mirror of
https://github.com/python/cpython.git
synced 2024-12-05 15:54:17 +08:00
1051 lines
32 KiB
C
1051 lines
32 KiB
C
#include "Python.h"
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#include "pycore_object.h" // _PyObject_GET_WEAKREFS_LISTPTR()
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#include "structmember.h" // PyMemberDef
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#define GET_WEAKREFS_LISTPTR(o) \
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((PyWeakReference **) _PyObject_GET_WEAKREFS_LISTPTR(o))
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Py_ssize_t
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_PyWeakref_GetWeakrefCount(PyWeakReference *head)
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{
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Py_ssize_t count = 0;
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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 void
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init_weakref(PyWeakReference *self, PyObject *ob, PyObject *callback)
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{
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self->hash = -1;
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self->wr_object = ob;
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self->wr_prev = NULL;
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self->wr_next = NULL;
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Py_XINCREF(callback);
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self->wr_callback = callback;
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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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result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType);
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if (result) {
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init_weakref(result, ob, 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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if (self->wr_object != Py_None) {
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PyWeakReference **list = GET_WEAKREFS_LISTPTR(self->wr_object);
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if (*list == self)
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/* If 'self' is the end of the list (and thus self->wr_next == NULL)
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then the weakref list itself (and thus the value of *list) will
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end up being set to NULL. */
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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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/* 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(PyObject *self)
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{
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PyObject_GC_UnTrack(self);
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clear_weakref((PyWeakReference *) self);
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Py_TYPE(self)->tp_free(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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Py_VISIT(self->wr_callback);
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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 *kwlist[] = {NULL};
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if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", kwlist)) {
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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 Py_hash_t
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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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PyObject* obj = PyWeakref_GET_OBJECT(self);
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if (obj == 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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Py_INCREF(obj);
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self->hash = PyObject_Hash(obj);
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Py_DECREF(obj);
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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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PyObject *name, *repr;
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_Py_IDENTIFIER(__name__);
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PyObject* obj = PyWeakref_GET_OBJECT(self);
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if (obj == Py_None) {
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return PyUnicode_FromFormat("<weakref at %p; dead>", self);
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}
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Py_INCREF(obj);
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if (_PyObject_LookupAttrId(obj, &PyId___name__, &name) < 0) {
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Py_DECREF(obj);
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return NULL;
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}
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if (name == NULL || !PyUnicode_Check(name)) {
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repr = PyUnicode_FromFormat(
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"<weakref at %p; to '%s' at %p>",
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self,
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Py_TYPE(PyWeakref_GET_OBJECT(self))->tp_name,
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obj);
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}
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else {
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repr = PyUnicode_FromFormat(
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"<weakref at %p; to '%s' at %p (%U)>",
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self,
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Py_TYPE(PyWeakref_GET_OBJECT(self))->tp_name,
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obj,
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name);
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}
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Py_DECREF(obj);
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Py_XDECREF(name);
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return repr;
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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 && op != Py_NE) ||
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!PyWeakref_Check(self) ||
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!PyWeakref_Check(other)) {
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Py_RETURN_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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int res = (self == other);
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if (op == Py_NE)
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res = !res;
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if (res)
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Py_RETURN_TRUE;
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else
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Py_RETURN_FALSE;
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}
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PyObject* obj = PyWeakref_GET_OBJECT(self);
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PyObject* other_obj = PyWeakref_GET_OBJECT(other);
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Py_INCREF(obj);
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Py_INCREF(other_obj);
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PyObject* res = PyObject_RichCompare(obj, other_obj, op);
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Py_DECREF(obj);
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Py_DECREF(other_obj);
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return res;
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}
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/* Given the head of an object's list of weak references, extract the
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* two callback-less refs (ref and proxy). Used to determine if the
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* shared references exist and to determine the back link for newly
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* inserted references.
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*/
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static void
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get_basic_refs(PyWeakReference *head,
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PyWeakReference **refp, PyWeakReference **proxyp)
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{
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*refp = NULL;
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*proxyp = NULL;
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if (head != NULL && head->wr_callback == NULL) {
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/* We need to be careful that the "basic refs" aren't
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subclasses of the main types. That complicates this a
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little. */
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if (PyWeakref_CheckRefExact(head)) {
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*refp = head;
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head = head->wr_next;
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}
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if (head != NULL
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&& head->wr_callback == NULL
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&& PyWeakref_CheckProxy(head)) {
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*proxyp = head;
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/* head = head->wr_next; */
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}
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}
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}
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/* Insert 'newref' in the list after 'prev'. Both must be non-NULL. */
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static void
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insert_after(PyWeakReference *newref, PyWeakReference *prev)
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{
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newref->wr_prev = prev;
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newref->wr_next = prev->wr_next;
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if (prev->wr_next != NULL)
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prev->wr_next->wr_prev = newref;
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prev->wr_next = newref;
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}
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/* Insert 'newref' at the head of the list; 'list' points to the variable
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* that stores the head.
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*/
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static void
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insert_head(PyWeakReference *newref, PyWeakReference **list)
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{
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PyWeakReference *next = *list;
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newref->wr_prev = NULL;
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newref->wr_next = next;
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if (next != NULL)
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next->wr_prev = newref;
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*list = newref;
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}
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static int
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parse_weakref_init_args(const char *funcname, PyObject *args, PyObject *kwargs,
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PyObject **obp, PyObject **callbackp)
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{
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return PyArg_UnpackTuple(args, funcname, 1, 2, obp, callbackp);
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}
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static PyObject *
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weakref___new__(PyTypeObject *type, PyObject *args, PyObject *kwargs)
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{
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PyWeakReference *self = NULL;
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PyObject *ob, *callback = NULL;
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if (parse_weakref_init_args("__new__", args, kwargs, &ob, &callback)) {
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PyWeakReference *ref, *proxy;
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PyWeakReference **list;
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if (!PyType_SUPPORTS_WEAKREFS(Py_TYPE(ob))) {
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PyErr_Format(PyExc_TypeError,
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"cannot create weak reference to '%s' object",
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Py_TYPE(ob)->tp_name);
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return NULL;
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}
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if (callback == Py_None)
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callback = NULL;
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list = GET_WEAKREFS_LISTPTR(ob);
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get_basic_refs(*list, &ref, &proxy);
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if (callback == NULL && type == &_PyWeakref_RefType) {
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if (ref != NULL) {
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/* We can re-use an existing reference. */
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Py_INCREF(ref);
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return (PyObject *)ref;
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}
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}
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/* We have to create a new reference. */
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/* Note: the tp_alloc() can trigger cyclic GC, so the weakref
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list on ob can be mutated. This means that the ref and
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proxy pointers we got back earlier may have been collected,
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so we need to compute these values again before we use
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them. */
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self = (PyWeakReference *) (type->tp_alloc(type, 0));
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if (self != NULL) {
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init_weakref(self, ob, callback);
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if (callback == NULL && type == &_PyWeakref_RefType) {
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insert_head(self, list);
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}
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else {
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PyWeakReference *prev;
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get_basic_refs(*list, &ref, &proxy);
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prev = (proxy == NULL) ? ref : proxy;
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if (prev == NULL)
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insert_head(self, list);
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else
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insert_after(self, prev);
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}
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}
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}
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return (PyObject *)self;
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}
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static int
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weakref___init__(PyObject *self, PyObject *args, PyObject *kwargs)
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{
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PyObject *tmp;
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if (!_PyArg_NoKeywords("ref", kwargs))
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return -1;
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if (parse_weakref_init_args("__init__", args, kwargs, &tmp, &tmp))
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return 0;
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else
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return -1;
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}
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static PyMemberDef weakref_members[] = {
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{"__callback__", T_OBJECT, offsetof(PyWeakReference, wr_callback), READONLY},
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{NULL} /* Sentinel */
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};
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static PyMethodDef weakref_methods[] = {
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{"__class_getitem__", (PyCFunction)Py_GenericAlias,
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METH_O|METH_CLASS, PyDoc_STR("See PEP 585")},
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{NULL} /* Sentinel */
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};
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PyTypeObject
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_PyWeakref_RefType = {
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PyVarObject_HEAD_INIT(&PyType_Type, 0)
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"weakref",
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sizeof(PyWeakReference),
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0,
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weakref_dealloc, /*tp_dealloc*/
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0, /*tp_vectorcall_offset*/
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0, /*tp_getattr*/
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0, /*tp_setattr*/
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0, /*tp_as_async*/
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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
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| Py_TPFLAGS_BASETYPE, /*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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(richcmpfunc)weakref_richcompare, /*tp_richcompare*/
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0, /*tp_weaklistoffset*/
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0, /*tp_iter*/
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0, /*tp_iternext*/
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weakref_methods, /*tp_methods*/
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weakref_members, /*tp_members*/
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0, /*tp_getset*/
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0, /*tp_base*/
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0, /*tp_dict*/
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0, /*tp_descr_get*/
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0, /*tp_descr_set*/
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0, /*tp_dictoffset*/
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weakref___init__, /*tp_init*/
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PyType_GenericAlloc, /*tp_alloc*/
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weakref___new__, /*tp_new*/
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PyObject_GC_Del, /*tp_free*/
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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 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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Py_INCREF(proxy); \
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PyObject* res = generic(proxy); \
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Py_DECREF(proxy); \
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return res; \
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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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Py_INCREF(x); \
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Py_INCREF(y); \
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PyObject* res = generic(x, y); \
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Py_DECREF(x); \
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Py_DECREF(y); \
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return res; \
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}
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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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Py_INCREF(proxy); \
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Py_INCREF(v); \
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Py_XINCREF(w); \
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PyObject* res = generic(proxy, v, w); \
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Py_DECREF(proxy); \
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Py_DECREF(v); \
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Py_XDECREF(w); \
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return res; \
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}
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#define WRAP_METHOD(method, special) \
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static PyObject * \
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method(PyObject *proxy, PyObject *Py_UNUSED(ignored)) { \
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_Py_IDENTIFIER(special); \
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UNWRAP(proxy); \
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Py_INCREF(proxy); \
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PyObject* res = _PyObject_CallMethodIdNoArgs(proxy, &PyId_##special); \
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Py_DECREF(proxy); \
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return res; \
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}
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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, PyObject_Call)
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static PyObject *
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proxy_repr(PyWeakReference *proxy)
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{
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return PyUnicode_FromFormat(
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"<weakproxy at %p to %s at %p>",
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proxy,
|
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Py_TYPE(PyWeakref_GET_OBJECT(proxy))->tp_name,
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PyWeakref_GET_OBJECT(proxy));
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}
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|
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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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PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
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Py_INCREF(obj);
|
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int res = PyObject_SetAttr(obj, name, value);
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Py_DECREF(obj);
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return res;
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}
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|
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static PyObject *
|
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proxy_richcompare(PyObject *proxy, PyObject *v, int op)
|
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{
|
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UNWRAP(proxy);
|
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UNWRAP(v);
|
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return PyObject_RichCompare(proxy, v, op);
|
|
}
|
|
|
|
/* number slots */
|
|
WRAP_BINARY(proxy_add, PyNumber_Add)
|
|
WRAP_BINARY(proxy_sub, PyNumber_Subtract)
|
|
WRAP_BINARY(proxy_mul, PyNumber_Multiply)
|
|
WRAP_BINARY(proxy_floor_div, PyNumber_FloorDivide)
|
|
WRAP_BINARY(proxy_true_div, PyNumber_TrueDivide)
|
|
WRAP_BINARY(proxy_mod, PyNumber_Remainder)
|
|
WRAP_BINARY(proxy_divmod, PyNumber_Divmod)
|
|
WRAP_TERNARY(proxy_pow, PyNumber_Power)
|
|
WRAP_UNARY(proxy_neg, PyNumber_Negative)
|
|
WRAP_UNARY(proxy_pos, PyNumber_Positive)
|
|
WRAP_UNARY(proxy_abs, PyNumber_Absolute)
|
|
WRAP_UNARY(proxy_invert, PyNumber_Invert)
|
|
WRAP_BINARY(proxy_lshift, PyNumber_Lshift)
|
|
WRAP_BINARY(proxy_rshift, PyNumber_Rshift)
|
|
WRAP_BINARY(proxy_and, PyNumber_And)
|
|
WRAP_BINARY(proxy_xor, PyNumber_Xor)
|
|
WRAP_BINARY(proxy_or, PyNumber_Or)
|
|
WRAP_UNARY(proxy_int, PyNumber_Long)
|
|
WRAP_UNARY(proxy_float, PyNumber_Float)
|
|
WRAP_BINARY(proxy_iadd, PyNumber_InPlaceAdd)
|
|
WRAP_BINARY(proxy_isub, PyNumber_InPlaceSubtract)
|
|
WRAP_BINARY(proxy_imul, PyNumber_InPlaceMultiply)
|
|
WRAP_BINARY(proxy_ifloor_div, PyNumber_InPlaceFloorDivide)
|
|
WRAP_BINARY(proxy_itrue_div, PyNumber_InPlaceTrueDivide)
|
|
WRAP_BINARY(proxy_imod, PyNumber_InPlaceRemainder)
|
|
WRAP_TERNARY(proxy_ipow, PyNumber_InPlacePower)
|
|
WRAP_BINARY(proxy_ilshift, PyNumber_InPlaceLshift)
|
|
WRAP_BINARY(proxy_irshift, PyNumber_InPlaceRshift)
|
|
WRAP_BINARY(proxy_iand, PyNumber_InPlaceAnd)
|
|
WRAP_BINARY(proxy_ixor, PyNumber_InPlaceXor)
|
|
WRAP_BINARY(proxy_ior, PyNumber_InPlaceOr)
|
|
WRAP_UNARY(proxy_index, PyNumber_Index)
|
|
WRAP_BINARY(proxy_matmul, PyNumber_MatrixMultiply)
|
|
WRAP_BINARY(proxy_imatmul, PyNumber_InPlaceMatrixMultiply)
|
|
|
|
static int
|
|
proxy_bool(PyWeakReference *proxy)
|
|
{
|
|
PyObject *o = PyWeakref_GET_OBJECT(proxy);
|
|
if (!proxy_checkref(proxy)) {
|
|
return -1;
|
|
}
|
|
Py_INCREF(o);
|
|
int res = PyObject_IsTrue(o);
|
|
Py_DECREF(o);
|
|
return res;
|
|
}
|
|
|
|
static void
|
|
proxy_dealloc(PyWeakReference *self)
|
|
{
|
|
if (self->wr_callback != NULL)
|
|
PyObject_GC_UnTrack((PyObject *)self);
|
|
clear_weakref(self);
|
|
PyObject_GC_Del(self);
|
|
}
|
|
|
|
/* sequence slots */
|
|
|
|
static int
|
|
proxy_contains(PyWeakReference *proxy, PyObject *value)
|
|
{
|
|
if (!proxy_checkref(proxy))
|
|
return -1;
|
|
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
int res = PySequence_Contains(obj, value);
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
/* mapping slots */
|
|
|
|
static Py_ssize_t
|
|
proxy_length(PyWeakReference *proxy)
|
|
{
|
|
if (!proxy_checkref(proxy))
|
|
return -1;
|
|
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
Py_ssize_t res = PyObject_Length(obj);
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
WRAP_BINARY(proxy_getitem, PyObject_GetItem)
|
|
|
|
static int
|
|
proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value)
|
|
{
|
|
if (!proxy_checkref(proxy))
|
|
return -1;
|
|
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
int res;
|
|
if (value == NULL) {
|
|
res = PyObject_DelItem(obj, key);
|
|
} else {
|
|
res = PyObject_SetItem(obj, key, value);
|
|
}
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
/* iterator slots */
|
|
|
|
static PyObject *
|
|
proxy_iter(PyWeakReference *proxy)
|
|
{
|
|
if (!proxy_checkref(proxy))
|
|
return NULL;
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
PyObject* res = PyObject_GetIter(obj);
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
static PyObject *
|
|
proxy_iternext(PyWeakReference *proxy)
|
|
{
|
|
if (!proxy_checkref(proxy))
|
|
return NULL;
|
|
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
PyObject* res = PyIter_Next(obj);
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
|
|
WRAP_METHOD(proxy_bytes, __bytes__)
|
|
WRAP_METHOD(proxy_reversed, __reversed__)
|
|
|
|
|
|
static PyMethodDef proxy_methods[] = {
|
|
{"__bytes__", proxy_bytes, METH_NOARGS},
|
|
{"__reversed__", proxy_reversed, METH_NOARGS},
|
|
{NULL, NULL}
|
|
};
|
|
|
|
|
|
static PyNumberMethods proxy_as_number = {
|
|
proxy_add, /*nb_add*/
|
|
proxy_sub, /*nb_subtract*/
|
|
proxy_mul, /*nb_multiply*/
|
|
proxy_mod, /*nb_remainder*/
|
|
proxy_divmod, /*nb_divmod*/
|
|
proxy_pow, /*nb_power*/
|
|
proxy_neg, /*nb_negative*/
|
|
proxy_pos, /*nb_positive*/
|
|
proxy_abs, /*nb_absolute*/
|
|
(inquiry)proxy_bool, /*nb_bool*/
|
|
proxy_invert, /*nb_invert*/
|
|
proxy_lshift, /*nb_lshift*/
|
|
proxy_rshift, /*nb_rshift*/
|
|
proxy_and, /*nb_and*/
|
|
proxy_xor, /*nb_xor*/
|
|
proxy_or, /*nb_or*/
|
|
proxy_int, /*nb_int*/
|
|
0, /*nb_reserved*/
|
|
proxy_float, /*nb_float*/
|
|
proxy_iadd, /*nb_inplace_add*/
|
|
proxy_isub, /*nb_inplace_subtract*/
|
|
proxy_imul, /*nb_inplace_multiply*/
|
|
proxy_imod, /*nb_inplace_remainder*/
|
|
proxy_ipow, /*nb_inplace_power*/
|
|
proxy_ilshift, /*nb_inplace_lshift*/
|
|
proxy_irshift, /*nb_inplace_rshift*/
|
|
proxy_iand, /*nb_inplace_and*/
|
|
proxy_ixor, /*nb_inplace_xor*/
|
|
proxy_ior, /*nb_inplace_or*/
|
|
proxy_floor_div, /*nb_floor_divide*/
|
|
proxy_true_div, /*nb_true_divide*/
|
|
proxy_ifloor_div, /*nb_inplace_floor_divide*/
|
|
proxy_itrue_div, /*nb_inplace_true_divide*/
|
|
proxy_index, /*nb_index*/
|
|
proxy_matmul, /*nb_matrix_multiply*/
|
|
proxy_imatmul, /*nb_inplace_matrix_multiply*/
|
|
};
|
|
|
|
static PySequenceMethods proxy_as_sequence = {
|
|
(lenfunc)proxy_length, /*sq_length*/
|
|
0, /*sq_concat*/
|
|
0, /*sq_repeat*/
|
|
0, /*sq_item*/
|
|
0, /*sq_slice*/
|
|
0, /*sq_ass_item*/
|
|
0, /*sq_ass_slice*/
|
|
(objobjproc)proxy_contains, /* sq_contains */
|
|
};
|
|
|
|
static PyMappingMethods proxy_as_mapping = {
|
|
(lenfunc)proxy_length, /*mp_length*/
|
|
proxy_getitem, /*mp_subscript*/
|
|
(objobjargproc)proxy_setitem, /*mp_ass_subscript*/
|
|
};
|
|
|
|
|
|
static Py_hash_t
|
|
proxy_hash(PyObject *self)
|
|
{
|
|
PyWeakReference *proxy = (PyWeakReference *)self;
|
|
if (!proxy_checkref(proxy)) {
|
|
return -1;
|
|
}
|
|
PyObject *obj = PyWeakref_GET_OBJECT(proxy);
|
|
Py_INCREF(obj);
|
|
Py_hash_t res = PyObject_Hash(obj);
|
|
Py_DECREF(obj);
|
|
return res;
|
|
}
|
|
|
|
|
|
PyTypeObject
|
|
_PyWeakref_ProxyType = {
|
|
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
|
"weakproxy",
|
|
sizeof(PyWeakReference),
|
|
0,
|
|
/* methods */
|
|
(destructor)proxy_dealloc, /* tp_dealloc */
|
|
0, /* tp_vectorcall_offset */
|
|
0, /* tp_getattr */
|
|
0, /* tp_setattr */
|
|
0, /* tp_as_async */
|
|
(reprfunc)proxy_repr, /* tp_repr */
|
|
&proxy_as_number, /* tp_as_number */
|
|
&proxy_as_sequence, /* tp_as_sequence */
|
|
&proxy_as_mapping, /* tp_as_mapping */
|
|
proxy_hash, /* tp_hash */
|
|
0, /* tp_call */
|
|
proxy_str, /* tp_str */
|
|
proxy_getattr, /* tp_getattro */
|
|
(setattrofunc)proxy_setattr, /* tp_setattro */
|
|
0, /* tp_as_buffer */
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
|
|
0, /* tp_doc */
|
|
(traverseproc)gc_traverse, /* tp_traverse */
|
|
(inquiry)gc_clear, /* tp_clear */
|
|
proxy_richcompare, /* tp_richcompare */
|
|
0, /* tp_weaklistoffset */
|
|
(getiterfunc)proxy_iter, /* tp_iter */
|
|
(iternextfunc)proxy_iternext, /* tp_iternext */
|
|
proxy_methods, /* tp_methods */
|
|
};
|
|
|
|
|
|
PyTypeObject
|
|
_PyWeakref_CallableProxyType = {
|
|
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
|
"weakcallableproxy",
|
|
sizeof(PyWeakReference),
|
|
0,
|
|
/* methods */
|
|
(destructor)proxy_dealloc, /* tp_dealloc */
|
|
0, /* tp_vectorcall_offset */
|
|
0, /* tp_getattr */
|
|
0, /* tp_setattr */
|
|
0, /* tp_as_async */
|
|
(unaryfunc)proxy_repr, /* tp_repr */
|
|
&proxy_as_number, /* tp_as_number */
|
|
&proxy_as_sequence, /* tp_as_sequence */
|
|
&proxy_as_mapping, /* tp_as_mapping */
|
|
0, /* tp_hash */
|
|
proxy_call, /* tp_call */
|
|
proxy_str, /* tp_str */
|
|
proxy_getattr, /* tp_getattro */
|
|
(setattrofunc)proxy_setattr, /* tp_setattro */
|
|
0, /* tp_as_buffer */
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, /* tp_flags */
|
|
0, /* tp_doc */
|
|
(traverseproc)gc_traverse, /* tp_traverse */
|
|
(inquiry)gc_clear, /* tp_clear */
|
|
proxy_richcompare, /* tp_richcompare */
|
|
0, /* tp_weaklistoffset */
|
|
(getiterfunc)proxy_iter, /* tp_iter */
|
|
(iternextfunc)proxy_iternext, /* tp_iternext */
|
|
};
|
|
|
|
|
|
|
|
PyObject *
|
|
PyWeakref_NewRef(PyObject *ob, PyObject *callback)
|
|
{
|
|
PyWeakReference *result = NULL;
|
|
PyWeakReference **list;
|
|
PyWeakReference *ref, *proxy;
|
|
|
|
if (!PyType_SUPPORTS_WEAKREFS(Py_TYPE(ob))) {
|
|
PyErr_Format(PyExc_TypeError,
|
|
"cannot create weak reference to '%s' object",
|
|
Py_TYPE(ob)->tp_name);
|
|
return NULL;
|
|
}
|
|
list = GET_WEAKREFS_LISTPTR(ob);
|
|
get_basic_refs(*list, &ref, &proxy);
|
|
if (callback == Py_None)
|
|
callback = NULL;
|
|
if (callback == NULL)
|
|
/* return existing weak reference if it exists */
|
|
result = ref;
|
|
if (result != NULL)
|
|
Py_INCREF(result);
|
|
else {
|
|
/* Note: new_weakref() can trigger cyclic GC, so the weakref
|
|
list on ob can be mutated. This means that the ref and
|
|
proxy pointers we got back earlier may have been collected,
|
|
so we need to compute these values again before we use
|
|
them. */
|
|
result = new_weakref(ob, callback);
|
|
if (result != NULL) {
|
|
get_basic_refs(*list, &ref, &proxy);
|
|
if (callback == NULL) {
|
|
if (ref == NULL)
|
|
insert_head(result, list);
|
|
else {
|
|
/* Someone else added a ref without a callback
|
|
during GC. Return that one instead of this one
|
|
to avoid violating the invariants of the list
|
|
of weakrefs for ob. */
|
|
Py_DECREF(result);
|
|
Py_INCREF(ref);
|
|
result = ref;
|
|
}
|
|
}
|
|
else {
|
|
PyWeakReference *prev;
|
|
|
|
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(Py_TYPE(ob))) {
|
|
PyErr_Format(PyExc_TypeError,
|
|
"cannot create weak reference to '%s' object",
|
|
Py_TYPE(ob)->tp_name);
|
|
return NULL;
|
|
}
|
|
list = GET_WEAKREFS_LISTPTR(ob);
|
|
get_basic_refs(*list, &ref, &proxy);
|
|
if (callback == Py_None)
|
|
callback = NULL;
|
|
if (callback == NULL)
|
|
/* attempt to return an existing weak reference if it exists */
|
|
result = proxy;
|
|
if (result != NULL)
|
|
Py_INCREF(result);
|
|
else {
|
|
/* Note: new_weakref() can trigger cyclic GC, so the weakref
|
|
list on ob can be mutated. This means that the ref and
|
|
proxy pointers we got back earlier may have been collected,
|
|
so we need to compute these values again before we use
|
|
them. */
|
|
result = new_weakref(ob, callback);
|
|
if (result != NULL) {
|
|
PyWeakReference *prev;
|
|
|
|
if (PyCallable_Check(ob)) {
|
|
Py_SET_TYPE(result, &_PyWeakref_CallableProxyType);
|
|
}
|
|
else {
|
|
Py_SET_TYPE(result, &_PyWeakref_ProxyType);
|
|
}
|
|
get_basic_refs(*list, &ref, &proxy);
|
|
if (callback == NULL) {
|
|
if (proxy != NULL) {
|
|
/* Someone else added a proxy without a callback
|
|
during GC. Return that one instead of this one
|
|
to avoid violating the invariants of the list
|
|
of weakrefs for ob. */
|
|
Py_DECREF(result);
|
|
result = proxy;
|
|
Py_INCREF(result);
|
|
goto skip_insert;
|
|
}
|
|
prev = ref;
|
|
}
|
|
else
|
|
prev = (proxy == NULL) ? ref : proxy;
|
|
|
|
if (prev == NULL)
|
|
insert_head(result, list);
|
|
else
|
|
insert_after(result, prev);
|
|
skip_insert:
|
|
;
|
|
}
|
|
}
|
|
return (PyObject *) result;
|
|
}
|
|
|
|
|
|
PyObject *
|
|
PyWeakref_GetObject(PyObject *ref)
|
|
{
|
|
if (ref == NULL || !PyWeakref_Check(ref)) {
|
|
PyErr_BadInternalCall();
|
|
return NULL;
|
|
}
|
|
return PyWeakref_GET_OBJECT(ref);
|
|
}
|
|
|
|
/* Note that there's an inlined copy-paste of handle_callback() in gcmodule.c's
|
|
* handle_weakrefs().
|
|
*/
|
|
static void
|
|
handle_callback(PyWeakReference *ref, PyObject *callback)
|
|
{
|
|
PyObject *cbresult = PyObject_CallOneArg(callback, (PyObject *)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(Py_TYPE(object))
|
|
|| Py_REFCNT(object) != 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;
|
|
Py_ssize_t count = _PyWeakref_GetWeakrefCount(current);
|
|
PyObject *err_type, *err_value, *err_tb;
|
|
|
|
PyErr_Fetch(&err_type, &err_value, &err_tb);
|
|
if (count == 1) {
|
|
PyObject *callback = current->wr_callback;
|
|
|
|
current->wr_callback = NULL;
|
|
clear_weakref(current);
|
|
if (callback != NULL) {
|
|
if (Py_REFCNT((PyObject *)current) > 0) {
|
|
handle_callback(current, callback);
|
|
}
|
|
Py_DECREF(callback);
|
|
}
|
|
}
|
|
else {
|
|
PyObject *tuple;
|
|
Py_ssize_t i = 0;
|
|
|
|
tuple = PyTuple_New(count * 2);
|
|
if (tuple == NULL) {
|
|
_PyErr_ChainExceptions(err_type, err_value, err_tb);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < count; ++i) {
|
|
PyWeakReference *next = current->wr_next;
|
|
|
|
if (Py_REFCNT((PyObject *)current) > 0) {
|
|
Py_INCREF(current);
|
|
PyTuple_SET_ITEM(tuple, i * 2, (PyObject *) current);
|
|
PyTuple_SET_ITEM(tuple, i * 2 + 1, current->wr_callback);
|
|
}
|
|
else {
|
|
Py_DECREF(current->wr_callback);
|
|
}
|
|
current->wr_callback = NULL;
|
|
clear_weakref(current);
|
|
current = next;
|
|
}
|
|
for (i = 0; i < count; ++i) {
|
|
PyObject *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1);
|
|
|
|
/* The tuple may have slots left to NULL */
|
|
if (callback != NULL) {
|
|
PyObject *item = PyTuple_GET_ITEM(tuple, i * 2);
|
|
handle_callback((PyWeakReference *)item, callback);
|
|
}
|
|
}
|
|
Py_DECREF(tuple);
|
|
}
|
|
assert(!PyErr_Occurred());
|
|
PyErr_Restore(err_type, err_value, err_tb);
|
|
}
|
|
}
|