Fix MemoryError caused by moving around code in PR #886; nbytes was sometimes used unitinitalized (in non-debug builds, when use_calloc was false and elsize was 0).
Make a non-Py_DEBUG, asserts-enabled build of CPython possible. This means
making sure helper functions are defined when NDEBUG is not defined, not
just when Py_DEBUG is defined.
Also fix a division-by-zero in obmalloc.c that went unnoticed because in Py_DEBUG mode, elsize is never zero.
- Rename Py_ADDRESS_IN_RANGE to address_in_range and make it a static
function instead of macro. Any compiler worth its salt will inline this
function.
- Remove the duplicated function version of Py_ADDRESS_IN_RANGE used when memory
analysis was active. Instead, we can simply mark address_in_range as allergic
to dynamic memory checking. We can now remove the
__attribute__((no_address_safety_analysis)) from _PyObject_Free and
_PyObject_Realloc. All the badness is contained in address_in_range now.
- Fix the code that tried to only read pool->arenaindex once. Putting something
in a variable is no guarantee that it won't be read multiple times. We must
use volatile for that.
Issue #26249: PyMem_Malloc() allocator family now uses the pymalloc allocator
rather than system malloc(). Applications calling PyMem_Malloc() without
holding the GIL can now crash: use PYTHONMALLOC=debug environment variable to
validate the usage of memory allocators in your application.
Issue #26563: Debug hooks on Python memory allocators now raise a fatal error
if functions of the PyMem_Malloc() family are called without holding the GIL.
Issue #26564: _PyObject_DebugDumpAddress() now dumps the traceback where a
memory block was allocated on memory block. Use the tracemalloc module to get
the traceback.
Issue #26516:
* Add PYTHONMALLOC environment variable to set the Python memory
allocators and/or install debug hooks.
* PyMem_SetupDebugHooks() can now also be used on Python compiled in release
mode.
* The PYTHONMALLOCSTATS environment variable can now also be used on Python
compiled in release mode. It now has no effect if set to an empty string.
* In debug mode, debug hooks are now also installed on Python memory allocators
when Python is configured without pymalloc.
PyObject_Calloc(), _PyObject_GC_Calloc(). bytes(int) and bytearray(int) are now
using ``calloc()`` instead of ``malloc()`` for large objects which is faster
and use less memory (until the bytearray buffer is filled with data).
_PyMem_RawMalloc/Realloc/Free, instead of _PyMem_Malloc/Realloc/Free. So it
becomes possible to use the fast pymalloc allocator for the PYMEM_DOMAIN_MEM
domain (PyMem_Malloc/Realloc/Free functions).
This patch appropriately marks known false alarms in the
small object allocator when address sanity checking is
enabled (patch contributed by Dhiru Kholia).
Issue #18942: sys._debugmallocstats() output was damaged on Windows.
_PyDebugAllocatorStats() called PyOS_snprintf() with a %zd format
code, but MS doesn't support that code. Interpolated
PY_FORMAT_SIZE_T in place of the "z".
_PyDebugAllocatorStats() called PyOS_snprintf() with a %zd format
code, but MS doesn't support that code. Interpolated
PY_FORMAT_SIZE_T in place of the "z".
Don't mark old extra memory dead before calling realloc(). realloc() can fail
and realloc() must not touch the original buffer on failure.
So mark old extra memory dead only on success if the new buffer did not move
(has the same address).
Add new enum:
* PyMemAllocatorDomain
Add new structures:
* PyMemAllocator
* PyObjectArenaAllocator
Add new functions:
* PyMem_RawMalloc(), PyMem_RawRealloc(), PyMem_RawFree()
* PyMem_GetAllocator(), PyMem_SetAllocator()
* PyObject_GetArenaAllocator(), PyObject_SetArenaAllocator()
* PyMem_SetupDebugHooks()
Changes:
* PyMem_Malloc()/PyObject_Realloc() now always call malloc()/realloc(), instead
of calling PyObject_Malloc()/PyObject_Realloc() in debug mode.
* PyObject_Malloc()/PyObject_Realloc() now falls back to
PyMem_Malloc()/PyMem_Realloc() for allocations larger than 512 bytes.
* Redesign debug checks on memory block allocators as hooks, instead of using C
macros
* Add a new PyMemAllocators structure
* New functions:
- PyMem_RawMalloc(), PyMem_RawRealloc(), PyMem_RawFree(): GIL-free memory
allocator functions
- PyMem_GetRawAllocators(), PyMem_SetRawAllocators()
- PyMem_GetAllocators(), PyMem_SetAllocators()
- PyMem_SetupDebugHooks()
- _PyObject_GetArenaAllocators(), _PyObject_SetArenaAllocators()
* Add unit test for PyMem_Malloc(0) and PyObject_Malloc(0)
* Add unit test for new get/set allocators functions
* PyObject_Malloc() now falls back on PyMem_Malloc() instead of malloc() if
size is bigger than SMALL_REQUEST_THRESHOLD, and PyObject_Realloc() falls
back on PyMem_Realloc() instead of realloc()
* PyMem_Malloc() and PyMem_Realloc() now always call malloc() and realloc(),
instead of calling PyObject_Malloc() and PyObject_Realloc() in debug mode
T. Wouters
Benjamin Peterson
Victor Stinner
Serhiy Storchaka
Antoine Pitrou
Nick Coghlan
Georg Brandl
Tim Peters
Martin v. Löwis
David Malcolm
Brett Cannon
Stefan Krah