246 lines
8.8 KiB
C
246 lines
8.8 KiB
C
/* The PyMem_ family: low-level memory allocation interfaces.
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See objimpl.h for the PyObject_ memory family.
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*/
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#ifndef Py_PYMEM_H
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#define Py_PYMEM_H
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#include "pyport.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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#ifndef Py_LIMITED_API
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PyAPI_FUNC(void *) PyMem_RawMalloc(size_t size);
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PyAPI_FUNC(void *) PyMem_RawCalloc(size_t nelem, size_t elsize);
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PyAPI_FUNC(void *) PyMem_RawRealloc(void *ptr, size_t new_size);
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PyAPI_FUNC(void) PyMem_RawFree(void *ptr);
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/* Configure the Python memory allocators. Pass NULL to use default
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allocators. */
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PyAPI_FUNC(int) _PyMem_SetupAllocators(const char *opt);
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/* Try to get the allocators name set by _PyMem_SetupAllocators(). */
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PyAPI_FUNC(const char*) _PyMem_GetAllocatorsName(void);
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/* Track an allocated memory block in the tracemalloc module.
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Return 0 on success, return -1 on error (failed to allocate memory to store
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the trace).
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Return -2 if tracemalloc is disabled.
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If memory block is already tracked, update the existing trace. */
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PyAPI_FUNC(int) PyTraceMalloc_Track(
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unsigned int domain,
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uintptr_t ptr,
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size_t size);
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/* Untrack an allocated memory block in the tracemalloc module.
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Do nothing if the block was not tracked.
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Return -2 if tracemalloc is disabled, otherwise return 0. */
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PyAPI_FUNC(int) PyTraceMalloc_Untrack(
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unsigned int domain,
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uintptr_t ptr);
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/* Get the traceback where a memory block was allocated.
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Return a tuple of (filename: str, lineno: int) tuples.
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Return None if the tracemalloc module is disabled or if the memory block
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is not tracked by tracemalloc.
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Raise an exception and return NULL on error. */
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PyAPI_FUNC(PyObject*) _PyTraceMalloc_GetTraceback(
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unsigned int domain,
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uintptr_t ptr);
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PyAPI_FUNC(int) _PyMem_IsFreed(void *ptr, size_t size);
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#endif /* !defined(Py_LIMITED_API) */
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/* BEWARE:
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Each interface exports both functions and macros. Extension modules should
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use the functions, to ensure binary compatibility across Python versions.
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Because the Python implementation is free to change internal details, and
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the macros may (or may not) expose details for speed, if you do use the
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macros you must recompile your extensions with each Python release.
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Never mix calls to PyMem_ with calls to the platform malloc/realloc/
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calloc/free. For example, on Windows different DLLs may end up using
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different heaps, and if you use PyMem_Malloc you'll get the memory from the
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heap used by the Python DLL; it could be a disaster if you free()'ed that
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directly in your own extension. Using PyMem_Free instead ensures Python
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can return the memory to the proper heap. As another example, in
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PYMALLOC_DEBUG mode, Python wraps all calls to all PyMem_ and PyObject_
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memory functions in special debugging wrappers that add additional
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debugging info to dynamic memory blocks. The system routines have no idea
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what to do with that stuff, and the Python wrappers have no idea what to do
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with raw blocks obtained directly by the system routines then.
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The GIL must be held when using these APIs.
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*/
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/*
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* Raw memory interface
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* ====================
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*/
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/* Functions
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Functions supplying platform-independent semantics for malloc/realloc/
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free. These functions make sure that allocating 0 bytes returns a distinct
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non-NULL pointer (whenever possible -- if we're flat out of memory, NULL
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may be returned), even if the platform malloc and realloc don't.
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Returned pointers must be checked for NULL explicitly. No action is
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performed on failure (no exception is set, no warning is printed, etc).
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*/
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PyAPI_FUNC(void *) PyMem_Malloc(size_t size);
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#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
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PyAPI_FUNC(void *) PyMem_Calloc(size_t nelem, size_t elsize);
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#endif
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PyAPI_FUNC(void *) PyMem_Realloc(void *ptr, size_t new_size);
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PyAPI_FUNC(void) PyMem_Free(void *ptr);
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#ifndef Py_LIMITED_API
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/* strdup() using PyMem_RawMalloc() */
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PyAPI_FUNC(char *) _PyMem_RawStrdup(const char *str);
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/* strdup() using PyMem_Malloc() */
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PyAPI_FUNC(char *) _PyMem_Strdup(const char *str);
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/* wcsdup() using PyMem_RawMalloc() */
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PyAPI_FUNC(wchar_t*) _PyMem_RawWcsdup(const wchar_t *str);
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#endif
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/* Macros. */
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/* PyMem_MALLOC(0) means malloc(1). Some systems would return NULL
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for malloc(0), which would be treated as an error. Some platforms
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would return a pointer with no memory behind it, which would break
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pymalloc. To solve these problems, allocate an extra byte. */
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/* Returns NULL to indicate error if a negative size or size larger than
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Py_ssize_t can represent is supplied. Helps prevents security holes. */
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#define PyMem_MALLOC(n) PyMem_Malloc(n)
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#define PyMem_REALLOC(p, n) PyMem_Realloc(p, n)
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#define PyMem_FREE(p) PyMem_Free(p)
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/*
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* Type-oriented memory interface
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* ==============================
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*
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* Allocate memory for n objects of the given type. Returns a new pointer
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* or NULL if the request was too large or memory allocation failed. Use
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* these macros rather than doing the multiplication yourself so that proper
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* overflow checking is always done.
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*/
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#define PyMem_New(type, n) \
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( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
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( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
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#define PyMem_NEW(type, n) \
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( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
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( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
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/*
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* The value of (p) is always clobbered by this macro regardless of success.
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* The caller MUST check if (p) is NULL afterwards and deal with the memory
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* error if so. This means the original value of (p) MUST be saved for the
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* caller's memory error handler to not lose track of it.
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*/
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#define PyMem_Resize(p, type, n) \
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( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
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(type *) PyMem_Realloc((p), (n) * sizeof(type)) )
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#define PyMem_RESIZE(p, type, n) \
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( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
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(type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
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/* PyMem{Del,DEL} are left over from ancient days, and shouldn't be used
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* anymore. They're just confusing aliases for PyMem_{Free,FREE} now.
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*/
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#define PyMem_Del PyMem_Free
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#define PyMem_DEL PyMem_FREE
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#ifndef Py_LIMITED_API
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typedef enum {
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/* PyMem_RawMalloc(), PyMem_RawRealloc() and PyMem_RawFree() */
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PYMEM_DOMAIN_RAW,
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/* PyMem_Malloc(), PyMem_Realloc() and PyMem_Free() */
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PYMEM_DOMAIN_MEM,
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/* PyObject_Malloc(), PyObject_Realloc() and PyObject_Free() */
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PYMEM_DOMAIN_OBJ
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} PyMemAllocatorDomain;
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typedef struct {
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/* user context passed as the first argument to the 4 functions */
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void *ctx;
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/* allocate a memory block */
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void* (*malloc) (void *ctx, size_t size);
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/* allocate a memory block initialized by zeros */
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void* (*calloc) (void *ctx, size_t nelem, size_t elsize);
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/* allocate or resize a memory block */
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void* (*realloc) (void *ctx, void *ptr, size_t new_size);
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/* release a memory block */
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void (*free) (void *ctx, void *ptr);
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} PyMemAllocatorEx;
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/* Get the memory block allocator of the specified domain. */
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PyAPI_FUNC(void) PyMem_GetAllocator(PyMemAllocatorDomain domain,
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PyMemAllocatorEx *allocator);
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/* Set the memory block allocator of the specified domain.
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The new allocator must return a distinct non-NULL pointer when requesting
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zero bytes.
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For the PYMEM_DOMAIN_RAW domain, the allocator must be thread-safe: the GIL
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is not held when the allocator is called.
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If the new allocator is not a hook (don't call the previous allocator), the
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PyMem_SetupDebugHooks() function must be called to reinstall the debug hooks
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on top on the new allocator. */
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PyAPI_FUNC(void) PyMem_SetAllocator(PyMemAllocatorDomain domain,
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PyMemAllocatorEx *allocator);
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/* Setup hooks to detect bugs in the following Python memory allocator
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functions:
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- PyMem_RawMalloc(), PyMem_RawRealloc(), PyMem_RawFree()
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- PyMem_Malloc(), PyMem_Realloc(), PyMem_Free()
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- PyObject_Malloc(), PyObject_Realloc() and PyObject_Free()
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Newly allocated memory is filled with the byte 0xCB, freed memory is filled
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with the byte 0xDB. Additional checks:
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- detect API violations, ex: PyObject_Free() called on a buffer allocated
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by PyMem_Malloc()
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- detect write before the start of the buffer (buffer underflow)
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- detect write after the end of the buffer (buffer overflow)
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The function does nothing if Python is not compiled is debug mode. */
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PyAPI_FUNC(void) PyMem_SetupDebugHooks(void);
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#endif
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#ifdef Py_BUILD_CORE
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/* Set the memory allocator of the specified domain to the default.
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Save the old allocator into *old_alloc if it's non-NULL.
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Return on success, or return -1 if the domain is unknown. */
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PyAPI_FUNC(int) _PyMem_SetDefaultAllocator(
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PyMemAllocatorDomain domain,
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PyMemAllocatorEx *old_alloc);
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#endif
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#ifdef __cplusplus
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}
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#endif
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#endif /* !Py_PYMEM_H */
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