annotate DEPENDENCIES/mingw32/Python27/include/pymem.h @ 118:770eb830ec19 emscripten

Typo fix
author Chris Cannam
date Wed, 18 May 2016 16:14:08 +0100
parents 2a2c65a20a8b
children
rev   line source
Chris@87 1 /* The PyMem_ family: low-level memory allocation interfaces.
Chris@87 2 See objimpl.h for the PyObject_ memory family.
Chris@87 3 */
Chris@87 4
Chris@87 5 #ifndef Py_PYMEM_H
Chris@87 6 #define Py_PYMEM_H
Chris@87 7
Chris@87 8 #include "pyport.h"
Chris@87 9
Chris@87 10 #ifdef __cplusplus
Chris@87 11 extern "C" {
Chris@87 12 #endif
Chris@87 13
Chris@87 14 /* BEWARE:
Chris@87 15
Chris@87 16 Each interface exports both functions and macros. Extension modules should
Chris@87 17 use the functions, to ensure binary compatibility across Python versions.
Chris@87 18 Because the Python implementation is free to change internal details, and
Chris@87 19 the macros may (or may not) expose details for speed, if you do use the
Chris@87 20 macros you must recompile your extensions with each Python release.
Chris@87 21
Chris@87 22 Never mix calls to PyMem_ with calls to the platform malloc/realloc/
Chris@87 23 calloc/free. For example, on Windows different DLLs may end up using
Chris@87 24 different heaps, and if you use PyMem_Malloc you'll get the memory from the
Chris@87 25 heap used by the Python DLL; it could be a disaster if you free()'ed that
Chris@87 26 directly in your own extension. Using PyMem_Free instead ensures Python
Chris@87 27 can return the memory to the proper heap. As another example, in
Chris@87 28 PYMALLOC_DEBUG mode, Python wraps all calls to all PyMem_ and PyObject_
Chris@87 29 memory functions in special debugging wrappers that add additional
Chris@87 30 debugging info to dynamic memory blocks. The system routines have no idea
Chris@87 31 what to do with that stuff, and the Python wrappers have no idea what to do
Chris@87 32 with raw blocks obtained directly by the system routines then.
Chris@87 33
Chris@87 34 The GIL must be held when using these APIs.
Chris@87 35 */
Chris@87 36
Chris@87 37 /*
Chris@87 38 * Raw memory interface
Chris@87 39 * ====================
Chris@87 40 */
Chris@87 41
Chris@87 42 /* Functions
Chris@87 43
Chris@87 44 Functions supplying platform-independent semantics for malloc/realloc/
Chris@87 45 free. These functions make sure that allocating 0 bytes returns a distinct
Chris@87 46 non-NULL pointer (whenever possible -- if we're flat out of memory, NULL
Chris@87 47 may be returned), even if the platform malloc and realloc don't.
Chris@87 48 Returned pointers must be checked for NULL explicitly. No action is
Chris@87 49 performed on failure (no exception is set, no warning is printed, etc).
Chris@87 50 */
Chris@87 51
Chris@87 52 PyAPI_FUNC(void *) PyMem_Malloc(size_t);
Chris@87 53 PyAPI_FUNC(void *) PyMem_Realloc(void *, size_t);
Chris@87 54 PyAPI_FUNC(void) PyMem_Free(void *);
Chris@87 55
Chris@87 56 /* Starting from Python 1.6, the wrappers Py_{Malloc,Realloc,Free} are
Chris@87 57 no longer supported. They used to call PyErr_NoMemory() on failure. */
Chris@87 58
Chris@87 59 /* Macros. */
Chris@87 60 #ifdef PYMALLOC_DEBUG
Chris@87 61 /* Redirect all memory operations to Python's debugging allocator. */
Chris@87 62 #define PyMem_MALLOC _PyMem_DebugMalloc
Chris@87 63 #define PyMem_REALLOC _PyMem_DebugRealloc
Chris@87 64 #define PyMem_FREE _PyMem_DebugFree
Chris@87 65
Chris@87 66 #else /* ! PYMALLOC_DEBUG */
Chris@87 67
Chris@87 68 /* PyMem_MALLOC(0) means malloc(1). Some systems would return NULL
Chris@87 69 for malloc(0), which would be treated as an error. Some platforms
Chris@87 70 would return a pointer with no memory behind it, which would break
Chris@87 71 pymalloc. To solve these problems, allocate an extra byte. */
Chris@87 72 /* Returns NULL to indicate error if a negative size or size larger than
Chris@87 73 Py_ssize_t can represent is supplied. Helps prevents security holes. */
Chris@87 74 #define PyMem_MALLOC(n) ((size_t)(n) > (size_t)PY_SSIZE_T_MAX ? NULL \
Chris@87 75 : malloc((n) ? (n) : 1))
Chris@87 76 #define PyMem_REALLOC(p, n) ((size_t)(n) > (size_t)PY_SSIZE_T_MAX ? NULL \
Chris@87 77 : realloc((p), (n) ? (n) : 1))
Chris@87 78 #define PyMem_FREE free
Chris@87 79
Chris@87 80 #endif /* PYMALLOC_DEBUG */
Chris@87 81
Chris@87 82 /*
Chris@87 83 * Type-oriented memory interface
Chris@87 84 * ==============================
Chris@87 85 *
Chris@87 86 * Allocate memory for n objects of the given type. Returns a new pointer
Chris@87 87 * or NULL if the request was too large or memory allocation failed. Use
Chris@87 88 * these macros rather than doing the multiplication yourself so that proper
Chris@87 89 * overflow checking is always done.
Chris@87 90 */
Chris@87 91
Chris@87 92 #define PyMem_New(type, n) \
Chris@87 93 ( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
Chris@87 94 ( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
Chris@87 95 #define PyMem_NEW(type, n) \
Chris@87 96 ( ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
Chris@87 97 ( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
Chris@87 98
Chris@87 99 /*
Chris@87 100 * The value of (p) is always clobbered by this macro regardless of success.
Chris@87 101 * The caller MUST check if (p) is NULL afterwards and deal with the memory
Chris@87 102 * error if so. This means the original value of (p) MUST be saved for the
Chris@87 103 * caller's memory error handler to not lose track of it.
Chris@87 104 */
Chris@87 105 #define PyMem_Resize(p, type, n) \
Chris@87 106 ( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
Chris@87 107 (type *) PyMem_Realloc((p), (n) * sizeof(type)) )
Chris@87 108 #define PyMem_RESIZE(p, type, n) \
Chris@87 109 ( (p) = ((size_t)(n) > PY_SSIZE_T_MAX / sizeof(type)) ? NULL : \
Chris@87 110 (type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
Chris@87 111
Chris@87 112 /* PyMem{Del,DEL} are left over from ancient days, and shouldn't be used
Chris@87 113 * anymore. They're just confusing aliases for PyMem_{Free,FREE} now.
Chris@87 114 */
Chris@87 115 #define PyMem_Del PyMem_Free
Chris@87 116 #define PyMem_DEL PyMem_FREE
Chris@87 117
Chris@87 118 #ifdef __cplusplus
Chris@87 119 }
Chris@87 120 #endif
Chris@87 121
Chris@87 122 #endif /* !Py_PYMEM_H */