Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 1 | # |
| 2 | # Module which supports allocation of ctypes objects from shared memory |
| 3 | # |
| 4 | # multiprocessing/sharedctypes.py |
| 5 | # |
R. David Murray | d382066 | 2010-12-14 01:41:07 +0000 | [diff] [blame] | 6 | # Copyright (c) 2006-2008, R Oudkerk |
Richard Oudkerk | 3e268aa | 2012-04-30 12:13:55 +0100 | [diff] [blame] | 7 | # Licensed to PSF under a Contributor Agreement. |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 8 | # |
| 9 | |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 10 | import ctypes |
| 11 | import weakref |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 12 | |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 13 | from . import heap |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 14 | from . import get_context |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 15 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 16 | from .context import assert_spawning |
Richard Oudkerk | 84ed9a6 | 2013-08-14 15:35:41 +0100 | [diff] [blame] | 17 | from .reduction import ForkingPickler |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 18 | |
| 19 | __all__ = ['RawValue', 'RawArray', 'Value', 'Array', 'copy', 'synchronized'] |
| 20 | |
| 21 | # |
| 22 | # |
| 23 | # |
| 24 | |
| 25 | typecode_to_type = { |
| 26 | 'c': ctypes.c_char, 'u': ctypes.c_wchar, |
| 27 | 'b': ctypes.c_byte, 'B': ctypes.c_ubyte, |
| 28 | 'h': ctypes.c_short, 'H': ctypes.c_ushort, |
| 29 | 'i': ctypes.c_int, 'I': ctypes.c_uint, |
| 30 | 'l': ctypes.c_long, 'L': ctypes.c_ulong, |
| 31 | 'f': ctypes.c_float, 'd': ctypes.c_double |
| 32 | } |
| 33 | |
| 34 | # |
| 35 | # |
| 36 | # |
| 37 | |
| 38 | def _new_value(type_): |
| 39 | size = ctypes.sizeof(type_) |
| 40 | wrapper = heap.BufferWrapper(size) |
| 41 | return rebuild_ctype(type_, wrapper, None) |
| 42 | |
| 43 | def RawValue(typecode_or_type, *args): |
| 44 | ''' |
| 45 | Returns a ctypes object allocated from shared memory |
| 46 | ''' |
| 47 | type_ = typecode_to_type.get(typecode_or_type, typecode_or_type) |
| 48 | obj = _new_value(type_) |
| 49 | ctypes.memset(ctypes.addressof(obj), 0, ctypes.sizeof(obj)) |
| 50 | obj.__init__(*args) |
| 51 | return obj |
| 52 | |
| 53 | def RawArray(typecode_or_type, size_or_initializer): |
| 54 | ''' |
| 55 | Returns a ctypes array allocated from shared memory |
| 56 | ''' |
| 57 | type_ = typecode_to_type.get(typecode_or_type, typecode_or_type) |
| 58 | if isinstance(size_or_initializer, int): |
| 59 | type_ = type_ * size_or_initializer |
Mark Dickinson | 89461ef | 2011-03-26 10:19:03 +0000 | [diff] [blame] | 60 | obj = _new_value(type_) |
| 61 | ctypes.memset(ctypes.addressof(obj), 0, ctypes.sizeof(obj)) |
| 62 | return obj |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 63 | else: |
| 64 | type_ = type_ * len(size_or_initializer) |
| 65 | result = _new_value(type_) |
| 66 | result.__init__(*size_or_initializer) |
| 67 | return result |
| 68 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 69 | def Value(typecode_or_type, *args, lock=True, ctx=None): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 70 | ''' |
| 71 | Return a synchronization wrapper for a Value |
| 72 | ''' |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 73 | obj = RawValue(typecode_or_type, *args) |
Jesse Noller | b0516a6 | 2009-01-18 03:11:38 +0000 | [diff] [blame] | 74 | if lock is False: |
| 75 | return obj |
| 76 | if lock in (True, None): |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 77 | ctx = ctx or get_context() |
| 78 | lock = ctx.RLock() |
Jesse Noller | b0516a6 | 2009-01-18 03:11:38 +0000 | [diff] [blame] | 79 | if not hasattr(lock, 'acquire'): |
| 80 | raise AttributeError("'%r' has no method 'acquire'" % lock) |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 81 | return synchronized(obj, lock, ctx=ctx) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 82 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 83 | def Array(typecode_or_type, size_or_initializer, *, lock=True, ctx=None): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 84 | ''' |
| 85 | Return a synchronization wrapper for a RawArray |
| 86 | ''' |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 87 | obj = RawArray(typecode_or_type, size_or_initializer) |
Jesse Noller | b0516a6 | 2009-01-18 03:11:38 +0000 | [diff] [blame] | 88 | if lock is False: |
| 89 | return obj |
| 90 | if lock in (True, None): |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 91 | ctx = ctx or get_context() |
| 92 | lock = ctx.RLock() |
Jesse Noller | b0516a6 | 2009-01-18 03:11:38 +0000 | [diff] [blame] | 93 | if not hasattr(lock, 'acquire'): |
| 94 | raise AttributeError("'%r' has no method 'acquire'" % lock) |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 95 | return synchronized(obj, lock, ctx=ctx) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 96 | |
| 97 | def copy(obj): |
| 98 | new_obj = _new_value(type(obj)) |
| 99 | ctypes.pointer(new_obj)[0] = obj |
| 100 | return new_obj |
| 101 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 102 | def synchronized(obj, lock=None, ctx=None): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 103 | assert not isinstance(obj, SynchronizedBase), 'object already synchronized' |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 104 | ctx = ctx or get_context() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 105 | |
| 106 | if isinstance(obj, ctypes._SimpleCData): |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 107 | return Synchronized(obj, lock, ctx) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 108 | elif isinstance(obj, ctypes.Array): |
| 109 | if obj._type_ is ctypes.c_char: |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 110 | return SynchronizedString(obj, lock, ctx) |
| 111 | return SynchronizedArray(obj, lock, ctx) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 112 | else: |
| 113 | cls = type(obj) |
| 114 | try: |
| 115 | scls = class_cache[cls] |
| 116 | except KeyError: |
| 117 | names = [field[0] for field in cls._fields_] |
| 118 | d = dict((name, make_property(name)) for name in names) |
| 119 | classname = 'Synchronized' + cls.__name__ |
| 120 | scls = class_cache[cls] = type(classname, (SynchronizedBase,), d) |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 121 | return scls(obj, lock, ctx) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 122 | |
| 123 | # |
| 124 | # Functions for pickling/unpickling |
| 125 | # |
| 126 | |
| 127 | def reduce_ctype(obj): |
| 128 | assert_spawning(obj) |
| 129 | if isinstance(obj, ctypes.Array): |
| 130 | return rebuild_ctype, (obj._type_, obj._wrapper, obj._length_) |
| 131 | else: |
| 132 | return rebuild_ctype, (type(obj), obj._wrapper, None) |
| 133 | |
| 134 | def rebuild_ctype(type_, wrapper, length): |
| 135 | if length is not None: |
| 136 | type_ = type_ * length |
Amaury Forgeot d'Arc | 949d47d | 2008-08-19 21:30:55 +0000 | [diff] [blame] | 137 | ForkingPickler.register(type_, reduce_ctype) |
Richard Oudkerk | 26cdf1f | 2012-05-26 22:09:59 +0100 | [diff] [blame] | 138 | buf = wrapper.create_memoryview() |
| 139 | obj = type_.from_buffer(buf) |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 140 | obj._wrapper = wrapper |
| 141 | return obj |
| 142 | |
| 143 | # |
| 144 | # Function to create properties |
| 145 | # |
| 146 | |
| 147 | def make_property(name): |
| 148 | try: |
| 149 | return prop_cache[name] |
| 150 | except KeyError: |
| 151 | d = {} |
| 152 | exec(template % ((name,)*7), d) |
| 153 | prop_cache[name] = d[name] |
| 154 | return d[name] |
| 155 | |
| 156 | template = ''' |
| 157 | def get%s(self): |
| 158 | self.acquire() |
| 159 | try: |
| 160 | return self._obj.%s |
| 161 | finally: |
| 162 | self.release() |
| 163 | def set%s(self, value): |
| 164 | self.acquire() |
| 165 | try: |
| 166 | self._obj.%s = value |
| 167 | finally: |
| 168 | self.release() |
| 169 | %s = property(get%s, set%s) |
| 170 | ''' |
| 171 | |
| 172 | prop_cache = {} |
| 173 | class_cache = weakref.WeakKeyDictionary() |
| 174 | |
| 175 | # |
| 176 | # Synchronized wrappers |
| 177 | # |
| 178 | |
| 179 | class SynchronizedBase(object): |
| 180 | |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 181 | def __init__(self, obj, lock=None, ctx=None): |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 182 | self._obj = obj |
Richard Oudkerk | b1694cf | 2013-10-16 16:41:56 +0100 | [diff] [blame] | 183 | if lock: |
| 184 | self._lock = lock |
| 185 | else: |
| 186 | ctx = ctx or get_context(force=True) |
| 187 | self._lock = ctx.RLock() |
Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame] | 188 | self.acquire = self._lock.acquire |
| 189 | self.release = self._lock.release |
| 190 | |
| 191 | def __reduce__(self): |
| 192 | assert_spawning(self) |
| 193 | return synchronized, (self._obj, self._lock) |
| 194 | |
| 195 | def get_obj(self): |
| 196 | return self._obj |
| 197 | |
| 198 | def get_lock(self): |
| 199 | return self._lock |
| 200 | |
| 201 | def __repr__(self): |
| 202 | return '<%s wrapper for %s>' % (type(self).__name__, self._obj) |
| 203 | |
| 204 | |
| 205 | class Synchronized(SynchronizedBase): |
| 206 | value = make_property('value') |
| 207 | |
| 208 | |
| 209 | class SynchronizedArray(SynchronizedBase): |
| 210 | |
| 211 | def __len__(self): |
| 212 | return len(self._obj) |
| 213 | |
| 214 | def __getitem__(self, i): |
| 215 | self.acquire() |
| 216 | try: |
| 217 | return self._obj[i] |
| 218 | finally: |
| 219 | self.release() |
| 220 | |
| 221 | def __setitem__(self, i, value): |
| 222 | self.acquire() |
| 223 | try: |
| 224 | self._obj[i] = value |
| 225 | finally: |
| 226 | self.release() |
| 227 | |
| 228 | def __getslice__(self, start, stop): |
| 229 | self.acquire() |
| 230 | try: |
| 231 | return self._obj[start:stop] |
| 232 | finally: |
| 233 | self.release() |
| 234 | |
| 235 | def __setslice__(self, start, stop, values): |
| 236 | self.acquire() |
| 237 | try: |
| 238 | self._obj[start:stop] = values |
| 239 | finally: |
| 240 | self.release() |
| 241 | |
| 242 | |
| 243 | class SynchronizedString(SynchronizedArray): |
| 244 | value = make_property('value') |
| 245 | raw = make_property('raw') |