kolibrios/programs/develop/open watcom/trunk/clib/heap/nmalloc.c
Sergey Semyonov (Serge) 836c97f0ac Clib string & memory functions
git-svn-id: svn://kolibrios.org@553 a494cfbc-eb01-0410-851d-a64ba20cac60
2007-06-26 00:54:22 +00:00

125 lines
3.8 KiB
C

/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: Implementation of near malloc() and _nmalloc().
*
****************************************************************************/
//#include "dll.h" // needs to be first
#include "variety.h"
#include <stddef.h>
#include <stdlib.h>
#include <malloc.h>
#include "extfunc.h"
#include "heapacc.h"
#include "heap.h"
#if defined(_M_IX86)
#pragma aux (__outside_CLIB) __nmemneed;
#endif
mheapptr _WCNEAR __nheapbeg = NULL;
struct miniheapblkp _WCNEAR *__MiniHeapRover = NULL;
unsigned int __LargestSizeB4MiniHeapRover = 0;
#if defined(__SMALL_DATA__)
_WCRTLINK void *malloc( size_t amount )
{
return( _nmalloc( amount ) );
}
#endif
_WCRTLINK void _WCNEAR *_nmalloc( size_t amt )
{
unsigned largest;
unsigned size;
unsigned ptr;
unsigned char expanded;
mheapptr miniheap_ptr;
if( (amt == 0) || (amt > -sizeof(struct heapblk)) ) {
return( (void _WCNEAR *)NULL );
}
// Try to determine which miniheap to begin allocating from.
// first, round up the amount
size = (amt + TAG_SIZE + ROUND_SIZE) & ~ROUND_SIZE;
if( size < FRL_SIZE ) {
size = FRL_SIZE;
}
_AccessNHeap();
ptr = NULL;
expanded = 0;
for(;;) {
if( size > __LargestSizeB4MiniHeapRover ) {
miniheap_ptr = __MiniHeapRover;
if( miniheap_ptr == NULL ) {
__LargestSizeB4MiniHeapRover = 0;
miniheap_ptr = __nheapbeg;
}
} else {
__LargestSizeB4MiniHeapRover = 0; // force value to be updated
miniheap_ptr = __nheapbeg;
}
for(;;) {
if( miniheap_ptr == NULL ) {
break;
}
__MiniHeapRover = miniheap_ptr;
largest = miniheap_ptr->largest_blk;
if( largest >= amt ) {
ptr = __MemAllocator( amt, _DGroup(), (unsigned)miniheap_ptr );
if( ptr != NULL ) {
goto lbl_release_heap;
}
}
if( largest > __LargestSizeB4MiniHeapRover ) {
__LargestSizeB4MiniHeapRover = largest;
}
miniheap_ptr = miniheap_ptr->next;
}
if( expanded || !__ExpandDGROUP( amt ) ) {
if( !__nmemneed( amt ) ) {
break;
}
expanded = 0;
} else {
expanded = 1;
}
}
lbl_release_heap:
_ReleaseNHeap();
return( (void _WCNEAR *)ptr );
}