factor/vm/old_space.hpp

40 lines
938 B
C++

namespace factor
{
static const cell card_starts_inside_object = 0xff;
struct old_space : zone {
card *object_start_offsets;
card *object_start_offsets_end;
old_space(cell size_, cell start_);
~old_space();
cell object_start_map_index(cell address)
{
return (address - start) >> card_bits;
}
/* Find the first object starting on or after the given address */
cell first_object_in_card(cell address)
{
return object_start_offsets[object_start_map_index(address)];
}
/* Find the card which contains the header of the object which contains
the given address */
cell find_card_containing_header(cell address)
{
cell i = object_start_map_index(address);
while(i >= 0 && object_start_offsets[i] == card_starts_inside_object) i--;
return i;
}
void record_object_start_offset(object *obj);
object *allot(cell size);
void clear_object_start_offsets();
cell next_object_after(factor_vm *myvm, cell scan);
};
}