/*** *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 * and removed #include . * 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 #include #include #include #include #include #include #include /*** *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 __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 #include #include #include #include #include /*** *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: * * *******************************************************************************/ #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 */