kolibrios/programs/develop/open watcom/trunk/clib/heap/nfree.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

124 lines
3.7 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 free() and _nfree().
*
****************************************************************************/
//#include "dll.h" // needs to be first
#include "variety.h"
#include <stddef.h>
#include <malloc.h>
#include "heap.h"
#include "heapacc.h"
#if defined(__SMALL_DATA__)
_WCRTLINK void free( void *stg )
{
_nfree( stg );
}
#endif
struct miniheapblkp _WCNEAR *__MiniHeapFreeRover;
_WCRTLINK void _nfree( void _WCNEAR *stg )
{
mheapptr p1,p2;
if( !stg )
return;
_AccessNHeap();
do {
// first try some likely locations
p1 = __MiniHeapFreeRover;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
p2 = p1;
p1 = p1->prev;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
}
p1 = p2->next;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
}
}
p1 = __MiniHeapRover;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
p2 = p1;
p1 = p1->prev;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
}
p1 = p2->next;
if( p1 ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
break;
}
}
}
// not found near rover, so search the list
for( p1 = __nheapbeg; p1; p1 = p1->next ) {
if( (PTR)p1 <= (PTR)stg && (PTR)p1+p1->len > (PTR)stg ) {
// break twice!
goto found_it;
}
}
// this pointer is not in the heap
_ReleaseNHeap();
return;
} while( 0 );
found_it:
// we found the miniheap, free the storage
__MemFree( (unsigned)stg, _DGroup(), (unsigned) p1 );
__MiniHeapFreeRover = p1;
if( p1 < __MiniHeapRover ) {
if( p1->largest_blk > __LargestSizeB4MiniHeapRover ) {
__LargestSizeB4MiniHeapRover = p1->largest_blk;
}
}
_ReleaseNHeap();
}