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[factor.git] / vm / write_barrier.hpp

diff --git a/vm/write_barrier.hpp b/vm/write_barrier.hpp
index ae7fbb25ddba643a102adcfe8c27b370a7d3f654..2dda02297cc1a758acdc5b0d2c1ab3b0901dcf8a 100644 (file)
--- a/vm/write_barrier.hpp
+++ b/vm/write_barrier.hpp
@@ -1,87 +1,33 @@
-/* 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.
+// 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 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. */
+// the offset of the first object is set by the allocator.
 
-namespace factor
-{
+namespace factor {
 
-/* if CARD_POINTS_TO_NURSERY is set, CARD_POINTS_TO_AGING must also be set. */
-#define CARD_POINTS_TO_NURSERY 0x80
-#define CARD_POINTS_TO_AGING 0x40
-#define CARD_MARK_MASK (CARD_POINTS_TO_NURSERY | CARD_POINTS_TO_AGING)
-typedef u8 card;
+// 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 uint8_t card;
 
-#define CARD_BITS 8
-#define CARD_SIZE (1<<CARD_BITS)
-#define ADDR_CARD_MASK (CARD_SIZE-1)
+static const cell card_bits = 8;
+static const cell card_size = 1 << card_bits;
+static const cell addr_card_mask = card_size - 1;
 
-VM_C_API cell cards_offset;
+typedef uint8_t card_deck;
 
-inline static card *addr_to_card(cell a)
-{
-       return (card*)(((cell)(a) >> CARD_BITS) + cards_offset);
-}
-
-inline static cell card_to_addr(card *c)
-{
-       return ((cell)c - cards_offset) << CARD_BITS;
-}
-
-inline static cell card_offset(card *c)
-{
-       return *(c - (cell)data->cards + (cell)data->allot_markers);
-}
-
-typedef u8 card_deck;
+static const cell deck_bits = card_bits + 10;
+// Number of bytes on the heap a deck addresses. Each deck as 1024
+// cards. So 256 kb.
+static const cell deck_size = 1 << deck_bits;
+static const cell cards_per_deck = 1 << 10;
 
-#define DECK_BITS (CARD_BITS + 10)
-#define DECK_SIZE (1<<DECK_BITS)
-#define ADDR_DECK_MASK (DECK_SIZE-1)
-
-VM_C_API cell decks_offset;
-
-inline static card_deck *addr_to_deck(cell a)
-{
-       return (card_deck *)(((cell)a >> DECK_BITS) + decks_offset);
-}
-
-inline static cell deck_to_addr(card_deck *c)
-{
-       return ((cell)c - decks_offset) << DECK_BITS;
-}
-
-inline static card *deck_to_card(card_deck *d)
-{
-       return (card *)((((cell)d - decks_offset) << (DECK_BITS - CARD_BITS)) + cards_offset);
-}
-
-#define INVALID_ALLOT_MARKER 0xff
-
-VM_C_API cell allot_markers_offset;
-
-inline static card *addr_to_allot_marker(object *a)
-{
-       return (card *)(((cell)a >> CARD_BITS) + allot_markers_offset);
-}
-
-/* the write barrier must be called any time we are potentially storing a
-pointer from an older generation to a younger one */
-inline static void write_barrier(object *obj)
-{
-       *addr_to_card((cell)obj) = CARD_MARK_MASK;
-       *addr_to_deck((cell)obj) = CARD_MARK_MASK;
-}
-
-/* we need to remember the first object allocated in the card */
-inline static void allot_barrier(object *address)
-{
-       card *ptr = addr_to_allot_marker(address);
-       if(*ptr == INVALID_ALLOT_MARKER)
-               *ptr = ((cell)address & ADDR_CARD_MASK);
-}
+inline cell addr_to_card(cell a) { return a >> card_bits; }
 
+inline cell addr_to_deck(cell a) { return a >> deck_bits; }
 }