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      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 # All rights reserved.
      8 #
      9 # Redistribution and use in source and binary forms, with or without
     10 # modification, are permitted provided that the following conditions
     11 # are met:
     12 #
     13 # 1. Redistributions of source code must retain the above copyright
     14 #    notice, this list of conditions and the following disclaimer.
     15 # 2. Redistributions in binary form must reproduce the above copyright
     16 #    notice, this list of conditions and the following disclaimer in the
     17 #    documentation and/or other materials provided with the distribution.
     18 # 3. Neither the name of author nor the names of any contributors may be
     19 #    used to endorse or promote products derived from this software
     20 #    without specific prior written permission.
     21 #
     22 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
     23 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     26 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32 # SUCH DAMAGE.
     33 #
     34 
     35 __all__ = [ 'Client', 'Listener', 'Pipe' ]
     36 
     37 from Queue import Queue
     38 
     39 
     40 families = [None]
     41 
     42 
     43 class Listener(object):
     44 
     45     def __init__(self, address=None, family=None, backlog=1):
     46         self._backlog_queue = Queue(backlog)
     47 
     48     def accept(self):
     49         return Connection(*self._backlog_queue.get())
     50 
     51     def close(self):
     52         self._backlog_queue = None
     53 
     54     address = property(lambda self: self._backlog_queue)
     55 
     56 
     57 def Client(address):
     58     _in, _out = Queue(), Queue()
     59     address.put((_out, _in))
     60     return Connection(_in, _out)
     61 
     62 
     63 def Pipe(duplex=True):
     64     a, b = Queue(), Queue()
     65     return Connection(a, b), Connection(b, a)
     66 
     67 
     68 class Connection(object):
     69 
     70     def __init__(self, _in, _out):
     71         self._out = _out
     72         self._in = _in
     73         self.send = self.send_bytes = _out.put
     74         self.recv = self.recv_bytes = _in.get
     75 
     76     def poll(self, timeout=0.0):
     77         if self._in.qsize() > 0:
     78             return True
     79         if timeout <= 0.0:
     80             return False
     81         self._in.not_empty.acquire()
     82         self._in.not_empty.wait(timeout)
     83         self._in.not_empty.release()
     84         return self._in.qsize() > 0
     85 
     86     def close(self):
     87         pass
     88