38 lines
1002 B
C++
38 lines
1002 B
C++
/* card marking write barrier. a card is a byte storing a mark flag,
|
|
and the offset (in cells) of the first object in the card.
|
|
|
|
the mark flag is set by the write barrier when an object in the
|
|
card has a slot written to.
|
|
|
|
the offset of the first object is set by the allocator. */
|
|
|
|
namespace factor
|
|
{
|
|
|
|
/* if card_points_to_nursery is set, card_points_to_aging must also be set. */
|
|
static const cell card_points_to_nursery = 0x80;
|
|
static const cell card_points_to_aging = 0x40;
|
|
static const cell card_mark_mask = (card_points_to_nursery | card_points_to_aging);
|
|
typedef u8 card;
|
|
|
|
static const cell card_bits = 8;
|
|
static const cell card_size = (1<<card_bits);
|
|
static const cell addr_card_mask = (card_size-1);
|
|
|
|
typedef u8 card_deck;
|
|
|
|
static const cell deck_bits = (card_bits + 10);
|
|
static const cell deck_size = (1<<deck_bits);
|
|
static const cell addr_deck_mask = (deck_size-1);
|
|
|
|
inline cell addr_to_card(cell a)
|
|
{
|
|
return a >> card_bits;
|
|
}
|
|
|
|
inline cell addr_to_deck(cell a)
|
|
{
|
|
return a >> deck_bits;
|
|
}
|
|
}
|