| /* 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 | |
| /* 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); | |
| PyAPI_FUNC(void *) PyMem_Realloc(void *, size_t); | |
| PyAPI_FUNC(void) PyMem_Free(void *); | |
| /* Starting from Python 1.6, the wrappers Py_{Malloc,Realloc,Free} are | |
| no longer supported. They used to call PyErr_NoMemory() on failure. */ | |
| /* Macros. */ | |
| #ifdef PYMALLOC_DEBUG | |
| /* Redirect all memory operations to Python's debugging allocator. */ | |
| #define PyMem_MALLOC _PyMem_DebugMalloc | |
| #define PyMem_REALLOC _PyMem_DebugRealloc | |
| #define PyMem_FREE _PyMem_DebugFree | |
| #else /* ! PYMALLOC_DEBUG */ | |
| /* 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) ((size_t)(n) > (size_t)PY_SSIZE_T_MAX ? NULL \ | |
| : malloc((n) ? (n) : 1)) | |
| #define PyMem_REALLOC(p, n) ((size_t)(n) > (size_t)PY_SSIZE_T_MAX ? NULL \ | |
| : realloc((p), (n) ? (n) : 1)) | |
| #define PyMem_FREE free | |
| #endif /* PYMALLOC_DEBUG */ | |
| /* | |
| * 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 | |
| #ifdef __cplusplus | |
| } | |
| #endif | |
| #endif /* !Py_PYMEM_H */ |