cpython/Include/cpython/pymem.h
Dino Viehland 05f2f0ac92
gh-90815: Add mimalloc memory allocator (#109914)
* Add mimalloc v2.12

Modified src/alloc.c to remove include of alloc-override.c and not
compile new handler.

Did not include the following files:

 - include/mimalloc-new-delete.h
 - include/mimalloc-override.h
 - src/alloc-override-osx.c
 - src/alloc-override.c
 - src/static.c
 - src/region.c

mimalloc is thread safe and shares a single heap across all runtimes,
therefore finalization and getting global allocated blocks across all
runtimes is different.

* mimalloc: minimal changes for use in Python:

 - remove debug spam for freeing large allocations
 - use same bytes (0xDD) for freed allocations in CPython and mimalloc
   This is important for the test_capi debug memory tests

* Don't export mimalloc symbol in libpython.
* Enable mimalloc as Python allocator option.
* Add mimalloc MIT license.
* Log mimalloc in Lib/test/pythoninfo.py.
* Document new mimalloc support.
* Use macro defs for exports as done in:
  https://github.com/python/cpython/pull/31164/

Co-authored-by: Sam Gross <colesbury@gmail.com>
Co-authored-by: Christian Heimes <christian@python.org>
Co-authored-by: Victor Stinner <vstinner@python.org>
2023-10-30 15:43:11 +00:00

84 lines
2.8 KiB
C

#ifndef Py_CPYTHON_PYMEM_H
# error "this header file must not be included directly"
#endif
typedef enum {
/* PyMem_RawMalloc(), PyMem_RawRealloc() and PyMem_RawFree() */
PYMEM_DOMAIN_RAW,
/* PyMem_Malloc(), PyMem_Realloc() and PyMem_Free() */
PYMEM_DOMAIN_MEM,
/* PyObject_Malloc(), PyObject_Realloc() and PyObject_Free() */
PYMEM_DOMAIN_OBJ
} PyMemAllocatorDomain;
typedef enum {
PYMEM_ALLOCATOR_NOT_SET = 0,
PYMEM_ALLOCATOR_DEFAULT = 1,
PYMEM_ALLOCATOR_DEBUG = 2,
PYMEM_ALLOCATOR_MALLOC = 3,
PYMEM_ALLOCATOR_MALLOC_DEBUG = 4,
#ifdef WITH_PYMALLOC
PYMEM_ALLOCATOR_PYMALLOC = 5,
PYMEM_ALLOCATOR_PYMALLOC_DEBUG = 6,
#endif
#ifdef WITH_MIMALLOC
PYMEM_ALLOCATOR_MIMALLOC = 7,
PYMEM_ALLOCATOR_MIMALLOC_DEBUG = 8,
#endif
} PyMemAllocatorName;
typedef struct {
/* user context passed as the first argument to the 4 functions */
void *ctx;
/* allocate a memory block */
void* (*malloc) (void *ctx, size_t size);
/* allocate a memory block initialized by zeros */
void* (*calloc) (void *ctx, size_t nelem, size_t elsize);
/* allocate or resize a memory block */
void* (*realloc) (void *ctx, void *ptr, size_t new_size);
/* release a memory block */
void (*free) (void *ctx, void *ptr);
} PyMemAllocatorEx;
/* Get the memory block allocator of the specified domain. */
PyAPI_FUNC(void) PyMem_GetAllocator(PyMemAllocatorDomain domain,
PyMemAllocatorEx *allocator);
/* Set the memory block allocator of the specified domain.
The new allocator must return a distinct non-NULL pointer when requesting
zero bytes.
For the PYMEM_DOMAIN_RAW domain, the allocator must be thread-safe: the GIL
is not held when the allocator is called.
If the new allocator is not a hook (don't call the previous allocator), the
PyMem_SetupDebugHooks() function must be called to reinstall the debug hooks
on top on the new allocator. */
PyAPI_FUNC(void) PyMem_SetAllocator(PyMemAllocatorDomain domain,
PyMemAllocatorEx *allocator);
/* Setup hooks to detect bugs in the following Python memory allocator
functions:
- PyMem_RawMalloc(), PyMem_RawRealloc(), PyMem_RawFree()
- PyMem_Malloc(), PyMem_Realloc(), PyMem_Free()
- PyObject_Malloc(), PyObject_Realloc() and PyObject_Free()
Newly allocated memory is filled with the byte 0xCB, freed memory is filled
with the byte 0xDB. Additional checks:
- detect API violations, ex: PyObject_Free() called on a buffer allocated
by PyMem_Malloc()
- detect write before the start of the buffer (buffer underflow)
- detect write after the end of the buffer (buffer overflow)
The function does nothing if Python is not compiled is debug mode. */
PyAPI_FUNC(void) PyMem_SetupDebugHooks(void);