factor/vm/old_space.cpp

75 lines
1.5 KiB
C++

#include "master.hpp"
namespace factor
{
old_space::old_space(cell size_, cell start_) : zone(size_,start_)
{
object_start_offsets = new card[addr_to_card(size_)];
object_start_offsets_end = object_start_offsets + addr_to_card(size_);
}
old_space::~old_space()
{
delete[] object_start_offsets;
}
cell old_space::first_object_in_card(cell card_index)
{
return object_start_offsets[card_index];
}
cell old_space::find_object_containing_card(cell card_index)
{
if(card_index == 0)
return start;
else
{
card_index--;
while(first_object_in_card(card_index) == card_starts_inside_object)
{
#ifdef FACTOR_DEBUG
/* First card should start with an object */
assert(card_index > 0);
#endif
card_index--;
}
return start + (card_index << card_bits) + first_object_in_card(card_index);
}
}
/* we need to remember the first object allocated in the card */
void old_space::record_object_start_offset(object *obj)
{
cell idx = addr_to_card((cell)obj - start);
if(object_start_offsets[idx] == card_starts_inside_object)
object_start_offsets[idx] = ((cell)obj & addr_card_mask);
}
object *old_space::allot(cell size)
{
if(here + size > end) return NULL;
object *obj = zone::allot(size);
record_object_start_offset(obj);
return obj;
}
void old_space::clear_object_start_offsets()
{
memset(object_start_offsets,card_starts_inside_object,addr_to_card(size));
}
cell old_space::next_object_after(factor_vm *parent, cell scan)
{
cell size = parent->untagged_object_size((object *)scan);
if(scan + size < here)
return scan + size;
else
return 0;
}
}