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      1 #
      2 # Support for the API of the multiprocessing package using threads
      3 #
      4 # multiprocessing/dummy/__init__.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__ = [
     36     'Process', 'current_process', 'active_children', 'freeze_support',
     37     'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Condition',
     38     'Event', 'Queue', 'Manager', 'Pipe', 'Pool', 'JoinableQueue'
     39     ]
     40 
     41 #
     42 # Imports
     43 #
     44 
     45 import threading
     46 import sys
     47 import weakref
     48 import array
     49 import itertools
     50 
     51 from multiprocessing import TimeoutError, cpu_count
     52 from multiprocessing.dummy.connection import Pipe
     53 from threading import Lock, RLock, Semaphore, BoundedSemaphore
     54 from threading import Event
     55 from Queue import Queue
     56 
     57 #
     58 #
     59 #
     60 
     61 class DummyProcess(threading.Thread):
     62 
     63     def __init__(self, group=None, target=None, name=None, args=(), kwargs={}):
     64         threading.Thread.__init__(self, group, target, name, args, kwargs)
     65         self._pid = None
     66         self._children = weakref.WeakKeyDictionary()
     67         self._start_called = False
     68         self._parent = current_process()
     69 
     70     def start(self):
     71         assert self._parent is current_process()
     72         self._start_called = True
     73         if hasattr(self._parent, '_children'):
     74             self._parent._children[self] = None
     75         threading.Thread.start(self)
     76 
     77     @property
     78     def exitcode(self):
     79         if self._start_called and not self.is_alive():
     80             return 0
     81         else:
     82             return None
     83 
     84 #
     85 #
     86 #
     87 
     88 class Condition(threading._Condition):
     89     notify_all = threading._Condition.notify_all.im_func
     90 
     91 #
     92 #
     93 #
     94 
     95 Process = DummyProcess
     96 current_process = threading.current_thread
     97 current_process()._children = weakref.WeakKeyDictionary()
     98 
     99 def active_children():
    100     children = current_process()._children
    101     for p in list(children):
    102         if not p.is_alive():
    103             children.pop(p, None)
    104     return list(children)
    105 
    106 def freeze_support():
    107     pass
    108 
    109 #
    110 #
    111 #
    112 
    113 class Namespace(object):
    114     def __init__(self, **kwds):
    115         self.__dict__.update(kwds)
    116     def __repr__(self):
    117         items = self.__dict__.items()
    118         temp = []
    119         for name, value in items:
    120             if not name.startswith('_'):
    121                 temp.append('%s=%r' % (name, value))
    122         temp.sort()
    123         return 'Namespace(%s)' % str.join(', ', temp)
    124 
    125 dict = dict
    126 list = list
    127 
    128 def Array(typecode, sequence, lock=True):
    129     return array.array(typecode, sequence)
    130 
    131 class Value(object):
    132     def __init__(self, typecode, value, lock=True):
    133         self._typecode = typecode
    134         self._value = value
    135     def _get(self):
    136         return self._value
    137     def _set(self, value):
    138         self._value = value
    139     value = property(_get, _set)
    140     def __repr__(self):
    141         return '<%r(%r, %r)>'%(type(self).__name__,self._typecode,self._value)
    142 
    143 def Manager():
    144     return sys.modules[__name__]
    145 
    146 def shutdown():
    147     pass
    148 
    149 def Pool(processes=None, initializer=None, initargs=()):
    150     from multiprocessing.pool import ThreadPool
    151     return ThreadPool(processes, initializer, initargs)
    152 
    153 JoinableQueue = Queue
    154