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/***
*heapgrow.c - Grow the heap** Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.**Purpose:* Get memory from OS and add to the heap.**Revision History:* 06-06-89 JCR Module created.* 07-19-89 JCR Added region support* 11-07-89 JCR Region table is no longer "packed"* 11-08-89 JCR Use new _ROUND/_ROUND2 macros* 11-10-89 JCR Don't abort on ERROR_NOT_ENOUGH_MEMORY* 11-13-89 GJF Fixed copyright* 12-18-89 GJF Removed DEBUG286 stuff, a little tuning, cleaned up* the formatting a bit, changed header file name to* heap.h, also added _cdecl to functions (that didn't* already have explicit calling type)* 03-11-90 GJF Replaced _cdecl with _CALLTYPE1, added #include* <cruntime.h> and removed #include <register.h>.* 03-29-90 GJF Made _heap_new_region() _CALLTYPE4.* 07-24-90 SBM Compiles cleanly with -W3 (tentatively removed* unreferenced labels), removed '32' from API names* 09-28-90 GJF New-style function declarators.* 12-04-90 SRW Changed to include <oscalls.h> instead of <doscalls.h>* 12-06-90 SRW Added _CRUISER_ and _WIN32 conditionals.* 02-01-91 SRW Changed for new VirtualAlloc interface (_WIN32_)* 04-09-91 PNT Added _MAC_ conditional* 04-26-91 SRW Removed level 3 warnings* 04-06-93 SKS Replace _CRTAPI* with __cdecl* 04-26-93 SKS Change _HEAP_MAXREGIONSIZE to _heap_maxregsize* 09-06-94 CFW Remove Cruiser support.* 02-14-95 GJF Appended Mac version of source file.* 04-30-95 GJF Made conditional on WINHEAP.* 05-17-99 PML Remove all Macintosh support.********************************************************************************/
#ifndef WINHEAP
#include <cruntime.h>
#include <oscalls.h>
#include <heap.h>
#include <malloc.h>
#include <stdlib.h>
static int __cdecl _heap_new_region(unsigned, size_t);
/***
*_heap_grow() - Grow the heap**Purpose:* Get memory from the OS and add it to the heap.**Entry:* size_t _size = user's block request**Exit:* 0 = success, new mem is in the heap* -1 = failure**Exceptions:********************************************************************************/
int __cdecl _heap_grow ( REG1 size_t size ){ REG2 int index; int free_entry = -1;
/*
* Bump size to include header and round to nearest page boundary. */
size += _HDRSIZE; size = _ROUND2(size,_PAGESIZE_);
/*
* Loop through the region table looking for an existing region * we can grow. Remember the index of the first null region entry. * * size = size of grow request */
for (index = 0; index < _HEAP_REGIONMAX; index++) {
if ( (_heap_regions[index]._totalsize - _heap_regions[index]._currsize) >= size )
/*
* Grow this region to satisfy the request. */
return( _heap_grow_region(index, size) );
if ( (free_entry == -1) && (_heap_regions[index]._regbase == NULL) )
/*
* Remember 1st free table entry for later */
free_entry = index;
}
/*
* Could not find any existing regions to grow. Try to * get a new region. * * size = size of grow request * free_entry = index of first free entry in table */
if ( free_entry >= 0 )
/*
* Get a new region to satisfy the request. */
return( _heap_new_region(free_entry, size) );
else /*
* No free table entries: return an error. */
return(-1);
}
/***
*_heap_new_region() - Get a new heap region**Purpose:* Get a new heap region and put it in the region table.* Also, grow it large enough to support the caller's* request.** NOTES:* (1) Caller has verified that there is room in the _heap_region* table for another region.* (2) The caller must have rounded the size to a page boundary.**Entry:* int index = index in table where new region data should go* size_t size = size of request (this has been rounded to a* page-sized boundary)**Exit:* 0 = success* -1 = failure**Exceptions:********************************************************************************/
static int __cdecl _heap_new_region ( REG1 unsigned index, size_t size ){ void * region; REG2 unsigned int regsize;
#ifdef DEBUG
int i;
/*
* Make sure the size has been rounded to a page boundary */
if (size & (_PAGESIZE_-1)) _heap_abort();
/*
* Make sure there's a free slot in the table */
for (i=0; i < _HEAP_REGIONMAX; i++) { if (_heap_regions[i]._regbase == NULL) break; }
if (i >= _HEAP_REGIONMAX) _heap_abort();
#endif
/*
* Round the heap region size to a page boundary (in case * the user played with it). */
regsize = _ROUND2(_heap_regionsize, _PAGESIZE_);
/*
* To acommodate large users, request twice * as big a region next time around. */
if ( _heap_regionsize < _heap_maxregsize ) _heap_regionsize *= 2 ;
/*
* See if region is big enough for request */
if (regsize < size) regsize = size;
/*
* Go get the new region */
if (!(region = VirtualAlloc(NULL, regsize, MEM_RESERVE, PAGE_READWRITE))) goto error;
/*
* Put the new region in the table. */
_heap_regions[index]._regbase = region; _heap_regions[index]._totalsize = regsize; _heap_regions[index]._currsize = 0;
/*
* Grow the region to satisfy the size request. */
if (_heap_grow_region(index, size) != 0) {
/*
* Ouch. Allocated a region but couldn't commit * any pages in it. Free region and return error. */
_heap_free_region(index); goto error; }
/*
* Good return */
/* done: unreferenced label to be removed */ return(0);
/*
* Error return */
error: return(-1);
}
/***
*_heap_grow_region() - Grow a heap region**Purpose:* Grow a region and add the new memory to the heap.** NOTES:* (1) The caller must have rounded the size to a page boundary.**Entry:* unsigned index = index of region in the _heap_regions[] table* size_t size = size of request (this has been rounded to a* page-sized boundary)**Exit:* 0 = success* -1 = failure**Exceptions:********************************************************************************/
int __cdecl _heap_grow_region ( REG1 unsigned index, size_t size ){ size_t left; REG2 size_t growsize; void * base; unsigned dosretval;
/*
* Init some variables * left = space left in region * base = base of next section of region to validate */
left = _heap_regions[index]._totalsize - _heap_regions[index]._currsize;
base = (char *) _heap_regions[index]._regbase + _heap_regions[index]._currsize;
/*
* Make sure we can satisfy request */
if (left < size) goto error;
/*
* Round size up to next _heap_growsize boundary. * (Must round _heap_growsize itself to page boundary, in * case user set it himself). */
growsize = _ROUND2(_heap_growsize, _PAGESIZE_); growsize = _ROUND(size, growsize);
if (left < growsize) growsize = left;
/*
* Validate the new portion of the region */
if (!VirtualAlloc(base, growsize, MEM_COMMIT, PAGE_READWRITE)) dosretval = GetLastError(); else dosretval = 0;
if (dosretval) /*
* Error committing pages. If out of memory, return * error, else abort. */
if (dosretval == ERROR_NOT_ENOUGH_MEMORY) goto error; else _heap_abort();
/*
* Update the region data base */
_heap_regions[index]._currsize += growsize;
#ifdef DEBUG
/*
* The current size should never be greater than the total size */
if (_heap_regions[index]._currsize > _heap_regions[index]._totalsize) _heap_abort();#endif
/*
* Add the memory to the heap */
if (_heap_addblock(base, growsize) != 0) _heap_abort();
/*
* Good return */
/* done: unreferenced label to be removed */ return(0);
/*
* Error return */
error: return(-1);
}
/***
*_heap_free_region() - Free up a region**Purpose:* Return a heap region to the OS and zero out* corresponding region data entry.**Entry:* int index = index of region to be freed**Exit:* void**Exceptions:********************************************************************************/
void __cdecl _heap_free_region ( REG1 int index ){
/*
* Give the memory back to the OS */
if (!VirtualFree(_heap_regions[index]._regbase, 0, MEM_RELEASE)) _heap_abort();
/*
* Zero out the heap region entry */
_heap_regions[index]._regbase = NULL; _heap_regions[index]._currsize = _heap_regions[index]._totalsize = 0;
}
#endif /* WINHEAP */
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