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loewisloewis
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Merged revisions 65654 via svnmerge from
svn+ssh://[email protected]/python/trunk ........ r65654 | martin.v.loewis | 2008-08-12 16:49:50 +0200 (Tue, 12 Aug 2008) | 6 lines Issue #3139: Make buffer-interface thread-safe wrt. PyArg_ParseTuple, by denying s# to parse objects that have a releasebuffer procedure, and introducing s*. More module might need to get converted to use s*. ........
1 parent 688356f commit 423be95

32 files changed

Lines changed: 720 additions & 389 deletions

‎Doc/c-api/arg.rst‎

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@@ -40,6 +40,12 @@ variable(s) whose address should be passed.
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other read-buffer compatible objects pass back a reference to the raw internal
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data representation.
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``s*`` (string, Unicode, or any buffer compatible object) [Py_buffer \*]
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Similar to ``s#``, this code fills a Py_buffer structure provided by the caller.
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The buffer gets locked, so that the caller can subsequently use the buffer even
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inside a ``Py_BEGIN_ALLOW_THREADS`` block; the caller is responsible for calling
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``PyBuffer_Release`` with the structure after it has processed the data.
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``y`` (bytes object) [const char \*]
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This variant on ``s`` convert a Python bytes object to a C pointer to a
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character string. The bytes object must not contain embedded NUL bytes; if it
@@ -49,13 +55,19 @@ variable(s) whose address should be passed.
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This variant on ``s#`` stores into two C variables, the first one a pointer to a
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character string, the second one its length. This only accepts bytes objects.
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``y*`` (bytes object) [Py_buffer \*]
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This is to ``s*`` as ``y`` is to ``s``.
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``z`` (string or ``None``) [const char \*]
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Like ``s``, but the Python object may also be ``None``, in which case the C
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pointer is set to *NULL*.
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``z#`` (string or ``None`` or any read buffer compatible object) [const char \*, int]
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This is to ``s#`` as ``z`` is to ``s``.
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``z*`` (string or ``None`` or any buffer compatible object) [Py_buffer*]
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This is to ``s*`` as ``z`` is to ``s``.
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``u`` (Unicode object) [Py_UNICODE \*]
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Convert a Python Unicode object to a C pointer to a NUL-terminated buffer of
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16-bit Unicode (UTF-16) data. As with ``s``, there is no need to provide
@@ -244,6 +256,9 @@ variable(s) whose address should be passed.
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single-segment buffer objects are accepted; :exc:`TypeError` is raised for all
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others.
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``w*`` (read-write byte-oriented buffer) [Py_buffer \*]
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This is to ``w`` what ``s*`` is to ``s``.
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``(items)`` (tuple) [*matching-items*]
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The object must be a Python sequence whose length is the number of format units
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in *items*. The C arguments must correspond to the individual format units in

‎Doc/whatsnew/2.6.rst‎

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@@ -1064,7 +1064,7 @@ about the object's memory representation. Objects
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can use this operation to lock memory in place
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while an external caller could be modifying the contents,
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so there's a corresponding
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``PyObject_ReleaseBuffer(PyObject *obj, Py_buffer *view)`` to
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``PyBuffer_Release(Py_buffer *view)`` to
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indicate that the external caller is done.
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The **flags** argument to :cfunc:`PyObject_GetBuffer` specifies
@@ -2841,7 +2841,7 @@ Changes to Python's build process and to the C API include:
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* The new buffer interface, previously described in
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`the PEP 3118 section <#pep-3118-revised-buffer-protocol>`__,
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adds :cfunc:`PyObject_GetBuffer` and :cfunc:`PyObject_ReleaseBuffer`,
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adds :cfunc:`PyObject_GetBuffer` and :cfunc:`PyBuffer_Release`,
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as well as a few other functions.
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* Python's use of the C stdio library is now thread-safe, or at least

‎Include/abstract.h‎

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@@ -526,24 +526,6 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
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*/
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PyAPI_FUNC(void) PyObject_ReleaseBuffer(PyObject *obj, Py_buffer *view);
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/* C-API version of the releasebuffer function call. It
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checks to make sure the object has the required function
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pointer and issues the call. The obj must have the buffer
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interface or this function will cause a segfault (i.e. it
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is assumed to be called only after a corresponding
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getbuffer which already verified the existence of the
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tp_as_buffer pointer).
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Returns 0 on success and -1 (with an error raised) on
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failure. This function always succeeds (as a NO-OP) if
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there is no releasebuffer function for the object so that
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it can always be called when the consumer is done with the
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buffer
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*/
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PyAPI_FUNC(void *) PyBuffer_GetPointer(Py_buffer *view, Py_ssize_t *indices);
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/* Get the memory area pointed to by the indices for the buffer given.
@@ -600,7 +582,7 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
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per element.
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*/
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PyAPI_FUNC(int) PyBuffer_FillInfo(Py_buffer *view, void *buf,
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PyAPI_FUNC(int) PyBuffer_FillInfo(Py_buffer *view, PyObject *o, void *buf,
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Py_ssize_t len, int readonly,
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int flags);
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@@ -610,6 +592,10 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
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and -1 (with raising an error) on error.
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*/
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PyAPI_FUNC(void) PyBuffer_Release(Py_buffer *view);
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/* Releases a Py_buffer obtained from getbuffer ParseTuple's s*.
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*/
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PyAPI_FUNC(PyObject *) PyObject_Format(PyObject* obj,
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PyObject *format_spec);

‎Include/object.h‎

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@@ -142,7 +142,8 @@ typedef int(*objobjargproc)(PyObject *, PyObject *, PyObject *);
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/* buffer interface */
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typedef struct bufferinfo {
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void *buf;
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void *buf;
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PyObject *obj; /* borrowed reference */
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Py_ssize_t len;
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Py_ssize_t itemsize; /* This is Py_ssize_t so it can be
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pointed to by strides in simple case.*/

‎Lib/test/test_sys.py‎

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@@ -550,7 +550,7 @@ def get_gen(): yield 1
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check(32768*32768-1, size(vh) + 2*self.H)
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check(32768*32768, size(vh) + 3*self.H)
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# memory
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check(memoryview(b''), size(h + 'P P2P2i5P'))
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check(memoryview(b''), size(h + 'P PP2P2i5P'))
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# module
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check(unittest, size(h + '3P'))
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# None

‎Modules/_bsddb.c‎

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@@ -288,7 +288,7 @@ static void free_dbt(DBT *dbt)
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static void free_buf_view(PyObject *obj, Py_buffer *view)
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{
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if (view) {
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PyObject_ReleaseBuffer(obj, view);
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PyBuffer_Release(view);
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PyMem_Free(view);
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}
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}
@@ -319,7 +319,7 @@ static Py_buffer * _malloc_view(PyObject *obj)
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if (view->ndim > 1) {
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PyErr_SetString(PyExc_BufferError,
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"buffers must be single dimension");
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PyObject_ReleaseBuffer(obj, view);
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PyBuffer_Release(view);
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PyMem_Free(view);
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return NULL;
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}

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