
14         print(f"{time.strftime('%H:%M:%S')} task2 输出信息")
15         time.sleep(1)
16         n -= 1
17     lock.release()
18 
19 def task3(lock):
20     lock.acquire()
21     n = 5
22     while n > 1:
23         print(f"{time.strftime('%H:%M:%S')} task3 输出信息")
24         time.sleep(1)
25         n -= 1
26     lock.release()
27 if __name__ == "__main__":
28     lock = multiprocessing.Lock()
29     p1 = multiprocessing.Process(target=task1,args=(lock,))
30     p2 = multiprocessing.Process(target=task2,args=(lock,))
31     p3 = multiprocessing.Process(target=task3,args=(lock,))
32     p1.start()
33     p2.start()
34     p3.start()

 1 import multiprocessing,time
 2 
 3 def wait_for_event(e):
 4     e.wait()
 5     time.sleep(1)
 6     #唤醒后清除Event状态，为后续继续等待
 7     e.clear()
 8     print(f"{time.strftime('%H:%M:%S')} 进程 A：我们是兄弟，我等你...")
 9     e.wait()
10     print(f"{time.strftime('%H:%M:%S')} 进程 A：好的，是兄弟一起走")
11 def wait_for_event_timeout(e,t):
12     e.wait()
13     time.sleep(1)
14     # 唤醒后清除Event状态，为后续继续等待
15     e.clear()
16     print(f"{time.strftime('%H:%M:%S')} 进程 B：好吧，我最多等你{t}秒")
17     e.wait(t)
18     print(f"{time.strftime('%H:%M:%S')} 进程 B：{t}秒时间到，我继续往前走了")
19 if __name__ == "__main__":
20     e = multiprocessing.Event()
21     w1 = multiprocessing.Process(target=wait_for_event,args=(e,))
22     w2 = multiprocessing.Process(target=wait_for_event_timeout, args=(e,5))
23     w1.start()
24     w2.start()
25     #主进程发话：
26     print(f"{time.strftime('%H:%M:%S')} 主进程：谁等我下，我需要8s时间")
27     #唤醒进程：
28     e.set()
29     time.sleep(8)
30     print(f"{time.strftime('%H:%M:%S')} 主进程：好了，我赶上了")
31     #再次唤醒等待的进程：
32     e.set()
33     w1.join()
34     w2.join()
35     print(f"{time.strftime('%H:%M:%S')} 主进程：退出")