267 lines
7.5 KiB
Python
267 lines
7.5 KiB
Python
#
|
|
# 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, 'u': ctypes.c_wchar,
|
|
'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
|
|
}
|
|
|
|
#
|
|
#
|
|
#
|
|
|
|
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')
|