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[factor.git] / vm / write_barrier.hpp

diff --git a/vm/write_barrier.hpp b/vm/write_barrier.hpp
old mode 100755 (executable)
new mode 100644 (file)
index e874600..2dda022
--- a/vm/write_barrier.hpp
+++ b/vm/write_barrier.hpp
@@ -1,131 +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.
 
-VM_C_API factor::cell cards_offset;
-VM_C_API factor::cell decks_offset;
+namespace factor {
 
-namespace factor
-{
-
-/* if card_points_to_nursery is set, card_points_to_aging must also be set. */
+// 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_mark_mask =
+    (card_points_to_nursery | card_points_to_aging);
+typedef uint8_t card;
 
 static const cell card_bits = 8;
-static const cell card_size = (1<<card_bits);
-static const cell addr_card_mask = (card_size-1);
-
-inline card *factorvm::addr_to_card(cell a)
-{
-       return (card*)(((cell)(a) >> card_bits) + cards_offset);
-}
-
-inline card *addr_to_card(cell a)
-{
-       return vm->addr_to_card(a);
-}
-
-inline cell factorvm::card_to_addr(card *c)
-{
-       return ((cell)c - cards_offset) << card_bits;
-}
-
-inline cell card_to_addr(card *c)
-{
-       return vm->card_to_addr(c);
-}
-
-inline cell factorvm::card_offset(card *c)
-{
-       return *(c - (cell)data->cards + (cell)data->allot_markers);
-}
-
-inline cell card_offset(card *c)
-{
-       return vm->card_offset(c);
-}
-
-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 card_deck *factorvm::addr_to_deck(cell a)
-{
-       return (card_deck *)(((cell)a >> deck_bits) + decks_offset);
-}
-
-inline card_deck *addr_to_deck(cell a)
-{
-       return vm->addr_to_deck(a);
-}
+static const cell card_size = 1 << card_bits;
+static const cell addr_card_mask = card_size - 1;
 
-inline cell factorvm::deck_to_addr(card_deck *c)
-{
-       return ((cell)c - decks_offset) << deck_bits;
-}
-
-inline cell deck_to_addr(card_deck *c)
-{
-       return vm->deck_to_addr(c);
-}
-
-inline card *factorvm::deck_to_card(card_deck *d)
-{
-       return (card *)((((cell)d - decks_offset) << (deck_bits - card_bits)) + cards_offset);
-}
+typedef uint8_t card_deck;
 
-inline card *deck_to_card(card_deck *d)
-{
-       return vm->deck_to_card(d);
-}
-
-static const cell invalid_allot_marker = 0xff;
-
-extern cell allot_markers_offset;
-
-inline card *factorvm::addr_to_allot_marker(object *a)
-{
-       return (card *)(((cell)a >> card_bits) + allot_markers_offset);
-}
+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;
 
-inline card *addr_to_allot_marker(object *a)
-{
-       return vm->addr_to_allot_marker(a);
-}
-
-/* the write barrier must be called any time we are potentially storing a
-pointer from an older generation to a younger one */
-inline void factorvm::write_barrier(object *obj)
-{
-       *addr_to_card((cell)obj) = card_mark_mask;
-       *addr_to_deck((cell)obj) = card_mark_mask;
-}
-
-inline void write_barrier(object *obj)
-{
-       return vm->write_barrier(obj);
-}
-
-/* we need to remember the first object allocated in the card */
-inline void factorvm::allot_barrier(object *address)
-{
-       card *ptr = addr_to_allot_marker(address);
-       if(*ptr == invalid_allot_marker)
-               *ptr = ((cell)address & addr_card_mask);
-}
-
-inline void allot_barrier(object *address)
-{
-       return vm->allot_barrier(address);
-}
+inline cell addr_to_card(cell a) { return a >> card_bits; }
 
+inline cell addr_to_deck(cell a) { return a >> deck_bits; }
 }