Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 1 | #include "Python.h" |
| 2 | #include "structmember.h" |
| 3 | |
| 4 | |
| 5 | #define GET_WEAKREFS_LISTPTR(o) \ |
| 6 | ((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o)) |
| 7 | |
| 8 | static PyWeakReference * |
| 9 | free_list = NULL; |
| 10 | |
| 11 | |
| 12 | long |
| 13 | _PyWeakref_GetWeakrefCount(PyWeakReference *head) |
| 14 | { |
| 15 | long count = 0; |
| 16 | |
| 17 | while (head != NULL) { |
| 18 | ++count; |
| 19 | head = head->wr_next; |
| 20 | } |
| 21 | return count; |
| 22 | } |
| 23 | |
| 24 | |
| 25 | static PyWeakReference * |
| 26 | new_weakref(void) |
| 27 | { |
| 28 | PyWeakReference *result; |
| 29 | |
| 30 | if (free_list != NULL) { |
| 31 | result = free_list; |
| 32 | free_list = result->wr_next; |
| 33 | result->ob_type = &_PyWeakref_RefType; |
| 34 | _Py_NewReference((PyObject *)result); |
| 35 | } |
| 36 | else { |
| 37 | result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType); |
| 38 | } |
| 39 | if (result) |
| 40 | result->hash = -1; |
| 41 | return result; |
| 42 | } |
| 43 | |
| 44 | |
| 45 | /* This function clears the passed-in reference and removes it from the |
| 46 | * list of weak references for the referent. This is the only code that |
| 47 | * removes an item from the doubly-linked list of weak references for an |
| 48 | * object; it is also responsible for clearing the callback slot. |
| 49 | */ |
| 50 | static void |
| 51 | clear_weakref(PyWeakReference *self) |
| 52 | { |
| 53 | PyObject *callback = self->wr_callback; |
| 54 | |
| 55 | if (PyWeakref_GET_OBJECT(self) != Py_None) { |
| 56 | PyWeakReference **list = GET_WEAKREFS_LISTPTR( |
| 57 | PyWeakref_GET_OBJECT(self)); |
| 58 | |
| 59 | if (*list == self) |
| 60 | *list = self->wr_next; |
| 61 | self->wr_object = Py_None; |
| 62 | self->wr_callback = NULL; |
| 63 | if (self->wr_prev != NULL) |
| 64 | self->wr_prev->wr_next = self->wr_next; |
| 65 | if (self->wr_next != NULL) |
| 66 | self->wr_next->wr_prev = self->wr_prev; |
| 67 | self->wr_prev = NULL; |
| 68 | self->wr_next = NULL; |
| 69 | Py_XDECREF(callback); |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | |
| 74 | static void |
| 75 | weakref_dealloc(PyWeakReference *self) |
| 76 | { |
| 77 | PyObject_GC_UnTrack((PyObject *)self); |
| 78 | clear_weakref(self); |
| 79 | self->wr_next = free_list; |
| 80 | free_list = self; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | static int |
| 85 | gc_traverse(PyWeakReference *self, visitproc visit, void *arg) |
| 86 | { |
| 87 | if (self->wr_callback != NULL) |
| 88 | return visit(self->wr_callback, arg); |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | |
| 93 | static int |
| 94 | gc_clear(PyWeakReference *self) |
| 95 | { |
| 96 | clear_weakref(self); |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | |
| 101 | static PyObject * |
| 102 | weakref_call(PyWeakReference *self, PyObject *args, PyObject *kw) |
| 103 | { |
| 104 | static char *argnames[] = {NULL}; |
| 105 | |
| 106 | if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", argnames)) { |
| 107 | PyObject *object = PyWeakref_GET_OBJECT(self); |
| 108 | Py_INCREF(object); |
| 109 | return (object); |
| 110 | } |
| 111 | return NULL; |
| 112 | } |
| 113 | |
| 114 | |
| 115 | static long |
| 116 | weakref_hash(PyWeakReference *self) |
| 117 | { |
| 118 | if (self->hash != -1) |
| 119 | return self->hash; |
| 120 | if (PyWeakref_GET_OBJECT(self) == Py_None) { |
| 121 | PyErr_SetString(PyExc_TypeError, "weak object has gone away"); |
| 122 | return -1; |
| 123 | } |
| 124 | self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self)); |
| 125 | return self->hash; |
| 126 | } |
| 127 | |
| 128 | |
| 129 | static PyObject * |
| 130 | weakref_repr(PyWeakReference *self) |
| 131 | { |
| 132 | char buffer[256]; |
| 133 | if (PyWeakref_GET_OBJECT(self) == Py_None) { |
Barry Warsaw | d586756 | 2001-11-28 21:01:56 +0000 | [diff] [blame] | 134 | PyOS_snprintf(buffer, sizeof(buffer), "<weakref at %lx; dead>", |
| 135 | (long)(self)); |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 136 | } |
| 137 | else { |
Barry Warsaw | d586756 | 2001-11-28 21:01:56 +0000 | [diff] [blame] | 138 | PyOS_snprintf(buffer, sizeof(buffer), |
| 139 | "<weakref at %#lx; to '%.50s' at %#lx>", |
| 140 | (long)(self), |
| 141 | PyWeakref_GET_OBJECT(self)->ob_type->tp_name, |
| 142 | (long)(PyWeakref_GET_OBJECT(self))); |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 143 | } |
| 144 | return PyString_FromString(buffer); |
| 145 | } |
| 146 | |
| 147 | /* Weak references only support equality, not ordering. Two weak references |
| 148 | are equal if the underlying objects are equal. If the underlying object has |
| 149 | gone away, they are equal if they are identical. */ |
| 150 | |
| 151 | static PyObject * |
| 152 | weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op) |
| 153 | { |
| 154 | if (op != Py_EQ || self->ob_type != other->ob_type) { |
| 155 | Py_INCREF(Py_NotImplemented); |
| 156 | return Py_NotImplemented; |
| 157 | } |
| 158 | if (PyWeakref_GET_OBJECT(self) == Py_None |
| 159 | || PyWeakref_GET_OBJECT(other) == Py_None) { |
| 160 | PyObject *res = self==other ? Py_True : Py_False; |
| 161 | Py_INCREF(res); |
| 162 | return res; |
| 163 | } |
| 164 | return PyObject_RichCompare(PyWeakref_GET_OBJECT(self), |
| 165 | PyWeakref_GET_OBJECT(other), op); |
| 166 | } |
| 167 | |
| 168 | |
| 169 | PyTypeObject |
| 170 | _PyWeakref_RefType = { |
| 171 | PyObject_HEAD_INIT(&PyType_Type) |
| 172 | 0, |
| 173 | "weakref", |
| 174 | sizeof(PyWeakReference), |
| 175 | 0, |
| 176 | (destructor)weakref_dealloc,/*tp_dealloc*/ |
| 177 | 0, /*tp_print*/ |
| 178 | 0, /*tp_getattr*/ |
| 179 | 0, /*tp_setattr*/ |
| 180 | 0, /*tp_compare*/ |
| 181 | (reprfunc)weakref_repr, /*tp_repr*/ |
| 182 | 0, /*tp_as_number*/ |
| 183 | 0, /*tp_as_sequence*/ |
| 184 | 0, /*tp_as_mapping*/ |
| 185 | (hashfunc)weakref_hash, /*tp_hash*/ |
| 186 | (ternaryfunc)weakref_call, /*tp_call*/ |
| 187 | 0, /*tp_str*/ |
| 188 | 0, /*tp_getattro*/ |
| 189 | 0, /*tp_setattro*/ |
| 190 | 0, /*tp_as_buffer*/ |
| 191 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_RICHCOMPARE, |
| 192 | 0, /*tp_doc*/ |
| 193 | (traverseproc)gc_traverse, /*tp_traverse*/ |
| 194 | (inquiry)gc_clear, /*tp_clear*/ |
| 195 | (richcmpfunc)weakref_richcompare, /*tp_richcompare*/ |
| 196 | 0, /*tp_weaklistoffset*/ |
| 197 | }; |
| 198 | |
| 199 | |
| 200 | static int |
| 201 | proxy_checkref(PyWeakReference *proxy) |
| 202 | { |
| 203 | if (PyWeakref_GET_OBJECT(proxy) == Py_None) { |
| 204 | PyErr_SetString(PyExc_ReferenceError, |
| 205 | "weakly-referenced object no longer exists"); |
| 206 | return 0; |
| 207 | } |
| 208 | return 1; |
| 209 | } |
| 210 | |
| 211 | |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 212 | /* If a parameter is a proxy, check that it is still "live" and wrap it, |
| 213 | * replacing the original value with the raw object. Raises ReferenceError |
| 214 | * if the param is a dead proxy. |
| 215 | */ |
| 216 | #define UNWRAP(o) \ |
| 217 | if (PyWeakref_CheckProxy(o)) { \ |
| 218 | if (!proxy_checkref((PyWeakReference *)o)) \ |
| 219 | return NULL; \ |
| 220 | o = PyWeakref_GET_OBJECT(o); \ |
| 221 | } |
| 222 | |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 223 | #define WRAP_UNARY(method, generic) \ |
| 224 | static PyObject * \ |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 225 | method(PyObject *proxy) { \ |
| 226 | UNWRAP(proxy); \ |
| 227 | return generic(proxy); \ |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 228 | } |
| 229 | |
| 230 | #define WRAP_BINARY(method, generic) \ |
| 231 | static PyObject * \ |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 232 | method(PyObject *x, PyObject *y) { \ |
| 233 | UNWRAP(x); \ |
| 234 | UNWRAP(y); \ |
| 235 | return generic(x, y); \ |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 236 | } |
| 237 | |
Fred Drake | 31f4d1f | 2001-10-18 19:21:46 +0000 | [diff] [blame] | 238 | /* Note that the third arg needs to be checked for NULL since the tp_call |
| 239 | * slot can receive NULL for this arg. |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 240 | */ |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 241 | #define WRAP_TERNARY(method, generic) \ |
| 242 | static PyObject * \ |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 243 | method(PyObject *proxy, PyObject *v, PyObject *w) { \ |
| 244 | UNWRAP(proxy); \ |
Fred Drake | 31f4d1f | 2001-10-18 19:21:46 +0000 | [diff] [blame] | 245 | UNWRAP(v); \ |
Fred Drake | 73006d0 | 2001-10-18 18:04:18 +0000 | [diff] [blame] | 246 | if (w != NULL) \ |
| 247 | UNWRAP(w); \ |
| 248 | return generic(proxy, v, w); \ |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 249 | } |
| 250 | |
| 251 | |
| 252 | /* direct slots */ |
| 253 | |
| 254 | WRAP_BINARY(proxy_getattr, PyObject_GetAttr) |
| 255 | WRAP_UNARY(proxy_str, PyObject_Str) |
| 256 | WRAP_TERNARY(proxy_call, PyEval_CallObjectWithKeywords) |
| 257 | |
| 258 | static int |
| 259 | proxy_print(PyWeakReference *proxy, FILE *fp, int flags) |
| 260 | { |
| 261 | if (!proxy_checkref(proxy)) |
| 262 | return -1; |
| 263 | return PyObject_Print(PyWeakref_GET_OBJECT(proxy), fp, flags); |
| 264 | } |
| 265 | |
| 266 | static PyObject * |
| 267 | proxy_repr(PyWeakReference *proxy) |
| 268 | { |
| 269 | char buf[160]; |
Barry Warsaw | d586756 | 2001-11-28 21:01:56 +0000 | [diff] [blame] | 270 | PyOS_snprintf(buf, sizeof(buf), |
| 271 | "<weakref at %p to %.100s at %p>", proxy, |
| 272 | PyWeakref_GET_OBJECT(proxy)->ob_type->tp_name, |
| 273 | PyWeakref_GET_OBJECT(proxy)); |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 274 | return PyString_FromString(buf); |
| 275 | } |
| 276 | |
| 277 | |
| 278 | static int |
| 279 | proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value) |
| 280 | { |
| 281 | if (!proxy_checkref(proxy)) |
| 282 | return -1; |
| 283 | return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value); |
| 284 | } |
| 285 | |
| 286 | static int |
| 287 | proxy_compare(PyWeakReference *proxy, PyObject *v) |
| 288 | { |
| 289 | if (!proxy_checkref(proxy)) |
| 290 | return -1; |
| 291 | return PyObject_Compare(PyWeakref_GET_OBJECT(proxy), v); |
| 292 | } |
| 293 | |
| 294 | /* number slots */ |
| 295 | WRAP_BINARY(proxy_add, PyNumber_Add) |
| 296 | WRAP_BINARY(proxy_sub, PyNumber_Subtract) |
| 297 | WRAP_BINARY(proxy_mul, PyNumber_Multiply) |
| 298 | WRAP_BINARY(proxy_div, PyNumber_Divide) |
| 299 | WRAP_BINARY(proxy_mod, PyNumber_Remainder) |
| 300 | WRAP_BINARY(proxy_divmod, PyNumber_Divmod) |
| 301 | WRAP_TERNARY(proxy_pow, PyNumber_Power) |
| 302 | WRAP_UNARY(proxy_neg, PyNumber_Negative) |
| 303 | WRAP_UNARY(proxy_pos, PyNumber_Positive) |
| 304 | WRAP_UNARY(proxy_abs, PyNumber_Absolute) |
| 305 | WRAP_UNARY(proxy_invert, PyNumber_Invert) |
| 306 | WRAP_BINARY(proxy_lshift, PyNumber_Lshift) |
| 307 | WRAP_BINARY(proxy_rshift, PyNumber_Rshift) |
| 308 | WRAP_BINARY(proxy_and, PyNumber_And) |
| 309 | WRAP_BINARY(proxy_xor, PyNumber_Xor) |
| 310 | WRAP_BINARY(proxy_or, PyNumber_Or) |
| 311 | WRAP_UNARY(proxy_int, PyNumber_Int) |
| 312 | WRAP_UNARY(proxy_long, PyNumber_Long) |
| 313 | WRAP_UNARY(proxy_float, PyNumber_Float) |
| 314 | WRAP_BINARY(proxy_iadd, PyNumber_InPlaceAdd) |
| 315 | WRAP_BINARY(proxy_isub, PyNumber_InPlaceSubtract) |
| 316 | WRAP_BINARY(proxy_imul, PyNumber_InPlaceMultiply) |
| 317 | WRAP_BINARY(proxy_idiv, PyNumber_InPlaceDivide) |
| 318 | WRAP_BINARY(proxy_imod, PyNumber_InPlaceRemainder) |
| 319 | WRAP_TERNARY(proxy_ipow, PyNumber_InPlacePower) |
| 320 | WRAP_BINARY(proxy_ilshift, PyNumber_InPlaceLshift) |
| 321 | WRAP_BINARY(proxy_irshift, PyNumber_InPlaceRshift) |
| 322 | WRAP_BINARY(proxy_iand, PyNumber_InPlaceAnd) |
| 323 | WRAP_BINARY(proxy_ixor, PyNumber_InPlaceXor) |
| 324 | WRAP_BINARY(proxy_ior, PyNumber_InPlaceOr) |
| 325 | |
| 326 | static int |
| 327 | proxy_nonzero(PyWeakReference *proxy) |
| 328 | { |
| 329 | PyObject *o = PyWeakref_GET_OBJECT(proxy); |
| 330 | if (!proxy_checkref(proxy)) |
| 331 | return 1; |
| 332 | if (o->ob_type->tp_as_number && |
| 333 | o->ob_type->tp_as_number->nb_nonzero) |
| 334 | return (*o->ob_type->tp_as_number->nb_nonzero)(o); |
| 335 | else |
| 336 | return 1; |
| 337 | } |
| 338 | |
| 339 | /* sequence slots */ |
| 340 | |
| 341 | static PyObject * |
| 342 | proxy_slice(PyWeakReference *proxy, int i, int j) |
| 343 | { |
| 344 | if (!proxy_checkref(proxy)) |
| 345 | return NULL; |
| 346 | return PySequence_GetSlice(PyWeakref_GET_OBJECT(proxy), i, j); |
| 347 | } |
| 348 | |
| 349 | static int |
| 350 | proxy_ass_slice(PyWeakReference *proxy, int i, int j, PyObject *value) |
| 351 | { |
| 352 | if (!proxy_checkref(proxy)) |
| 353 | return -1; |
| 354 | return PySequence_SetSlice(PyWeakref_GET_OBJECT(proxy), i, j, value); |
| 355 | } |
| 356 | |
| 357 | static int |
| 358 | proxy_contains(PyWeakReference *proxy, PyObject *value) |
| 359 | { |
| 360 | if (!proxy_checkref(proxy)) |
| 361 | return -1; |
| 362 | return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value); |
| 363 | } |
| 364 | |
| 365 | |
| 366 | /* mapping slots */ |
| 367 | |
| 368 | static int |
| 369 | proxy_length(PyWeakReference *proxy) |
| 370 | { |
| 371 | if (!proxy_checkref(proxy)) |
| 372 | return -1; |
| 373 | return PyObject_Length(PyWeakref_GET_OBJECT(proxy)); |
| 374 | } |
| 375 | |
| 376 | WRAP_BINARY(proxy_getitem, PyObject_GetItem) |
| 377 | |
| 378 | static int |
| 379 | proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value) |
| 380 | { |
| 381 | if (!proxy_checkref(proxy)) |
| 382 | return -1; |
| 383 | return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value); |
| 384 | } |
| 385 | |
| 386 | |
| 387 | static PyNumberMethods proxy_as_number = { |
| 388 | (binaryfunc)proxy_add, /*nb_add*/ |
| 389 | (binaryfunc)proxy_sub, /*nb_subtract*/ |
| 390 | (binaryfunc)proxy_mul, /*nb_multiply*/ |
| 391 | (binaryfunc)proxy_div, /*nb_divide*/ |
| 392 | (binaryfunc)proxy_mod, /*nb_remainder*/ |
| 393 | (binaryfunc)proxy_divmod, /*nb_divmod*/ |
| 394 | (ternaryfunc)proxy_pow, /*nb_power*/ |
| 395 | (unaryfunc)proxy_neg, /*nb_negative*/ |
| 396 | (unaryfunc)proxy_pos, /*nb_positive*/ |
| 397 | (unaryfunc)proxy_abs, /*nb_absolute*/ |
| 398 | (inquiry)proxy_nonzero, /*nb_nonzero*/ |
| 399 | (unaryfunc)proxy_invert, /*nb_invert*/ |
| 400 | (binaryfunc)proxy_lshift, /*nb_lshift*/ |
| 401 | (binaryfunc)proxy_rshift, /*nb_rshift*/ |
| 402 | (binaryfunc)proxy_and, /*nb_and*/ |
| 403 | (binaryfunc)proxy_xor, /*nb_xor*/ |
| 404 | (binaryfunc)proxy_or, /*nb_or*/ |
| 405 | (coercion)0, /*nb_coerce*/ |
| 406 | (unaryfunc)proxy_int, /*nb_int*/ |
| 407 | (unaryfunc)proxy_long, /*nb_long*/ |
| 408 | (unaryfunc)proxy_float, /*nb_float*/ |
| 409 | (unaryfunc)0, /*nb_oct*/ |
| 410 | (unaryfunc)0, /*nb_hex*/ |
| 411 | (binaryfunc)proxy_iadd, /*nb_inplace_add*/ |
| 412 | (binaryfunc)proxy_isub, /*nb_inplace_subtract*/ |
| 413 | (binaryfunc)proxy_imul, /*nb_inplace_multiply*/ |
| 414 | (binaryfunc)proxy_idiv, /*nb_inplace_divide*/ |
| 415 | (binaryfunc)proxy_imod, /*nb_inplace_remainder*/ |
| 416 | (ternaryfunc)proxy_ipow, /*nb_inplace_power*/ |
| 417 | (binaryfunc)proxy_ilshift, /*nb_inplace_lshift*/ |
| 418 | (binaryfunc)proxy_irshift, /*nb_inplace_rshift*/ |
| 419 | (binaryfunc)proxy_iand, /*nb_inplace_and*/ |
| 420 | (binaryfunc)proxy_ixor, /*nb_inplace_xor*/ |
| 421 | (binaryfunc)proxy_ior, /*nb_inplace_or*/ |
| 422 | }; |
| 423 | |
| 424 | static PySequenceMethods proxy_as_sequence = { |
| 425 | (inquiry)proxy_length, /*sq_length*/ |
| 426 | 0, /*sq_concat*/ |
| 427 | 0, /*sq_repeat*/ |
| 428 | 0, /*sq_item*/ |
| 429 | (intintargfunc)proxy_slice, /*sq_slice*/ |
| 430 | 0, /*sq_ass_item*/ |
| 431 | (intintobjargproc)proxy_ass_slice, /*sq_ass_slice*/ |
| 432 | (objobjproc)proxy_contains, /* sq_contains */ |
| 433 | }; |
| 434 | |
| 435 | static PyMappingMethods proxy_as_mapping = { |
| 436 | (inquiry)proxy_length, /*mp_length*/ |
| 437 | (binaryfunc)proxy_getitem, /*mp_subscript*/ |
| 438 | (objobjargproc)proxy_setitem, /*mp_ass_subscript*/ |
| 439 | }; |
| 440 | |
| 441 | |
| 442 | PyTypeObject |
| 443 | _PyWeakref_ProxyType = { |
| 444 | PyObject_HEAD_INIT(&PyType_Type) |
| 445 | 0, |
| 446 | "weakproxy", |
| 447 | sizeof(PyWeakReference), |
| 448 | 0, |
| 449 | /* methods */ |
| 450 | (destructor)weakref_dealloc,/*tp_dealloc*/ |
| 451 | (printfunc)proxy_print, /*tp_print*/ |
| 452 | 0, /*tp_getattr*/ |
| 453 | 0, /*tp_setattr*/ |
| 454 | (cmpfunc)proxy_compare, /*tp_compare*/ |
| 455 | (unaryfunc)proxy_repr, /*tp_repr*/ |
| 456 | &proxy_as_number, /*tp_as_number*/ |
| 457 | &proxy_as_sequence, /*tp_as_sequence*/ |
| 458 | &proxy_as_mapping, /*tp_as_mapping*/ |
| 459 | 0, /*tp_hash*/ |
| 460 | (ternaryfunc)0, /*tp_call*/ |
| 461 | (unaryfunc)proxy_str, /*tp_str*/ |
| 462 | (getattrofunc)proxy_getattr,/*tp_getattro*/ |
| 463 | (setattrofunc)proxy_setattr,/*tp_setattro*/ |
| 464 | 0, /*tp_as_buffer*/ |
| 465 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
| 466 | |Py_TPFLAGS_CHECKTYPES, /*tp_flags*/ |
| 467 | 0, /*tp_doc*/ |
| 468 | (traverseproc)gc_traverse, /*tp_traverse*/ |
| 469 | (inquiry)gc_clear, /*tp_clear*/ |
| 470 | }; |
| 471 | |
| 472 | |
| 473 | PyTypeObject |
| 474 | _PyWeakref_CallableProxyType = { |
| 475 | PyObject_HEAD_INIT(&PyType_Type) |
| 476 | 0, |
| 477 | "weakcallableproxy", |
| 478 | sizeof(PyWeakReference), |
| 479 | 0, |
| 480 | /* methods */ |
| 481 | (destructor)weakref_dealloc,/*tp_dealloc*/ |
| 482 | (printfunc)proxy_print, /*tp_print*/ |
| 483 | 0, /*tp_getattr*/ |
| 484 | 0, /*tp_setattr*/ |
| 485 | (cmpfunc)proxy_compare, /*tp_compare*/ |
| 486 | (unaryfunc)proxy_repr, /*tp_repr*/ |
| 487 | &proxy_as_number, /*tp_as_number*/ |
| 488 | &proxy_as_sequence, /*tp_as_sequence*/ |
| 489 | &proxy_as_mapping, /*tp_as_mapping*/ |
| 490 | 0, /*tp_hash*/ |
| 491 | (ternaryfunc)proxy_call, /*tp_call*/ |
| 492 | (unaryfunc)proxy_str, /*tp_str*/ |
| 493 | (getattrofunc)proxy_getattr,/*tp_getattro*/ |
| 494 | (setattrofunc)proxy_setattr,/*tp_setattro*/ |
| 495 | 0, /*tp_as_buffer*/ |
| 496 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
| 497 | |Py_TPFLAGS_CHECKTYPES, /*tp_flags*/ |
| 498 | 0, /*tp_doc*/ |
| 499 | (traverseproc)gc_traverse, /*tp_traverse*/ |
| 500 | (inquiry)gc_clear, /*tp_clear*/ |
| 501 | }; |
| 502 | |
| 503 | |
| 504 | /* Given the head of an object's list of weak references, extract the |
| 505 | * two callback-less refs (ref and proxy). Used to determine if the |
| 506 | * shared references exist and to determine the back link for newly |
| 507 | * inserted references. |
| 508 | */ |
| 509 | static void |
| 510 | get_basic_refs(PyWeakReference *head, |
| 511 | PyWeakReference **refp, PyWeakReference **proxyp) |
| 512 | { |
| 513 | *refp = NULL; |
| 514 | *proxyp = NULL; |
| 515 | |
| 516 | if (head != NULL && head->wr_callback == NULL) { |
| 517 | if (head->ob_type == &_PyWeakref_RefType) { |
| 518 | *refp = head; |
| 519 | head = head->wr_next; |
| 520 | } |
| 521 | if (head != NULL && head->wr_callback == NULL) { |
| 522 | *proxyp = head; |
| 523 | head = head->wr_next; |
| 524 | } |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | /* Insert 'newref' in the list after 'prev'. Both must be non-NULL. */ |
| 529 | static void |
| 530 | insert_after(PyWeakReference *newref, PyWeakReference *prev) |
| 531 | { |
| 532 | newref->wr_prev = prev; |
| 533 | newref->wr_next = prev->wr_next; |
| 534 | if (prev->wr_next != NULL) |
| 535 | prev->wr_next->wr_prev = newref; |
| 536 | prev->wr_next = newref; |
| 537 | } |
| 538 | |
| 539 | /* Insert 'newref' at the head of the list; 'list' points to the variable |
| 540 | * that stores the head. |
| 541 | */ |
| 542 | static void |
| 543 | insert_head(PyWeakReference *newref, PyWeakReference **list) |
| 544 | { |
| 545 | PyWeakReference *next = *list; |
| 546 | |
| 547 | newref->wr_prev = NULL; |
| 548 | newref->wr_next = next; |
| 549 | if (next != NULL) |
| 550 | next->wr_prev = newref; |
| 551 | *list = newref; |
| 552 | } |
| 553 | |
| 554 | |
| 555 | PyObject * |
| 556 | PyWeakref_NewRef(PyObject *ob, PyObject *callback) |
| 557 | { |
| 558 | PyWeakReference *result = NULL; |
| 559 | PyWeakReference **list; |
| 560 | PyWeakReference *ref, *proxy; |
| 561 | |
| 562 | if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { |
| 563 | PyErr_Format(PyExc_TypeError, |
Jeremy Hylton | 996fad3 | 2001-10-22 16:31:40 +0000 | [diff] [blame] | 564 | "cannot create weak reference to '%s' object", |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 565 | ob->ob_type->tp_name); |
| 566 | return NULL; |
| 567 | } |
| 568 | list = GET_WEAKREFS_LISTPTR(ob); |
| 569 | get_basic_refs(*list, &ref, &proxy); |
| 570 | if (callback == NULL || callback == Py_None) |
| 571 | /* return existing weak reference if it exists */ |
| 572 | result = ref; |
| 573 | if (result != NULL) |
| 574 | Py_XINCREF(result); |
| 575 | else { |
| 576 | result = new_weakref(); |
| 577 | if (result != NULL) { |
| 578 | Py_XINCREF(callback); |
| 579 | result->wr_callback = callback; |
| 580 | result->wr_object = ob; |
| 581 | if (callback == NULL) { |
| 582 | insert_head(result, list); |
| 583 | } |
| 584 | else { |
| 585 | PyWeakReference *prev = (proxy == NULL) ? ref : proxy; |
| 586 | |
| 587 | if (prev == NULL) |
| 588 | insert_head(result, list); |
| 589 | else |
| 590 | insert_after(result, prev); |
| 591 | } |
| 592 | PyObject_GC_Track(result); |
| 593 | } |
| 594 | } |
| 595 | return (PyObject *) result; |
| 596 | } |
| 597 | |
| 598 | |
| 599 | PyObject * |
| 600 | PyWeakref_NewProxy(PyObject *ob, PyObject *callback) |
| 601 | { |
| 602 | PyWeakReference *result = NULL; |
| 603 | PyWeakReference **list; |
| 604 | PyWeakReference *ref, *proxy; |
| 605 | |
| 606 | if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { |
| 607 | PyErr_Format(PyExc_TypeError, |
Jeremy Hylton | 996fad3 | 2001-10-22 16:31:40 +0000 | [diff] [blame] | 608 | "cannot create weak reference to '%s' object", |
Fred Drake | 8844d52 | 2001-10-05 21:52:26 +0000 | [diff] [blame] | 609 | ob->ob_type->tp_name); |
| 610 | return NULL; |
| 611 | } |
| 612 | list = GET_WEAKREFS_LISTPTR(ob); |
| 613 | get_basic_refs(*list, &ref, &proxy); |
| 614 | if (callback == NULL) |
| 615 | /* attempt to return an existing weak reference if it exists */ |
| 616 | result = proxy; |
| 617 | if (result != NULL) |
| 618 | Py_XINCREF(result); |
| 619 | else { |
| 620 | result = new_weakref(); |
| 621 | if (result != NULL) { |
| 622 | PyWeakReference *prev; |
| 623 | |
| 624 | if (PyCallable_Check(ob)) |
| 625 | result->ob_type = &_PyWeakref_CallableProxyType; |
| 626 | else |
| 627 | result->ob_type = &_PyWeakref_ProxyType; |
| 628 | result->wr_object = ob; |
| 629 | Py_XINCREF(callback); |
| 630 | result->wr_callback = callback; |
| 631 | if (callback == NULL) |
| 632 | prev = ref; |
| 633 | else |
| 634 | prev = (proxy == NULL) ? ref : proxy; |
| 635 | |
| 636 | if (prev == NULL) |
| 637 | insert_head(result, list); |
| 638 | else |
| 639 | insert_after(result, prev); |
| 640 | PyObject_GC_Track(result); |
| 641 | } |
| 642 | } |
| 643 | return (PyObject *) result; |
| 644 | } |
| 645 | |
| 646 | |
| 647 | PyObject * |
| 648 | PyWeakref_GetObject(PyObject *ref) |
| 649 | { |
| 650 | if (ref == NULL || !PyWeakref_Check(ref)) { |
| 651 | PyErr_BadInternalCall(); |
| 652 | return NULL; |
| 653 | } |
| 654 | return PyWeakref_GET_OBJECT(ref); |
| 655 | } |
| 656 | |
| 657 | |
| 658 | /* This is the implementation of the PyObject_ClearWeakRefs() function; it |
| 659 | * is installed in the init_weakref() function. It is called by the |
| 660 | * tp_dealloc handler to clear weak references. |
| 661 | * |
| 662 | * This iterates through the weak references for 'object' and calls callbacks |
| 663 | * for those references which have one. It returns when all callbacks have |
| 664 | * been attempted. |
| 665 | */ |
| 666 | void |
| 667 | PyObject_ClearWeakRefs(PyObject *object) |
| 668 | { |
| 669 | PyWeakReference **list; |
| 670 | |
| 671 | if (object == NULL |
| 672 | || !PyType_SUPPORTS_WEAKREFS(object->ob_type) |
| 673 | || object->ob_refcnt != 0) { |
| 674 | PyErr_BadInternalCall(); |
| 675 | return; |
| 676 | } |
| 677 | list = GET_WEAKREFS_LISTPTR(object); |
| 678 | /* Remove the callback-less basic and proxy references */ |
| 679 | if (*list != NULL && (*list)->wr_callback == NULL) { |
| 680 | clear_weakref(*list); |
| 681 | if (*list != NULL && (*list)->wr_callback == NULL) |
| 682 | clear_weakref(*list); |
| 683 | } |
| 684 | if (*list != NULL) { |
| 685 | int count = _PyWeakref_GetWeakrefCount(*list); |
| 686 | |
| 687 | if (count == 1) { |
| 688 | PyWeakReference *current = *list; |
| 689 | PyObject *callback = current->wr_callback; |
| 690 | PyObject *cbresult; |
| 691 | |
| 692 | Py_INCREF(callback); |
| 693 | clear_weakref(current); |
| 694 | cbresult = PyObject_CallFunction(callback, "O", current); |
| 695 | if (cbresult == NULL) |
| 696 | PyErr_WriteUnraisable(callback); |
| 697 | else |
| 698 | Py_DECREF(cbresult); |
| 699 | Py_DECREF(callback); |
| 700 | } |
| 701 | else { |
| 702 | PyObject *tuple = PyTuple_New(count * 2); |
| 703 | PyWeakReference *current = *list; |
| 704 | int i = 0; |
| 705 | |
| 706 | for (i = 0; i < count; ++i) { |
| 707 | PyWeakReference *next = current->wr_next; |
| 708 | |
| 709 | Py_INCREF(current); |
| 710 | PyTuple_SET_ITEM(tuple, i * 2, (PyObject *) current); |
| 711 | PyTuple_SET_ITEM(tuple, i * 2 + 1, current->wr_callback); |
| 712 | current->wr_callback = NULL; |
| 713 | next = current->wr_next; |
| 714 | clear_weakref(current); |
| 715 | current = next; |
| 716 | } |
| 717 | for (i = 0; i < count; ++i) { |
| 718 | PyObject *current = PyTuple_GET_ITEM(tuple, i * 2); |
| 719 | PyObject *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1); |
| 720 | PyObject *cbresult = PyObject_CallFunction(callback, "O", |
| 721 | current); |
| 722 | if (cbresult == NULL) |
| 723 | PyErr_WriteUnraisable(callback); |
| 724 | else |
| 725 | Py_DECREF(cbresult); |
| 726 | } |
| 727 | Py_DECREF(tuple); |
| 728 | } |
| 729 | } |
| 730 | } |