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783 lines
23 KiB
783 lines
23 KiB
#include "Python.h" |
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#include "structmember.h" |
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#define GET_WEAKREFS_LISTPTR(o) \ |
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((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o)) |
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long |
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_PyWeakref_GetWeakrefCount(PyWeakReference *head) |
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{ |
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long count = 0; |
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|
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while (head != NULL) { |
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++count; |
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head = head->wr_next; |
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} |
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return count; |
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} |
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static PyWeakReference * |
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new_weakref(PyObject *ob, PyObject *callback) |
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{ |
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PyWeakReference *result; |
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|
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result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType); |
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if (result) { |
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result->hash = -1; |
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result->wr_object = ob; |
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Py_XINCREF(callback); |
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result->wr_callback = callback; |
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PyObject_GC_Track(result); |
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} |
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return result; |
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} |
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/* This function clears the passed-in reference and removes it from the |
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* list of weak references for the referent. This is the only code that |
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* removes an item from the doubly-linked list of weak references for an |
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* object; it is also responsible for clearing the callback slot. |
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*/ |
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static void |
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clear_weakref(PyWeakReference *self) |
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{ |
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PyObject *callback = self->wr_callback; |
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|
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if (PyWeakref_GET_OBJECT(self) != Py_None) { |
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PyWeakReference **list = GET_WEAKREFS_LISTPTR( |
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PyWeakref_GET_OBJECT(self)); |
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|
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if (*list == self) |
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*list = self->wr_next; |
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self->wr_object = Py_None; |
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if (self->wr_prev != NULL) |
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self->wr_prev->wr_next = self->wr_next; |
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if (self->wr_next != NULL) |
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self->wr_next->wr_prev = self->wr_prev; |
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self->wr_prev = NULL; |
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self->wr_next = NULL; |
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} |
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if (callback != NULL) { |
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Py_DECREF(callback); |
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self->wr_callback = NULL; |
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} |
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} |
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|
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/* Cyclic gc uses this to *just* clear the passed-in reference, leaving |
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* the callback intact and uncalled. It must be possible to call self's |
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* tp_dealloc() after calling this, so self has to be left in a sane enough |
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* state for that to work. We expect tp_dealloc to decref the callback |
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* then. The reason for not letting clear_weakref() decref the callback |
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* right now is that if the callback goes away, that may in turn trigger |
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* another callback (if a weak reference to the callback exists) -- running |
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* arbitrary Python code in the middle of gc is a disaster. The convolution |
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* here allows gc to delay triggering such callbacks until the world is in |
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* a sane state again. |
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*/ |
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void |
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_PyWeakref_ClearRef(PyWeakReference *self) |
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{ |
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PyObject *callback; |
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assert(self != NULL); |
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assert(PyWeakref_Check(self)); |
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/* Preserve and restore the callback around clear_weakref. */ |
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callback = self->wr_callback; |
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self->wr_callback = NULL; |
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clear_weakref(self); |
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self->wr_callback = callback; |
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} |
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static void |
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weakref_dealloc(PyWeakReference *self) |
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{ |
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PyObject_GC_UnTrack((PyObject *)self); |
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clear_weakref(self); |
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PyObject_GC_Del(self); |
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} |
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static int |
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gc_traverse(PyWeakReference *self, visitproc visit, void *arg) |
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{ |
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if (self->wr_callback != NULL) |
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return visit(self->wr_callback, arg); |
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return 0; |
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} |
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static int |
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gc_clear(PyWeakReference *self) |
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{ |
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clear_weakref(self); |
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return 0; |
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} |
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static PyObject * |
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weakref_call(PyWeakReference *self, PyObject *args, PyObject *kw) |
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{ |
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static char *argnames[] = {NULL}; |
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if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", argnames)) { |
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PyObject *object = PyWeakref_GET_OBJECT(self); |
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Py_INCREF(object); |
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return (object); |
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} |
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return NULL; |
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} |
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static long |
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weakref_hash(PyWeakReference *self) |
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{ |
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if (self->hash != -1) |
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return self->hash; |
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if (PyWeakref_GET_OBJECT(self) == Py_None) { |
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PyErr_SetString(PyExc_TypeError, "weak object has gone away"); |
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return -1; |
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} |
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self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self)); |
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return self->hash; |
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} |
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static PyObject * |
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weakref_repr(PyWeakReference *self) |
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{ |
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char buffer[256]; |
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if (PyWeakref_GET_OBJECT(self) == Py_None) { |
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PyOS_snprintf(buffer, sizeof(buffer), "<weakref at %p; dead>", self); |
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} |
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else { |
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char *name = NULL; |
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PyObject *nameobj = PyObject_GetAttrString(PyWeakref_GET_OBJECT(self), |
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"__name__"); |
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if (nameobj == NULL) |
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PyErr_Clear(); |
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else if (PyString_Check(nameobj)) |
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name = PyString_AS_STRING(nameobj); |
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PyOS_snprintf(buffer, sizeof(buffer), |
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name ? "<weakref at %p; to '%.50s' at %p (%s)>" |
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: "<weakref at %p; to '%.50s' at %p>", |
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self, |
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PyWeakref_GET_OBJECT(self)->ob_type->tp_name, |
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PyWeakref_GET_OBJECT(self), |
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name); |
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Py_XDECREF(nameobj); |
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} |
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return PyString_FromString(buffer); |
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} |
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/* Weak references only support equality, not ordering. Two weak references |
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are equal if the underlying objects are equal. If the underlying object has |
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gone away, they are equal if they are identical. */ |
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static PyObject * |
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weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op) |
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{ |
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if (op != Py_EQ || self->ob_type != other->ob_type) { |
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Py_INCREF(Py_NotImplemented); |
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return Py_NotImplemented; |
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} |
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if (PyWeakref_GET_OBJECT(self) == Py_None |
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|| PyWeakref_GET_OBJECT(other) == Py_None) { |
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PyObject *res = self==other ? Py_True : Py_False; |
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Py_INCREF(res); |
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return res; |
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} |
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return PyObject_RichCompare(PyWeakref_GET_OBJECT(self), |
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PyWeakref_GET_OBJECT(other), op); |
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} |
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PyTypeObject |
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_PyWeakref_RefType = { |
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PyObject_HEAD_INIT(&PyType_Type) |
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0, |
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"weakref", |
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sizeof(PyWeakReference), |
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0, |
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(destructor)weakref_dealloc,/*tp_dealloc*/ |
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0, /*tp_print*/ |
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0, /*tp_getattr*/ |
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0, /*tp_setattr*/ |
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0, /*tp_compare*/ |
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(reprfunc)weakref_repr, /*tp_repr*/ |
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0, /*tp_as_number*/ |
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0, /*tp_as_sequence*/ |
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0, /*tp_as_mapping*/ |
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(hashfunc)weakref_hash, /*tp_hash*/ |
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(ternaryfunc)weakref_call, /*tp_call*/ |
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0, /*tp_str*/ |
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0, /*tp_getattro*/ |
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0, /*tp_setattro*/ |
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0, /*tp_as_buffer*/ |
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Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_RICHCOMPARE, |
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0, /*tp_doc*/ |
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(traverseproc)gc_traverse, /*tp_traverse*/ |
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(inquiry)gc_clear, /*tp_clear*/ |
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(richcmpfunc)weakref_richcompare, /*tp_richcompare*/ |
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0, /*tp_weaklistoffset*/ |
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}; |
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static int |
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proxy_checkref(PyWeakReference *proxy) |
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{ |
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if (PyWeakref_GET_OBJECT(proxy) == Py_None) { |
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PyErr_SetString(PyExc_ReferenceError, |
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"weakly-referenced object no longer exists"); |
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return 0; |
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} |
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return 1; |
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} |
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/* If a parameter is a proxy, check that it is still "live" and wrap it, |
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* replacing the original value with the raw object. Raises ReferenceError |
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* if the param is a dead proxy. |
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*/ |
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#define UNWRAP(o) \ |
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if (PyWeakref_CheckProxy(o)) { \ |
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if (!proxy_checkref((PyWeakReference *)o)) \ |
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return NULL; \ |
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o = PyWeakref_GET_OBJECT(o); \ |
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} |
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#define UNWRAP_I(o) \ |
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if (PyWeakref_CheckProxy(o)) { \ |
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if (!proxy_checkref((PyWeakReference *)o)) \ |
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return -1; \ |
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o = PyWeakref_GET_OBJECT(o); \ |
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} |
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#define WRAP_UNARY(method, generic) \ |
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static PyObject * \ |
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method(PyObject *proxy) { \ |
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UNWRAP(proxy); \ |
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return generic(proxy); \ |
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} |
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#define WRAP_BINARY(method, generic) \ |
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static PyObject * \ |
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method(PyObject *x, PyObject *y) { \ |
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UNWRAP(x); \ |
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UNWRAP(y); \ |
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return generic(x, y); \ |
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} |
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/* Note that the third arg needs to be checked for NULL since the tp_call |
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* slot can receive NULL for this arg. |
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*/ |
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#define WRAP_TERNARY(method, generic) \ |
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static PyObject * \ |
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method(PyObject *proxy, PyObject *v, PyObject *w) { \ |
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UNWRAP(proxy); \ |
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UNWRAP(v); \ |
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if (w != NULL) \ |
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UNWRAP(w); \ |
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return generic(proxy, v, w); \ |
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} |
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/* direct slots */ |
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WRAP_BINARY(proxy_getattr, PyObject_GetAttr) |
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WRAP_UNARY(proxy_str, PyObject_Str) |
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WRAP_TERNARY(proxy_call, PyEval_CallObjectWithKeywords) |
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static PyObject * |
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proxy_repr(PyWeakReference *proxy) |
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{ |
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char buf[160]; |
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PyOS_snprintf(buf, sizeof(buf), |
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"<weakproxy at %p to %.100s at %p>", proxy, |
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PyWeakref_GET_OBJECT(proxy)->ob_type->tp_name, |
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PyWeakref_GET_OBJECT(proxy)); |
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return PyString_FromString(buf); |
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} |
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static int |
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proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value) |
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{ |
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if (!proxy_checkref(proxy)) |
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return -1; |
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return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value); |
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} |
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static int |
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proxy_compare(PyObject *proxy, PyObject *v) |
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{ |
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UNWRAP_I(proxy); |
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UNWRAP_I(v); |
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return PyObject_Compare(proxy, v); |
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} |
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/* number slots */ |
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WRAP_BINARY(proxy_add, PyNumber_Add) |
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WRAP_BINARY(proxy_sub, PyNumber_Subtract) |
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WRAP_BINARY(proxy_mul, PyNumber_Multiply) |
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WRAP_BINARY(proxy_div, PyNumber_Divide) |
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WRAP_BINARY(proxy_mod, PyNumber_Remainder) |
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WRAP_BINARY(proxy_divmod, PyNumber_Divmod) |
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WRAP_TERNARY(proxy_pow, PyNumber_Power) |
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WRAP_UNARY(proxy_neg, PyNumber_Negative) |
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WRAP_UNARY(proxy_pos, PyNumber_Positive) |
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WRAP_UNARY(proxy_abs, PyNumber_Absolute) |
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WRAP_UNARY(proxy_invert, PyNumber_Invert) |
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WRAP_BINARY(proxy_lshift, PyNumber_Lshift) |
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WRAP_BINARY(proxy_rshift, PyNumber_Rshift) |
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WRAP_BINARY(proxy_and, PyNumber_And) |
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WRAP_BINARY(proxy_xor, PyNumber_Xor) |
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WRAP_BINARY(proxy_or, PyNumber_Or) |
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WRAP_UNARY(proxy_int, PyNumber_Int) |
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WRAP_UNARY(proxy_long, PyNumber_Long) |
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WRAP_UNARY(proxy_float, PyNumber_Float) |
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WRAP_BINARY(proxy_iadd, PyNumber_InPlaceAdd) |
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WRAP_BINARY(proxy_isub, PyNumber_InPlaceSubtract) |
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WRAP_BINARY(proxy_imul, PyNumber_InPlaceMultiply) |
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WRAP_BINARY(proxy_idiv, PyNumber_InPlaceDivide) |
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WRAP_BINARY(proxy_imod, PyNumber_InPlaceRemainder) |
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WRAP_TERNARY(proxy_ipow, PyNumber_InPlacePower) |
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WRAP_BINARY(proxy_ilshift, PyNumber_InPlaceLshift) |
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WRAP_BINARY(proxy_irshift, PyNumber_InPlaceRshift) |
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WRAP_BINARY(proxy_iand, PyNumber_InPlaceAnd) |
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WRAP_BINARY(proxy_ixor, PyNumber_InPlaceXor) |
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WRAP_BINARY(proxy_ior, PyNumber_InPlaceOr) |
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static int |
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proxy_nonzero(PyWeakReference *proxy) |
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{ |
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PyObject *o = PyWeakref_GET_OBJECT(proxy); |
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if (!proxy_checkref(proxy)) |
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return 1; |
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if (o->ob_type->tp_as_number && |
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o->ob_type->tp_as_number->nb_nonzero) |
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return (*o->ob_type->tp_as_number->nb_nonzero)(o); |
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else |
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return 1; |
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} |
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|
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/* sequence slots */ |
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|
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static PyObject * |
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proxy_slice(PyWeakReference *proxy, int i, int j) |
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{ |
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if (!proxy_checkref(proxy)) |
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return NULL; |
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return PySequence_GetSlice(PyWeakref_GET_OBJECT(proxy), i, j); |
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} |
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static int |
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proxy_ass_slice(PyWeakReference *proxy, int i, int j, PyObject *value) |
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{ |
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if (!proxy_checkref(proxy)) |
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return -1; |
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return PySequence_SetSlice(PyWeakref_GET_OBJECT(proxy), i, j, value); |
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} |
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static int |
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proxy_contains(PyWeakReference *proxy, PyObject *value) |
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{ |
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if (!proxy_checkref(proxy)) |
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return -1; |
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return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value); |
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} |
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/* mapping slots */ |
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static int |
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proxy_length(PyWeakReference *proxy) |
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{ |
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if (!proxy_checkref(proxy)) |
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return -1; |
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return PyObject_Length(PyWeakref_GET_OBJECT(proxy)); |
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} |
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WRAP_BINARY(proxy_getitem, PyObject_GetItem) |
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static int |
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proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value) |
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{ |
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if (!proxy_checkref(proxy)) |
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return -1; |
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if (value == NULL) |
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return PyObject_DelItem(PyWeakref_GET_OBJECT(proxy), key); |
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else |
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return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value); |
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} |
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|
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/* iterator slots */ |
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static PyObject * |
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proxy_iter(PyWeakReference *proxy) |
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{ |
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if (!proxy_checkref(proxy)) |
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return NULL; |
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return PyObject_GetIter(PyWeakref_GET_OBJECT(proxy)); |
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} |
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static PyObject * |
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proxy_iternext(PyWeakReference *proxy) |
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{ |
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if (!proxy_checkref(proxy)) |
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return NULL; |
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return PyIter_Next(PyWeakref_GET_OBJECT(proxy)); |
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} |
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static PyNumberMethods proxy_as_number = { |
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(binaryfunc)proxy_add, /*nb_add*/ |
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(binaryfunc)proxy_sub, /*nb_subtract*/ |
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(binaryfunc)proxy_mul, /*nb_multiply*/ |
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(binaryfunc)proxy_div, /*nb_divide*/ |
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(binaryfunc)proxy_mod, /*nb_remainder*/ |
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(binaryfunc)proxy_divmod, /*nb_divmod*/ |
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(ternaryfunc)proxy_pow, /*nb_power*/ |
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(unaryfunc)proxy_neg, /*nb_negative*/ |
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(unaryfunc)proxy_pos, /*nb_positive*/ |
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(unaryfunc)proxy_abs, /*nb_absolute*/ |
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(inquiry)proxy_nonzero, /*nb_nonzero*/ |
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(unaryfunc)proxy_invert, /*nb_invert*/ |
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(binaryfunc)proxy_lshift, /*nb_lshift*/ |
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(binaryfunc)proxy_rshift, /*nb_rshift*/ |
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(binaryfunc)proxy_and, /*nb_and*/ |
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(binaryfunc)proxy_xor, /*nb_xor*/ |
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(binaryfunc)proxy_or, /*nb_or*/ |
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(coercion)0, /*nb_coerce*/ |
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(unaryfunc)proxy_int, /*nb_int*/ |
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(unaryfunc)proxy_long, /*nb_long*/ |
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(unaryfunc)proxy_float, /*nb_float*/ |
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(unaryfunc)0, /*nb_oct*/ |
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(unaryfunc)0, /*nb_hex*/ |
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(binaryfunc)proxy_iadd, /*nb_inplace_add*/ |
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(binaryfunc)proxy_isub, /*nb_inplace_subtract*/ |
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(binaryfunc)proxy_imul, /*nb_inplace_multiply*/ |
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(binaryfunc)proxy_idiv, /*nb_inplace_divide*/ |
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(binaryfunc)proxy_imod, /*nb_inplace_remainder*/ |
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(ternaryfunc)proxy_ipow, /*nb_inplace_power*/ |
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(binaryfunc)proxy_ilshift, /*nb_inplace_lshift*/ |
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(binaryfunc)proxy_irshift, /*nb_inplace_rshift*/ |
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(binaryfunc)proxy_iand, /*nb_inplace_and*/ |
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(binaryfunc)proxy_ixor, /*nb_inplace_xor*/ |
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(binaryfunc)proxy_ior, /*nb_inplace_or*/ |
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}; |
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|
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static PySequenceMethods proxy_as_sequence = { |
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(inquiry)proxy_length, /*sq_length*/ |
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0, /*sq_concat*/ |
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0, /*sq_repeat*/ |
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0, /*sq_item*/ |
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(intintargfunc)proxy_slice, /*sq_slice*/ |
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0, /*sq_ass_item*/ |
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(intintobjargproc)proxy_ass_slice, /*sq_ass_slice*/ |
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(objobjproc)proxy_contains, /* sq_contains */ |
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}; |
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|
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static PyMappingMethods proxy_as_mapping = { |
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(inquiry)proxy_length, /*mp_length*/ |
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(binaryfunc)proxy_getitem, /*mp_subscript*/ |
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(objobjargproc)proxy_setitem, /*mp_ass_subscript*/ |
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}; |
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|
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PyTypeObject |
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_PyWeakref_ProxyType = { |
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PyObject_HEAD_INIT(&PyType_Type) |
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0, |
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"weakproxy", |
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sizeof(PyWeakReference), |
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0, |
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/* methods */ |
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(destructor)weakref_dealloc, /* tp_dealloc */ |
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0, /* tp_print */ |
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0, /* tp_getattr */ |
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0, /* tp_setattr */ |
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proxy_compare, /* tp_compare */ |
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(unaryfunc)proxy_repr, /* tp_repr */ |
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&proxy_as_number, /* tp_as_number */ |
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&proxy_as_sequence, /* tp_as_sequence */ |
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&proxy_as_mapping, /* tp_as_mapping */ |
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0, /* tp_hash */ |
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(ternaryfunc)0, /* tp_call */ |
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(unaryfunc)proxy_str, /* tp_str */ |
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(getattrofunc)proxy_getattr, /* tp_getattro */ |
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(setattrofunc)proxy_setattr, /* tp_setattro */ |
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0, /* tp_as_buffer */ |
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Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
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| Py_TPFLAGS_CHECKTYPES, /* tp_flags */ |
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0, /* tp_doc */ |
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(traverseproc)gc_traverse, /* tp_traverse */ |
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(inquiry)gc_clear, /* tp_clear */ |
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0, /* tp_richcompare */ |
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0, /* tp_weaklistoffset */ |
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(getiterfunc)proxy_iter, /* tp_iter */ |
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(iternextfunc)proxy_iternext, /* tp_iternext */ |
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}; |
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|
|
|
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PyTypeObject |
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_PyWeakref_CallableProxyType = { |
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PyObject_HEAD_INIT(&PyType_Type) |
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0, |
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"weakcallableproxy", |
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sizeof(PyWeakReference), |
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0, |
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/* methods */ |
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(destructor)weakref_dealloc, /* tp_dealloc */ |
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0, /* tp_print */ |
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0, /* tp_getattr */ |
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0, /* tp_setattr */ |
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proxy_compare, /* tp_compare */ |
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(unaryfunc)proxy_repr, /* tp_repr */ |
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&proxy_as_number, /* tp_as_number */ |
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&proxy_as_sequence, /* tp_as_sequence */ |
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&proxy_as_mapping, /* tp_as_mapping */ |
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0, /* tp_hash */ |
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(ternaryfunc)proxy_call, /* tp_call */ |
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(unaryfunc)proxy_str, /* tp_str */ |
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(getattrofunc)proxy_getattr, /* tp_getattro */ |
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(setattrofunc)proxy_setattr, /* tp_setattro */ |
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0, /* tp_as_buffer */ |
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Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
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| Py_TPFLAGS_CHECKTYPES, /* tp_flags */ |
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0, /* tp_doc */ |
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(traverseproc)gc_traverse, /* tp_traverse */ |
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(inquiry)gc_clear, /* tp_clear */ |
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0, /* tp_richcompare */ |
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0, /* tp_weaklistoffset */ |
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(getiterfunc)proxy_iter, /* tp_iter */ |
|
(iternextfunc)proxy_iternext, /* tp_iternext */ |
|
}; |
|
|
|
|
|
/* Given the head of an object's list of weak references, extract the |
|
* two callback-less refs (ref and proxy). Used to determine if the |
|
* shared references exist and to determine the back link for newly |
|
* inserted references. |
|
*/ |
|
static void |
|
get_basic_refs(PyWeakReference *head, |
|
PyWeakReference **refp, PyWeakReference **proxyp) |
|
{ |
|
*refp = NULL; |
|
*proxyp = NULL; |
|
|
|
if (head != NULL && head->wr_callback == NULL) { |
|
if (head->ob_type == &_PyWeakref_RefType) { |
|
*refp = head; |
|
head = head->wr_next; |
|
} |
|
if (head != NULL && head->wr_callback == NULL) { |
|
*proxyp = head; |
|
head = head->wr_next; |
|
} |
|
} |
|
} |
|
|
|
/* Insert 'newref' in the list after 'prev'. Both must be non-NULL. */ |
|
static void |
|
insert_after(PyWeakReference *newref, PyWeakReference *prev) |
|
{ |
|
newref->wr_prev = prev; |
|
newref->wr_next = prev->wr_next; |
|
if (prev->wr_next != NULL) |
|
prev->wr_next->wr_prev = newref; |
|
prev->wr_next = newref; |
|
} |
|
|
|
/* Insert 'newref' at the head of the list; 'list' points to the variable |
|
* that stores the head. |
|
*/ |
|
static void |
|
insert_head(PyWeakReference *newref, PyWeakReference **list) |
|
{ |
|
PyWeakReference *next = *list; |
|
|
|
newref->wr_prev = NULL; |
|
newref->wr_next = next; |
|
if (next != NULL) |
|
next->wr_prev = newref; |
|
*list = newref; |
|
} |
|
|
|
|
|
PyObject * |
|
PyWeakref_NewRef(PyObject *ob, PyObject *callback) |
|
{ |
|
PyWeakReference *result = NULL; |
|
PyWeakReference **list; |
|
PyWeakReference *ref, *proxy; |
|
|
|
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { |
|
PyErr_Format(PyExc_TypeError, |
|
"cannot create weak reference to '%s' object", |
|
ob->ob_type->tp_name); |
|
return NULL; |
|
} |
|
list = GET_WEAKREFS_LISTPTR(ob); |
|
get_basic_refs(*list, &ref, &proxy); |
|
if (callback == NULL || callback == Py_None) |
|
/* return existing weak reference if it exists */ |
|
result = ref; |
|
if (result != NULL) |
|
Py_XINCREF(result); |
|
else { |
|
result = new_weakref(ob, callback); |
|
if (result != NULL) { |
|
if (callback == NULL) { |
|
insert_head(result, list); |
|
} |
|
else { |
|
PyWeakReference *prev = (proxy == NULL) ? ref : proxy; |
|
|
|
if (prev == NULL) |
|
insert_head(result, list); |
|
else |
|
insert_after(result, prev); |
|
} |
|
} |
|
} |
|
return (PyObject *) result; |
|
} |
|
|
|
|
|
PyObject * |
|
PyWeakref_NewProxy(PyObject *ob, PyObject *callback) |
|
{ |
|
PyWeakReference *result = NULL; |
|
PyWeakReference **list; |
|
PyWeakReference *ref, *proxy; |
|
|
|
if (!PyType_SUPPORTS_WEAKREFS(ob->ob_type)) { |
|
PyErr_Format(PyExc_TypeError, |
|
"cannot create weak reference to '%s' object", |
|
ob->ob_type->tp_name); |
|
return NULL; |
|
} |
|
list = GET_WEAKREFS_LISTPTR(ob); |
|
get_basic_refs(*list, &ref, &proxy); |
|
if (callback == NULL) |
|
/* attempt to return an existing weak reference if it exists */ |
|
result = proxy; |
|
if (result != NULL) |
|
Py_XINCREF(result); |
|
else { |
|
result = new_weakref(ob, callback); |
|
if (result != NULL) { |
|
PyWeakReference *prev; |
|
|
|
if (PyCallable_Check(ob)) |
|
result->ob_type = &_PyWeakref_CallableProxyType; |
|
else |
|
result->ob_type = &_PyWeakref_ProxyType; |
|
if (callback == NULL) |
|
prev = ref; |
|
else |
|
prev = (proxy == NULL) ? ref : proxy; |
|
|
|
if (prev == NULL) |
|
insert_head(result, list); |
|
else |
|
insert_after(result, prev); |
|
} |
|
} |
|
return (PyObject *) result; |
|
} |
|
|
|
|
|
PyObject * |
|
PyWeakref_GetObject(PyObject *ref) |
|
{ |
|
if (ref == NULL || !PyWeakref_Check(ref)) { |
|
PyErr_BadInternalCall(); |
|
return NULL; |
|
} |
|
return PyWeakref_GET_OBJECT(ref); |
|
} |
|
|
|
|
|
static void |
|
handle_callback(PyWeakReference *ref, PyObject *callback) |
|
{ |
|
PyObject *cbresult = PyObject_CallFunction(callback, "O", ref); |
|
|
|
if (cbresult == NULL) |
|
PyErr_WriteUnraisable(callback); |
|
else |
|
Py_DECREF(cbresult); |
|
} |
|
|
|
/* This function is called by the tp_dealloc handler to clear weak references. |
|
* |
|
* This iterates through the weak references for 'object' and calls callbacks |
|
* for those references which have one. It returns when all callbacks have |
|
* been attempted. |
|
*/ |
|
void |
|
PyObject_ClearWeakRefs(PyObject *object) |
|
{ |
|
PyWeakReference **list; |
|
|
|
if (object == NULL |
|
|| !PyType_SUPPORTS_WEAKREFS(object->ob_type) |
|
|| object->ob_refcnt != 0) { |
|
PyErr_BadInternalCall(); |
|
return; |
|
} |
|
list = GET_WEAKREFS_LISTPTR(object); |
|
/* Remove the callback-less basic and proxy references */ |
|
if (*list != NULL && (*list)->wr_callback == NULL) { |
|
clear_weakref(*list); |
|
if (*list != NULL && (*list)->wr_callback == NULL) |
|
clear_weakref(*list); |
|
} |
|
if (*list != NULL) { |
|
PyWeakReference *current = *list; |
|
int count = _PyWeakref_GetWeakrefCount(current); |
|
int restore_error = PyErr_Occurred() ? 1 : 0; |
|
PyObject *err_type, *err_value, *err_tb; |
|
|
|
if (restore_error) |
|
PyErr_Fetch(&err_type, &err_value, &err_tb); |
|
if (count == 1) { |
|
PyObject *callback = current->wr_callback; |
|
|
|
current->wr_callback = NULL; |
|
clear_weakref(current); |
|
handle_callback(current, callback); |
|
Py_DECREF(callback); |
|
} |
|
else { |
|
PyObject *tuple = PyTuple_New(count * 2); |
|
int i = 0; |
|
|
|
for (i = 0; i < count; ++i) { |
|
PyWeakReference *next = current->wr_next; |
|
|
|
Py_INCREF(current); |
|
PyTuple_SET_ITEM(tuple, i * 2, (PyObject *) current); |
|
PyTuple_SET_ITEM(tuple, i * 2 + 1, current->wr_callback); |
|
current->wr_callback = NULL; |
|
clear_weakref(current); |
|
current = next; |
|
} |
|
for (i = 0; i < count; ++i) { |
|
PyObject *current = PyTuple_GET_ITEM(tuple, i * 2); |
|
PyObject *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1); |
|
|
|
handle_callback((PyWeakReference *)current, callback); |
|
} |
|
Py_DECREF(tuple); |
|
} |
|
if (restore_error) |
|
PyErr_Restore(err_type, err_value, err_tb); |
|
} |
|
}
|
|
|