void *__ReAllocDPMIBlock( frlptr p1, unsigned req_size )
{
mheapptr mhp;
struct dpmi_hdr *dpmi;
struct dpmi_hdr *prev_dpmi;
unsigned size;
frlptr flp, flp2;
if( !__heap_enabled )
return( 0 );
__FreeDPMIBlocks();
prev_dpmi = NULL;
for( mhp = __nheapbeg; mhp; mhp = mhp->next ) {
if( ((PTR)mhp + sizeof(struct miniheapblkp) == (PTR)p1)
&& (mhp->numalloc == 1) ) {
// The mini-heap contains only this memblk
__unlink( mhp );
dpmi = ((struct dpmi_hdr *)mhp) - 1;
if( dpmi->dos_seg_value != 0 )
return( NULL );
size = mhp->len + sizeof(struct dpmi_hdr) + TAG_SIZE;
size += ( req_size - (p1->len-TAG_SIZE) );
size += BLKSIZE_ALIGN_MASK;
size &= ~BLKSIZE_ALIGN_MASK;
prev_dpmi = dpmi;
dpmi = TinyDPMIRealloc( dpmi, size );
if( dpmi == NULL ) {
dpmi = prev_dpmi;
return( NULL ); // indicate resize failed
}
dpmi->dos_seg_value = 0;
mhp = (mheapptr)( dpmi + 1 );
mhp->len = size - sizeof(struct dpmi_hdr) - TAG_SIZE;
flp = __LinkUpNewMHeap( mhp );
mhp->numalloc = 1;
// round up to even number
req_size = (req_size + 1) & ~1;
size = flp->len - req_size;
if( size >= FRL_SIZE ) { // Enough to spare a free block
flp->len = req_size | 1;// adjust size and set allocated bit
// Make up a free block at the end
flp2 = (frlptr)((PTR)flp + req_size);
flp2->len = size | 1;
++mhp->numalloc;
mhp->largest_blk = 0;
_nfree( (PTR)flp2 + TAG_SIZE );
} else {
flp->len |= 1; // set allocated bit
}
return( flp );
}
}
return( NULL );
}
static void *RationalAlloc( size_t size )
{
dpmi_hdr *dpmi;
mheapptr mhp;
tiny_ret_t save_DOS_block;
tiny_ret_t DOS_block;
__FreeDPMIBlocks();
/* size is a multiple of 4k */
dpmi = TinyDPMIAlloc( size );
if( dpmi != NULL ) {
mhp = (mheapptr)( dpmi + 1 );
mhp->len = size - sizeof( dpmi_hdr );
dpmi->dos_seg_value = 0; // indicate DPMI block
return( (void *)mhp );
}
if( __minreal & 0xfff00000 ) {
/* checks for users that want >1M real memory saved */
__minreal = 0xfffff;
}
if( size > 0x00010000 ) {
/* cannot allocate more than 64k from DOS real memory */
return( NULL );
}
save_DOS_block = TinyAllocBlock( __ROUND_DOWN_SIZE_TO_PARA( __minreal ) | 1 );
if( TINY_OK( save_DOS_block ) ) {
DOS_block = TinyAllocBlock( __ROUND_DOWN_SIZE_TO_PARA( size ) );
TinyFreeBlock( save_DOS_block );
if( TINY_OK( DOS_block ) ) {
dpmi = (dpmi_hdr *)TinyDPMIBase( DOS_block );
dpmi->dos_seg_value = DOS_block;
mhp = (mheapptr)( dpmi + 1 );
mhp->len = size - sizeof( dpmi_hdr );
return( (void *)mhp );
}
}
return( NULL );
}
_WCRTLINK int _nheapshrink( void )
{
mheapptr mhp;
#if !defined(__WARP__) && \
!defined(__WINDOWS_286__) && \
!defined(__WINDOWS_386__) && \
!defined(__NT__) && \
!defined(__CALL21__) && \
!defined(__SNAP__)
// Shrink by adjusting _curbrk
frlptr last_free;
frlptr end_tag;
unsigned new_brk;
_AccessNHeap();
#if defined(__DOS_EXT__)
if( !_IsRationalZeroBase() && !_IsCodeBuilder() ) {
#endif
if( __nheapbeg == NULL ) {
_ReleaseNHeap();
return( 0 ); // No near heap, can't shrink
}
/* Goto the end of miniheaplist (if there's more than 1 blk) */
for( mhp = __nheapbeg; mhp->next; mhp = mhp->next );
/* check that last free block is at end of heap */
last_free = mhp->freehead.prev;
end_tag = (frlptr) ( (PTR)last_free + last_free->len );
if( end_tag->len != END_TAG ) {
_ReleaseNHeap();
return( 0 );
}
if( end_tag != (frlptr) ((PTR)mhp + mhp->len ) ) {
_ReleaseNHeap();
return( 0 );
}
#if defined(__DOS_EXT__)
// only shrink if we can shave off at least 4k
if( last_free->len < 0x1000 ) {
_ReleaseNHeap();
return( 0 );
}
#else
if( last_free->len <= sizeof( frl ) ) {
_ReleaseNHeap();
return( 0 );
}
#endif
/* make sure there hasn't been an external change in _curbrk */
if( sbrk( 0 ) != &(end_tag->prev) ) {
_ReleaseNHeap();
return( 0 );
}
/* calculate adjustment factor */
if( mhp->len-last_free->len > sizeof( struct miniheapblkp ) ) {
// this miniheapblk is still being used
#if defined(__DOS_EXT__)
frlptr new_last_free;
new_last_free = (frlptr)((((unsigned)last_free + 0xfff) & ~0xfff) - TAG_SIZE);
if( new_last_free == last_free ) {
#endif
// remove entire entry
mhp->len -= last_free->len;
--mhp->numfree;
// Relink the freelist entries, and update the rover
mhp->freehead.prev = last_free->prev;
last_free->prev->next = &mhp->freehead;
if( mhp->rover == last_free ) mhp->rover = last_free->prev;
#if defined(__DOS_EXT__)
} else {
// just shrink the last free entry
mhp->len -= last_free->len;
last_free->len = (PTR)new_last_free - (PTR)last_free;
mhp->len += last_free->len;
last_free = new_last_free;
}
#endif
last_free->len = END_TAG;
new_brk = (unsigned) ((PTR)last_free + TAG_SIZE );
} else {
// we can remove this miniheapblk
if( mhp->prev ) { // Not the first miniheapblk
mhp->prev->next = NULL;
new_brk = (unsigned)mhp;//->prev + (unsigned)mhp->prev->len;
} else { // Is the first miniheapblk
new_brk = (unsigned)__nheapbeg;
__nheapbeg = NULL;
}
// Update rover info
if( __MiniHeapRover == mhp ) {
__MiniHeapRover = __nheapbeg;
__LargestSizeB4MiniHeapRover = 0;
}
}
if( __brk( new_brk ) == (void _WCNEAR *) -1 ) {
_ReleaseNHeap();
return( -1 );
}
_ReleaseNHeap();
return( 0 );
#if defined(__DOS_EXT__)
}
__FreeDPMIBlocks(); // For RSI/zero-base and Intel CB
_ReleaseNHeap();
return( 0 );
#endif
#else
// Shrink by releasing mini-heaps
{
mheapptr pnext;
_AccessNHeap();
for( mhp = __nheapbeg; mhp; mhp = pnext ) {
pnext = mhp->next;
if( mhp->len - sizeof(struct miniheapblkp) ==
(mhp->freehead.prev)->len ) __ReleaseMiniHeap( mhp );
}
_ReleaseNHeap();
return( 0 );
}
#endif
}
