Process
1 import socket
2 import time
3 from multiprocessing import Process
4
5 def talk(conn):
6 if type(conn)==socket.socket():
7 conn.send(b‘connected‘)
8 msg = conn.recv(1024)
9 print(msg)
10 conn.close()
11
12
13 if __name__ == ‘__main__‘:
14 sk = socket.socket()
15 sk.bind((‘127.0.0.1‘,8080))
16 sk.listen()
17 while True:
18 conn,addr = sk.accept()
19 print(addr,time.ctime())
20 p = Process(target=talk,args=(conn,))
21 p.start()
22
23 sk.close()
Lock
1 # from multiprocessing import Lock
2 # lock = Lock()
3 # lock.acquire() # 需要锁，拿钥匙
4 # lock.acquire() # 需要锁，阻塞
5 # lock.release() # 释放锁，还钥匙
6
7 # 锁 就是在并发编程中，保证数据安全
8
9 # 多进程 实现并发
10
11 import json
12 import time
13 import random
14 from multiprocessing import Lock
15 from multiprocessing import Process
16
17 # with open(‘ticket‘,‘w‘) as f:
18 # json.dump({‘count‘:20},f)
19
20
21 def search(i):
22 with open(‘ticket‘) as f:
23 print(i,json.load(f)[‘count‘])
24 def get(i):
25 with open(‘ticket‘) as f:
26 ticket_num = json.load(f)[‘count‘]
27 time.sleep(random.random())
28 if ticket_num>0:
29 with open(‘ticket‘,‘w‘) as f:
30 json.dump({‘count‘:ticket_num-1},f)
31 print(‘%s买到票了‘%i)
32 else:
33 print(‘%s没票了‘%i)
34 def task(i,lock):
35 search(i)
36 lock.acquire()
37 get(i)
38 lock.release()
39 if __name__ == ‘__main__‘:
40 pass
41
42 lock = Lock()
43 for i in range(20):
44 p = Process(target=task,args=(i,lock))
45 p.start()
View CodeSemaphore
1 # from multiprocessing import Semaphore
2 # sem = Semaphore(4)
3 # sem.acquire()
4 # print(0)
5 # sem.acquire()
6 # print(1)
7 # sem.acquire()
8 # print(2)
9 # sem.acquire()
10 # print(3)
11 # sem.release()
12 # sem.acquire()
13 # print(4)
14
15 import time
16 import random
17 from multiprocessing import Semaphore
18 from multiprocessing import Process
19
20 def sing(i,sem):
21 sem.acquire()
22 print(‘%s : 进入ktv‘%i)
23 time.sleep(random.randint(1,3))
24 print(‘%s ：出ktv‘%i)
25 sem.release()
26
27 if __name__ == ‘__main__‘:
28 sem = Semaphore(4)
29 for i in range(20):
30 Process(target=sing,args=(i,sem)).start()
View Code
守护进程
1 # start 开启一个进程
2 # join 用join可以让主进程等待子进程结束
3
4 # 守护进程
5 # 守护进程会随着主进程的代码执行结束而结束
6 # 正常的子进程没有执行完的时候主进程要一直等着
7
8 # import time
9 # from multiprocessing import Process
10 # def func():
11 # print(‘--‘*10)
12 # time.sleep(15)
13 # print(‘--‘*10)
14 #
15 # def cal_time():
16 # while True:
17 # time.sleep(1)
18 # print(‘过去了1秒‘)
19 #
20 # if __name__ == ‘__main__‘:
21 # p = Process(target=cal_time)
22 # p.daemon = True
23 # p.start()
24 # p2 = Process(target=func)
25 # p2.start()
26 # for i in range(100):
27 # time.sleep(0.1)
28 # print(‘*‘*i)
29 # p2.join()
30 # 守护进程的作用：
31 # 会随着主进程的代码执行结束而结束，不会等待其他子进程
32 # 守护进程 要再start之前设置
33 # 守护进程中，不能再开启子进程
34
35
36 # is_alive # 进程是否还活着，True代表进程还在， False代表进程不在了
37 # terminate #结束一个进程，但是这个进程不会立刻被杀死
38
39 # import time
40 # from multiprocessing import Process
41 # def func():
42 # print(‘wahaha‘)
43 # time.sleep(5)
44 # print(‘qqxing‘)
45 # if __name__ == ‘__main__‘:
46 # p = Process(target=func)
47 # p.start()
48 # print(p.is_alive())
49 # time.sleep(0.1)
50 # p.terminate()
51 # print(p.is_alive())
52 # time.sleep(1)
53 # print(p.is_alive())
54
55 # 进程的其他属性
56 # pid 查看这个进程的进程id
57 # name 查看进程的名字,可以修改
58 # import time
59 # from multiprocessing import Process
60 # def func():
61 # print(‘wahaha‘)
62 # time.sleep(5)
63 # print(‘qqxing‘)
64 # if __name__ == ‘__main__‘:
65 # p = Process(target=func)
66 # p.start()
67 # print(p.name,p.pid)
68 # p.name = ‘WAHAHAHA‘
69 # print(p.name)
View Code
Event
1 import time
2 import random
3 from multiprocessing import Process
4 from multiprocessing import Event
5
6 # e = Event() # 实例化一个事件 标志/交通信号灯
7 # e.set() # 将标志变成非阻塞/交通灯变绿
8 # e.wait() # 刚实例化出来的一个事件对象，默认的信号是阻塞信号/默认是红灯
9 # # 执行到wait，要先看灯，绿灯行红灯停，如果在停的过程中灯绿了，
10 # # 就变成非阻塞了
11 # e.clear() # 将标志又变成阻塞/交通灯变红
12 #
13 # e.is_set() # 是否阻塞 True就是绿灯 False就是红灯
14
15 def traffic_light(e):
16 while True:
17 if e.is_set(): # 是否阻塞，True就是绿灯，False就是红灯
18 e.clear()
19 print(‘红灯亮‘)
20 time.sleep(3)
21 else:
22 e.set()
23 print(‘绿灯亮‘)
24 time.sleep(3)
25
26 def car(name,e):
27 e.wait()
28 print(‘%s 通过‘%name)
29
30 if __name__ == ‘__main__‘:
31 e = Event()
32 Process(target=traffic_light,args=(e,)).start()
33 for i in range(50):
34 if i%random.randint(1,5)==0:
35 time.sleep(random.randint(1,3))
36 p = Process(target=car,args=(i,e))
37 p.start()
View Code
