251 lines
8.9 KiB
C
251 lines
8.9 KiB
C
/* The PyMem_ family: low-level memory allocation interfaces.
|
|
See objimpl.h for the PyObject_ memory family.
|
|
*/
|
|
|
|
#ifndef Py_PYMEM_H
|
|
#define Py_PYMEM_H
|
|
|
|
#include "pyport.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifndef Py_LIMITED_API
|
|
PyAPI_FUNC(void *) PyMem_RawMalloc(size_t size);
|
|
PyAPI_FUNC(void *) PyMem_RawCalloc(size_t nelem, size_t elsize);
|
|
PyAPI_FUNC(void *) PyMem_RawRealloc(void *ptr, size_t new_size);
|
|
PyAPI_FUNC(void) PyMem_RawFree(void *ptr);
|
|
|
|
/* Configure the Python memory allocators. Pass NULL to use default
|
|
allocators. */
|
|
PyAPI_FUNC(int) _PyMem_SetupAllocators(const char *opt);
|
|
|
|
/* Try to get the allocators name set by _PyMem_SetupAllocators(). */
|
|
PyAPI_FUNC(const char*) _PyMem_GetAllocatorsName(void);
|
|
|
|
PyAPI_FUNC(int) _PyMem_IsFreed(void *ptr, size_t size);
|
|
#endif /* !defined(Py_LIMITED_API) */
|
|
|
|
|
|
/* BEWARE:
|
|
|
|
Each interface exports both functions and macros. Extension modules should
|
|
use the functions, to ensure binary compatibility across Python versions.
|
|
Because the Python implementation is free to change internal details, and
|
|
the macros may (or may not) expose details for speed, if you do use the
|
|
macros you must recompile your extensions with each Python release.
|
|
|
|
Never mix calls to PyMem_ with calls to the platform malloc/realloc/
|
|
calloc/free. For example, on Windows different DLLs may end up using
|
|
different heaps, and if you use PyMem_Malloc you'll get the memory from the
|
|
heap used by the Python DLL; it could be a disaster if you free()'ed that
|
|
directly in your own extension. Using PyMem_Free instead ensures Python
|
|
can return the memory to the proper heap. As another example, in
|
|
PYMALLOC_DEBUG mode, Python wraps all calls to all PyMem_ and PyObject_
|
|
memory functions in special debugging wrappers that add additional
|
|
debugging info to dynamic memory blocks. The system routines have no idea
|
|
what to do with that stuff, and the Python wrappers have no idea what to do
|
|
with raw blocks obtained directly by the system routines then.
|
|
|
|
The GIL must be held when using these APIs.
|
|
*/
|
|
|
|
/*
|
|
* Raw memory interface
|
|
* ====================
|
|
*/
|
|
|
|
/* Functions
|
|
|
|
Functions supplying platform-independent semantics for malloc/realloc/
|
|
free. These functions make sure that allocating 0 bytes returns a distinct
|
|
non-NULL pointer (whenever possible -- if we're flat out of memory, NULL
|
|
may be returned), even if the platform malloc and realloc don't.
|
|
Returned pointers must be checked for NULL explicitly. No action is
|
|
performed on failure (no exception is set, no warning is printed, etc).
|
|
*/
|
|
|
|
PyAPI_FUNC(void *) PyMem_Malloc(size_t size);
|
|
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
|
|
PyAPI_FUNC(void *) PyMem_Calloc(size_t nelem, size_t elsize);
|
|
#endif
|
|
PyAPI_FUNC(void *) PyMem_Realloc(void *ptr, size_t new_size);
|
|
PyAPI_FUNC(void) PyMem_Free(void *ptr);
|
|
|
|
#ifndef Py_LIMITED_API
|
|
/* strdup() using PyMem_RawMalloc() */
|
|
PyAPI_FUNC(char *) _PyMem_RawStrdup(const char *str);
|
|
|
|
/* strdup() using PyMem_Malloc() */
|
|
PyAPI_FUNC(char *) _PyMem_Strdup(const char *str);
|
|
|
|
/* wcsdup() using PyMem_RawMalloc() */
|
|
PyAPI_FUNC(wchar_t*) _PyMem_RawWcsdup(const wchar_t *str);
|
|
#endif
|
|
|
|
/* Macros. */
|
|
|
|
/* PyMem_MALLOC(0) means malloc(1). Some systems would return NULL
|
|
for malloc(0), which would be treated as an error. Some platforms
|
|
would return a pointer with no memory behind it, which would break
|
|
pymalloc. To solve these problems, allocate an extra byte. */
|
|
/* Returns NULL to indicate error if a negative size or size larger than
|
|
Py_ssize_t can represent is supplied. Helps prevents security holes. */
|
|
#define PyMem_MALLOC(n) PyMem_Malloc(n)
|
|
#define PyMem_REALLOC(p, n) PyMem_Realloc(p, n)
|
|
#define PyMem_FREE(p) PyMem_Free(p)
|
|
|
|
/*
|
|
* Type-oriented memory interface
|
|
* ==============================
|
|
*
|
|
* Allocate memory for n objects of the given type. Returns a new pointer
|
|
* or NULL if the request was too large or memory allocation failed. Use
|
|
* these macros rather than doing the multiplication yourself so that proper
|
|
* overflow checking is always done.
|
|
*/
|
|
|
|
#define PyMem_New(type, n) \
|
|
( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
|
|
( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
|
|
#define PyMem_NEW(type, n) \
|
|
( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
|
|
( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
|
|
|
|
/*
|
|
* The value of (p) is always clobbered by this macro regardless of success.
|
|
* The caller MUST check if (p) is NULL afterwards and deal with the memory
|
|
* error if so. This means the original value of (p) MUST be saved for the
|
|
* caller's memory error handler to not lose track of it.
|
|
*/
|
|
#define PyMem_Resize(p, type, n) \
|
|
( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
|
|
(type *) PyMem_Realloc((p), (n) * sizeof(type)) )
|
|
#define PyMem_RESIZE(p, type, n) \
|
|
( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
|
|
(type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
|
|
|
|
/* PyMem{Del,DEL} are left over from ancient days, and shouldn't be used
|
|
* anymore. They're just confusing aliases for PyMem_{Free,FREE} now.
|
|
*/
|
|
#define PyMem_Del PyMem_Free
|
|
#define PyMem_DEL PyMem_FREE
|
|
|
|
#ifndef Py_LIMITED_API
|
|
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 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);
|
|
#endif /* Py_LIMITED_API */
|
|
|
|
#ifdef Py_BUILD_CORE
|
|
/* Set the memory allocator of the specified domain to the default.
|
|
Save the old allocator into *old_alloc if it's non-NULL.
|
|
Return on success, or return -1 if the domain is unknown. */
|
|
PyAPI_FUNC(int) _PyMem_SetDefaultAllocator(
|
|
PyMemAllocatorDomain domain,
|
|
PyMemAllocatorEx *old_alloc);
|
|
#endif
|
|
|
|
|
|
/* bpo-35053: expose _Py_tracemalloc_config for performance:
|
|
_Py_NewReference() needs an efficient check to test if tracemalloc is
|
|
tracing.
|
|
|
|
It has to be defined in pymem.h, before object.h is included. */
|
|
struct _PyTraceMalloc_Config {
|
|
/* Module initialized?
|
|
Variable protected by the GIL */
|
|
enum {
|
|
TRACEMALLOC_NOT_INITIALIZED,
|
|
TRACEMALLOC_INITIALIZED,
|
|
TRACEMALLOC_FINALIZED
|
|
} initialized;
|
|
|
|
/* Is tracemalloc tracing memory allocations?
|
|
Variable protected by the GIL */
|
|
int tracing;
|
|
|
|
/* limit of the number of frames in a traceback, 1 by default.
|
|
Variable protected by the GIL. */
|
|
int max_nframe;
|
|
|
|
/* use domain in trace key?
|
|
Variable protected by the GIL. */
|
|
int use_domain;
|
|
};
|
|
|
|
PyAPI_DATA(struct _PyTraceMalloc_Config) _Py_tracemalloc_config;
|
|
|
|
#define _PyTraceMalloc_Config_INIT \
|
|
{.initialized = TRACEMALLOC_NOT_INITIALIZED, \
|
|
.tracing = 0, \
|
|
.max_nframe = 1, \
|
|
.use_domain = 0}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* !Py_PYMEM_H */
|