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lib64
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python2.7
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multiprocessing
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sharedctypes.py
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# # Module which supports allocation of ctypes objects from shared memory # # multiprocessing/sharedctypes.py # # Copyright (c) 2006-2008, R Oudkerk # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # 3. Neither the name of author nor the names of any contributors may be # used to endorse or promote products derived from this software # without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # import sys import ctypes import weakref from multiprocessing import heap, RLock from multiprocessing.forking import assert_spawning, ForkingPickler __all__ = ['RawValue', 'RawArray', 'Value', 'Array', 'copy', 'synchronized'] # # # typecode_to_type = { 'c': ctypes.c_char, 'b': ctypes.c_byte, 'B': ctypes.c_ubyte, 'h': ctypes.c_short, 'H': ctypes.c_ushort, 'i': ctypes.c_int, 'I': ctypes.c_uint, 'l': ctypes.c_long, 'L': ctypes.c_ulong, 'f': ctypes.c_float, 'd': ctypes.c_double } try: typecode_to_type['u'] = ctypes.c_wchar except AttributeError: pass # # # def _new_value(type_): size = ctypes.sizeof(type_) wrapper = heap.BufferWrapper(size) return rebuild_ctype(type_, wrapper, None) def RawValue(typecode_or_type, *args): ''' Returns a ctypes object allocated from shared memory ''' type_ = typecode_to_type.get(typecode_or_type, typecode_or_type) obj = _new_value(type_) ctypes.memset(ctypes.addressof(obj), 0, ctypes.sizeof(obj)) obj.__init__(*args) return obj def RawArray(typecode_or_type, size_or_initializer): ''' Returns a ctypes array allocated from shared memory ''' type_ = typecode_to_type.get(typecode_or_type, typecode_or_type) if isinstance(size_or_initializer, (int, long)): type_ = type_ * size_or_initializer obj = _new_value(type_) ctypes.memset(ctypes.addressof(obj), 0, ctypes.sizeof(obj)) return obj else: type_ = type_ * len(size_or_initializer) result = _new_value(type_) result.__init__(*size_or_initializer) return result def Value(typecode_or_type, *args, **kwds): ''' Return a synchronization wrapper for a Value ''' lock = kwds.pop('lock', None) if kwds: raise ValueError('unrecognized keyword argument(s): %s' % kwds.keys()) obj = RawValue(typecode_or_type, *args) if lock is False: return obj if lock in (True, None): lock = RLock() if not hasattr(lock, 'acquire'): raise AttributeError("'%r' has no method 'acquire'" % lock) return synchronized(obj, lock) def Array(typecode_or_type, size_or_initializer, **kwds): ''' Return a synchronization wrapper for a RawArray ''' lock = kwds.pop('lock', None) if kwds: raise ValueError('unrecognized keyword argument(s): %s' % kwds.keys()) obj = RawArray(typecode_or_type, size_or_initializer) if lock is False: return obj if lock in (True, None): lock = RLock() if not hasattr(lock, 'acquire'): raise AttributeError("'%r' has no method 'acquire'" % lock) return synchronized(obj, lock) def copy(obj): new_obj = _new_value(type(obj)) ctypes.pointer(new_obj)[0] = obj return new_obj def synchronized(obj, lock=None): assert not isinstance(obj, SynchronizedBase), 'object already synchronized' if isinstance(obj, ctypes._SimpleCData): return Synchronized(obj, lock) elif isinstance(obj, ctypes.Array): if obj._type_ is ctypes.c_char: return SynchronizedString(obj, lock) return SynchronizedArray(obj, lock) else: cls = type(obj) try: scls = class_cache[cls] except KeyError: names = [field[0] for field in cls._fields_] d = dict((name, make_property(name)) for name in names) classname = 'Synchronized' + cls.__name__ scls = class_cache[cls] = type(classname, (SynchronizedBase,), d) return scls(obj, lock) # # Functions for pickling/unpickling # def reduce_ctype(obj): assert_spawning(obj) if isinstance(obj, ctypes.Array): return rebuild_ctype, (obj._type_, obj._wrapper, obj._length_) else: return rebuild_ctype, (type(obj), obj._wrapper, None) def rebuild_ctype(type_, wrapper, length): if length is not None: type_ = type_ * length ForkingPickler.register(type_, reduce_ctype) obj = type_.from_address(wrapper.get_address()) obj._wrapper = wrapper return obj # # Function to create properties # def make_property(name): try: return prop_cache[name] except KeyError: d = {} exec template % ((name,)*7) in d prop_cache[name] = d[name] return d[name] template = ''' def get%s(self): self.acquire() try: return self._obj.%s finally: self.release() def set%s(self, value): self.acquire() try: self._obj.%s = value finally: self.release() %s = property(get%s, set%s) ''' prop_cache = {} class_cache = weakref.WeakKeyDictionary() # # Synchronized wrappers # class SynchronizedBase(object): def __init__(self, obj, lock=None): self._obj = obj self._lock = lock or RLock() self.acquire = self._lock.acquire self.release = self._lock.release def __reduce__(self): assert_spawning(self) return synchronized, (self._obj, self._lock) def get_obj(self): return self._obj def get_lock(self): return self._lock def __repr__(self): return '<%s wrapper for %s>' % (type(self).__name__, self._obj) class Synchronized(SynchronizedBase): value = make_property('value') class SynchronizedArray(SynchronizedBase): def __len__(self): return len(self._obj) def __getitem__(self, i): self.acquire() try: return self._obj[i] finally: self.release() def __setitem__(self, i, value): self.acquire() try: self._obj[i] = value finally: self.release() def __getslice__(self, start, stop): self.acquire() try: return self._obj[start:stop] finally: self.release() def __setslice__(self, start, stop, values): self.acquire() try: self._obj[start:stop] = values finally: self.release() class SynchronizedString(SynchronizedArray): value = make_property('value') raw = make_property('raw')