python select epoll poll的解析

server

# Sockets from which we expect to read
inputs = [ server ]# Sockets to which we expect to write
outputs = [ ]

# Outgoing message queues (socket:Queue)
message_queues = {}

while inputs: # Wait for at least one of the sockets to be ready for processing
print >>sys.stderr, '\nwaiting for the next event'
readable, writable, exceptional = select.select(inputs, outputs, inputs)

当你把inputs,outputs,exceptional(这里跟inputs共用)传给select()后，它返回3个新的list，我们上面将他们分别赋值为readable,writable,exceptional, 所有在readable list中的socket连接代表有数据可接收(recv),所有在writable list中的存放着你可以对其进行发送(send)操作的socket连接，当连接通信出现error时会把error写到exceptional列表中。

#coding:UTF8 import socket
import sys messages = [ 'This is the message. ',
'It will be sent ',
'in parts.',
]
server_address = ('localhost', 10003) # Create a TCP/IP socket
socks = [ socket.socket(socket.AF_INET, socket.SOCK_STREAM),
socket.socket(socket.AF_INET, socket.SOCK_STREAM),
] # Connect the socket to the port where the server is listening
print >>sys.stderr, 'connecting to %s port %s' % server_address
for s in socks:
s.connect(server_address) for message in messages: # Send messages on both sockets
for s in socks:
print >>sys.stderr, '%s: sending "%s"' % (s.getsockname(), message)
s.send(message) # Read responses on both sockets
for s in socks:
data = s.recv(1024)
print >>sys.stderr, '%s: received "%s"' % (s.getsockname(), data)
if not data:
print >>sys.stderr, 'closing socket', s.getsockname()

server：
starting up on localhost prot 10000waiting for the next event
new connection from ('127.0.0.1', 54812)waiting for the next event
new connection from ('127.0.0.1', 54813)
received "This is the message. " from ('127.0.0.1', 54812)waiting for the next event
received "This is the message. " from ('127.0.0.1', 54813)
sending "This is the message. " to ('127.0.0.1', 54812)waiting for the next event
output queue for ('127.0.0.1', 54812) is empty
sending "This is the message. " to ('127.0.0.1', 54813)waiting for the next event
output queue for ('127.0.0.1', 54813) is emptywaiting for the next event
received "It will be sent " from ('127.0.0.1', 54812)
received "It will be sent " from ('127.0.0.1', 54813)waiting for the next event
sending "It will be sent " to ('127.0.0.1', 54812)
sending "It will be sent " to ('127.0.0.1', 54813)waiting for the next event
output queue for ('127.0.0.1', 54812) is empty
output queue for ('127.0.0.1', 54813) is emptywaiting for the next event
received "in parts." from ('127.0.0.1', 54812)
received "in parts." from ('127.0.0.1', 54813)waiting for the next event
sending "in parts." to ('127.0.0.1', 54812)
sending "in parts." to ('127.0.0.1', 54813)waiting for the next event
output queue for ('127.0.0.1', 54812) is empty
output queue for ('127.0.0.1', 54813) is emptywaiting for the next event
closing ('127.0.0.1', 54813) after reading no data
closing ('127.0.0.1', 54813) after reading no datawaiting for the next eventclient：
connecting to localhost port 10000
('127.0.0.1', 54812): sending "This is the message. "
('127.0.0.1', 54813): sending "This is the message. "
('127.0.0.1', 54812): received "THIS IS THE MESSAGE. "
('127.0.0.1', 54813): received "THIS IS THE MESSAGE. "
('127.0.0.1', 54812): sending "It will be sent "
('127.0.0.1', 54813): sending "It will be sent "
('127.0.0.1', 54812): received "IT WILL BE SENT "
('127.0.0.1', 54813): received "IT WILL BE SENT "
('127.0.0.1', 54812): sending "in parts."
('127.0.0.1', 54813): sending "in parts."
('127.0.0.1', 54812): received "IN PARTS."
('127.0.0.1', 54813): received "IN PARTS."

#coding: utf-8 import select, socketresponse = b"hello world"serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serversocket.bind(('localhost', 10000))
serversocket.listen(1)
serversocket.setblocking(0)#
poll = select.poll()
poll.register(serversocket.fileno(), select.POLLIN)connections = {}
while True:
for fd, event in poll.poll():
if event == select.POLLIN:
if fd == serversocket.fileno():
con, addr = serversocket.accept()
poll.register(con.fileno(), select.POLLIN)
connections[con.fileno()] = con
else:
con = connections[fd]
data = con.recv(1024)
if data:
poll.modify(con.fileno(), select.POLLOUT)
elif event == select.POLLOUT:
con = connections[fd]
con.send(response)
poll.unregister(con.fileno())
con.close()

#coding:Utf8
import socket, select EOL1 = b'\n\n'
EOL2 = b'\n\r\n'
response = b'HTTP/1.0 200 OK\r\nDate: Mon, 1 Jan 1996 01:01:01 GMT\r\n'
response += b'Content-Type: text/plain\r\nContent-Length: 13\r\n\r\n'
response += b'Hello, world!' serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serversocket.bind(('localhost', 10000))
serversocket.listen(1)
serversocket.setblocking(0) epoll = select.epoll()
epoll.register(serversocket.fileno(), select.EPOLLIN) try:
connections = {}; requests = {}; responses = {}
while True:
events = epoll.poll(1)
for fileno, event in events:
if fileno == serversocket.fileno():
connection, address = serversocket.accept()
connection.setblocking(0)
epoll.register(connection.fileno(), select.EPOLLIN)
connections[connection.fileno()] = connection
requests[connection.fileno()] = b''
responses[connection.fileno()] = response
elif event & select.EPOLLIN:
requests[fileno] += connections[fileno].recv(1024)
if EOL1 in requests[fileno] or EOL2 in requests[fileno]:
epoll.modify(fileno, select.EPOLLOUT)
print('-'*40 + '\n' + requests[fileno].decode()[:-2])
elif event & select.EPOLLOUT:
byteswritten = connections[fileno].send(responses[fileno])
responses[fileno] = responses[fileno][byteswritten:]
if len(responses[fileno]) == 0:
epoll.modify(fileno, 0)
connections[fileno].shutdown(socket.SHUT_RDWR)
elif event & select.EPOLLHUP:
epoll.unregister(fileno)
connections[fileno].close()
del connections[fileno]
finally:
epoll.unregister(serversocket.fileno())
epoll.close()
serversocket.close()