Staging
v0.5.1
https://github.com/python/cpython
Revision 33fe8093df5c13e41d7dba764279c71c142a4a7d authored by Christian Heimes on 13 April 2008, 13:53:33 UTC, committed by Christian Heimes on 13 April 2008, 13:53:33 UTC
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r62260 | gregory.p.smith | 2008-04-10 01:11:56 +0200 (Thu, 10 Apr 2008) | 2 lines

  better diagnostics
........
  r62261 | gregory.p.smith | 2008-04-10 01:16:37 +0200 (Thu, 10 Apr 2008) | 3 lines

  Raise SystemError when size < 0 is passed into PyString_FromStringAndSize,
  PyBytes_FromStringAndSize or PyUnicode_FromStringAndSize.  [issue2587]
........
  r62266 | neal.norwitz | 2008-04-10 07:46:39 +0200 (Thu, 10 Apr 2008) | 5 lines

  Remove the test file before writing it in case there is no write permission.
  This might help fix some of the failures on Windows box(es).  It doesn't hurt
  either way and ensure the tests are a little more self contained (ie have
  less assumptions).
........
  r62271 | gregory.p.smith | 2008-04-10 21:50:36 +0200 (Thu, 10 Apr 2008) | 2 lines

  get rid of assert (size >= 0) now that an explicit if (size < 0) is in the code.
........
  r62277 | andrew.kuchling | 2008-04-10 23:27:10 +0200 (Thu, 10 Apr 2008) | 1 line

  Remove forward-looking statement
........
  r62278 | andrew.kuchling | 2008-04-10 23:28:51 +0200 (Thu, 10 Apr 2008) | 1 line

  Add punctuation
........
  r62279 | andrew.kuchling | 2008-04-10 23:29:01 +0200 (Thu, 10 Apr 2008) | 1 line

  Use issue directive
........
  r62289 | thomas.heller | 2008-04-11 15:05:38 +0200 (Fri, 11 Apr 2008) | 3 lines

  Move backwards compatibility macro to the correct place;
  PyIndex_Check() was introduced in Python 2.5.
........
  r62290 | thomas.heller | 2008-04-11 16:20:26 +0200 (Fri, 11 Apr 2008) | 2 lines

  Performance improvements.
........
  r62293 | christian.heimes | 2008-04-12 15:03:03 +0200 (Sat, 12 Apr 2008) | 2 lines

  Applied patch #2617 from Frank Wierzbicki wit some extras from me
  -J and -X are now reserved for Jython and non-standard arguments (e.g. IronPython). I've added some extra comments to make sure the reservation don't get missed in the future.
........
  r62294 | georg.brandl | 2008-04-12 20:11:18 +0200 (Sat, 12 Apr 2008) | 2 lines

  Use absolute path in sys.path.
........
  r62295 | georg.brandl | 2008-04-12 20:36:09 +0200 (Sat, 12 Apr 2008) | 2 lines

  #2615: small consistency update by Jeroen Ruigrok van der Werven.
........
  r62296 | georg.brandl | 2008-04-12 21:00:20 +0200 (Sat, 12 Apr 2008) | 2 lines

  Add Jeroen.
........
  r62297 | georg.brandl | 2008-04-12 21:05:37 +0200 (Sat, 12 Apr 2008) | 2 lines

  Don't offend snake lovers.
........
  r62298 | gregory.p.smith | 2008-04-12 22:37:48 +0200 (Sat, 12 Apr 2008) | 2 lines

  fix compiler warnings
........
  r62302 | gregory.p.smith | 2008-04-13 00:24:04 +0200 (Sun, 13 Apr 2008) | 3 lines

  socket.error inherits from IOError, it no longer needs listing in
  the all_errors tuple.
........
  r62303 | brett.cannon | 2008-04-13 01:44:07 +0200 (Sun, 13 Apr 2008) | 8 lines

  Re-implement the 'warnings' module in C. This allows for usage of the
  'warnings' code in places where it was previously not possible (e.g., the
  parser). It could also potentially lead to a speed-up in interpreter start-up
  if the C version of the code (_warnings) is imported over the use of the
  Python version in key places.

  Closes issue #1631171.
........
  r62304 | gregory.p.smith | 2008-04-13 02:03:25 +0200 (Sun, 13 Apr 2008) | 3 lines

  Adds a profile-opt target for easy compilation of a python binary using
  gcc's profile guided optimization.
........
  r62305 | brett.cannon | 2008-04-13 02:18:44 +0200 (Sun, 13 Apr 2008) | 3 lines

  Fix a bug in PySys_HasWarnOption() where it was not properly checking the
  length of the list storing the warning options.
........
  r62306 | brett.cannon | 2008-04-13 02:25:15 +0200 (Sun, 13 Apr 2008) | 2 lines

  Fix an accidental bug of an non-existent init function.
........
  r62308 | andrew.kuchling | 2008-04-13 03:05:59 +0200 (Sun, 13 Apr 2008) | 1 line

  Mention -J, -X
........
  r62311 | benjamin.peterson | 2008-04-13 04:20:05 +0200 (Sun, 13 Apr 2008) | 2 lines

  Give the "Interactive Interpreter Changes" section in 2.6 whatsnew a unique link name
........
  r62313 | brett.cannon | 2008-04-13 04:42:36 +0200 (Sun, 13 Apr 2008) | 3 lines

  Fix test_warnings by making the state of things more consistent for each test
  when it is run.
........
  r62314 | skip.montanaro | 2008-04-13 05:17:30 +0200 (Sun, 13 Apr 2008) | 2 lines

  spelling
........
  r62315 | georg.brandl | 2008-04-13 09:07:44 +0200 (Sun, 13 Apr 2008) | 2 lines

  Fix markup.
........
  r62319 | christian.heimes | 2008-04-13 11:30:17 +0200 (Sun, 13 Apr 2008) | 1 line

  Fix compiler warning Include/warnings.h:19:28: warning: no newline at end of file
........
  r62320 | christian.heimes | 2008-04-13 11:33:24 +0200 (Sun, 13 Apr 2008) | 1 line

  Use PyString_InternFromString instead of PyString_FromString for static vars
........
  r62321 | christian.heimes | 2008-04-13 11:37:05 +0200 (Sun, 13 Apr 2008) | 1 line

  Added new files to the pcbuild files
........
1 parent 659d32d
Raw File
Tip revision: 33fe8093df5c13e41d7dba764279c71c142a4a7d authored by Christian Heimes on 13 April 2008, 13:53:33 UTC
Merged revisions 62260-62261,62266,62271,62277-62279,62289-62290,62293-62298,62302-62306,62308,62311,62313-62315,62319-62321 via svnmerge from
Tip revision: 33fe809
weakrefobject.c
#include "Python.h"
#include "structmember.h"


#define GET_WEAKREFS_LISTPTR(o) \
        ((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o))


Py_ssize_t
_PyWeakref_GetWeakrefCount(PyWeakReference *head)
{
    Py_ssize_t count = 0;

    while (head != NULL) {
        ++count;
        head = head->wr_next;
    }
    return count;
}


static void
init_weakref(PyWeakReference *self, PyObject *ob, PyObject *callback)
{
    self->hash = -1;
    self->wr_object = ob;
    Py_XINCREF(callback);
    self->wr_callback = callback;
}

static PyWeakReference *
new_weakref(PyObject *ob, PyObject *callback)
{
    PyWeakReference *result;

    result = PyObject_GC_New(PyWeakReference, &_PyWeakref_RefType);
    if (result) {
        init_weakref(result, ob, callback);
        PyObject_GC_Track(result);
    }
    return result;
}


/* This function clears the passed-in reference and removes it from the
 * list of weak references for the referent.  This is the only code that
 * removes an item from the doubly-linked list of weak references for an
 * object; it is also responsible for clearing the callback slot.
 */
static void
clear_weakref(PyWeakReference *self)
{
    PyObject *callback = self->wr_callback;

    if (PyWeakref_GET_OBJECT(self) != Py_None) {
        PyWeakReference **list = GET_WEAKREFS_LISTPTR(
            PyWeakref_GET_OBJECT(self));

        if (*list == self)
	    /* If 'self' is the end of the list (and thus self->wr_next == NULL)
	       then the weakref list itself (and thus the value of *list) will
	       end up being set to NULL. */
            *list = self->wr_next;
        self->wr_object = Py_None;
        if (self->wr_prev != NULL)
            self->wr_prev->wr_next = self->wr_next;
        if (self->wr_next != NULL)
            self->wr_next->wr_prev = self->wr_prev;
        self->wr_prev = NULL;
        self->wr_next = NULL;
    }
    if (callback != NULL) {
        Py_DECREF(callback);
        self->wr_callback = NULL;
    }
}

/* Cyclic gc uses this to *just* clear the passed-in reference, leaving
 * the callback intact and uncalled.  It must be possible to call self's
 * tp_dealloc() after calling this, so self has to be left in a sane enough
 * state for that to work.  We expect tp_dealloc to decref the callback
 * then.  The reason for not letting clear_weakref() decref the callback
 * right now is that if the callback goes away, that may in turn trigger
 * another callback (if a weak reference to the callback exists) -- running
 * arbitrary Python code in the middle of gc is a disaster.  The convolution
 * here allows gc to delay triggering such callbacks until the world is in
 * a sane state again.
 */
void
_PyWeakref_ClearRef(PyWeakReference *self)
{
    PyObject *callback;

    assert(self != NULL);
    assert(PyWeakref_Check(self));
    /* Preserve and restore the callback around clear_weakref. */
    callback = self->wr_callback;
    self->wr_callback = NULL;
    clear_weakref(self);
    self->wr_callback = callback;
}

static void
weakref_dealloc(PyObject *self)
{
    PyObject_GC_UnTrack(self);
    clear_weakref((PyWeakReference *) self);
    Py_TYPE(self)->tp_free(self);
}


static int
gc_traverse(PyWeakReference *self, visitproc visit, void *arg)
{
    Py_VISIT(self->wr_callback);
    return 0;
}


static int
gc_clear(PyWeakReference *self)
{
    clear_weakref(self);
    return 0;
}


static PyObject *
weakref_call(PyWeakReference *self, PyObject *args, PyObject *kw)
{
    static char *kwlist[] = {NULL};

    if (PyArg_ParseTupleAndKeywords(args, kw, ":__call__", kwlist)) {
        PyObject *object = PyWeakref_GET_OBJECT(self);
        Py_INCREF(object);
        return (object);
    }
    return NULL;
}


static long
weakref_hash(PyWeakReference *self)
{
    if (self->hash != -1)
        return self->hash;
    if (PyWeakref_GET_OBJECT(self) == Py_None) {
        PyErr_SetString(PyExc_TypeError, "weak object has gone away");
        return -1;
    }
    self->hash = PyObject_Hash(PyWeakref_GET_OBJECT(self));
    return self->hash;
}


static PyObject *
weakref_repr(PyWeakReference *self)
{
    char buffer[256];
    if (PyWeakref_GET_OBJECT(self) == Py_None) {
        PyOS_snprintf(buffer, sizeof(buffer), "<weakref at %p; dead>", self);
    }
    else {
	char *name = NULL;
	PyObject *nameobj = PyObject_GetAttrString(PyWeakref_GET_OBJECT(self),
						   "__name__");
	if (nameobj == NULL)
		PyErr_Clear();
	else if (PyUnicode_Check(nameobj))
		name = PyUnicode_AsString(nameobj);
        PyOS_snprintf(buffer, sizeof(buffer),
		      name ? "<weakref at %p; to '%.50s' at %p (%s)>"
		           : "<weakref at %p; to '%.50s' at %p>",
		      self,
		      Py_TYPE(PyWeakref_GET_OBJECT(self))->tp_name,
		      PyWeakref_GET_OBJECT(self),
		      name);
	Py_XDECREF(nameobj);
    }
    return PyUnicode_FromString(buffer);
}

/* Weak references only support equality, not ordering. Two weak references
   are equal if the underlying objects are equal. If the underlying object has
   gone away, they are equal if they are identical. */

static PyObject *
weakref_richcompare(PyWeakReference* self, PyWeakReference* other, int op)
{
    if ((op != Py_EQ && op != Py_NE) ||
	!PyWeakref_Check(self) ||
	!PyWeakref_Check(other)) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    if (PyWeakref_GET_OBJECT(self) == Py_None
        || PyWeakref_GET_OBJECT(other) == Py_None) {
        PyObject *res = self==other ? Py_True : Py_False;
        Py_INCREF(res);
        return res;
    }
    return PyObject_RichCompare(PyWeakref_GET_OBJECT(self),
                                PyWeakref_GET_OBJECT(other), op);
}

/* 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) {
        /* We need to be careful that the "basic refs" aren't
           subclasses of the main types.  That complicates this a
           little. */
        if (PyWeakref_CheckRefExact(head)) {
            *refp = head;
            head = head->wr_next;
        }
        if (head != NULL
            && head->wr_callback == NULL
            && PyWeakref_CheckProxy(head)) {
            *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;
}

static int
parse_weakref_init_args(char *funcname, PyObject *args, PyObject *kwargs,
                        PyObject **obp, PyObject **callbackp)
{
    /* XXX Should check that kwargs == NULL or is empty. */
    return PyArg_UnpackTuple(args, funcname, 1, 2, obp, callbackp);
}

static PyObject *
weakref___new__(PyTypeObject *type, PyObject *args, PyObject *kwargs)
{
    PyWeakReference *self = NULL;
    PyObject *ob, *callback = NULL;

    if (parse_weakref_init_args("__new__", args, kwargs, &ob, &callback)) {
        PyWeakReference *ref, *proxy;
        PyWeakReference **list;

        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;
        }
        if (callback == Py_None)
            callback = NULL;
        list = GET_WEAKREFS_LISTPTR(ob);
        get_basic_refs(*list, &ref, &proxy);
        if (callback == NULL && type == &_PyWeakref_RefType) {
            if (ref != NULL) {
                /* We can re-use an existing reference. */
                Py_INCREF(ref);
                return (PyObject *)ref;
            }
        }
        /* We have to create a new reference. */
        /* Note: the tp_alloc() 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. */
        self = (PyWeakReference *) (type->tp_alloc(type, 0));
        if (self != NULL) {
            init_weakref(self, ob, callback);
            if (callback == NULL && type == &_PyWeakref_RefType) {
                insert_head(self, list);
            }
            else {
                PyWeakReference *prev;

                get_basic_refs(*list, &ref, &proxy);
                prev = (proxy == NULL) ? ref : proxy;
                if (prev == NULL)
                    insert_head(self, list);
                else
                    insert_after(self, prev);
            }
        }
    }
    return (PyObject *)self;
}

static int
weakref___init__(PyObject *self, PyObject *args, PyObject *kwargs)
{
    PyObject *tmp;

    if (parse_weakref_init_args("__init__", args, kwargs, &tmp, &tmp))
        return 0;
    else
        return 1;
}


PyTypeObject
_PyWeakref_RefType = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "weakref",
    sizeof(PyWeakReference),
    0,
    weakref_dealloc,            /*tp_dealloc*/
    0,	                        /*tp_print*/
    0,                          /*tp_getattr*/
    0,                          /*tp_setattr*/
    0,	                        /*tp_compare*/
    (reprfunc)weakref_repr,     /*tp_repr*/
    0,                          /*tp_as_number*/
    0,                          /*tp_as_sequence*/
    0,                          /*tp_as_mapping*/
    (hashfunc)weakref_hash,     /*tp_hash*/
    (ternaryfunc)weakref_call,  /*tp_call*/
    0,                          /*tp_str*/
    0,                          /*tp_getattro*/
    0,                          /*tp_setattro*/
    0,                          /*tp_as_buffer*/
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC
        | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
    0,                          /*tp_doc*/
    (traverseproc)gc_traverse,  /*tp_traverse*/
    (inquiry)gc_clear,          /*tp_clear*/
    (richcmpfunc)weakref_richcompare,	/*tp_richcompare*/
    0,                          /*tp_weaklistoffset*/
    0,                          /*tp_iter*/
    0,                          /*tp_iternext*/
    0,                          /*tp_methods*/
    0,                          /*tp_members*/
    0,                          /*tp_getset*/
    0,                          /*tp_base*/
    0,                          /*tp_dict*/
    0,                          /*tp_descr_get*/
    0,                          /*tp_descr_set*/
    0,                          /*tp_dictoffset*/
    weakref___init__,           /*tp_init*/
    PyType_GenericAlloc,        /*tp_alloc*/
    weakref___new__,            /*tp_new*/
    PyObject_GC_Del,            /*tp_free*/
};


static int
proxy_checkref(PyWeakReference *proxy)
{
    if (PyWeakref_GET_OBJECT(proxy) == Py_None) {
        PyErr_SetString(PyExc_ReferenceError,
                        "weakly-referenced object no longer exists");
        return 0;
    }
    return 1;
}


/* If a parameter is a proxy, check that it is still "live" and wrap it,
 * replacing the original value with the raw object.  Raises ReferenceError
 * if the param is a dead proxy.
 */
#define UNWRAP(o) \
        if (PyWeakref_CheckProxy(o)) { \
            if (!proxy_checkref((PyWeakReference *)o)) \
                return NULL; \
            o = PyWeakref_GET_OBJECT(o); \
        }

#define UNWRAP_I(o) \
        if (PyWeakref_CheckProxy(o)) { \
            if (!proxy_checkref((PyWeakReference *)o)) \
                return -1; \
            o = PyWeakref_GET_OBJECT(o); \
        }

#define WRAP_UNARY(method, generic) \
    static PyObject * \
    method(PyObject *proxy) { \
        UNWRAP(proxy); \
        return generic(proxy); \
    }

#define WRAP_BINARY(method, generic) \
    static PyObject * \
    method(PyObject *x, PyObject *y) { \
        UNWRAP(x); \
        UNWRAP(y); \
        return generic(x, y); \
    }

/* Note that the third arg needs to be checked for NULL since the tp_call
 * slot can receive NULL for this arg.
 */
#define WRAP_TERNARY(method, generic) \
    static PyObject * \
    method(PyObject *proxy, PyObject *v, PyObject *w) { \
        UNWRAP(proxy); \
        UNWRAP(v); \
        if (w != NULL) \
            UNWRAP(w); \
        return generic(proxy, v, w); \
    }


/* direct slots */

WRAP_BINARY(proxy_getattr, PyObject_GetAttr)
WRAP_UNARY(proxy_str, PyObject_Str)
WRAP_TERNARY(proxy_call, PyEval_CallObjectWithKeywords)

static PyObject *
proxy_repr(PyWeakReference *proxy)
{
    char buf[160];
    PyOS_snprintf(buf, sizeof(buf),
		  "<weakproxy at %p to %.100s at %p>", proxy,
		  Py_TYPE(PyWeakref_GET_OBJECT(proxy))->tp_name,
		  PyWeakref_GET_OBJECT(proxy));
    return PyUnicode_FromString(buf);
}


static int
proxy_setattr(PyWeakReference *proxy, PyObject *name, PyObject *value)
{
    if (!proxy_checkref(proxy))
        return -1;
    return PyObject_SetAttr(PyWeakref_GET_OBJECT(proxy), name, value);
}

static PyObject *
proxy_richcompare(PyObject *proxy, PyObject *v, int op)
{
    UNWRAP(proxy);
    UNWRAP(v);
    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_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_Int)
WRAP_UNARY(proxy_long, 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_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)

static int
proxy_bool(PyWeakReference *proxy)
{
    PyObject *o = PyWeakref_GET_OBJECT(proxy);
    if (!proxy_checkref(proxy))
        return -1;
    return PyObject_IsTrue(o);
}

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;
    return PySequence_Contains(PyWeakref_GET_OBJECT(proxy), value);
}


/* mapping slots */

static Py_ssize_t
proxy_length(PyWeakReference *proxy)
{
    if (!proxy_checkref(proxy))
        return -1;
    return PyObject_Length(PyWeakref_GET_OBJECT(proxy));
}

WRAP_BINARY(proxy_getitem, PyObject_GetItem)

static int
proxy_setitem(PyWeakReference *proxy, PyObject *key, PyObject *value)
{
    if (!proxy_checkref(proxy))
        return -1;

    if (value == NULL)
        return PyObject_DelItem(PyWeakref_GET_OBJECT(proxy), key);
    else
        return PyObject_SetItem(PyWeakref_GET_OBJECT(proxy), key, value);
}

/* iterator slots */

static PyObject *
proxy_iter(PyWeakReference *proxy)
{
    if (!proxy_checkref(proxy))
        return NULL;
    return PyObject_GetIter(PyWeakref_GET_OBJECT(proxy));
}

static PyObject *
proxy_iternext(PyWeakReference *proxy)
{
    if (!proxy_checkref(proxy))
        return NULL;
    return PyIter_Next(PyWeakref_GET_OBJECT(proxy));
}


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*/
    0,                      /*nb_reserved*/
    proxy_int,              /*nb_int*/
    proxy_long,             /*nb_long*/
    proxy_float,            /*nb_float*/
    0,                      /*nb_oct*/
    0,                      /*nb_hex*/
    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*/
};

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*/
};


PyTypeObject
_PyWeakref_ProxyType = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "weakproxy",
    sizeof(PyWeakReference),
    0,
    /* methods */
    (destructor)proxy_dealloc,          /* tp_dealloc */
    0,				        /* tp_print */
    0,				        /* tp_getattr */
    0, 				        /* tp_setattr */
    0,				        /* tp_compare */
    (reprfunc)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 */
    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 */
};


PyTypeObject
_PyWeakref_CallableProxyType = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "weakcallableproxy",
    sizeof(PyWeakReference),
    0,
    /* methods */
    (destructor)proxy_dealloc,          /* tp_dealloc */
    0,				        /* tp_print */
    0,				        /* tp_getattr */
    0, 				        /* tp_setattr */
    0,				        /* tp_compare */
    (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_TYPE(result) = &_PyWeakref_CallableProxyType;
            else
                Py_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);
                    Py_INCREF(result = proxy);
                    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_CallFunctionObjArgs(callback, ref, NULL);

    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))
        || 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;
        Py_ssize_t 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);
            if (callback != NULL) {
                handle_callback(current, callback);
                Py_DECREF(callback);
            }
        }
        else {
            PyObject *tuple;
            Py_ssize_t i = 0;
    
            tuple = PyTuple_New(count * 2);
            if (tuple == NULL) {
                if (restore_error)
                    PyErr_Fetch(&err_type, &err_value, &err_tb);
                return;
            }

            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 *callback = PyTuple_GET_ITEM(tuple, i * 2 + 1);

                if (callback != NULL) {
                    PyObject *item = PyTuple_GET_ITEM(tuple, i * 2);
                    handle_callback((PyWeakReference *)item, callback);
                }
            }
            Py_DECREF(tuple);
        }
        if (restore_error)
            PyErr_Restore(err_type, err_value, err_tb);
    }
}
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