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| 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 | |||
| 9 | Py_ssize_t | ||
| 10 | _PyWeakref_GetWeakrefCount(PyWeakReference *head) | ||
| 11 | { | ||
| 12 | Py_ssize_t count = 0; | ||
| 13 | |||
| 14 | while (head != NULL) { | ||
| 15 | ++count; | ||
| 16 | head = head->wr_next; | ||
| 17 | } | ||
| 18 | return count; | ||
| 19 | } | ||
| 20 | |||
| 21 | |||
| 22 | static void | ||
| 23 | init_weakref(PyWeakReference *self, PyObject *ob, PyObject *callback) | ||
| 24 | { | ||
| 25 | self->hash = -1; | ||
| 26 | self->wr_object = ob; | ||
| 27 | Py_XINCREF(callback); | ||
| 28 | self->wr_callback = callback; | ||
| 29 | } | ||
| 30 | |||
| 31 | static PyWeakReference * | ||
| 32 | new_weakref(PyObject *ob, PyObject *callback) | ||
| 33 | { | ||
| 34 | PyWeakReference *result; | ||
| 35 | |||
| 36 | result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType); | ||
| 37 | if (result) { | ||
| 38 | init_weakref(result, ob, callback); | ||
| 39 | PyObject_GC_Track(result); | ||
| 40 | } | ||
| 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 | /* If 'self' is the end of the list (and thus self->wr_next == NULL) | ||
| 61 | then the weakref list itself (and thus the value of *list) will | ||
| 62 | end up being set to NULL. */ | ||
| 63 | *list = self->wr_next; | ||
| 64 | self->wr_object = Py_None; | ||
| 65 | if (self->wr_prev != NULL) | ||
| 66 | self->wr_prev->wr_next = self->wr_next; | ||
| 67 | if (self->wr_next != NULL) | ||
| 68 | self->wr_next->wr_prev = self->wr_prev; | ||
| 69 | self->wr_prev = NULL; | ||
| 70 | self->wr_next = NULL; | ||
| 71 | } | ||
| 72 | if (callback != NULL) { | ||
| 73 | Py_DECREF(callback); | ||
| 74 | self->wr_callback = NULL; | ||
| 75 | } | ||
| 76 | } | ||
| 77 | |||
| 78 | /* Cyclic gc uses this to *just* clear the passed-in reference, leaving | ||
| 79 | * the callback intact and uncalled. It must be possible to call self's | ||
| 80 | * tp_dealloc() after calling this, so self has to be left in a sane enough | ||
| 81 | * state for that to work. We expect tp_dealloc to decref the callback | ||
| 82 | * then. The reason for not letting clear_weakref() decref the callback | ||
| 83 | * right now is that if the callback goes away, that may in turn trigger | ||
| 84 | * another callback (if a weak reference to the callback exists) -- running | ||
| 85 | * arbitrary Python code in the middle of gc is a disaster. The convolution | ||
| 86 | * here allows gc to delay triggering such callbacks until the world is in | ||
| 87 | * a sane state again. | ||
| 88 | */ | ||
| 89 | void | ||
| 90 | _PyWeakref_ClearRef(PyWeakReference *self) | ||
| 91 | { | ||
| 92 | PyObject *callback; | ||
| 93 | |||
| 94 | assert(self != NULL); | ||
| 95 | assert(PyWeakref_Check(self)); | ||
| 96 | /* Preserve and restore the callback around clear_weakref. */ | ||
| 97 | callback = self->wr_callback; | ||
| 98 | self->wr_callback = NULL; | ||
| 99 | clear_weakref(self); | ||
| 100 | self->wr_callback = callback; | ||
| 101 | } | ||
| 102 | |||
| 103 | static void | ||
| 104 | weakref_dealloc(PyObject *self) | ||
| 105 | { | ||
| 106 | PyObject_GC_UnTrack(self); | ||
| 107 | clear_weakref((PyWeakReference *) self); | ||
| 108 | self->ob_type->tp_free(self); | ||
| 109 | } | ||
| 110 | |||
| 111 | |||
| 112 | static int | ||
| 113 | gc_traverse(PyWeakReference *self, visitproc visit, void *arg) | ||
| 114 | { | ||
| 115 | Py_VISIT(self->wr_callback); | ||
| 116 | return 0; | ||
| 117 | } | ||
| 118 | |||
| 119 | |||
| 120 | static int | ||
| 121 | gc_clear(PyWeakReference *self) | ||
| 122 | { | ||
| 123 | clear_weakref(self); | ||
| 124 | return 0; | ||
| 125 | } | ||
| 126 | |||
| 127 | |||
| 128 | static PyObject * | ||
| 129 | weakref_call(PyWeakReference *self, PyObject *args, PyObject *kw) | ||
| 130 | { | ||
| 131 | static char *kwlist[] = {NULL}; | ||
| 132 | |||
| 133 | if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", kwlist)) { | ||
| 134 | PyObject *object = PyWeakref_GET_OBJECT(self); | ||
| 135 | Py_INCREF(object); | ||
| 136 | return (object); | ||
| 137 | } | ||
| 138 | return NULL; | ||
| 139 | } | ||
| 140 | |||
| 141 | |||
| 142 | static long | ||
| 143 | weakref_hash(PyWeakReference *self) | ||
| 144 | { | ||
| 145 | if (self->hash != -1) | ||
| 146 | return self->hash; | ||
| 147 | if (PyWeakref_GET_OBJECT(self) == Py_None) { | ||
| 148 | PyErr_SetString(PyExc_TypeError, "weak object has gone away"); | ||
| 149 | return -1; | ||
| 150 | } | ||
| 151 | self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self)); | ||
| 152 | return self->hash; | ||
| 153 | } | ||
| 154 | |||
| 155 | |||
| 156 | static PyObject * | ||
| 157 | weakref_repr(PyWeakReference *self) | ||
| 158 | { | ||
| 159 | char buffer[256]; | ||
| 160 | if (PyWeakref_GET_OBJECT(self) == Py_None) { | ||
| 161 | PyOS_snprintf(buffer, sizeof(buffer), "<weakref at %p; dead>", self); | ||
| 162 | } | ||
| 163 | else { | ||
| 164 | char *name = NULL; | ||
| 165 | PyObject *nameobj = PyObject_GetAttrString(PyWeakref_GET_OBJECT(self), | ||
| 166 | "__name__"); | ||
| 167 | if (nameobj == NULL) | ||
| 168 | PyErr_Clear(); | ||
| 169 | else if (PyString_Check(nameobj)) | ||
| 170 | name = PyString_AS_STRING(nameobj); | ||
| 171 | PyOS_snprintf(buffer, sizeof(buffer), | ||
| 172 | name ? "<weakref at %p; to '%.50s' at %p (%s)>" | ||
| 173 | : "<weakref at %p; to '%.50s' at %p>", | ||
| 174 | self, | ||
| 175 | PyWeakref_GET_OBJECT(self)->ob_type->tp_name, | ||
| 176 | PyWeakref_GET_OBJECT(self), | ||
| 177 | name); | ||
| 178 | Py_XDECREF(nameobj); | ||
| 179 | } | ||
| 180 | return PyString_FromString(buffer); | ||
| 181 | } | ||
| 182 | |||
| 183 | /* Weak references only support equality, not ordering. Two weak references | ||
| 184 | are equal if the underlying objects are equal. If the underlying object has | ||
| 185 | gone away, they are equal if they are identical. */ | ||
| 186 | |||
| 187 | static PyObject * | ||
| 188 | weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op) | ||
| 189 | { | ||
| 190 | if (op != Py_EQ || self->ob_type != other->ob_type) { | ||
| 191 | Py_INCREF(Py_NotImplemented); | ||
| 192 | return Py_NotImplemented; | ||
| 193 | } | ||
| 194 | if (PyWeakref_GET_OBJECT(self) == Py_None | ||
| 195 | || PyWeakref_GET_OBJECT(other) == Py_None) { | ||
| 196 | PyObject *res = self==other ? Py_True : Py_False; | ||
| 197 | Py_INCREF(res); | ||
| 198 | return res; | ||
| 199 | } | ||
| 200 | return PyObject_RichCompare(PyWeakref_GET_OBJECT(self), | ||
| 201 | PyWeakref_GET_OBJECT(other), op); | ||
| 202 | } | ||
| 203 | |||
| 204 | /* Given the head of an object's list of weak references, extract the | ||
| 205 | * two callback-less refs (ref and proxy). Used to determine if the | ||
| 206 | * shared references exist and to determine the back link for newly | ||
| 207 | * inserted references. | ||
| 208 | */ | ||
| 209 | static void | ||
| 210 | get_basic_refs(PyWeakReference *head, | ||
| 211 | PyWeakReference **refp, PyWeakReference **proxyp) | ||
| 212 | { | ||
| 213 | *refp = NULL; | ||
| 214 | *proxyp = NULL; | ||
| 215 | |||
| 216 | if (head != NULL && head->wr_callback == NULL) { | ||
| 217 | /* We need to be careful that the "basic refs" aren't | ||
| 218 | subclasses of the main types. That complicates this a | ||
| 219 | little. */ | ||
| 220 | if (PyWeakref_CheckRefExact(head)) { | ||
| 221 | *refp = head; | ||
| 222 | head = head->wr_next; | ||
| 223 | } | ||
| 224 | if (head != NULL | ||
| 225 | && head->wr_callback == NULL | ||
| 226 | && PyWeakref_CheckProxy(head)) { | ||
| 227 | *proxyp = head; | ||
| 228 | /* head = head->wr_next; */ | ||
| 229 | } | ||
| 230 | } | ||
| 231 | } | ||
| 232 | |||
| 233 | /* Insert 'newref' in the list after 'prev'. Both must be non-NULL. */ | ||
| 234 | static void | ||
| 235 | insert_after(PyWeakReference *newref, PyWeakReference *prev) | ||
| 236 | { | ||
| 237 | newref->wr_prev = prev; | ||
| 238 | newref->wr_next = prev->wr_next; | ||
| 239 | if (prev->wr_next != NULL) | ||
| 240 | prev->wr_next->wr_prev = newref; | ||
| 241 | prev->wr_next = newref; | ||
| 242 | } | ||
| 243 | |||
| 244 | /* Insert 'newref' at the head of the list; 'list' points to the variable | ||
| 245 | * that stores the head. | ||
| 246 | */ | ||
| 247 | static void | ||
| 248 | insert_head(PyWeakReference *newref, PyWeakReference **list) | ||
| 249 | { | ||
| 250 | PyWeakReference *next = *list; | ||
| 251 | |||
| 252 | newref->wr_prev = NULL; | ||
| 253 | newref->wr_next = next; | ||
| 254 | if (next != NULL) | ||
| 255 | next->wr_prev = newref; | ||
| 256 | *list = newref; | ||
| 257 | } | ||
| 258 | |||
| 259 | static int | ||
| 260 | parse_weakref_init_args(char *funcname, PyObject *args, PyObject *kwargs, | ||
| 261 | PyObject **obp, PyObject **callbackp) | ||
| 262 | { | ||
| 263 | /* XXX Should check that kwargs == NULL or is empty. */ | ||
| 264 | return PyArg_UnpackTuple(args, funcname, 1, 2, obp, callbackp); | ||
| 265 | } | ||
| 266 | |||
| 267 | static PyObject * | ||
| 268 | weakref___new__(PyTypeObject *type, PyObject *args, PyObject *kwargs) | ||
| 269 | { | ||
| 270 | PyWeakReference *self = NULL; | ||
| 271 | PyObject *ob, *callback = NULL; | ||
| 272 | |||
| 273 | if (parse_weakref_init_args("__new__", args, kwargs, &ob, &callback)) { | ||
| 274 | PyWeakReference *ref, *proxy; | ||
| 275 | PyWeakReference **list; | ||
| 276 | |||
| 277 | if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { | ||
| 278 | PyErr_Format(PyExc_TypeError, | ||
| 279 | "cannot create weak reference to '%s' object", | ||
| 280 | ob->ob_type->tp_name); | ||
| 281 | return NULL; | ||
| 282 | } | ||
| 283 | if (callback == Py_None) | ||
| 284 | callback = NULL; | ||
| 285 | list = GET_WEAKREFS_LISTPTR(ob); | ||
| 286 | get_basic_refs(*list, &ref, &proxy); | ||
| 287 | if (callback == NULL && type == &_PyWeakref_RefType) { | ||
| 288 | if (ref != NULL) { | ||
| 289 | /* We can re-use an existing reference. */ | ||
| 290 | Py_INCREF(ref); | ||
| 291 | return (PyObject *)ref; | ||
| 292 | } | ||
| 293 | } | ||
| 294 | /* We have to create a new reference. */ | ||
| 295 | /* Note: the tp_alloc() can trigger cyclic GC, so the weakref | ||
| 296 | list on ob can be mutated. This means that the ref and | ||
| 297 | proxy pointers we got back earlier may have been collected, | ||
| 298 | so we need to compute these values again before we use | ||
| 299 | them. */ | ||
| 300 | self = (PyWeakReference *) (type->tp_alloc(type, 0)); | ||
| 301 | if (self != NULL) { | ||
| 302 | init_weakref(self, ob, callback); | ||
| 303 | if (callback == NULL && type == &_PyWeakref_RefType) { | ||
| 304 | insert_head(self, list); | ||
| 305 | } | ||
| 306 | else { | ||
| 307 | PyWeakReference *prev; | ||
| 308 | |||
| 309 | get_basic_refs(*list, &ref, &proxy); | ||
| 310 | prev = (proxy == NULL) ? ref : proxy; | ||
| 311 | if (prev == NULL) | ||
| 312 | insert_head(self, list); | ||
| 313 | else | ||
| 314 | insert_after(self, prev); | ||
| 315 | } | ||
| 316 | } | ||
| 317 | } | ||
| 318 | return (PyObject *)self; | ||
| 319 | } | ||
| 320 | |||
| 321 | static int | ||
| 322 | weakref___init__(PyObject *self, PyObject *args, PyObject *kwargs) | ||
| 323 | { | ||
| 324 | PyObject *tmp; | ||
| 325 | |||
| 326 | if (parse_weakref_init_args("__init__", args, kwargs, &tmp, &tmp)) | ||
| 327 | return 0; | ||
| 328 | else | ||
| 329 | return 1; | ||
| 330 | } | ||
| 331 | |||
| 332 | |||
| 333 | PyTypeObject | ||
| 334 | _PyWeakref_RefType = { | ||
| 335 | PyObject_HEAD_INIT(&PyType_Type) | ||
| 336 | 0, | ||
| 337 | "weakref", | ||
| 338 | sizeof(PyWeakReference), | ||
| 339 | 0, | ||
| 340 | weakref_dealloc, /*tp_dealloc*/ | ||
| 341 | 0, /*tp_print*/ | ||
| 342 | 0, /*tp_getattr*/ | ||
| 343 | 0, /*tp_setattr*/ | ||
| 344 | 0, /*tp_compare*/ | ||
| 345 | (reprfunc)weakref_repr, /*tp_repr*/ | ||
| 346 | 0, /*tp_as_number*/ | ||
| 347 | 0, /*tp_as_sequence*/ | ||
| 348 | 0, /*tp_as_mapping*/ | ||
| 349 | (hashfunc)weakref_hash, /*tp_hash*/ | ||
| 350 | (ternaryfunc)weakref_call, /*tp_call*/ | ||
| 351 | 0, /*tp_str*/ | ||
| 352 | 0, /*tp_getattro*/ | ||
| 353 | 0, /*tp_setattro*/ | ||
| 354 | 0, /*tp_as_buffer*/ | ||
| 355 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_RICHCOMPARE | ||
| 356 | | Py_TPFLAGS_BASETYPE, /*tp_flags*/ | ||
| 357 | 0, /*tp_doc*/ | ||
| 358 | (traverseproc)gc_traverse, /*tp_traverse*/ | ||
| 359 | (inquiry)gc_clear, /*tp_clear*/ | ||
| 360 | (richcmpfunc)weakref_richcompare, /*tp_richcompare*/ | ||
| 361 | 0, /*tp_weaklistoffset*/ | ||
| 362 | 0, /*tp_iter*/ | ||
| 363 | 0, /*tp_iternext*/ | ||
| 364 | 0, /*tp_methods*/ | ||
| 365 | 0, /*tp_members*/ | ||
| 366 | 0, /*tp_getset*/ | ||
| 367 | 0, /*tp_base*/ | ||
| 368 | 0, /*tp_dict*/ | ||
| 369 | 0, /*tp_descr_get*/ | ||
| 370 | 0, /*tp_descr_set*/ | ||
| 371 | 0, /*tp_dictoffset*/ | ||
| 372 | weakref___init__, /*tp_init*/ | ||
| 373 | PyType_GenericAlloc, /*tp_alloc*/ | ||
| 374 | weakref___new__, /*tp_new*/ | ||
| 375 | PyObject_GC_Del, /*tp_free*/ | ||
| 376 | }; | ||
| 377 | |||
| 378 | |||
| 379 | static int | ||
| 380 | proxy_checkref(PyWeakReference *proxy) | ||
| 381 | { | ||
| 382 | if (PyWeakref_GET_OBJECT(proxy) == Py_None) { | ||
| 383 | PyErr_SetString(PyExc_ReferenceError, | ||
| 384 | "weakly-referenced object no longer exists"); | ||
| 385 | return 0; | ||
| 386 | } | ||
| 387 | return 1; | ||
| 388 | } | ||
| 389 | |||
| 390 | |||
| 391 | /* If a parameter is a proxy, check that it is still "live" and wrap it, | ||
| 392 | * replacing the original value with the raw object. Raises ReferenceError | ||
| 393 | * if the param is a dead proxy. | ||
| 394 | */ | ||
| 395 | #define UNWRAP(o) \ | ||
| 396 | if (PyWeakref_CheckProxy(o)) { \ | ||
| 397 | if (!proxy_checkref((PyWeakReference *)o)) \ | ||
| 398 | return NULL; \ | ||
| 399 | o = PyWeakref_GET_OBJECT(o); \ | ||
| 400 | } | ||
| 401 | |||
| 402 | #define UNWRAP_I(o) \ | ||
| 403 | if (PyWeakref_CheckProxy(o)) { \ | ||
| 404 | if (!proxy_checkref((PyWeakReference *)o)) \ | ||
| 405 | return -1; \ | ||
| 406 | o = PyWeakref_GET_OBJECT(o); \ | ||
| 407 | } | ||
| 408 | |||
| 409 | #define WRAP_UNARY(method, generic) \ | ||
| 410 | static PyObject * \ | ||
| 411 | method(PyObject *proxy) { \ | ||
| 412 | UNWRAP(proxy); \ | ||
| 413 | return generic(proxy); \ | ||
| 414 | } | ||
| 415 | |||
| 416 | #define WRAP_BINARY(method, generic) \ | ||
| 417 | static PyObject * \ | ||
| 418 | method(PyObject *x, PyObject *y) { \ | ||
| 419 | UNWRAP(x); \ | ||
| 420 | UNWRAP(y); \ | ||
| 421 | return generic(x, y); \ | ||
| 422 | } | ||
| 423 | |||
| 424 | /* Note that the third arg needs to be checked for NULL since the tp_call | ||
| 425 | * slot can receive NULL for this arg. | ||
| 426 | */ | ||
| 427 | #define WRAP_TERNARY(method, generic) \ | ||
| 428 | static PyObject * \ | ||
| 429 | method(PyObject *proxy, PyObject *v, PyObject *w) { \ | ||
| 430 | UNWRAP(proxy); \ | ||
| 431 | UNWRAP(v); \ | ||
| 432 | if (w != NULL) \ | ||
| 433 | UNWRAP(w); \ | ||
| 434 | return generic(proxy, v, w); \ | ||
| 435 | } | ||
| 436 | |||
| 437 | |||
| 438 | /* direct slots */ | ||
| 439 | |||
| 440 | WRAP_BINARY(proxy_getattr, PyObject_GetAttr) | ||
| 441 | WRAP_UNARY(proxy_str, PyObject_Str) | ||
| 442 | WRAP_TERNARY(proxy_call, PyEval_CallObjectWithKeywords) | ||
| 443 | |||
| 444 | static PyObject * | ||
| 445 | proxy_repr(PyWeakReference *proxy) | ||
| 446 | { | ||
| 447 | char buf[160]; | ||
| 448 | PyOS_snprintf(buf, sizeof(buf), | ||
| 449 | "<weakproxy at %p to %.100s at %p>", proxy, | ||
| 450 | PyWeakref_GET_OBJECT(proxy)->ob_type->tp_name, | ||
| 451 | PyWeakref_GET_OBJECT(proxy)); | ||
| 452 | return PyString_FromString(buf); | ||
| 453 | } | ||
| 454 | |||
| 455 | |||
| 456 | static int | ||
| 457 | proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value) | ||
| 458 | { | ||
| 459 | if (!proxy_checkref(proxy)) | ||
| 460 | return -1; | ||
| 461 | return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value); | ||
| 462 | } | ||
| 463 | |||
| 464 | static int | ||
| 465 | proxy_compare(PyObject *proxy, PyObject *v) | ||
| 466 | { | ||
| 467 | UNWRAP_I(proxy); | ||
| 468 | UNWRAP_I(v); | ||
| 469 | return PyObject_Compare(proxy, v); | ||
| 470 | } | ||
| 471 | |||
| 472 | /* number slots */ | ||
| 473 | WRAP_BINARY(proxy_add, PyNumber_Add) | ||
| 474 | WRAP_BINARY(proxy_sub, PyNumber_Subtract) | ||
| 475 | WRAP_BINARY(proxy_mul, PyNumber_Multiply) | ||
| 476 | WRAP_BINARY(proxy_div, PyNumber_Divide) | ||
| 477 | WRAP_BINARY(proxy_mod, PyNumber_Remainder) | ||
| 478 | WRAP_BINARY(proxy_divmod, PyNumber_Divmod) | ||
| 479 | WRAP_TERNARY(proxy_pow, PyNumber_Power) | ||
| 480 | WRAP_UNARY(proxy_neg, PyNumber_Negative) | ||
| 481 | WRAP_UNARY(proxy_pos, PyNumber_Positive) | ||
| 482 | WRAP_UNARY(proxy_abs, PyNumber_Absolute) | ||
| 483 | WRAP_UNARY(proxy_invert, PyNumber_Invert) | ||
| 484 | WRAP_BINARY(proxy_lshift, PyNumber_Lshift) | ||
| 485 | WRAP_BINARY(proxy_rshift, PyNumber_Rshift) | ||
| 486 | WRAP_BINARY(proxy_and, PyNumber_And) | ||
| 487 | WRAP_BINARY(proxy_xor, PyNumber_Xor) | ||
| 488 | WRAP_BINARY(proxy_or, PyNumber_Or) | ||
| 489 | WRAP_UNARY(proxy_int, PyNumber_Int) | ||
| 490 | WRAP_UNARY(proxy_long, PyNumber_Long) | ||
| 491 | WRAP_UNARY(proxy_float, PyNumber_Float) | ||
| 492 | WRAP_BINARY(proxy_iadd, PyNumber_InPlaceAdd) | ||
| 493 | WRAP_BINARY(proxy_isub, PyNumber_InPlaceSubtract) | ||
| 494 | WRAP_BINARY(proxy_imul, PyNumber_InPlaceMultiply) | ||
| 495 | WRAP_BINARY(proxy_idiv, PyNumber_InPlaceDivide) | ||
| 496 | WRAP_BINARY(proxy_imod, PyNumber_InPlaceRemainder) | ||
| 497 | WRAP_TERNARY(proxy_ipow, PyNumber_InPlacePower) | ||
| 498 | WRAP_BINARY(proxy_ilshift, PyNumber_InPlaceLshift) | ||
| 499 | WRAP_BINARY(proxy_irshift, PyNumber_InPlaceRshift) | ||
| 500 | WRAP_BINARY(proxy_iand, PyNumber_InPlaceAnd) | ||
| 501 | WRAP_BINARY(proxy_ixor, PyNumber_InPlaceXor) | ||
| 502 | WRAP_BINARY(proxy_ior, PyNumber_InPlaceOr) | ||
| 503 | |||
| 504 | static int | ||
| 505 | proxy_nonzero(PyWeakReference *proxy) | ||
| 506 | { | ||
| 507 | PyObject *o = PyWeakref_GET_OBJECT(proxy); | ||
| 508 | if (!proxy_checkref(proxy)) | ||
| 509 | return -1; | ||
| 510 | return PyObject_IsTrue(o); | ||
| 511 | } | ||
| 512 | |||
| 513 | static void | ||
| 514 | proxy_dealloc(PyWeakReference *self) | ||
| 515 | { | ||
| 516 | if (self->wr_callback != NULL) | ||
| 517 | PyObject_GC_UnTrack((PyObject *)self); | ||
| 518 | clear_weakref(self); | ||
| 519 | PyObject_GC_Del(self); | ||
| 520 | } | ||
| 521 | |||
| 522 | /* sequence slots */ | ||
| 523 | |||
| 524 | static PyObject * | ||
| 525 | proxy_slice(PyWeakReference *proxy, Py_ssize_t i, Py_ssize_t j) | ||
| 526 | { | ||
| 527 | if (!proxy_checkref(proxy)) | ||
| 528 | return NULL; | ||
| 529 | return PySequence_GetSlice(PyWeakref_GET_OBJECT(proxy), i, j); | ||
| 530 | } | ||
| 531 | |||
| 532 | static int | ||
| 533 | proxy_ass_slice(PyWeakReference *proxy, Py_ssize_t i, Py_ssize_t j, PyObject *value) | ||
| 534 | { | ||
| 535 | if (!proxy_checkref(proxy)) | ||
| 536 | return -1; | ||
| 537 | return PySequence_SetSlice(PyWeakref_GET_OBJECT(proxy), i, j, value); | ||
| 538 | } | ||
| 539 | |||
| 540 | static int | ||
| 541 | proxy_contains(PyWeakReference *proxy, PyObject *value) | ||
| 542 | { | ||
| 543 | if (!proxy_checkref(proxy)) | ||
| 544 | return -1; | ||
| 545 | return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value); | ||
| 546 | } | ||
| 547 | |||
| 548 | |||
| 549 | /* mapping slots */ | ||
| 550 | |||
| 551 | static Py_ssize_t | ||
| 552 | proxy_length(PyWeakReference *proxy) | ||
| 553 | { | ||
| 554 | if (!proxy_checkref(proxy)) | ||
| 555 | return -1; | ||
| 556 | return PyObject_Length(PyWeakref_GET_OBJECT(proxy)); | ||
| 557 | } | ||
| 558 | |||
| 559 | WRAP_BINARY(proxy_getitem, PyObject_GetItem) | ||
| 560 | |||
| 561 | static int | ||
| 562 | proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value) | ||
| 563 | { | ||
| 564 | if (!proxy_checkref(proxy)) | ||
| 565 | return -1; | ||
| 566 | |||
| 567 | if (value == NULL) | ||
| 568 | return PyObject_DelItem(PyWeakref_GET_OBJECT(proxy), key); | ||
| 569 | else | ||
| 570 | return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value); | ||
| 571 | } | ||
| 572 | |||
| 573 | /* iterator slots */ | ||
| 574 | |||
| 575 | static PyObject * | ||
| 576 | proxy_iter(PyWeakReference *proxy) | ||
| 577 | { | ||
| 578 | if (!proxy_checkref(proxy)) | ||
| 579 | return NULL; | ||
| 580 | return PyObject_GetIter(PyWeakref_GET_OBJECT(proxy)); | ||
| 581 | } | ||
| 582 | |||
| 583 | static PyObject * | ||
| 584 | proxy_iternext(PyWeakReference *proxy) | ||
| 585 | { | ||
| 586 | if (!proxy_checkref(proxy)) | ||
| 587 | return NULL; | ||
| 588 | return PyIter_Next(PyWeakref_GET_OBJECT(proxy)); | ||
| 589 | } | ||
| 590 | |||
| 591 | |||
| 592 | static PyNumberMethods proxy_as_number = { | ||
| 593 | proxy_add, /*nb_add*/ | ||
| 594 | proxy_sub, /*nb_subtract*/ | ||
| 595 | proxy_mul, /*nb_multiply*/ | ||
| 596 | proxy_div, /*nb_divide*/ | ||
| 597 | proxy_mod, /*nb_remainder*/ | ||
| 598 | proxy_divmod, /*nb_divmod*/ | ||
| 599 | proxy_pow, /*nb_power*/ | ||
| 600 | proxy_neg, /*nb_negative*/ | ||
| 601 | proxy_pos, /*nb_positive*/ | ||
| 602 | proxy_abs, /*nb_absolute*/ | ||
| 603 | (inquiry)proxy_nonzero, /*nb_nonzero*/ | ||
| 604 | proxy_invert, /*nb_invert*/ | ||
| 605 | proxy_lshift, /*nb_lshift*/ | ||
| 606 | proxy_rshift, /*nb_rshift*/ | ||
| 607 | proxy_and, /*nb_and*/ | ||
| 608 | proxy_xor, /*nb_xor*/ | ||
| 609 | proxy_or, /*nb_or*/ | ||
| 610 | 0, /*nb_coerce*/ | ||
| 611 | proxy_int, /*nb_int*/ | ||
| 612 | proxy_long, /*nb_long*/ | ||
| 613 | proxy_float, /*nb_float*/ | ||
| 614 | 0, /*nb_oct*/ | ||
| 615 | 0, /*nb_hex*/ | ||
| 616 | proxy_iadd, /*nb_inplace_add*/ | ||
| 617 | proxy_isub, /*nb_inplace_subtract*/ | ||
| 618 | proxy_imul, /*nb_inplace_multiply*/ | ||
| 619 | proxy_idiv, /*nb_inplace_divide*/ | ||
| 620 | proxy_imod, /*nb_inplace_remainder*/ | ||
| 621 | proxy_ipow, /*nb_inplace_power*/ | ||
| 622 | proxy_ilshift, /*nb_inplace_lshift*/ | ||
| 623 | proxy_irshift, /*nb_inplace_rshift*/ | ||
| 624 | proxy_iand, /*nb_inplace_and*/ | ||
| 625 | proxy_ixor, /*nb_inplace_xor*/ | ||
| 626 | proxy_ior, /*nb_inplace_or*/ | ||
| 627 | }; | ||
| 628 | |||
| 629 | static PySequenceMethods proxy_as_sequence = { | ||
| 630 | (lenfunc)proxy_length, /*sq_length*/ | ||
| 631 | 0, /*sq_concat*/ | ||
| 632 | 0, /*sq_repeat*/ | ||
| 633 | 0, /*sq_item*/ | ||
| 634 | (ssizessizeargfunc)proxy_slice, /*sq_slice*/ | ||
| 635 | 0, /*sq_ass_item*/ | ||
| 636 | (ssizessizeobjargproc)proxy_ass_slice, /*sq_ass_slice*/ | ||
| 637 | (objobjproc)proxy_contains, /* sq_contains */ | ||
| 638 | }; | ||
| 639 | |||
| 640 | static PyMappingMethods proxy_as_mapping = { | ||
| 641 | (lenfunc)proxy_length, /*mp_length*/ | ||
| 642 | proxy_getitem, /*mp_subscript*/ | ||
| 643 | (objobjargproc)proxy_setitem, /*mp_ass_subscript*/ | ||
| 644 | }; | ||
| 645 | |||
| 646 | |||
| 647 | PyTypeObject | ||
| 648 | _PyWeakref_ProxyType = { | ||
| 649 | PyObject_HEAD_INIT(&PyType_Type) | ||
| 650 | 0, | ||
| 651 | "weakproxy", | ||
| 652 | sizeof(PyWeakReference), | ||
| 653 | 0, | ||
| 654 | /* methods */ | ||
| 655 | (destructor)proxy_dealloc, /* tp_dealloc */ | ||
| 656 | 0, /* tp_print */ | ||
| 657 | 0, /* tp_getattr */ | ||
| 658 | 0, /* tp_setattr */ | ||
| 659 | proxy_compare, /* tp_compare */ | ||
| 660 | (reprfunc)proxy_repr, /* tp_repr */ | ||
| 661 | &proxy_as_number, /* tp_as_number */ | ||
| 662 | &proxy_as_sequence, /* tp_as_sequence */ | ||
| 663 | &proxy_as_mapping, /* tp_as_mapping */ | ||
| 664 | 0, /* tp_hash */ | ||
| 665 | 0, /* tp_call */ | ||
| 666 | proxy_str, /* tp_str */ | ||
| 667 | proxy_getattr, /* tp_getattro */ | ||
| 668 | (setattrofunc)proxy_setattr, /* tp_setattro */ | ||
| 669 | 0, /* tp_as_buffer */ | ||
| 670 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | ||
| 671 | | Py_TPFLAGS_CHECKTYPES, /* tp_flags */ | ||
| 672 | 0, /* tp_doc */ | ||
| 673 | (traverseproc)gc_traverse, /* tp_traverse */ | ||
| 674 | (inquiry)gc_clear, /* tp_clear */ | ||
| 675 | 0, /* tp_richcompare */ | ||
| 676 | 0, /* tp_weaklistoffset */ | ||
| 677 | (getiterfunc)proxy_iter, /* tp_iter */ | ||
| 678 | (iternextfunc)proxy_iternext, /* tp_iternext */ | ||
| 679 | }; | ||
| 680 | |||
| 681 | |||
| 682 | PyTypeObject | ||
| 683 | _PyWeakref_CallableProxyType = { | ||
| 684 | PyObject_HEAD_INIT(&PyType_Type) | ||
| 685 | 0, | ||
| 686 | "weakcallableproxy", | ||
| 687 | sizeof(PyWeakReference), | ||
| 688 | 0, | ||
| 689 | /* methods */ | ||
| 690 | (destructor)proxy_dealloc, /* tp_dealloc */ | ||
| 691 | 0, /* tp_print */ | ||
| 692 | 0, /* tp_getattr */ | ||
| 693 | 0, /* tp_setattr */ | ||
| 694 | proxy_compare, /* tp_compare */ | ||
| 695 | (unaryfunc)proxy_repr, /* tp_repr */ | ||
| 696 | &proxy_as_number, /* tp_as_number */ | ||
| 697 | &proxy_as_sequence, /* tp_as_sequence */ | ||
| 698 | &proxy_as_mapping, /* tp_as_mapping */ | ||
| 699 | 0, /* tp_hash */ | ||
| 700 | proxy_call, /* tp_call */ | ||
| 701 | proxy_str, /* tp_str */ | ||
| 702 | proxy_getattr, /* tp_getattro */ | ||
| 703 | (setattrofunc)proxy_setattr, /* tp_setattro */ | ||
| 704 | 0, /* tp_as_buffer */ | ||
| 705 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | ||
| 706 | | Py_TPFLAGS_CHECKTYPES, /* tp_flags */ | ||
| 707 | 0, /* tp_doc */ | ||
| 708 | (traverseproc)gc_traverse, /* tp_traverse */ | ||
| 709 | (inquiry)gc_clear, /* tp_clear */ | ||
| 710 | 0, /* tp_richcompare */ | ||
| 711 | 0, /* tp_weaklistoffset */ | ||
| 712 | (getiterfunc)proxy_iter, /* tp_iter */ | ||
| 713 | (iternextfunc)proxy_iternext, /* tp_iternext */ | ||
| 714 | }; | ||
| 715 | |||
| 716 | |||
| 717 | |||
| 718 | PyObject * | ||
| 719 | PyWeakref_NewRef(PyObject *ob, PyObject *callback) | ||
| 720 | { | ||
| 721 | PyWeakReference *result = NULL; | ||
| 722 | PyWeakReference **list; | ||
| 723 | PyWeakReference *ref, *proxy; | ||
| 724 | |||
| 725 | if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { | ||
| 726 | PyErr_Format(PyExc_TypeError, | ||
| 727 | "cannot create weak reference to '%s' object", | ||
| 728 | ob->ob_type->tp_name); | ||
| 729 | return NULL; | ||
| 730 | } | ||
| 731 | list = GET_WEAKREFS_LISTPTR(ob); | ||
| 732 | get_basic_refs(*list, &ref, &proxy); | ||
| 733 | if (callback == Py_None) | ||
| 734 | callback = NULL; | ||
| 735 | if (callback == NULL) | ||
| 736 | /* return existing weak reference if it exists */ | ||
| 737 | result = ref; | ||
| 738 | if (result != NULL) | ||
| 739 | Py_INCREF(result); | ||
| 740 | else { | ||
| 741 | /* Note: new_weakref() can trigger cyclic GC, so the weakref | ||
| 742 | list on ob can be mutated. This means that the ref and | ||
| 743 | proxy pointers we got back earlier may have been collected, | ||
| 744 | so we need to compute these values again before we use | ||
| 745 | them. */ | ||
| 746 | result = new_weakref(ob, callback); | ||
| 747 | if (result != NULL) { | ||
| 748 | get_basic_refs(*list, &ref, &proxy); | ||
| 749 | if (callback == NULL) { | ||
| 750 | if (ref == NULL) | ||
| 751 | insert_head(result, list); | ||
| 752 | else { | ||
| 753 | /* Someone else added a ref without a callback | ||
| 754 | during GC. Return that one instead of this one | ||
| 755 | to avoid violating the invariants of the list | ||
| 756 | of weakrefs for ob. */ | ||
| 757 | Py_DECREF(result); | ||
| 758 | Py_INCREF(ref); | ||
| 759 | result = ref; | ||
| 760 | } | ||
| 761 | } | ||
| 762 | else { | ||
| 763 | PyWeakReference *prev; | ||
| 764 | |||
| 765 | prev = (proxy == NULL) ? ref : proxy; | ||
| 766 | if (prev == NULL) | ||
| 767 | insert_head(result, list); | ||
| 768 | else | ||
| 769 | insert_after(result, prev); | ||
| 770 | } | ||
| 771 | } | ||
| 772 | } | ||
| 773 | return (PyObject *) result; | ||
| 774 | } | ||
| 775 | |||
| 776 | |||
| 777 | PyObject * | ||
| 778 | PyWeakref_NewProxy(PyObject *ob, PyObject *callback) | ||
| 779 | { | ||
| 780 | PyWeakReference *result = NULL; | ||
| 781 | PyWeakReference **list; | ||
| 782 | PyWeakReference *ref, *proxy; | ||
| 783 | |||
| 784 | if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { | ||
| 785 | PyErr_Format(PyExc_TypeError, | ||
| 786 | "cannot create weak reference to '%s' object", | ||
| 787 | ob->ob_type->tp_name); | ||
| 788 | return NULL; | ||
| 789 | } | ||
| 790 | list = GET_WEAKREFS_LISTPTR(ob); | ||
| 791 | get_basic_refs(*list, &ref, &proxy); | ||
| 792 | if (callback == Py_None) | ||
| 793 | callback = NULL; | ||
| 794 | if (callback == NULL) | ||
| 795 | /* attempt to return an existing weak reference if it exists */ | ||
| 796 | result = proxy; | ||
| 797 | if (result != NULL) | ||
| 798 | Py_INCREF(result); | ||
| 799 | else { | ||
| 800 | /* Note: new_weakref() can trigger cyclic GC, so the weakref | ||
| 801 | list on ob can be mutated. This means that the ref and | ||
| 802 | proxy pointers we got back earlier may have been collected, | ||
| 803 | so we need to compute these values again before we use | ||
| 804 | them. */ | ||
| 805 | result = new_weakref(ob, callback); | ||
| 806 | if (result != NULL) { | ||
| 807 | PyWeakReference *prev; | ||
| 808 | |||
| 809 | if (PyCallable_Check(ob)) | ||
| 810 | result->ob_type = &_PyWeakref_CallableProxyType; | ||
| 811 | else | ||
| 812 | result->ob_type = &_PyWeakref_ProxyType; | ||
| 813 | get_basic_refs(*list, &ref, &proxy); | ||
| 814 | if (callback == NULL) { | ||
| 815 | if (proxy != NULL) { | ||
| 816 | /* Someone else added a proxy without a callback | ||
| 817 | during GC. Return that one instead of this one | ||
| 818 | to avoid violating the invariants of the list | ||
| 819 | of weakrefs for ob. */ | ||
| 820 | Py_DECREF(result); | ||
| 821 | Py_INCREF(result = proxy); | ||
| 822 | goto skip_insert; | ||
| 823 | } | ||
| 824 | prev = ref; | ||
| 825 | } | ||
| 826 | else | ||
| 827 | prev = (proxy == NULL) ? ref : proxy; | ||
| 828 | |||
| 829 | if (prev == NULL) | ||
| 830 | insert_head(result, list); | ||
| 831 | else | ||
| 832 | insert_after(result, prev); | ||
| 833 | skip_insert: | ||
| 834 | ; | ||
| 835 | } | ||
| 836 | } | ||
| 837 | return (PyObject *) result; | ||
| 838 | } | ||
| 839 | |||
| 840 | |||
| 841 | PyObject * | ||
| 842 | PyWeakref_GetObject(PyObject *ref) | ||
| 843 | { | ||
| 844 | if (ref == NULL || !PyWeakref_Check(ref)) { | ||
| 845 | PyErr_BadInternalCall(); | ||
| 846 | return NULL; | ||
| 847 | } | ||
| 848 | return PyWeakref_GET_OBJECT(ref); | ||
| 849 | } | ||
| 850 | |||
| 851 | /* Note that there's an inlined copy-paste of handle_callback() in gcmodule.c's | ||
| 852 | * handle_weakrefs(). | ||
| 853 | */ | ||
| 854 | static void | ||
| 855 | handle_callback(PyWeakReference *ref, PyObject *callback) | ||
| 856 | { | ||
| 857 | PyObject *cbresult = PyObject_CallFunctionObjArgs(callback, ref, NULL); | ||
| 858 | |||
| 859 | if (cbresult == NULL) | ||
| 860 | PyErr_WriteUnraisable(callback); | ||
| 861 | else | ||
| 862 | Py_DECREF(cbresult); | ||
| 863 | } | ||
| 864 | |||
| 865 | /* This function is called by the tp_dealloc handler to clear weak references. | ||
| 866 | * | ||
| 867 | * This iterates through the weak references for 'object' and calls callbacks | ||
| 868 | * for those references which have one. It returns when all callbacks have | ||
| 869 | * been attempted. | ||
| 870 | */ | ||
| 871 | void | ||
| 872 | PyObject_ClearWeakRefs(PyObject *object) | ||
| 873 | { | ||
| 874 | PyWeakReference **list; | ||
| 875 | |||
| 876 | if (object == NULL | ||
| 877 | || !PyType_SUPPORTS_WEAKREFS(object->ob_type) | ||
| 878 | || object->ob_refcnt != 0) { | ||
| 879 | PyErr_BadInternalCall(); | ||
| 880 | return; | ||
| 881 | } | ||
| 882 | list = GET_WEAKREFS_LISTPTR(object); | ||
| 883 | /* Remove the callback-less basic and proxy references */ | ||
| 884 | if (*list != NULL && (*list)->wr_callback == NULL) { | ||
| 885 | clear_weakref(*list); | ||
| 886 | if (*list != NULL && (*list)->wr_callback == NULL) | ||
| 887 | clear_weakref(*list); | ||
| 888 | } | ||
| 889 | if (*list != NULL) { | ||
| 890 | PyWeakReference *current = *list; | ||
| 891 | Py_ssize_t count = _PyWeakref_GetWeakrefCount(current); | ||
| 892 | int restore_error = PyErr_Occurred() ? 1 : 0; | ||
| 893 | PyObject *err_type, *err_value, *err_tb; | ||
| 894 | |||
| 895 | if (restore_error) | ||
| 896 | PyErr_Fetch(&err_type, &err_value, &err_tb); | ||
| 897 | if (count == 1) { | ||
| 898 | PyObject *callback = current->wr_callback; | ||
| 899 | |||
| 900 | current->wr_callback = NULL; | ||
| 901 | clear_weakref(current); | ||
| 902 | if (callback != NULL) { | ||
| 903 | handle_callback(current, callback); | ||
| 904 | Py_DECREF(callback); | ||
| 905 | } | ||
| 906 | } | ||
| 907 | else { | ||
| 908 | PyObject *tuple; | ||
| 909 | Py_ssize_t i = 0; | ||
| 910 | |||
| 911 | tuple = PyTuple_New(count * 2); | ||
| 912 | if (tuple == NULL) { | ||
| 913 | if (restore_error) | ||
| 914 | PyErr_Fetch(&err_type, &err_value, &err_tb); | ||
| 915 | return; | ||
| 916 | } | ||
| 917 | |||
| 918 | for (i = 0; i < count; ++i) { | ||
| 919 | PyWeakReference *next = current->wr_next; | ||
| 920 | |||
| 921 | Py_INCREF(current); | ||
| 922 | PyTuple_SET_ITEM(tuple, i * 2, (PyObject *) current); | ||
| 923 | PyTuple_SET_ITEM(tuple, i * 2 + 1, current->wr_callback); | ||
| 924 | current->wr_callback = NULL; | ||
| 925 | clear_weakref(current); | ||
| 926 | current = next; | ||
| 927 | } | ||
| 928 | for (i = 0; i < count; ++i) { | ||
| 929 | PyObject *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1); | ||
| 930 | |||
| 931 | if (callback != NULL) { | ||
| 932 | PyObject *item = PyTuple_GET_ITEM(tuple, i * 2); | ||
| 933 | handle_callback((PyWeakReference *)item, callback); | ||
| 934 | } | ||
| 935 | } | ||
| 936 | Py_DECREF(tuple); | ||
| 937 | } | ||
| 938 | if (restore_error) | ||
| 939 | PyErr_Restore(err_type, err_value, err_tb); | ||
| 940 | } | ||
| 941 | } | ||