Python的Tornado框架异步编程入门实例

add_handler

def add_handler(self, fd, handler, events):
  self._handlers[fd] = stack_context.wrap(handler)
  self._impl.register(fd, events | self.ERROR)

update_handler

def update_handler(self, fd, events):
  self._impl.modify(fd, events | self.ERROR)

remove_handler

def remove_handler(self, fd):
  self._handlers.pop(fd, None)
  self._events.pop(fd, None)
  try:
    self._impl.unregister(fd)
  except Exception:
    gen_log.debug("Error deleting fd from IOLoop", exc_info=True)

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#
#  Author :  cold
#  E-mail :  wh_linux@126.com
#  Date  :  13/04/15 15:08:51
#  Desc  :  Tornado Echo Server
#  HOME  :  http://www.linuxzen.com
#
import Queue
import socket

from functools import partial

from tornado.ioloop import IOLoop

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setblocking(0)       # 将socket设置为非阻塞

server_address = ("localhost", 10000)

sock.bind(server_address)
sock.listen(5)

fd_map = {}       # 文件描述符到socket的映射
message_queue_map = {}  # socket到消息队列的映射

fd = sock.fileno()
fd_map[fd] = sock

ioloop = IOLoop.instance()

def handle_client(cli_addr, fd, event):
  s = fd_map[fd]
  if event & IOLoop.READ:
    data = s.recv(1024)
    if data:
      print "   received '%s' from %s" % (data, cli_addr)
      # 接收到消息更改事件为写, 用于发送数据到对端
      ioloop.update_handler(fd, IOLoop.WRITE)
      message_queue_map[s].put(data)
    else:
      print "   closing %s" % cli_addr
      ioloop.remove_handler(fd)
      s.close()
      del message_queue_map[s]

  if event & IOLoop.WRITE:
    try:
      next_msg = message_queue_map[s].get_nowait()
    except Queue.Empty:
      print "%s queue empty" % cli_addr
      ioloop.update_handler(fd, IOLoop.READ)
    else:
      print 'sending "%s" to %s' % (next_msg, cli_addr)
      s.send(next_msg)

  if event & IOLoop.ERROR:
    print " exception on %s" % cli_addr
    ioloop.remove_handler(fd)
    s.close()
    del message_queue_map[s]


def handle_server(fd, event):
  s = fd_map[fd]
  if event & IOLoop.READ:
    conn, cli_addr = s.accept()
    print "   connection %s" % cli_addr[0]
    conn.setblocking(0)
    conn_fd = conn.fileno()
    fd_map[conn_fd] = conn
    handle = partial(handle_client, cli_addr[0])  # 将cli_addr作为第一个参数
    # 将连接和handle注册为读事件加入到 tornado ioloop
    ioloop.add_handler(conn_fd, handle, IOLoop.READ)
    message_queue_map[conn] = Queue.Queue()  # 创建对应的消息队列


ioloop.add_handler(fd, handle_server, IOLoop.READ)

ioloop.start()