第三十七天

进程池、线程池提交任务的两种方式: 同步调用:提交完一个任务之后,就在原地等待,等待任务完完整整地运行完毕拿到结果后,再执行下一行代码,会导致任务是串行执行的异步调用:提交完一个任务之后,不在原地等待,结果???,而是直接执行下一行代码,会导致任务是并发执行的异步调用:提交完一个任务之后,不在原地等待,而是直接执行下一行代码,会导致任务是并发执行的,,结果futrue对象会在任务运行完毕后自动传给回调函数多线程实现套接字服务端支持并发客户端.py from socket import *

client=socket(AF_INET,SOCK_STREAM) client.connect(('127.0.0.1',8081))

while True: msg=input('>>: ').strip() if len(msg) == 0:continue client.send(msg.encode('utf-8')) data=client.recv(1024) print(data.decode('utf-8'))

服务端.py from socket import * from threading import Thread

def comunicate(conn): while True: # 通信循环 try: data = conn.recv(1024) if len(data) == 0: break conn.send(data.upper()) except ConnectionResetError: break conn.close()

def server(ip, port, backlog=5): server = socket(AF_INET, SOCK_STREAM) server.bind((ip, port)) server.listen(backlog)

while True: # 链接循环 conn, client_addr = server.accept() print(client_addr)

# 通信 t=Thread(target=comunicate,args=(conn,)) t.start()

if __name__ == '__main__': s=Thread(target=server,args=('127.0.0.1',8081)) s.start() 结果可以开启多个客户端，输入也有回复

from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor import time,random,os

def task(name,n): print('%s%s is running' %(name,os.getpid())) time.sleep(random.randint(1,3)) return n**2

if __name__ == '__main__': # print(os.cpu_count()) p=ProcessPoolExecutor(4) l=[] for i in range(5): # 同步提交 # res=p.submit(task,'进程pid: ',i).result() # print(res)

# 异步提交 future=p.submit(task,'进程pid: ',i) l.append(future)

p.shutdown(wait=True) #关闭进程池的入口,并且在原地等待进程池内所有任务运行完毕

for future in l: print(future.result()) print('主')

结果：进程pid: 5888 is running 进程pid: 2744 is running 进程pid: 3516 is running 进程pid: 6320 is running 进程pid: 6320 is running 1 4 9 16 25 主

同步提交：结果：进程pid: 5080 is running 0 进程pid: 3060 is running 1 进程pid: 6636 is running 4 进程pid: 3372 is running 9 进程pid: 5080 is running 16 进程pid: 3060 is running 25 进程pid: 6636 is running 36 进程pid: 3372 is running 49 进程pid: 5080 is running 64 进程pid: 3060 is running 81 主

单线程下实现并发的套接字客户端.py from threading import Thread,current_thread from socket import *

def client(): client=socket(AF_INET,SOCK_STREAM) client.connect(('127.0.0.1',8080))

n=0 while True: msg='%s say hello %s' %(current_thread().name,n) n+=1 client.send(msg.encode('utf-8')) data=client.recv(1024) print(data.decode('utf-8'))

if __name__ == '__main__': for i in range(500): t=Thread(target=client) t.start()

服务端.py from gevent import monkey;monkey.patch_all() from socket import * from gevent import spawn

def comunicate(conn): while True: # 通信循环 try: data = conn.recv(1024) if len(data) == 0: break conn.send(data.upper()) except ConnectionResetError: break conn.close()

def server(ip, port, backlog=5): server = socket(AF_INET, SOCK_STREAM) server.bind((ip, port)) server.listen(backlog)

while True: # 链接循环 conn, client_addr = server.accept() print(client_addr)

# 通信 spawn(comunicate,conn)

if __name__ == '__main__': g1=spawn(server,'127.0.0.1',8080) g1.join() 协程 1. 目标: 在线程下实现并发并发(多个任务看起来是同时执行就是并发):切换+保存状态

2. 协程: 协程是单线程实现并发注意:协程是程序员意淫出来的东西,操作系统里只有进程和线程的概念(操作系统调度的是线程)

在单线程下实现多个任务间遇到IO就切换就可以降低单线程的IO时间,从而最大限度地提升单线程的效率串行执行 import time

def func1(): for i in range(10000000): i+1

def func2(): for i in range(10000000): i+1

start = time.time() func1() func2() stop = time.time() print(stop - start) 结果： 4.8352766036987305

基于yield并发执行 import time def func1(): while True: print('func1') 10000000+1 yield

def func2(): g=func1() for i in range(10000000): print('func2') time.sleep(5) i+1 next(g)

start=time.time() func2() stop=time.time() print(stop-start) 结果： func2 func1 func2 func1 后面无限循环

from gevent import monkey;monkey.patch_all() from gevent import spawn,joinall #pip3 install gevent import time

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