_WCRTLINK __segment _bheapseg( size_t size )
{
__segment seg;
heapblk __based( seg ) *p;
seg = __AllocSeg( size );
if( seg == _NULLSEG )
return( _NULLSEG );
p = 0;
p->nextseg = __bheap;
__bheap = seg;
seg = p->nextseg;
if( seg != _NULLSEG ) {
p->prevseg = __bheap;
}
return( __bheap );
}
_WCRTLINK void _WCFAR *_fmalloc( size_t amt )
{
unsigned size;
unsigned offset;
unsigned short seg;
unsigned short prev_seg;
struct heapblk _WCFAR *p;
if( amt == 0 || amt > - (sizeof(struct heapblk) + TAG_SIZE*2) ) {
return( (void _WCFAR *)NULL );
}
// Try to determine which segment to begin allocating from.
// first, round up the amount
size = (amt + TAG_SIZE + ROUND_SIZE) & ~ROUND_SIZE;
if( size < FRL_SIZE ) {
size = FRL_SIZE;
}
_AccessFHeap();
for(;;) {
if( size > __LargestSizeB4Rover ) {
seg = __fheapRover;
} else {
__LargestSizeB4Rover = 0; // force value to be updated
seg = __fheap;
}
for(;;) {
if( seg == 0 ) {
seg = __AllocSeg( amt );
if( seg == 0 )
break;
if( __fheap == 0 ) {
__fheap = seg;
} else {
p->nextseg = seg;
p = MK_FP( seg, 0 );
p->prevseg = prev_seg;
}
}
for(;;) {
__fheapRover = seg;
offset = __MemAllocator( amt, seg, 0 );
if( offset != 0 )
goto release_heap;
if( __GrowSeg( seg, amt ) == 0 )
break;
}
prev_seg = seg;
p = MK_FP( seg, 0 );
if( p->largest_blk > __LargestSizeB4Rover ) {
__LargestSizeB4Rover = p->largest_blk;
}
seg = p->nextseg;
}
if( __fmemneed( amt ) == 0 )
break;
}
if( seg == 0 ) {
offset = (unsigned)_nmalloc( amt );
if( offset != 0 )
seg = _DGroup();
}
release_heap:
_ReleaseFHeap();
return( MK_FP( seg, offset ) );
}