WebSVN – Kolibri OS – Blame – /programs/develop/open watcom/trunk/clib/src/nheapmin.c

Rev	Author	Line No.	Line
359	serge	1	/****************************************************************************
		2	*
		3	* Open Watcom Project
		4	*
		5	* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
		6	*
		7	* ========================================================================
		8	*
		9	* This file contains Original Code and/or Modifications of Original
		10	* Code as defined in and that are subject to the Sybase Open Watcom
		11	* Public License version 1.0 (the 'License'). You may not use this file
		12	* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
		13	* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
		14	* provided with the Original Code and Modifications, and is also
		15	* available at www.sybase.com/developer/opensource.
		16	*
		17	* The Original Code and all software distributed under the License are
		18	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
		19	* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
		20	* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
		21	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
		22	* NON-INFRINGEMENT. Please see the License for the specific language
		23	* governing rights and limitations under the License.
		24	*
		25	* ========================================================================
		26	*
		27	* Description: Implementation of near _heapmin() and _nheapmin().
		28	*
		29	****************************************************************************/
		30
		31
		32	//#include "dll.h" // needs to be first
		33	#include "variety.h"
		34	#include
		35	#include
		36	#include
		37	#include "heap.h"
		38	#include "heapacc.h"
		39	#if defined(__DOS_EXT__)
		40	// #include "extender.h"
		41	#endif
		42	#if defined(__WINDOWS_286__) \|\| defined(__NT__)
		43	int _stdcall UserFree(void* p);
		44	// #include "windows.h"
		45	#endif
		46	#if defined(__OS2__)
		47	// #include
		48	#endif
		49	#if defined(__WINDOWS_386__)
		50	// extern int __pascal DPMIFree(unsigned long); // windows extender function
		51	#endif
		52	#if defined(__CALL21__)
		53	// #include "tinyio.h"
		54	#endif
		55
		56	#if defined(__SMALL_DATA__)
		57
		58	_WCRTLINK int _heapshrink( void )
		59	{
		60	return( _nheapshrink() );
		61	}
		62
		63	_WCRTLINK int _heapmin( void )
		64	{
		65	return( _nheapshrink() );
		66	}
		67
		68	#endif
		69
		70	_WCRTLINK int _nheapmin( void )
		71	{
		72	return( _nheapshrink() );
		73	}
		74
		75	#if defined(__WARP__) \|\| \
		76	defined(__WINDOWS_286__) \|\| \
		77	defined(__WINDOWS_386__) \|\| \
		78	defined(__NT__) \|\| \
		79	defined(__CALL21__)
		80	static int __ReturnMemToSystem( mheapptr mhp )
		81	{
		82	mheapptr pnext;
		83
		84	pnext = mhp->next;
		85	#if defined(__WARP__)
		86	if( DosFreeMem( (PBYTE)mhp ) ) return( -1 );
		87	#elif defined(__NT__)
		88	//if( LocalFree( (HLOCAL)mhp ) != NULL ) return( -1 );
		89	// if (!VirtualFree(mhp, 0, MEM_RELEASE))
		90	// return -1;
		91	if(!UserFree(mhp))
		92	return -1;
		93
		94	#elif defined(__WINDOWS_386__)
		95	if( DPMIFree( (unsigned long)mhp ) != 0 ) return( -1 );
		96	#elif defined(__WINDOWS_286__)
		97	if( LocalFree( (HLOCAL)mhp ) != NULL ) return( -1 );
		98	#elif defined(__CALL21__)
		99	// No way to free storage under OSI
		100	if( mhp ) return( -1 );
		101	#endif
		102	if( __MiniHeapRover == mhp ) { // Update rovers
		103	if( pnext ) {
		104	__MiniHeapRover = pnext;
		105	} else {
		106	__MiniHeapRover = __nheapbeg;
		107	__LargestSizeB4MiniHeapRover = 0;
		108	}
		109	}
		110	if( __MiniHeapFreeRover == mhp ) {
		111	__MiniHeapFreeRover = 0;
		112	}
		113	return( 0 ); // success
		114	}
		115
		116	static void __ReleaseMiniHeap( mheapptr mhp )
		117	{
		118	mheapptr pprev;
		119	mheapptr pnext;
		120
		121	pprev = mhp->prev;
		122	pnext = mhp->next;
		123	if( __ReturnMemToSystem( mhp ) == 0 ) {
		124	if( pprev == NULL ) {
		125	__nheapbeg = pnext;
		126	} else {
		127	pprev->next = pnext;
		128	}
		129	if( pnext != NULL ) pnext->prev = pprev;
		130	} //else: do not unlink if the memory cannot be freed successfully
		131	}
		132
		133	#endif
		134
		135	_WCRTLINK int _nheapshrink( void )
		136	{
		137	mheapptr mhp;
		138	#if !defined(__WARP__) && \
		139	!defined(__WINDOWS_286__) && \
		140	!defined(__WINDOWS_386__) && \
		141	!defined(__NT__) && \
		142	!defined(__CALL21__)
		143	// Shrink by adjusting _curbrk
		144
		145	frlptr last_free;
		146	frlptr end_tag;
		147	unsigned new_brk;
		148
		149	_AccessNHeap();
		150	#if defined(__DOS_EXT__)
		151	if( !_IsRationalZeroBase() && !_IsCodeBuilder() ) {
		152	#endif
		153	if( __nheapbeg == NULL ) {
		154	_ReleaseNHeap();
		155	return( 0 ); // No near heap, can't shrink
		156	}
		157	/* Goto the end of miniheaplist (if there's more than 1 blk) */
		158	for( mhp = __nheapbeg; mhp->next; mhp = mhp->next );
		159	/* check that last free block is at end of heap */
		160	last_free = mhp->freehead.prev;
		161	end_tag = (frlptr) ( (PTR)last_free + last_free->len );
		162	if( end_tag->len != END_TAG ) {
		163	_ReleaseNHeap();
		164	return( 0 );
		165	}
		166	if( end_tag != (frlptr) ((PTR)mhp + mhp->len ) ) {
		167	_ReleaseNHeap();
		168	return( 0 );
		169	}
		170	#if defined(__DOS_EXT__)
		171	// only shrink if we can shave off at least 4k
		172	if( last_free->len < 0x1000 ) {
		173	_ReleaseNHeap();
		174	return( 0 );
		175	}
		176	#else
		177	if( last_free->len <= sizeof( frl ) ) {
		178	_ReleaseNHeap();
		179	return( 0 );
		180	}
		181	#endif
		182	/* make sure there hasn't been an external change in _curbrk */
		183	if( sbrk( 0 ) != &(end_tag->prev) ) {
		184	_ReleaseNHeap();
		185	return( 0 );
		186	}
		187	/* calculate adjustment factor */
		188	if( mhp->len-last_free->len > sizeof( struct miniheapblkp ) ) {
		189	// this miniheapblk is still being used
		190	#if defined(__DOS_EXT__)
		191	frlptr new_last_free;
		192	new_last_free = (frlptr)((((unsigned)last_free + 0xfff) & ~0xfff) - TAG_SIZE);
		193	if( new_last_free == last_free ) {
		194	#endif
		195	// remove entire entry
		196	mhp->len -= last_free->len;
		197	--mhp->numfree;
		198	// Relink the freelist entries, and update the rover
		199	mhp->freehead.prev = last_free->prev;
		200	last_free->prev->next = &mhp->freehead;
		201	if( mhp->rover == last_free ) mhp->rover = last_free->prev;
		202	#if defined(__DOS_EXT__)
		203	} else {
		204	// just shrink the last free entry
		205	mhp->len -= last_free->len;
		206	last_free->len = (PTR)new_last_free - (PTR)last_free;
		207	mhp->len += last_free->len;
		208	last_free = new_last_free;
		209	}
		210	#endif
		211	last_free->len = END_TAG;
		212	new_brk = (unsigned) ((PTR)last_free + TAG_SIZE );
		213	} else {
		214	// we can remove this miniheapblk
		215	if( mhp->prev ) { // Not the first miniheapblk
		216	mhp->prev->next = NULL;
		217	new_brk = (unsigned)mhp;//->prev + (unsigned)mhp->prev->len;
		218	} else { // Is the first miniheapblk
		219	new_brk = (unsigned)__nheapbeg;
		220	__nheapbeg = NULL;
		221	}
		222	// Update rover info
		223	if( __MiniHeapRover == mhp ) {
		224	__MiniHeapRover = __nheapbeg;
		225	__LargestSizeB4MiniHeapRover = 0;
		226	}
		227	}
		228
		229	if( __brk( new_brk ) == (void _WCNEAR *) -1 ) {
		230	_ReleaseNHeap();
		231	return( -1 );
		232	}
		233	_ReleaseNHeap();
		234	return( 0 );
		235	#if defined(__DOS_EXT__)
		236	}
		237	__FreeDPMIBlocks(); // For RSI/zero-base and Intel CB
		238	_ReleaseNHeap();
		239	return( 0 );
		240	#endif
		241	#else
		242	// Shrink by releasing mini-heaps
		243	{
		244	mheapptr pnext;
		245
		246	_AccessNHeap();
		247	for( mhp = __nheapbeg; mhp; mhp = pnext ) {
		248	pnext = mhp->next;
		249	if( mhp->len - sizeof(struct miniheapblkp) ==
		250	(mhp->freehead.prev)->len ) __ReleaseMiniHeap( mhp );
		251	}
		252	_ReleaseNHeap();
		253	return( 0 );
		254	}
		255	#endif
		256	}

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(root)/programs/develop/open watcom/trunk/clib/src/nheapmin.c – Rev 359