Lib/multiprocessing/dummy/connection.py

   1 #
   2 # Analogue of `multiprocessing.connection` which uses queues instead of sockets
   3 #
   4 # multiprocessing/dummy/connection.py
   5 #
   6 # Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
   7 #
   8
   9 __all__ = [ 'Client', 'Listener', 'Pipe' ]
  10
  11 from Queue import Queue
  12
  13
  14 families = [None]
  15
  16
  17 class Listener(object):
  18
  19     def __init__(self, address=None, family=None, backlog=1):
  20         self._backlog_queue = Queue(backlog)
  21
  22     def accept(self):
  23         return Connection(*self._backlog_queue.get())
  24
  25     def close(self):
  26         self._backlog_queue = None
  27
  28     address = property(lambda self: self._backlog_queue)
  29
  30
  31 def Client(address):
  32     _in, _out = Queue(), Queue()
  33     address.put((_out, _in))
  34     return Connection(_in, _out)
  35
  36
  37 def Pipe(duplex=True):
  38     a, b = Queue(), Queue()
  39     return Connection(a, b), Connection(b, a)
  40
  41
  42 class Connection(object):
  43
  44     def __init__(self, _in, _out):
  45         self._out = _out
  46         self._in = _in
  47         self.send = self.send_bytes = _out.put
  48         self.recv = self.recv_bytes = _in.get
  49
  50     def poll(self, timeout=0.0):
  51         if self._in.qsize() > 0:
  52             return True
  53         if timeout <= 0.0:
  54             return False
  55         self._in.not_empty.acquire()
  56         self._in.not_empty.wait(timeout)
  57         self._in.not_empty.release()
  58         return self._in.qsize() > 0
  59
  60     def close(self):
  61         pass