--- a/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Fri Sep 27 13:41:07 2013 +0200
+++ b/hotspot/src/share/vm/memory/cardTableModRefBS.cpp Tue Sep 24 14:46:29 2013 +0200
@@ -423,60 +423,6 @@
inline_write_ref_field(field, newVal);
}
-/*
- Claimed and deferred bits are used together in G1 during the evacuation
- pause. These bits can have the following state transitions:
- 1. The claimed bit can be put over any other card state. Except that
- the "dirty -> dirty and claimed" transition is checked for in
- G1 code and is not used.
- 2. Deferred bit can be set only if the previous state of the card
- was either clean or claimed. mark_card_deferred() is wait-free.
- We do not care if the operation is be successful because if
- it does not it will only result in duplicate entry in the update
- buffer because of the "cache-miss". So it's not worth spinning.
- */
-
-
-bool CardTableModRefBS::claim_card(size_t card_index) {
- jbyte val = _byte_map[card_index];
- assert(val != dirty_card_val(), "Shouldn't claim a dirty card");
- while (val == clean_card_val() ||
- (val & (clean_card_mask_val() | claimed_card_val())) != claimed_card_val()) {
- jbyte new_val = val;
- if (val == clean_card_val()) {
- new_val = (jbyte)claimed_card_val();
- } else {
- new_val = val | (jbyte)claimed_card_val();
- }
- jbyte res = Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
- if (res == val) {
- return true;
- }
- val = res;
- }
- return false;
-}
-
-bool CardTableModRefBS::mark_card_deferred(size_t card_index) {
- jbyte val = _byte_map[card_index];
- // It's already processed
- if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
- return false;
- }
- // Cached bit can be installed either on a clean card or on a claimed card.
- jbyte new_val = val;
- if (val == clean_card_val()) {
- new_val = (jbyte)deferred_card_val();
- } else {
- if (val & claimed_card_val()) {
- new_val = val | (jbyte)deferred_card_val();
- }
- }
- if (new_val != val) {
- Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
- }
- return true;
-}
void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space* sp,
MemRegion mr,