libvirt/src/memory.h

111 lines
3.5 KiB
C
Raw Normal View History

/*
* memory.c: safer memory allocation
*
* Copyright (C) 2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __VIR_MEMORY_H_
#define __VIR_MEMORY_H_
#include "internal.h"
/* Return 1 if an array of N objects, each of size S, cannot exist due
to size arithmetic overflow. S must be positive and N must be
nonnegative. This is a macro, not an inline function, so that it
works correctly even when SIZE_MAX < N.
By gnulib convention, SIZE_MAX represents overflow in size
calculations, so the conservative dividend to use here is
SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
However, malloc (SIZE_MAX) fails on all known hosts where
sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
exactly-SIZE_MAX allocations on such hosts; this avoids a test and
branch when S is known to be 1. */
#ifndef xalloc_oversized
# define xalloc_oversized(n, s) \
((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
#endif
/* Don't call these directly - use the macros below */
2008-11-17 11:03:25 +00:00
int virAlloc(void *ptrptr, size_t size) ATTRIBUTE_RETURN_CHECK;
int virAllocN(void *ptrptr, size_t size, size_t count) ATTRIBUTE_RETURN_CHECK;
int virReallocN(void *ptrptr, size_t size, size_t count) ATTRIBUTE_RETURN_CHECK;
void virFree(void *ptrptr);
/**
* VIR_ALLOC:
* @ptr: pointer to hold address of allocated memory
*
* Allocate sizeof(*ptr) bytes of memory and store
* the address of allocated memory in 'ptr'. Fill the
* newly allocated memory with zeros.
*
* Returns -1 on failure, 0 on success
*/
2008-11-17 11:03:25 +00:00
#define VIR_ALLOC(ptr) virAlloc(&(ptr), sizeof(*(ptr)))
/**
* VIR_ALLOC_N:
* @ptr: pointer to hold address of allocated memory
* @count: number of elements to allocate
*
* Allocate an array of 'count' elements, each sizeof(*ptr)
* bytes long and store the address of allocated memory in
* 'ptr'. Fill the newly allocated memory with zeros.
*
* Returns -1 on failure, 0 on success
*/
2008-11-17 11:03:25 +00:00
#define VIR_ALLOC_N(ptr, count) virAllocN(&(ptr), sizeof(*(ptr)), (count))
/**
* VIR_REALLOC_N:
* @ptr: pointer to hold address of allocated memory
* @count: number of elements to allocate
*
* Re-allocate an array of 'count' elements, each sizeof(*ptr)
* bytes long and store the address of allocated memory in
* 'ptr'. Fill the newly allocated memory with zeros
*
* Returns -1 on failure, 0 on success
*/
2008-11-17 11:03:25 +00:00
#define VIR_REALLOC_N(ptr, count) virReallocN(&(ptr), sizeof(*(ptr)), (count))
/**
* VIR_FREE:
* @ptr: pointer holding address to be freed
*
* Free the memory stored in 'ptr' and update to point
* to NULL.
*/
2008-11-17 11:03:25 +00:00
#define VIR_FREE(ptr) virFree(&(ptr))
2008-05-29 15:13:07 +00:00
#if TEST_OOM
void virAllocTestInit(void);
int virAllocTestCount(void);
void virAllocTestOOM(int n, int m);
2008-05-29 18:47:00 +00:00
void virAllocTestHook(void (*func)(int, void*), void *data);
2008-05-29 15:13:07 +00:00
#endif
#endif /* __VIR_MEMORY_H_ */