在Python中使用非同步Socket編程效能測試

OK,首先寫一個python socket的server段,對開放三個連接埠:10000,10001,10002.krondo的例子中是每個server綁定一個連接埠,測試的時候需要分別開3個shell,分別運行.這太麻煩了,就分別用三個Thread來運行這些services.

import optparse import os import socket import time from threading import Thread import StringIO   txt = '''1111 2222 3333 4444 '''     def server(listen_socket):   while True:     buf = StringIO.StringIO(txt)     sock, addr = listen_socket.accept()     print 'Somebody at %s wants poetry!' % (addr,)     while True:         try:           line = buf.readline().strip()           if not line:             sock.close()             break           sock.sendall(line) # this is a blocking call           print 'send bytes to client:%s' % line           #sock.close()         except socket.error:           sock.close()           break         time.sleep(1) #server和client串連後，server會故意每發送一個單詞後等待一秒鐘後再發送另一個單詞     def main():   ports = [10000, 10001, 10002]   for port in ports:     listen_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)     listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)     addres = (str('127.0.0.1'), port)     listen_socket.bind(addres)     listen_socket.listen(5)     print "start listen at:%s" % (port,)     worker = Thread(target = server, args = [listen_socket])     worker.setDaemon(True)     worker.start()     if __name__ == '__main__':   main()   while True:     time.sleep(0.1) #如果不sleep的話,CPU會被Python完全佔用了     pass 

下面是一個client,沒有才用非同步網路,串連這個三個連接埠的server:

import socket     if __name__ == '__main__':   ports = [10000, 10001, 10002]   for port in ports:     address = (str('127.0.0.1'), port)     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)     sock.connect(address)     poem = ''     while True:       data = sock.recv(4)       if not data:         sock.close()         break       poem += data     print poem 

下面用非同步client來讀取，代碼如下：

import datetime, errno, optparse, select, socket   def connect(port):   """Connect to the given server and return a non-blocking socket."""   address = (str('127.0.0.1'), port)   sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)   sock.connect(address)   sock.setblocking(0)   return sock   def format_address(address):   host, port = address   return '%s:%s' % (host or '127.0.0.1', port)   if __name__ == '__main__':   ports = [10000, 10001, 10002]   start = datetime.datetime.now()     sockets = map(connect, ports)   poems = dict.fromkeys(sockets, '') # socket -> accumulated poem      # socket -> task numbers   sock2task = dict([(s, i + 1) for i, s in enumerate(sockets)])   sockets = list(sockets) # make a copy     while sockets:     #運用select來確保那些可讀取的非同步socket可以立即開始讀取IO     #OS不停的搜尋目前可以read的socket，有的話就返回rlist     rlist, _, _ = select.select(sockets, [], [])     for sock in rlist:       data = ''       while True:         try:           new_data = sock.recv(1024)         except socket.error, e:           if e.args[0] == errno.EWOULDBLOCK:             break           raise         else:           if not new_data:             break           else:             print new_data             data += new_data         task_num = sock2task[sock]       if not data:         sockets.remove(sock)         sock.close()         print 'Task %d finished' % task_num       else:         addr_fmt = format_address(sock.getpeername())         msg = 'Task %d: got %d bytes of poetry from %s'         print msg % (task_num, len(data), addr_fmt)         poems[sock] += data     elapsed = datetime.datetime.now() - start   print 'Got poems in %s' % elapsed 

結果只需要4秒就完成了讀取任務。效率是剛才同步socket的三倍。對用戶端的非同步改造主要有兩點：

同步模式下，用戶端分別建立socket；而在非同步模式下，client開始就建立了所有的socket。
通過“sock.setblocking(0)”設定socket為非同步模式。
通過Unix系統的select倆返回可讀取IO
最為核心的是26行和29行。尤其是29行的select操作返回待讀取socket的列表。

