32 lines
1022 B
C++
32 lines
1022 B
C++
/* card marking write barrier. a card is a byte storing a mark flag,
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and the offset (in cells) of the first object in the card.
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the mark flag is set by the write barrier when an object in the
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card has a slot written to.
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the offset of the first object is set by the allocator. */
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namespace factor {
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/* if card_points_to_nursery is set, card_points_to_aging must also be set. */
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static const cell card_points_to_nursery = 0x80;
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static const cell card_points_to_aging = 0x40;
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static const cell card_mark_mask =
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(card_points_to_nursery | card_points_to_aging);
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typedef uint8_t card;
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static const cell card_bits = 8;
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static const cell card_size = (1 << card_bits);
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static const cell addr_card_mask = (card_size - 1);
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typedef uint8_t card_deck;
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static const cell deck_bits = (card_bits + 10);
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static const cell deck_size = (1 << deck_bits);
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static const cell addr_deck_mask = (deck_size - 1);
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inline cell addr_to_card(cell a) { return a >> card_bits; }
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inline cell addr_to_deck(cell a) { return a >> deck_bits; }
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}
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