coding:utf-8
author = 'Alex Li'
import select import socket import sys import queue
Create a TCP/IP socket
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.setblocking(False)
Bind the socket to the port
server_address = ('localhost', 10000) print(sys.stderr, 'starting up on %s port %s' % server_address) server.bind(server_address)
Listen for incoming connections
server.listen(5)
Sockets from which we expect to read
inputs = [ server ]
Sockets to which we expect to write
outputs = [ ]
message_queues = {} while inputs:
代码语言：javascript复制# Wait for at least one of the sockets to be ready for processing
print( 'nwaiting for the next event')
readable, writable, exceptional = select.select(inputs, outputs, inputs)
# Handle inputs
for s in readable:
if s is server:
# A "readable" server socket is ready to accept a connection
connection, client_address = s.accept()
print('new connection from', client_address)
connection.setblocking(False)
inputs.append(connection)
# Give the connection a queue for data we want to send
message_queues[connection] = queue.Queue()
else:
data = s.recv(1024)
if data:
# A readable client socket has data
print(sys.stderr, 'received "%s" from %s' % (data, s.getpeername()) )
message_queues[s].put(data)
# Add output channel for response
if s not in outputs:
outputs.append(s)
else:
# Interpret empty result as closed connection
print('closing', client_address, 'after reading no data')
# Stop listening for input on the connection
if s in outputs:
outputs.remove(s) #既然客户端都断开了，我就不用再给它返回数据了，所以这时候如果这个客户端的连接对象还在outputs列表中，就把它删掉
inputs.remove(s) #inputs中也删除掉
s.close() #把这个连接关闭掉
# Remove message queue
del message_queues[s]
# Handle outputs
for s in writable:
try:
next_msg = message_queues[s].get_nowait()
except queue.Empty:
# No messages waiting so stop checking for writability.
print('output queue for', s.getpeername(), 'is empty')
outputs.remove(s)
else:
print( 'sending "%s" to %s' % (next_msg, s.getpeername()))
s.send(next_msg)
# Handle "exceptional conditions"
for s in exceptional:
print('handling exceptional condition for', s.getpeername() )
# Stop listening for input on the connection
inputs.remove(s)
if s in outputs:
outputs.remove(s)
s.close()
# Remove message queue
del message_queues[s]import sys, time from select import select from socket import socket, AF_INET, SOCK_STREAM def now(): return time.ctime(time.time())
myHost = '' # server machine, '' means local host myPort = 50007 # listen on a non-reserved port number if len(sys.argv) == 3: # allow host/port as cmdline args too myHost, myPort = sys.argv[1:] numPortSocks = 2 # number of ports for client connects
make main sockets for accepting new client requests
mainsocks, readsocks, writesocks = [], [], [] for i in range(numPortSocks): portsock = socket(AF_INET, SOCK_STREAM) # make a TCP/IP socket object portsock.bind((myHost, myPort)) # bind it to server port number portsock.listen(5) # listen, allow 5 pending connects mainsocks.append(portsock) # add to main list to identify readsocks.append(portsock) # add to select inputs list myPort = 1 # bind on consecutive ports
event loop: listen and multiplex until server process killed
print('select-server loop starting') while True: #print(readsocks) readables, writeables, exceptions = select(readsocks, writesocks, []) for sockobj in readables: if sockobj in mainsocks: # for ready input sockets # port socket: accept new client newsock, address = sockobj.accept() # accept should not block print('Connect:', address, id(newsock)) # newsock is a new socket readsocks.append(newsock) # add to select list, wait else: # client socket: read next line data = sockobj.recv(1024) # recv should not block print('tgot', data, 'on', id(sockobj)) if not data: # if closed by the clients sockobj.close() # close here and remv from readsocks.remove(sockobj) # del list else reselected else: # this may block: should really select for writes too reply = 'Echo=>%s at %s' % (data, now()) sockobj.send(reply.encode())
