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#3712: The memoryview object had a reference leak and didn't support cyclic garbage collection.

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Reviewed by Benjamin Peterson.
This commit is contained in:
Antoine Pitrou 2008-09-01 15:10:14 +00:00
parent d26782e863
commit c6b09ebe58
3 changed files with 101 additions and 34 deletions
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32
Lib/test/test_memoryview.py
View File

@ -6,6 +6,8 @@ XXX We need more tests! Some tests are in test_bytes
import unittest
import test.support
import sys
import gc
import weakref
class CommonMemoryTests:
@ -157,6 +159,36 @@ class CommonMemoryTests:
m = self.check_attributes_with_type(bytearray)
self.assertEquals(m.readonly, False)
def test_getbuffer(self):
# Test PyObject_GetBuffer() on a memoryview object.
b = self.base_object
oldrefcount = sys.getrefcount(b)
m = self._view(b)
oldviewrefcount = sys.getrefcount(m)
s = str(m, "utf-8")
self._check_contents(b, s.encode("utf-8"))
self.assertEquals(sys.getrefcount(m), oldviewrefcount)
m = None
self.assertEquals(sys.getrefcount(b), oldrefcount)
def test_gc(self):
class MyBytes(bytes):
pass
class MyObject:
pass
# Create a reference cycle through a memoryview object
b = MyBytes(b'abc')
m = self._view(b)
o = MyObject()
b.m = m
b.o = o
wr = weakref.ref(o)
b = m = o = None
# The cycle must be broken
gc.collect()
self.assert_(wr() is None, wr())
class MemoryviewTest(unittest.TestCase, CommonMemoryTests):

3
Misc/NEWS
View File

@ -12,6 +12,9 @@ What's New in Python 3.0 release candidate 1
Core and Builtins
-----------------
- Issue #3712: The memoryview object had a reference leak and didn't support
cyclic garbage collection.
- Issue #3668: Fix a memory leak with the "s*" argument parser in
PyArg_ParseTuple and friends, which occurred when the argument for "s*"
was correctly parsed but parsing of subsequent arguments failed.

100
Objects/memoryobject.c
View File

@ -3,24 +3,34 @@
#include "Python.h"
static void
dup_buffer(Py_buffer *dest, Py_buffer *src)
{
*dest = *src;
if (src->shape == &(src->len))
dest->shape = &(dest->len);
if (src->strides == &(src->itemsize))
dest->strides = &(dest->itemsize);
}
static int
memory_getbuf(PyMemoryViewObject *self, Py_buffer *view, int flags)
{
if (view != NULL) {
if (self->view.obj)
Py_INCREF(self->view.obj);
*view = self->view;
}
if (self->view.obj == NULL)
return 0;
return self->view.obj->ob_type->tp_as_buffer->bf_getbuffer(
self->view.obj, NULL, PyBUF_FULL);
int res = 0;
/* XXX for whatever reason fixing the flags seems necessary */
if (self->view.readonly)
flags &= ~PyBUF_WRITABLE;
if (self->view.obj != NULL)
res = PyObject_GetBuffer(self->view.obj, view, flags);
if (view)
dup_buffer(view, &self->view);
return res;
}
static void
memory_releasebuf(PyMemoryViewObject *self, Py_buffer *view)
{
PyBuffer_Release(&self->view);
PyBuffer_Release(view);
}
PyDoc_STRVAR(memory_doc,
@ -33,18 +43,15 @@ PyMemoryView_FromBuffer(Py_buffer *info)
{
PyMemoryViewObject *mview;
mview = (PyMemoryViewObject *)PyObject_New(PyMemoryViewObject,
&PyMemoryView_Type);
if (mview == NULL) return NULL;
mview = (PyMemoryViewObject *)
PyObject_GC_New(PyMemoryViewObject, &PyMemoryView_Type);
if (mview == NULL)
return NULL;
mview->base = NULL;
/* XXX there should be an API to duplicate a buffer object */
mview->view = *info;
if (info->shape == &(info->len))
mview->view.shape = &(mview->view.len);
if (info->strides == &(info->itemsize))
mview->view.strides = &(mview->view.itemsize);
dup_buffer(&mview->view, info);
/* NOTE: mview->view.obj should already have been incref'ed as
part of PyBuffer_FillInfo(). */
_PyObject_GC_TRACK(mview);
return (PyObject *)mview;
}
@ -60,9 +67,10 @@ PyMemoryView_FromObject(PyObject *base)
return NULL;
}
mview = (PyMemoryViewObject *)PyObject_New(PyMemoryViewObject,
&PyMemoryView_Type);
if (mview == NULL) return NULL;
mview = (PyMemoryViewObject *)
PyObject_GC_New(PyMemoryViewObject, &PyMemoryView_Type);
if (mview == NULL)
return NULL;
mview->base = NULL;
if (PyObject_GetBuffer(base, &(mview->view), PyBUF_FULL_RO) < 0) {
@ -72,6 +80,7 @@ PyMemoryView_FromObject(PyObject *base)
mview->base = base;
Py_INCREF(base);
_PyObject_GC_TRACK(mview);
return (PyObject *)mview;
}
@ -233,8 +242,9 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
return NULL;
}
mem = PyObject_New(PyMemoryViewObject, &PyMemoryView_Type);
if (mem == NULL) return NULL;
mem = PyObject_GC_New(PyMemoryViewObject, &PyMemoryView_Type);
if (mem == NULL)
return NULL;
view = &mem->view;
flags = PyBUF_FULL_RO;
@ -245,7 +255,7 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
}
if (PyObject_GetBuffer(obj, view, flags) != 0) {
PyObject_DEL(mem);
Py_DECREF(mem);
return NULL;
}
@ -253,11 +263,12 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
/* no copy needed */
Py_INCREF(obj);
mem->base = obj;
_PyObject_GC_TRACK(mem);
return (PyObject *)mem;
}
/* otherwise a copy is needed */
if (buffertype == PyBUF_WRITE) {
PyObject_DEL(mem);
Py_DECREF(mem);
PyErr_SetString(PyExc_BufferError,
"writable contiguous buffer requested "
"for a non-contiguousobject.");
@ -265,7 +276,7 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
}
bytes = PyBytes_FromStringAndSize(NULL, view->len);
if (bytes == NULL) {
PyBuffer_Release(view);
Py_DECREF(mem);
return NULL;
}
dest = PyBytes_AS_STRING(bytes);
@ -280,7 +291,7 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
else {
if (_indirect_copy_nd(dest, view, fort) < 0) {
Py_DECREF(bytes);
PyBuffer_Release(view);
Py_DECREF(mem);
return NULL;
}
}
@ -290,15 +301,16 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
mem->base = PyTuple_Pack(2, obj, bytes);
Py_DECREF(bytes);
if (mem->base == NULL) {
PyBuffer_Release(view);
Py_DECREF(mem);
return NULL;
}
}
else {
PyBuffer_Release(view);
PyBuffer_Release(view); /* XXX ? */
/* steal the reference */
mem->base = bytes;
}
_PyObject_GC_TRACK(mem);
return (PyObject *)mem;
}
@ -444,6 +456,7 @@ static PyMethodDef memory_methods[] = {
static void
memory_dealloc(PyMemoryViewObject *self)
{
_PyObject_GC_UNTRACK(self);
if (self->view.obj != NULL) {
if (self->base && PyTuple_Check(self->base)) {
/* Special case when first element is generic object
@ -468,7 +481,7 @@ memory_dealloc(PyMemoryViewObject *self)
}
Py_CLEAR(self->base);
}
PyObject_DEL(self);
PyObject_GC_Del(self);
}
static PyObject *
@ -749,6 +762,25 @@ _notimpl:
}
static int
memory_traverse(PyMemoryViewObject *self, visitproc visit, void *arg)
{
if (self->base != NULL)
Py_VISIT(self->base);
if (self->view.obj != NULL)
Py_VISIT(self->view.obj);
return 0;
}
static int
memory_clear(PyMemoryViewObject *self)
{
Py_CLEAR(self->base);
PyBuffer_Release(&self->view);
return 0;
}
/* As mapping */
static PyMappingMethods memory_as_mapping = {
(lenfunc)memory_length, /*mp_length*/
@ -785,10 +817,10 @@ PyTypeObject PyMemoryView_Type = {
PyObject_GenericGetAttr, /* tp_getattro */
0, /* tp_setattro */
&memory_as_buffer, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
memory_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
(traverseproc)memory_traverse, /* tp_traverse */
(inquiry)memory_clear, /* tp_clear */
memory_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */