进程池线程池 协程

from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor   
from threading import current_thread
import time
import os
'''
池子中创建的进程/线程创建一次就不会再创建了,这样的话节省了反复开辟进程/线程的资源
'''
# pool = ProcessPoolExecutor(5)   # 默认是当前计算机cpu的个数
pool = ThreadPoolExecutor(5) # 括号内可以传参数指定线程池内的线程个数,不传默认是当前所在计算机的cpu个数乘5
def test(n):
    # print(n,os.getpid())  # 查看当前进程号
    print(n,current_thread().name)  # 查看当前线程号
    time.sleep(1)
    return n**2
def call_back(n):
    print('haha',n.result())
"""
提交任务的方式
    同步：提交任务之后 原地等待任务的返回结果 期间不做任何事
    异步：提交任务之后 不等待任务的返回结果,直接执行下一行代码
"""
# pool.submit(task,1)  # 朝线程池中提交任务   异步提交
# print('主')
# 异步回调机制:当异步提交的任务有返回结果之后，会自动触发回调函数的执行
if __name__ == '__main__':
    for i in range(20):
        pool.submit(test,i).add_done_callback(call_back) # 提交任务的时候 绑定一个回调函数 一旦该任务有结果 立刻执行对于的回调函数
    pool.shutdown()  #关闭池子 等待池子中所有的任务执行完毕之后 才会往下运行代码

协程
#串行执行    0.8540799617767334
mport time
def func1():
    for i in range(1000000):
        i + 1
def func2():
    for i in range(1000000):
        i + 1
start = time.time()
func1()
func2()
stop = time.time()
print(stop-start)

#基于yield并发执行
import time
def func1():
    while True:
        10000000+1
        yield
def func2():
    g=func1()
    for i in range(5):
        #time.sleep(1)  # 模拟IO，yield并不会捕捉到并自动切换
        i+1
        next(g)
start=time.time()
func2()
stop=time.time()
print(stop-start)

gevent模块是能够识别IO的一个工具

from gevent import monkey;monkey.patch_all()  # 能够识别IO
from gevent import spawn  # 切换cpu
import time
def ha():
    print('ha')
    time.sleep(1)
    print('ha')
def hei():
    print('hei')
    time.sleep(1)
    print('hei')
start = time.time()
g1 = spawn(ha)   #spawn 会检测所有任务
g2 = spawn(hei)
g1.join()
g2.join()
print(time.time()-start)

通过协程实现并发

客户端
import socket
from threading import Thread,current_thread
def test():
    client = socket.socket()
    client.connect(('127.0.0.1',8080))
    n = 0
    while True:
        data = '%s  %s'%(current_thread().name,n)
        client.send(data.encode('utf-8'))
        res = client.recv(1024)
        print(res.decode('utf-8'))
        n += 1
for i in range(400):
    t = Thread(target=test)
    t.start()

服务端
from gevent import monkey;monkey.patch_all()
import socket
from gevent import spawn
server = socket.socket()
server.bind(('127.0.0.1',8080))
server.listen(5)
def task(conn):
    while True:
        try:
            res = conn.recv(1024)
            if len(res) == 0: break
            print(res.decode('utf-8'))
            conn.send(res.upper())
        except ConnectionResetError as e:
            print(e)
            break
    conn.close()
def server1():
    while True:
            conn, addr = server.accept()
            spawn(task,conn)
if __name__ == '__main__':
    g = spawn(server1)
    g.join()