| /* 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 PyObject_MALLOC |
| #define PyMem_REALLOC PyObject_REALLOC |
| #define PyMem_FREE PyObject_FREE |
| |
| #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) (((n) < 0 || (n) > PY_SSIZE_T_MAX) ? NULL \ |
| : malloc((n) ? (n) : 1)) |
| #define PyMem_REALLOC(p, n) (((n) < 0 || (n) > 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 */ |