gecko-dev/nsprpub/pr/include/prmem.h

127 строки
4.6 KiB
C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
** File: prmem.h
** Description: API to NSPR memory management functions
**
*/
#ifndef prmem_h___
#define prmem_h___
#include "prtypes.h"
#include <stdlib.h>
PR_BEGIN_EXTERN_C
/*
** Thread safe memory allocation.
**
** NOTE: pr wraps up malloc, free, calloc, realloc so they are already
** thread safe (and are not declared here - look in stdlib.h).
*/
/*
** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free have the same signatures
** as their libc equivalent malloc, calloc, realloc, and free, and have
** the same semantics. (Note that the argument type size_t is replaced
** by PRUint32.) Memory allocated by PR_Malloc, PR_Calloc, or PR_Realloc
** must be freed by PR_Free.
*/
NSPR_API(void *) PR_Malloc(PRUint32 size);
NSPR_API(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize);
NSPR_API(void *) PR_Realloc(void *ptr, PRUint32 size);
NSPR_API(void) PR_Free(void *ptr);
/*
** The following are some convenience macros defined in terms of
** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free.
*/
/***********************************************************************
** FUNCTION: PR_MALLOC()
** DESCRIPTION:
** PR_NEW() allocates an untyped item of size _size from the heap.
** INPUTS: _size: size in bytes of item to be allocated
** OUTPUTS: untyped pointer to the node allocated
** RETURN: pointer to node or error returned from malloc().
***********************************************************************/
#define PR_MALLOC(_bytes) (PR_Malloc((_bytes)))
/***********************************************************************
** FUNCTION: PR_NEW()
** DESCRIPTION:
** PR_NEW() allocates an item of type _struct from the heap.
** INPUTS: _struct: a data type
** OUTPUTS: pointer to _struct
** RETURN: pointer to _struct or error returns from malloc().
***********************************************************************/
#define PR_NEW(_struct) ((_struct *) PR_MALLOC(sizeof(_struct)))
/***********************************************************************
** FUNCTION: PR_REALLOC()
** DESCRIPTION:
** PR_REALLOC() re-allocates _ptr bytes from the heap as a _size
** untyped item.
** INPUTS: _ptr: pointer to node to reallocate
** _size: size of node to allocate
** OUTPUTS: pointer to node allocated
** RETURN: pointer to node allocated
***********************************************************************/
#define PR_REALLOC(_ptr, _size) (PR_Realloc((_ptr), (_size)))
/***********************************************************************
** FUNCTION: PR_CALLOC()
** DESCRIPTION:
** PR_CALLOC() allocates a _size bytes untyped item from the heap
** and sets the allocated memory to all 0x00.
** INPUTS: _size: size of node to allocate
** OUTPUTS: pointer to node allocated
** RETURN: pointer to node allocated
***********************************************************************/
#define PR_CALLOC(_size) (PR_Calloc(1, (_size)))
/***********************************************************************
** FUNCTION: PR_NEWZAP()
** DESCRIPTION:
** PR_NEWZAP() allocates an item of type _struct from the heap
** and sets the allocated memory to all 0x00.
** INPUTS: _struct: a data type
** OUTPUTS: pointer to _struct
** RETURN: pointer to _struct
***********************************************************************/
#define PR_NEWZAP(_struct) ((_struct*)PR_Calloc(1, sizeof(_struct)))
/***********************************************************************
** FUNCTION: PR_DELETE()
** DESCRIPTION:
** PR_DELETE() unallocates an object previosly allocated via PR_NEW()
** or PR_NEWZAP() to the heap.
** INPUTS: pointer to previously allocated object
** OUTPUTS: the referenced object is returned to the heap
** RETURN: void
***********************************************************************/
#define PR_DELETE(_ptr) { PR_Free(_ptr); (_ptr) = NULL; }
/***********************************************************************
** FUNCTION: PR_FREEIF()
** DESCRIPTION:
** PR_FREEIF() conditionally unallocates an object previously allocated
** vial PR_NEW() or PR_NEWZAP(). If the pointer to the object is
** equal to zero (0), the object is not released.
** INPUTS: pointer to previously allocated object
** OUTPUTS: the referenced object is conditionally returned to the heap
** RETURN: void
***********************************************************************/
#define PR_FREEIF(_ptr) if (_ptr) PR_DELETE(_ptr)
PR_END_EXTERN_C
#endif /* prmem_h___ */