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+/* 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 */