/***
*free.c - free an entry in the heap
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Defines the following functions:
* free() - free a memory block in the heap
*
*Revision History:
* 06-30-89 JCR Module created
* 07-07-89 GJF Fixed test for resetting proverdesc
* 11-10-89 GJF Added MTHREAD support. Also, a little cleanup.
* 12-18-89 GJF Change header file name to heap.h, added register
* declarations and added explicit _cdecl to function
* definitions
* 03-09-90 GJF Replaced _cdecl with _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 09-27-90 GJF New-style function declarators. Also, rewrote expr.
* so that a cast was not used as an lvalue.
* 03-05-91 GJF Changed strategy for rover - old version available
* by #define-ing _OLDROVER_.
* 04-08-91 GJF Temporary hack for Win32/DOS folks - special version
* of free that just calls HeapFree. Change conditioned
* on _WIN32DOS_.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 11-12-93 GJF Incorporated Jonathan Mark's suggestion for reducing
* fragmentation: if the block following the newly freed
* block is the rover block, reset the rover to the
* newly freed block. Also, replaced MTHREAD with _MT
* and deleted obsolete WIN32DOS support.
* 05-19-94 GJF Added __mark_block_as_free() for the sole use by
* __dllonexit() in the Win32s version of msvcrt*.dll.
* 06-06-94 GJF Removed __mark_block_as_free()!
* 11-03-94 CFW Debug heap support.
* 12-01-94 CFW Simplify debug interface.
* 01-12-95 GJF Fixed bogus test to reset rover. Also, purged
* _OLDROVER_ code.
* 02-01-95 GJF #ifdef out the *_base names for the Mac builds
* (temporary).
* 02-09-95 GJF Restored *_base names.
* 04-30-95 GJF Made conditional on WINHEAP.
* 03-01-96 GJF Added support fro small-block heap.
* 04-10-96 GJF Return type of __sbh_find_block and __sbh_free_block
* changed to __map_t *.
* 05-30-96 GJF Minor changes for latest version of small-block heap.
* 05-22-97 RDK New small-block heap scheme implemented.
* 09-26-97 BWT Fix POSIX
* 11-05-97 GJF Small POSIX fix from Roger Lanser.
* 12-17-97 GJF Exception-safe locking.
* 05-22-98 JWM Support for KFrei's RTC work.
* 07-28-98 JWM RTC update.
* 09-29-98 GJF Bypass all small-block heap code when __sbh_initialized
* is 0.
* 11-16-98 GJF Merged in VC++ 5.0 version of small-block heap.
* 05-01-99 PML Disable small-block heap for Win64.
* 05-17-99 PML Remove all Macintosh support.
* 05-26-99 KBF Updated RTC hook func params
* 06-22-99 GJF Removed old small-block heap from static libs.
*
*******************************************************************************/
#ifdef WINHEAP
#include <cruntime.h>
#include <malloc.h>
#include <winheap.h>
#include <windows.h>
#include <internal.h>
#include <mtdll.h>
#include <dbgint.h>
#include <rtcsup.h>
/***
*void free(pblock) - free a block in the heap
*
*Purpose:
* Free a memory block in the heap.
*
* Special ANSI Requirements:
*
* (1) free(NULL) is benign.
*
*Entry:
* void *pblock - pointer to a memory block in the heap
*
*Return:
* <void>
*
*******************************************************************************/
void __cdecl _free_base (void * pBlock)
{
#ifdef _POSIX_
HeapFree(_crtheap,
0,
pBlock
);
#else /* _POSIX_ */
#ifdef HEAPHOOK
/* call heap hook if installed */
if (_heaphook)
{
if ((*_heaphook)(_HEAP_FREE, 0, pBlock, NULL))
return;
}
#endif /* HEAPHOOK */
if (pBlock == NULL)
return;
RTCCALLBACK(_RTC_Free_hook, (pBlock, 0));
#ifndef _WIN64
if ( __active_heap == __V6_HEAP )
{
PHEADER pHeader;
#ifdef _MT
_mlock( _HEAP_LOCK );
__try {
#endif
if ((pHeader = __sbh_find_block(pBlock)) != NULL)
__sbh_free_block(pHeader, pBlock);
#ifdef _MT
}
__finally {
_munlock( _HEAP_LOCK );
}
#endif
if (pHeader == NULL)
HeapFree(_crtheap, 0, pBlock);
}
#ifdef CRTDLL
else if ( __active_heap == __V5_HEAP )
{
__old_sbh_region_t *preg;
__old_sbh_page_t * ppage;
__old_page_map_t * pmap;
#ifdef _MT
_mlock(_HEAP_LOCK );
__try {
#endif
if ( (pmap = __old_sbh_find_block(pBlock, &preg, &ppage)) != NULL )
__old_sbh_free_block(preg, ppage, pmap);
#ifdef _MT
}
__finally {
_munlock(_HEAP_LOCK );
}
#endif
if (pmap == NULL)
HeapFree(_crtheap, 0, pBlock);
}
#endif /* CRTDLL */
else // __active_heap == __SYSTEM_HEAP
#endif /* ndef _WIN64 */
{
HeapFree(_crtheap, 0, pBlock);
}
#endif /* _POSIX_ */
}
#else /* ndef WINHEAP */
#include <cruntime.h>
#include <heap.h>
#include <malloc.h>
#include <mtdll.h>
#include <stdlib.h>
#include <dbgint.h>
/***
*void free(pblock) - free a block in the heap
*
*Purpose:
* Free a memory block in the heap.
*
* Special Notes For Multi-thread: The non-multi-thread version is renamed
* to _free_lk(). The multi-thread free() simply locks the heap, calls
* _free_lk(), then unlocks the heap and returns.
*
*Entry:
* void *pblock - pointer to a memory block in the heap
*
*Return:
* <void>
*
*******************************************************************************/
#ifdef _MT
void __cdecl _free_base (
void *pblock
)
{
/* lock the heap
*/
_mlock(_HEAP_LOCK);
/* free the block
*/
_free_base_lk(pblock);
/* unlock the heap
*/
_munlock(_HEAP_LOCK);
}
/***
*void _free_lk(pblock) - non-locking form of free
*
*Purpose:
* Same as free() except that no locking is performed
*
*Entry:
* See free
*
*Return:
*
*******************************************************************************/
void __cdecl _free_base_lk (
#else /* ndef _MT */
void __cdecl _free_base (
#endif /* _MT */
REG1 void *pblock
)
{
REG2 _PBLKDESC pdesc;
#ifdef HEAPHOOK
/* call heap hook if installed */
if (_heaphook) {
if ((*_heaphook)(_HEAP_FREE, 0, pblock, NULL))
return;
}
#endif /* HEAPHOOK */
/*
* If the pointer is NULL, just return [ANSI].
*/
if (pblock == NULL)
return;
/*
* Point to block header and get the pointer back to the heap desc.
*/
pblock = (char *)pblock - _HDRSIZE;
pdesc = *(_PBLKDESC*)pblock;
/*
* Validate the back pointer.
*/
if (_ADDRESS(pdesc) != pblock)
_heap_abort();
/*
* Pointer is ok. Mark block free.
*/
_SET_FREE(pdesc);
/*
* Check for special conditions under which the rover is reset.
*/
if ( (_heap_resetsize != 0xffffffff) &&
(_heap_desc.proverdesc->pblock > pdesc->pblock) &&
(_BLKSIZE(pdesc) >= _heap_resetsize) )
{
_heap_desc.proverdesc = pdesc;
}
else if ( _heap_desc.proverdesc == pdesc->pnextdesc )
{
_heap_desc.proverdesc = pdesc;
}
}
#endif /* WINHEAP */