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
       7  # Licensed to PSF under a Contributor Agreement.
       8  #
       9  
      10  __all__ = [ 'Client', 'Listener', 'Pipe' ]
      11  
      12  from queue import Queue
      13  
      14  
      15  families = [None]
      16  
      17  
      18  class ESC[4;38;5;81mListener(ESC[4;38;5;149mobject):
      19  
      20      def __init__(self, address=None, family=None, backlog=1):
      21          self._backlog_queue = Queue(backlog)
      22  
      23      def accept(self):
      24          return Connection(*self._backlog_queue.get())
      25  
      26      def close(self):
      27          self._backlog_queue = None
      28  
      29      @property
      30      def address(self):
      31          return self._backlog_queue
      32  
      33      def __enter__(self):
      34          return self
      35  
      36      def __exit__(self, exc_type, exc_value, exc_tb):
      37          self.close()
      38  
      39  
      40  def Client(address):
      41      _in, _out = Queue(), Queue()
      42      address.put((_out, _in))
      43      return Connection(_in, _out)
      44  
      45  
      46  def Pipe(duplex=True):
      47      a, b = Queue(), Queue()
      48      return Connection(a, b), Connection(b, a)
      49  
      50  
      51  class ESC[4;38;5;81mConnection(ESC[4;38;5;149mobject):
      52  
      53      def __init__(self, _in, _out):
      54          self._out = _out
      55          self._in = _in
      56          self.send = self.send_bytes = _out.put
      57          self.recv = self.recv_bytes = _in.get
      58  
      59      def poll(self, timeout=0.0):
      60          if self._in.qsize() > 0:
      61              return True
      62          if timeout <= 0.0:
      63              return False
      64          with self._in.not_empty:
      65              self._in.not_empty.wait(timeout)
      66          return self._in.qsize() > 0
      67  
      68      def close(self):
      69          pass
      70  
      71      def __enter__(self):
      72          return self
      73  
      74      def __exit__(self, exc_type, exc_value, exc_tb):
      75          self.close()