标签:result 完全 切换 耗资源 客户端 [] tpi monkey imp
socket服务端实现并发
# 服务端 import socket from threading import Thread service = socket.socket() service.bind((‘127.0.0.1‘,8080)) service.listen(5) # 半连接池 def communicate(conn): while True: try: data = conn.recv(1024) #阻塞 if len(data) == 0:break print(data) conn.send(data.upper()) except ConnectionResetError: break conn.close() while True: conn,addr = service.accept() print(addr) print(conn) t = Thread(target=communicate,args=(conn,)) t.start() #客户端 import socket client = socket.socket() client.connect((‘127.0.0.1‘,8080)) while True: info = input(‘>>>:‘).encode(‘utf-8‘) if len(info) == 0:continue client.send(info) data = client.recv(1024) print(data)
# 注意在socker中listen中班连接池限制就失去作用了。可以使用线程池对连接数进行限制
无论是开线程还是进程都消耗资源,开线程消耗的资源比开进程小,
池:
为了减缓计算机硬件压力,避免计算机硬件设备崩溃
虽然减轻了计算机硬件的压力,但是一定程度上减低了持续的效率
进程池线程:
为了限制开设的进程和线程数,从而保证计算机硬件的安全。
如何使用:
使用进程池限制进程数
异步提交:
异步调用:提交完一个任务之后,不在原地等待,结果,而是直接执行下一个行代码,会导致任务是并发执行的
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor import time import os def task(name): print(‘%s %s is running‘% (name,os.getpid())) time.sleep(1) if __name__ == ‘__main__‘: p = ProcessPoolExecutor(4) #默认情况下不指定使用时cpu的核心数 for i in range(20): p.submit(task,‘进程%s的pid:‘%i) print(‘主‘) 输出结果: 进程12的pid: 11484 is running 进程13的pid: 11072 is running 进程14的pid: 2784 is running 进程15的pid: 12328 is running 进程16的pid: 11484 is running 进程17的pid: 11072 is running 进程18的pid: 2784 is running 进程19的pid: 12328 is running 根据结果可以看出一直是4个进程在进行运算,限制了进程数
同步提交 from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor import time import os def task(name): print(‘%s %s is running‘% (name,os.getpid())) time.sleep(1) return 123 # 返回结果 if __name__ == ‘__main__‘: p = ProcessPoolExecutor(4) #默认不指定参数,值是cpu核心数的5倍 for i in range(20): res = p.submit(task,‘进程%s的pid:‘%i).result() #提交完任务原地等待结果 print(res) print(‘主‘) 输出: 进程0的pid: 13900 is running 123 进程1的pid: 8996 is running 123 进程2的pid: 13496 is running 123 进程3的pid: 7548 is running 123 进程4的pid: 13900 is running 123 进程5的pid: 8996 is running 123 进程6的pid: 13496 is running 123
线程池
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor import time import os def task(name,n): print(‘%s %s is running‘% (name,os.getpid())) time.sleep(1) return n**2 if __name__ == ‘__main__‘: p = ThreadPoolExecutor(4) # 提交任务的两种方式 # 同步调用:提交完成一个任务后,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,而是直接执行下一个行代码,会导致任务是并发执行的 l=[] for i in range(10): future = p.submit(task,‘进程pid:‘,i) l.append(future) p.shutdown(wait=True) #关闭进程池的入口,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‘)
输出结果:
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
进程pid: 12932 is running
0
1
4
9
16
25
36
49
64
81
主
异步回调
# 回调函数,异步提交之后一旦任务有返回结果,自动交给另外一个任务执行 from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor import time import os pool = ProcessPoolExecutor(5) def task(n): print(n,os.getpid()) time.sleep(2) return n**2 def call_back(n): print(‘我拿到了结果:%s‘%n.result()) if __name__ == ‘__main__‘: t_list=[] for i in range(10): future = pool.submit(task,i).add_done_callback(call_back) t_list.append(future) print(‘主‘)
输出:
主
0 11468
1 12216
2 10784
3 5564
4 13252
5 11468
我拿到了结果:0
6 12216
我拿到了结果:1
7 10784
我拿到了结果:4
8 5564
我拿到了结果:9
9 13252
协程
进程:资源单位(车间)
线程:最小资源单位(流水线)
协程:单线程下实现并发
并发:看上去像是同时执行就可以称之为并发
多道技术:
空间上的复用
时间上的复用
核心:切换+保存状态
协程:完全是技术人员自己定义的
当任务是计算密集型:会降低效率
当任务是io密集型:会提升效率
from gevent import monkey;monkey.patch_all() # 添加该模块会自动识别所有代码中的io操作 from gevent import spawn # gevent本身不能识别time.sleep不属于该模块的io操作 import time def heng(name): print(‘%s 哼‘%name) time.sleep(2) print(‘%s 哼‘% name) def ha(name): print(‘%s 哈‘%name) time.sleep(3) print(‘%s 哈‘% name) start = time.time() # heng(‘egon‘) # ha(‘yzn‘) # print(‘主‘,time.time()-start) # 5.001242399215698 s1=spawn(heng,‘egon‘) s2=spawn(ha,‘echo‘) s1.join() s2.join() print(‘主‘,time.time()-start) # 3.0121893882751465
单线程sockert通信
from gevent import monkey;monkey.patch_all()
from gevent import spawn
import socket
def communicate(conn):
while True:
try:
data = conn.recv(1024)
if len(data) == 0:break
print(data.decode(‘utf-8‘))
conn.send(data.upper())
except ConnectionResetError:
break
conn.close()
def server():
server = socket.socket()
server.bind((‘127.0.0.1‘,8080))
server.listen(5)
while True:
conn,addr = server.accept()
spawn(communicate,conn)
if __name__ == ‘__main__‘:
s1 = spawn(server)
s1.join()
客户端:
from threading import Thread,current_thread
import socket
def client():
client = socket.socket()
client.connect((‘127.0.0.1‘,8080))
n = 1
while True:
data = ‘%s %s‘%(current_thread().name,n)
n += 1
client.send(data.encode(‘utf-8‘))
info = client.recv(1024)
print(info)
if __name__ == ‘__main__‘:
for i in range(500):
t = Thread(target=client)
t.start()
io模型:
阻塞IO
非阻塞IO(服务端通信针对accept用s.setblocking(False)加异常捕获,cpu占用率过高)
IO多路复用
在只检测一个套接字的情况下,他的效率连阻塞IO都比不上。因为select这个中间人增加了环节。
但是在检测多个套接字的情况下,就能省去wait for data过程
异步IO
标签:result 完全 切换 耗资源 客户端 [] tpi monkey imp
原文地址:https://www.cnblogs.com/yangzhaon/p/10841737.html