1.1 --- a/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp Fri Sep 27 13:41:07 2013 +0200
1.2 +++ b/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp Tue Sep 24 14:46:29 2013 +0200
1.3 @@ -89,6 +89,42 @@
1.4 write_ref_array_pre_work(dst, count);
1.5 }
1.6 }
1.7 +
1.8 +/*
1.9 + Claimed and deferred bits are used together in G1 during the evacuation
1.10 + pause. These bits can have the following state transitions:
1.11 + 1. The claimed bit can be put over any other card state. Except that
1.12 + the "dirty -> dirty and claimed" transition is checked for in
1.13 + G1 code and is not used.
1.14 + 2. Deferred bit can be set only if the previous state of the card
1.15 + was either clean or claimed. mark_card_deferred() is wait-free.
1.16 + We do not care if the operation is be successful because if
1.17 + it does not it will only result in duplicate entry in the update
1.18 + buffer because of the "cache-miss". So it's not worth spinning.
1.19 + */
1.20 +
1.21 + bool is_card_claimed(size_t card_index) {
1.22 + jbyte val = _byte_map[card_index];
1.23 + return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
1.24 + }
1.25 +
1.26 + void set_card_claimed(size_t card_index) {
1.27 + jbyte val = _byte_map[card_index];
1.28 + if (val == clean_card_val()) {
1.29 + val = (jbyte)claimed_card_val();
1.30 + } else {
1.31 + val |= (jbyte)claimed_card_val();
1.32 + }
1.33 + _byte_map[card_index] = val;
1.34 + }
1.35 +
1.36 + bool mark_card_deferred(size_t card_index);
1.37 +
1.38 + bool is_card_deferred(size_t card_index) {
1.39 + jbyte val = _byte_map[card_index];
1.40 + return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
1.41 + }
1.42 +
1.43 };
1.44
1.45 // Adds card-table logging to the post-barrier.
