# coding: utf-8
import select
import socket
import Queue
from time import sleep


# Create a TCP/IP
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setblocking(False)

# Bind the socket to the port
server_address = ('localhost', 8090)
print ('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
# 處理要發(fā)送的消息
outputs = []

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

while inputs:
 # Wait for at least one of the sockets to be ready for processing
 print ('waiting for the next event')
 # 開(kāi)始select 監(jiān)聽(tīng), 對(duì)input_list 中的服務(wù)器端server 進(jìn)行監(jiān)聽(tīng)
 # 一旦調(diào)用socket的send, recv函數(shù)，將會(huì)再次調(diào)用此模塊
 readable, writable, exceptional = select.select(inputs, outputs, inputs)

 # Handle inputs
 # 循環(huán)判斷是否有客戶端連接進(jìn)來(lái), 當(dāng)有客戶端連接進(jìn)來(lái)時(shí)select 將觸發(fā)
 for s in readable:
  # 判斷當(dāng)前觸發(fā)的是不是服務(wù)端對(duì)象, 當(dāng)觸發(fā)的對(duì)象是服務(wù)端對(duì)象時(shí),說(shuō)明有新客戶端連接進(jìn)來(lái)了
  # 表示有新用戶來(lái)連接
  if s is server:
   # A "readable" socket is ready to accept a connection
   connection, client_address = s.accept()
   print ('connection from', client_address)
   # this is connection not server
   connection.setblocking(0)
   # 將客戶端對(duì)象也加入到監(jiān)聽(tīng)的列表中, 當(dāng)客戶端發(fā)送消息時(shí) select 將觸發(fā)
   inputs.append(connection)

   # Give the connection a queue for data we want to send
   # 為連接的客戶端單獨(dú)創(chuàng)建一個(gè)消息隊(duì)列，用來(lái)保存客戶端發(fā)送的消息
   message_queues[connection] = Queue.Queue()
  else:
   # 有老用戶發(fā)消息, 處理接受
   # 由于客戶端連接進(jìn)來(lái)時(shí)服務(wù)端接收客戶端連接請(qǐng)求，將客戶端加入到了監(jiān)聽(tīng)列表中(input_list), 客戶端發(fā)送消息將觸發(fā)
   # 所以判斷是否是客戶端對(duì)象觸發(fā)
   data = s.recv(1024)
   # 客戶端未斷開(kāi)
   if data != '':
    # A readable client socket has data
    print ('received "%s" from %s' % (data, s.getpeername()))
    # 將收到的消息放入到相對(duì)應(yīng)的socket客戶端的消息隊(duì)列中
    message_queues[s].put(data)
    # Add output channel for response
    # 將需要進(jìn)行回復(fù)操作socket放到output 列表中, 讓select監(jiān)聽(tīng)
    if s not in outputs:
     outputs.append(s)
   else:
    # 客戶端斷開(kāi)了連接, 將客戶端的監(jiān)聽(tīng)從input列表中移除
    # Interpret empty result as closed connection
    print ('closing', client_address)
    # Stop listening for input on the connection
    if s in outputs:
     outputs.remove(s)
    inputs.remove(s)
    s.close()

    # Remove message queue
    # 移除對(duì)應(yīng)socket客戶端對(duì)象的消息隊(duì)列
    del message_queues[s]

 # Handle outputs
 # 如果現(xiàn)在沒(méi)有客戶端請(qǐng)求, 也沒(méi)有客戶端發(fā)送消息時(shí), 開(kāi)始對(duì)發(fā)送消息列表進(jìn)行處理, 是否需要發(fā)送消息
 # 存儲(chǔ)哪個(gè)客戶端發(fā)送過(guò)消息
 for s in writable:
  try:
   # 如果消息隊(duì)列中有消息,從消息隊(duì)列中獲取要發(fā)送的消息
   message_queue = message_queues.get(s)
   send_data = ''
   if message_queue is not None:
    send_data = message_queue.get_nowait()
   else:
    # 客戶端連接斷開(kāi)了
    print "has closed "
  except Queue.Empty:
   # 客戶端連接斷開(kāi)了
   print "%s" % (s.getpeername())
   outputs.remove(s)
  else:
   # print "sending %s to %s " % (send_data, s.getpeername)
   # print "send something"
   if message_queue is not None:
    s.send(send_data)
   else:
    print "has closed "
   # del message_queues[s]
   # writable.remove(s)
   # print "Client %s disconnected" % (client_address)

 # # Handle "exceptional conditions"
 # 處理異常的情況
 for s in exceptional:
  print ('exception condition on', 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]

 sleep(1)

# coding: utf-8
import socket


messages = ['This is the message ', 'It will be sent ', 'in parts ', ]

server_address = ('localhost', 8090)

# Create aTCP/IP socket

socks = [socket.socket(socket.AF_INET, socket.SOCK_STREAM), socket.socket(socket.AF_INET, socket.SOCK_STREAM), ]

# Connect thesocket to the port where the server is listening

print ('connecting to %s port %s' % server_address)
# 連接到服務(wù)器
for s in socks:
 s.connect(server_address)

for index, message in enumerate(messages):
 # Send messages on both sockets
 for s in socks:
  print ('%s: sending "%s"' % (s.getsockname(), message + str(index)))
  s.send(bytes(message + str(index)).decode('utf-8'))
 # Read responses on both sockets

for s in socks:
 data = s.recv(1024)
 print ('%s: received "%s"' % (s.getsockname(), data))
 if data != "":
  print ('closingsocket', s.getsockname())
  s.close()