factor/vm/object_start_map.cpp

96 lines
2.4 KiB
C++

#include "master.hpp"
namespace factor
{
object_start_map::object_start_map(cell size_, cell start_) :
size(size_), start(start_)
{
object_start_offsets = new card[addr_to_card(size_)];
object_start_offsets_end = object_start_offsets + addr_to_card(size_);
clear_object_start_offsets();
}
object_start_map::~object_start_map()
{
delete[] object_start_offsets;
}
cell object_start_map::first_object_in_card(cell card_index)
{
return object_start_offsets[card_index];
}
cell object_start_map::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 */
FACTOR_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 object_start_map::record_object_start_offset(object *obj)
{
cell idx = addr_to_card((cell)obj - start);
card obj_start = ((cell)obj & addr_card_mask);
object_start_offsets[idx] = std::min(object_start_offsets[idx],obj_start);
}
void object_start_map::clear_object_start_offsets()
{
memset(object_start_offsets,card_starts_inside_object,addr_to_card(size));
}
void object_start_map::update_card_for_sweep(cell index, u16 mask)
{
cell offset = object_start_offsets[index];
if(offset != card_starts_inside_object)
{
mask >>= (offset / data_alignment);
if(mask == 0)
{
/* The rest of the block after the old object start is free */
object_start_offsets[index] = card_starts_inside_object;
}
else
{
/* Move the object start forward if necessary */
object_start_offsets[index] = (card)(offset + (rightmost_set_bit(mask) * data_alignment));
}
}
}
void object_start_map::update_for_sweep(mark_bits<object> *state)
{
for(cell index = 0; index < state->bits_size; index++)
{
cell mask = state->marked[index];
#ifdef FACTOR_64
update_card_for_sweep(index * 4, mask & 0xffff);
update_card_for_sweep(index * 4 + 1, (mask >> 16) & 0xffff);
update_card_for_sweep(index * 4 + 2, (mask >> 32) & 0xffff);
update_card_for_sweep(index * 4 + 3, (mask >> 48) & 0xffff);
#else
update_card_for_sweep(index * 2, mask & 0xffff);
update_card_for_sweep(index * 2 + 1, (mask >> 16) & 0xffff);
#endif
}
}
}