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

127 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: Routines to grow heap (allocate memory from OS).
*
****************************************************************************/
//#include "dll.h" // needs to be first
#include "variety.h"
#include <stddef.h>
#include <stdlib.h>
#include <malloc.h>
#if defined(__QNX__)
#elif defined(__LINUX__)
#elif defined(__OS2__)
#elif defined(_M_IX86)
// #include "tinyio.h"
#endif
#include "heap.h"
#include "heapacc.h"
#if defined(M_I86)
_WCRTLINK void _fheapgrow( void )
{
/* multiple heaps are used so growing the far heaps is not necessary */
}
#endif
#if defined(__SMALL_DATA__)
_WCRTLINK void _heapgrow( void )
{
_nheapgrow();
}
#else
_WCRTLINK void _heapgrow( void )
{
_fheapgrow();
}
#endif
_WCRTLINK void _nheapgrow( void )
{
#if defined(__WINDOWS_286__) || defined(__386__) || defined(__AXP__) || defined(__PPC__) || defined(__MIPS__)
_nfree( _nmalloc( 1 ) ); /* get something into the heap */
#else
unsigned max_paras;
unsigned curr_paras;
unsigned diff_paras;
unsigned expand;
_AccessNHeap();
/* calculate # pages which always has extra slack space (ie. 0x10) */
curr_paras = (( _curbrk + 0x10 ) & ~0x0f ) >> 4;
if( curr_paras == 0 ) {
/* we're already at 64k */
_ReleaseNHeap();
return;
}
#if defined(__QNX__)
if( qnx_segment_realloc( _DGroup(), 65536L ) == -1 ) {
_ReleaseNHeap();
return;
}
max_paras = PARAS_IN_64K;
#elif defined(__OS2__)
if( DosReallocSeg( 0, _DGroup() ) ) {
_ReleaseNHeap();
return;
}
max_paras = PARAS_IN_64K;
#else
if( _osmode != DOS_MODE ) { /* 23-apr-91 */
max_paras = PARAS_IN_64K;
} else {
max_paras = TinyMaxSet( _psp );
/* subtract off code size */
max_paras -= _DGroup() - _psp;
if( max_paras > PARAS_IN_64K ) {
max_paras = PARAS_IN_64K;
}
}
#endif
if( max_paras <= curr_paras ) {
/* '<' -> something is wrong, '==' -> can't change size */
_ReleaseNHeap();
return;
}
diff_paras = max_paras - curr_paras;
expand = (( diff_paras + 1 ) << 4 ) - ( _curbrk & 0x0f );
expand += __LastFree(); /* compensate for _expand's adjustment */
_ReleaseNHeap();
_nfree( _nmalloc( expand - ( sizeof( size_t ) + sizeof(frl) ) ) );
#endif
}