/*****************************************************************************
*
* XVID MPEG-4 VIDEO CODEC
* - Aligned Memory Allocator -
*
* Copyright(C) 2002-2003 Edouard Gomez <ed.gomez@free.fr>
*
* This program is free software ; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation ; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: mem_align.cpp,v 1.3 2010-02-23 16:23:32 jeanlf Exp $
*
****************************************************************************/
#include "mem_align.h"
#include "global.h"
#ifdef __SYMBIAN32__
#include <e32std.h>
#endif
/*****************************************************************************
* xvid_malloc
*
* This function allocates 'size' bytes (usable by the user) on the heap and
* takes care of the requested 'alignment'.
* In order to align the allocated memory block, the xvid_malloc allocates
* 'size' bytes + 'alignment' bytes. So try to keep alignment very small
* when allocating small pieces of memory.
*
* NB : a block allocated by xvid_malloc _must_ be freed with xvid_free
* (the libc free will return an error)
*
* Returned value : - NULL on error
* - Pointer to the allocated aligned block
*
****************************************************************************/
#include "Rules.h"
void *xvid_malloc(long size, dword alignment) {
byte *mem_ptr;
if (!alignment) {
/* We have not to satisfy any alignment */
//mem_ptr = (byte*)gf_malloc(size + 1);
//mem_ptr = new(ELeave) byte[size+1];
mem_ptr = new byte[size+1];
if(mem_ptr) {
/* Store (mem_ptr - "real allocated memory") in *(mem_ptr-1) */
*mem_ptr = (byte)1;
/* Return the mem_ptr pointer */
return ((void *)(mem_ptr+1));
}
} else {
byte *tmp;
/* Allocate the required size memory + alignment so we
* can realign the data if necessary */
//tmp = (byte *) gf_malloc(size + alignment);
//tmp = new(ELeave) byte[size + alignment];
tmp = new byte[size + alignment];
if(tmp) {
/* Align the tmp pointer */
mem_ptr =
(byte *) ((dword)(tmp + alignment - 1) & (~(dword)(alignment - 1)));
/* Special case where gf_malloc have already satisfied the alignment
* We must add alignment to mem_ptr because we must store
* (mem_ptr - tmp) in *(mem_ptr-1)
* If we do not add alignment to mem_ptr then *(mem_ptr-1) points
* to a forbidden memory space */
if (mem_ptr == tmp)
mem_ptr += alignment;
/* (mem_ptr - tmp) is stored in *(mem_ptr-1) so we are able to retrieve
* the real gf_malloc block allocated and free it in xvid_free */
*(mem_ptr - 1) = (byte) (mem_ptr - tmp);
/* Return the aligned pointer */
return ((void *)mem_ptr);
}
}
return 0;
}
/*****************************************************************************
* xvid_free
*
* Free a previously 'xvid_malloc' allocated block. Does not free NULL
* references.
*
* Returned value : None.
*
****************************************************************************/
void xvid_free(void *mem_ptr) {
if(!mem_ptr)
return;
/* Aligned pointer */
byte *ptr = (byte*)mem_ptr;
/* *(ptr - 1) holds the offset to the real allocated block
* we sub that offset os we free the real pointer */
ptr -= *(ptr - 1);
/* Free the memory */
//free(ptr);
delete[] ptr;
}
//----------------------------