int __HeapManager_expand( __segment seg,
unsigned offset,
size_t req_size,
size_t *growth_size )
{
#if defined( _M_I86 )
typedef struct freelistp __based(seg) *fptr;
typedef char __based(void) *cptr;
struct miniheapblkp __based(seg) *hblk;
#else
typedef struct freelistp _WCNEAR *fptr;
typedef char _WCNEAR *cptr;
mheapptr hblk;
#endif
fptr p1;
fptr p2;
fptr pnext;
fptr pprev;
size_t new_size;
size_t old_size;
size_t free_size;
/* round (new_size + tag) to multiple of pointer size */
new_size = (req_size + TAG_SIZE + ROUND_SIZE) & ~ROUND_SIZE;
if( new_size < req_size ) new_size = ~0; //go for max
if( new_size < FRL_SIZE ) {
new_size = FRL_SIZE;
}
p1 = (fptr) ((cptr)offset - TAG_SIZE);
old_size = p1->len & ~1;
if( new_size > old_size ) {
/* enlarging the current allocation */
p2 = (fptr) ((cptr)p1 + old_size);
*growth_size = new_size - old_size;
for(;;) {
free_size = p2->len;
if( p2->len == END_TAG ) {
return( __HM_TRYGROW );
} else if( free_size & 1 ) { /* next piece is allocated */
break;
} else {
pnext = p2->next;
pprev = p2->prev;
if( seg == _DGroup() ) { // near heap
for( hblk = __nheapbeg; hblk->next; hblk = hblk->next ) {
if( (fptr)hblk <= (fptr)offset &&
(fptr)((PTR)hblk+hblk->len) > (fptr)offset ) break;
}
}
#if defined( _M_I86 )
else { // Based heap
hblk = 0;
}
#endif
if( hblk->rover == p2 ) { /* 09-feb-91 */
hblk->rover = p2->prev;
}
if( free_size < *growth_size ||
free_size - *growth_size < FRL_SIZE ) {
/* unlink small free block */
pprev->next = pnext;
pnext->prev = pprev;
p1->len += free_size;
hblk->numfree--;
if( free_size >= *growth_size ) {
return( __HM_SUCCESS );
}
*growth_size -= free_size;
p2 = (fptr) ((cptr)p2 + free_size);
} else {
p2 = (fptr) ((cptr)p2 + *growth_size);
p2->len = free_size - *growth_size;
p2->prev = pprev;
p2->next = pnext;
pprev->next = p2;
pnext->prev = p2;
p1->len += *growth_size;
return( __HM_SUCCESS );
}
}
}
/* no suitable free blocks behind, have to move block */
return( __HM_FAIL );
} else {
/* shrinking the current allocation */
if( old_size - new_size >= FRL_SIZE ) {
/* block big enough to split */
p1->len = new_size | 1;
p1 = (fptr) ((cptr)p1 + new_size);
p1->len = (old_size - new_size) | 1;
if( seg == _DGroup() ) { // near heap
for( hblk = __nheapbeg; hblk->next; hblk = hblk->next ) {
if( (fptr)hblk <= (fptr)offset &&
(fptr)((PTR)hblk+hblk->len) > (fptr)offset ) break;
}
}
#if defined( _M_I86 )
else // Based heap
hblk = 0;
#endif
/* _bfree will decrement 'numalloc' 08-jul-91 */
hblk->numalloc++;
#if defined( _M_I86 )
_bfree( seg, (cptr)p1 + TAG_SIZE );
/* free the top portion */
#else
_nfree( (cptr)p1 + TAG_SIZE );
#endif
}
}
return( __HM_SUCCESS );
}
int __HeapManager_expand( __segment seg, unsigned offset, size_t req_size, size_t *growth_size )
{
miniheapblkp SEG_BPTR( seg ) hblk;
freelistp SEG_BPTR( seg ) p1;
freelistp SEG_BPTR( seg ) p2;
freelistp SEG_BPTR( seg ) pnext;
freelistp SEG_BPTR( seg ) pprev;
size_t new_size;
size_t old_size;
size_t free_size;
/* round (new_size + tag) to multiple of pointer size */
new_size = __ROUND_UP_SIZE( req_size + TAG_SIZE, ROUND_SIZE );
if( new_size < req_size )
new_size = ~0; //go for max
if( new_size < FRL_SIZE ) {
new_size = FRL_SIZE;
}
p1 = FRL_BPTR( seg, offset, -TAG_SIZE );
old_size = MEMBLK_SIZE( p1 );
if( new_size > old_size ) {
/* enlarging the current allocation */
p2 = FRL_BPTR( seg, p1, old_size );
*growth_size = new_size - old_size;
for( ;; ) {
if( p2->len == END_TAG ) {
return( __HM_TRYGROW );
} else if( IS_MEMBLK_USED( p2 ) ) { /* next piece is allocated */
break;
} else {
free_size = p2->len;
pnext = p2->next;
pprev = p2->prev;
if( seg == _DGroup() ) { // near heap
for( hblk = __nheapbeg; hblk->next != NULL; hblk = hblk->next ) {
if( FRL_BPTR( seg, hblk, 0 ) <= FRL_BPTR( seg, offset, 0 )
&& FRL_BPTR( seg, hblk, hblk->len ) > FRL_BPTR( seg, offset, 0 ) ) {
break;
}
}
#if defined( _M_I86 )
} else { // Based heap
hblk = 0;
#endif
}
if( hblk->rover == p2 ) {
hblk->rover = p2->prev;
}
if( free_size < *growth_size || free_size - *growth_size < FRL_SIZE ) {
/* unlink small free block */
pprev->next = pnext;
pnext->prev = pprev;
p1->len += free_size;
hblk->numfree--;
if( free_size >= *growth_size ) {
return( __HM_SUCCESS );
}
*growth_size -= free_size;
p2 = FRL_BPTR( seg, p2, free_size );
} else {
p2 = FRL_BPTR( seg, p2, *growth_size );
p2->len = free_size - *growth_size;
p2->prev = pprev;
p2->next = pnext;
pprev->next = p2;
pnext->prev = p2;
p1->len += *growth_size;
return( __HM_SUCCESS );
}
}
}
/* no suitable free blocks behind, have to move block */
return( __HM_FAIL );
} else {
/* shrinking the current allocation */
if( old_size - new_size >= FRL_SIZE ) {
/* block big enough to split */
SET_MEMBLK_SIZE_USED( p1, new_size );
p1 = FRL_BPTR( seg, p1, new_size );
SET_MEMBLK_SIZE_USED( p1, old_size - new_size );
if( seg == _DGroup() ) { // near heap
for( hblk = __nheapbeg; hblk->next != NULL; hblk = hblk->next ) {
if( FRL_BPTR( seg, hblk, 0 ) <= FRL_BPTR( seg, offset, 0 )
&& FRL_BPTR( seg, hblk, hblk->len ) > FRL_BPTR( seg, offset, 0 ) ) {
break;
}
}
#if defined( _M_I86 )
} else { // Based heap
hblk = 0;
#endif
}
/* _bfree will decrement 'numalloc' 08-jul-91 */
hblk->numalloc++;
#if defined( _M_I86 )
_bfree( seg, FRL_BPTR( seg, p1, TAG_SIZE ) );
/* free the top portion */
#else
_nfree( FRL_BPTR( seg, p1, TAG_SIZE ) );
#endif
}
}
return( __HM_SUCCESS );
}
