Source code of Windows XP (NT5)
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/***
*heapinit.c - Initialze the heap
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*
*Revision History:
* 06-28-89 JCR Module created.
* 06-30-89 JCR Added _heap_grow_emptylist
* 11-13-89 GJF Fixed copyright
* 11-15-89 JCR Moved _heap_abort routine to another module
* 12-15-89 GJF Removed DEBUG286 stuff, did some tuning, changed header
* file name to heap.h and made functions explicitly
* _cdecl.
* 12-19-89 GJF Removed plastdesc field from _heap_desc_ struct
* 03-11-90 GJF Replaced _cdecl with _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 07-24-90 SBM Removed '32' from API names
* 10-03-90 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_)
* 03-05-91 GJF Added definition of _heap_resetsize (conditioned on
* _OLDROVER_ not being #define-d).
* 04-04-91 GJF Reduce _heap_regionsize to 1/2 a meg for Dosx32
* (_WIN32_).
* 04-05-91 GJF Temporary hack for Win32/DOS folks - special version
* of _heap_init which calls HeapCreate. The change
* conditioned on _WIN32DOS_.
* 04-09-91 PNT Added _MAC_ conditional
* 02-23-93 SKS Remove DOSX32 support under WIN32 ifdef
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 04-26-93 SKS Add variable _heap_maxregsize (was _HEAP_MAXREGIONSIZE)
* Initialize _heap_[max,]reg[,ion]size to Large defaults
* heapinit() tests _osver to detect Small memory case
* 05-06-93 SKS Add _heap_term() to return heap memory to the o.s.
* 01-17-94 SKS Check _osver AND _winmajor to detect Small memory case.
* 03-02-94 GJF Changed _heap_grow_emptylist so that it returns a
* failure code rather than calling _heap_abort.
* 03-30-94 GJF Made definitions/declarations of:
* _heap_desc
* _heap_descpages,
* _heap_growsize (aka, _amblksiz),
* _heap_maxregsize
* _heap_regionsize
* _heap_regions
* conditional on ndef DLL_FOR_WIN32S.
* 02-08-95 GJF Removed obsolete _OLDROVER_ support.
* 02-14-95 GJF Appended Mac version of source file.
* 04-30-95 GJF Spliced on winheap version.
* 03-06-96 GJF Added initialization and termination code for the
* small-block heap.
* 04-22-97 GJF Changed _heap_init to return 1 for success, 0 for
* failure.
* 05-30-96 GJF Minor changes for latest version of small-block heap.
* 05-22-97 RDK New small-block heap scheme implemented.
* 07-23-97 GJF Changed _heap_init() slightly to accomodate optional
* heap running directly on Win32 API (essentially the
* scheme we used in VC++ 4.0 and 4.1).
* 09-26-97 BWT Fix POSIX
* 09-28-98 GJF Don't initialize the small-block heap on NT 5.
* 11-18-98 GJF Merged in VC++ 5.0 small-block heap and a selection
* scheme from James "Triple-Expresso" MacCalman and
* Chairman Dan Spalding.
* 05-01-99 PML Disable small-block heap for Win64.
* 05-13-99 PML Remove Win32s
* 05-17-99 PML Remove all Macintosh support.
* 06-17-99 GJF Removed old small-block heap from static libs.
* 09-28-99 PML Processing heap-select env var must not do anything
* that uses the heap (vs7#44259). Also, check the env
* var before checking for NT5.0 or better.
* 03-28-01 PML Protect against GetModuleFileName overflow (vs7#231284)
* 06-25-01 BWT Alloc heap select strings off the process heap instead of
* the stack (ntbug: 423988)
*
*******************************************************************************/
#ifdef WINHEAP
#include <cruntime.h>
#include <malloc.h>
#include <stdlib.h>
#include <winheap.h>
HANDLE _crtheap;
#if !defined(_NTSDK)
/*
* Dummy definition of _amblksiz. Included primarily so the dll will build
* without having to change crtlib.c (there is an access function for _amblksiz
* defined in crtlib.c).
*/
unsigned int _amblksiz = BYTES_PER_PARA;
#endif
#ifndef _WIN64
int __active_heap;
#ifdef CRTDLL
void __cdecl _GetLinkerVersion(LinkerVersion * plv)
{
PIMAGE_DOS_HEADER pidh;
PIMAGE_NT_HEADERS pinh;
plv->dw = 0;
pidh = (PIMAGE_DOS_HEADER) GetModuleHandle(NULL);
if ( pidh->e_magic != IMAGE_DOS_SIGNATURE || pidh->e_lfanew == 0)
return;
pinh = (PIMAGE_NT_HEADERS)(((PBYTE)pidh) + pidh->e_lfanew);
plv->bverMajor = pinh->OptionalHeader.MajorLinkerVersion;
plv->bverMinor = pinh->OptionalHeader.MinorLinkerVersion;
}
#endif /* CRTDLL */
/***
*__heap_select() - Choose from the V6, V5 or system heaps
*
*Purpose:
* Check OS, environment and build bits to determine appropriate
* small-block heap for the app.
*
*Entry:
* <void>
*Exit:
* Returns __V6_HEAP, __V5_HEAP or __SYSTEM_HEAP
*
*Exceptions:
* none
*
*******************************************************************************/
int __cdecl __heap_select(void)
{
char *env_heap_type = NULL;
#ifdef CRTDLL
DWORD HeapStringSize;
char *cp, *env_heap_select_string = NULL;
int heap_choice;
LinkerVersion lv;
#endif /* CRTDLL */
#ifdef CRTDLL
// First, check the environment variable override
if (HeapStringSize = GetEnvironmentVariableA(__HEAP_ENV_STRING, env_heap_select_string, 0))
{
env_heap_select_string = HeapAlloc(GetProcessHeap(), 0, HeapStringSize);
if (env_heap_select_string)
{
if (GetEnvironmentVariableA(__HEAP_ENV_STRING, env_heap_select_string, HeapStringSize))
{
for (cp = env_heap_select_string; *cp; ++cp)
if ('a' <= *cp && *cp <= 'z')
*cp += 'A' - 'a';
if (!strncmp(__GLOBAL_HEAP_SELECTOR,env_heap_select_string,sizeof(__GLOBAL_HEAP_SELECTOR)-1))
env_heap_type = env_heap_select_string;
else
{
char *env_app_name = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PATH+1);
if (env_app_name) {
GetModuleFileName(NULL,env_app_name,sizeof(env_app_name)-1);
for (cp = env_app_name; *cp; ++cp)
if ('a' <= *cp && *cp <= 'z')
*cp += 'A' - 'a';
env_heap_type = strstr(env_heap_select_string,env_app_name);
HeapFree(GetProcessHeap(), 0, env_app_name);
}
}
if (env_heap_type)
{
if (env_heap_type = strchr(env_heap_type,','))
{
// Convert ASCII heap code to integer inline, since
// strtol would try to use the heap (for locale info).
cp = ++env_heap_type;
while (*cp == ' ')
++cp;
heap_choice = 0;
while (*cp >= '0' && *cp <= '9')
heap_choice = heap_choice * 10 + *cp++ - '0';
if ( (heap_choice == __V5_HEAP) ||
(heap_choice == __V6_HEAP) ||
(heap_choice == __SYSTEM_HEAP) )
{
HeapFree(GetProcessHeap(), 0, env_heap_select_string);
return heap_choice;
}
}
}
}
HeapFree(GetProcessHeap(), 0, env_heap_select_string);
}
}
#endif /* CRTDLL */
// Second, check the OS for NT >= 5.0
if ( (_osplatform == VER_PLATFORM_WIN32_NT) && (_winmajor >= 5) )
return __SYSTEM_HEAP;
#ifdef CRTDLL
// Third, check the build bits in the app; apps built with tools >= VC++ 6.0
// will get the V6 heap, apps built with older tools will get the V5 heap
_GetLinkerVersion(&lv);
if (lv.bverMajor >= 6)
return __V6_HEAP;
else
return __V5_HEAP;
#else /* ndef CRTDLL */
return __V6_HEAP;
#endif /* CRTDLL */
}
#endif /* ndef _WIN64 */
/***
*_heap_init() - Initialize the heap
*
*Purpose:
* Setup the initial C library heap.
*
* NOTES:
* (1) This routine should only be called once!
* (2) This routine must be called before any other heap requests.
*
*Entry:
* <void>
*Exit:
* Returns 1 if successful, 0 otherwise.
*
*Exceptions:
* If heap cannot be initialized, the program will be terminated
* with a fatal runtime error.
*
*******************************************************************************/
int __cdecl _heap_init (
int mtflag
)
{
#ifdef _POSIX_
_crtheap = GetProcessHeap();
#else
// Initialize the "big-block" heap first.
if ( (_crtheap = HeapCreate( mtflag ? 0 : HEAP_NO_SERIALIZE,
BYTES_PER_PAGE, 0 )) == NULL )
return 0;
#ifndef _WIN64
// Pick a heap, any heap
__active_heap = __heap_select();
if ( __active_heap == __V6_HEAP )
{
// Initialize the small-block heap
if (__sbh_heap_init(MAX_ALLOC_DATA_SIZE) == 0)
{
HeapDestroy(_crtheap);
return 0;
}
}
#ifdef CRTDLL
else if ( __active_heap == __V5_HEAP )
{
if ( __old_sbh_new_region() == NULL )
{
HeapDestroy( _crtheap );
return 0;
}
}
#endif /* CRTDLL */
#endif /* _ndef _WIN64 */
#endif /* _POSIX_ */
return 1;
}
/***
*_heap_term() - return the heap to the OS
*
*Purpose:
*
* NOTES:
* (1) This routine should only be called once!
* (2) This routine must be called AFTER any other heap requests.
*
*Entry:
* <void>
*Exit:
* <void>
*
*Exceptions:
*
*******************************************************************************/
void __cdecl _heap_term (void)
{
#ifndef _POSIX_
#ifndef _WIN64
// if it has been initialized, destroy the small-block heap
if ( __active_heap == __V6_HEAP )
{
PHEADER pHeader = __sbh_pHeaderList;
int cntHeader;
// scan through all the headers
for (cntHeader = 0; cntHeader < __sbh_cntHeaderList; cntHeader++)
{
// decommit and release the address space for the region
VirtualFree(pHeader->pHeapData, BYTES_PER_REGION, MEM_DECOMMIT);
VirtualFree(pHeader->pHeapData, 0, MEM_RELEASE);
// free the region data structure
HeapFree(_crtheap, 0, pHeader->pRegion);
pHeader++;
}
// free the header list
HeapFree(_crtheap, 0, __sbh_pHeaderList);
}
#ifdef CRTDLL
else if ( __active_heap == __V5_HEAP )
{
__old_sbh_region_t *preg = &__old_small_block_heap;
// Release the regions of the small-block heap
do
{
if ( preg->p_pages_begin != NULL )
VirtualFree( preg->p_pages_begin, 0, MEM_RELEASE );
}
while ( (preg = preg->p_next_region) != &__old_small_block_heap );
}
#endif /* CRTDLL */
#endif /* ndef _WIN64 */
// destroy the large-block heap
HeapDestroy(_crtheap);
#endif /* _POSIX_ */
}
#else /* ndef WINHEAP */
#include <cruntime.h>
#include <oscalls.h>
#include <dos.h>
#include <heap.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
/*
* Heap descriptor
*/
struct _heap_desc_ _heap_desc = {
&_heap_desc.sentinel, /* pfirstdesc */
&_heap_desc.sentinel, /* proverdesc */
NULL, /* emptylist */
NULL, /* sentinel.pnextdesc */
NULL /* sentinel.pblock */
};
/*
* Array of region structures
* [Note: We count on the fact that this is always initialized to zero
* by the compiler.]
*/
struct _heap_region_ _heap_regions[_HEAP_REGIONMAX];
void ** _heap_descpages; /* linked list of pages used for descriptors */
/*
* Control parameter locations
*/
unsigned int _heap_resetsize = 0xffffffff;
/* NOTE: Currenlty, _heap_growsize is a #define to _amblksiz */
unsigned int _heap_growsize = _HEAP_GROWSIZE; /* region inc size */
unsigned int _heap_regionsize = _HEAP_REGIONSIZE_L; /* region size */
unsigned int _heap_maxregsize = _HEAP_MAXREGSIZE_L; /* max region size */
/***
*_heap_init() - Initialize the heap
*
*Purpose:
* Setup the initial C library heap. All necessary memory and
* data bases are init'd appropriately so future requests work
* correctly.
*
* NOTES:
* (1) This routine should only be called once!
* (2) This routine must be called before any other heap requests.
*
*
*Entry:
* <void>
*Exit:
* <void>
*
*Exceptions:
* If heap cannot be initialized, the program will be terminated
* with a fatal runtime error.
*
*******************************************************************************/
void __cdecl _heap_init (
void
)
{
/*
* Test for Win32S or Phar Lap TNT environment
* which cannot allocate uncommitted memory
* without actually allocating physical memory
*
* High bit of _osver is set for both of those environments
* -AND- the Windows version will be less than 4.0.
*/
if ( ( _osver & 0x8000 ) && ( _winmajor < 4 ) )
{
_heap_regionsize = _HEAP_REGIONSIZE_S;
_heap_maxregsize = _HEAP_MAXREGSIZE_S;
}
}
/***
*_heap_term() - Clean-up the heap
*
*Purpose:
* This routine will decommit and release ALL of the CRT heap.
* All memory malloc-ed by the CRT will then be invalid.
*
* NOTES:
* (1) This routine should only be called once!
* (2) This routine must be called AFTER any other heap requests.
*
*Entry:
* <void>
*Exit:
* <void>
*
*Exceptions:
*
*******************************************************************************/
void __cdecl _heap_term (
void
)
{
int index;
void **pageptr;
/*
* Loop through the region descriptor table, decommitting
* and releasing (freeing up) each region that is in use.
*/
for ( index=0 ; index < _HEAP_REGIONMAX ; index++ ) {
void * regbase ;
if ( (regbase = _heap_regions[index]._regbase)
&& VirtualFree(regbase, _heap_regions[index]._currsize, MEM_DECOMMIT)
&& VirtualFree(regbase, 0, MEM_RELEASE) )
regbase = _heap_regions[index]._regbase = NULL ;
}
/*
* Now we need to decommit and release the pages used for descriptors
* _heap_descpages points to the head of a singly-linked list of the pages.
*/
pageptr = _heap_descpages;
while ( pageptr ) {
void **nextpage;
nextpage = *pageptr;
if(!VirtualFree(pageptr, 0, MEM_RELEASE))
break; /* if the linked list is corrupted, give up */
pageptr = nextpage;
}
}
/***
* _heap_grow_emptylist() - Grow the empty heap descriptor list
*
*Purpose:
* (1) Get memory from OS
* (2) Form it into a linked list of empty heap descriptors
* (3) Attach it to the master empty list
*
* NOTE: This routine assumes that the emptylist is NULL
* when called (i.e., there are no available empty heap descriptors).
*
*Entry:
* (void)
*
*Exit:
* 1, if the empty heap descriptor list was grown
* 0, if the empty heap descriptor list could not be grown.
*
*Exceptions:
*
*******************************************************************************/
static int __cdecl _heap_grow_emptylist (
void
)
{
REG1 _PBLKDESC first;
REG2 _PBLKDESC next;
_PBLKDESC last;
/*
* Get memory for the new empty heap descriptors
*
* Note that last is used to hold the returned pointer because
* first (and next) are register class.
*/
if ( !(last = VirtualAlloc(NULL,
_HEAP_EMPTYLIST_SIZE,
MEM_COMMIT,
PAGE_READWRITE)) )
return 0;
/*
* Add this descriptor block to the front of the list
*
* Advance "last" to skip over the
*/
*(void **)last = _heap_descpages;
_heap_descpages = (void **)(last++);
/*
* Init the empty heap descriptor list.
*/
_heap_desc.emptylist = first = last;
/*
* Carve the memory into an empty list
*/
last = (_PBLKDESC) ((char *) first + _HEAP_EMPTYLIST_SIZE - 2 * sizeof(_BLKDESC));
next = (_PBLKDESC) ((char *) first + sizeof(_BLKDESC));
while ( first < last ) {
/* Init this descriptor */
#ifdef DEBUG
first->pblock = NULL;
#endif
first->pnextdesc = next;
/* onto the next block */
first = next++;
}
/*
* Take care of the last descriptor (end of the empty list)
*/
last->pnextdesc = NULL;
#ifdef DEBUG
last->pblock = NULL;
#endif
return 1;
}
/***
*__getempty() - get an empty heap descriptor
*
*Purpose:
* Get a descriptor from the list of empty heap descriptors. If the list
* is empty, call _heap_grow_emptylist.
*
*Entry:
* no arguments
*
*Exit:
* If successful, a pointer to the descriptor is returned.
* Otherwise, NULL is returned.
*
*Exceptions:
*
*******************************************************************************/
_PBLKDESC __cdecl __getempty(
void
)
{
_PBLKDESC pdesc;
if ( (_heap_desc.emptylist == NULL) && (_heap_grow_emptylist()
== 0) )
return NULL;
pdesc = _heap_desc.emptylist;
_heap_desc.emptylist = pdesc->pnextdesc;
return pdesc;
}
#endif /* WINHEAP */