1.1 --- a/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp Mon Oct 23 06:39:54 2017 -0700
1.2 +++ b/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp Mon Feb 24 12:49:21 2014 +0100
1.3 @@ -514,7 +514,15 @@
1.4
1.5 PerRegionTable* first_prt = _fine_grain_regions[ind];
1.6 prt->set_collision_list_next(first_prt);
1.7 - _fine_grain_regions[ind] = prt;
1.8 + // The assignment into _fine_grain_regions allows the prt to
1.9 + // start being used concurrently. In addition to
1.10 + // collision_list_next which must be visible (else concurrent
1.11 + // parsing of the list, if any, may fail to see other entries),
1.12 + // the content of the prt must be visible (else for instance
1.13 + // some mark bits may not yet seem cleared or a 'later' update
1.14 + // performed by a concurrent thread could be undone when the
1.15 + // zeroing becomes visible). This requires store ordering.
1.16 + OrderAccess::release_store_ptr((volatile PerRegionTable*)&_fine_grain_regions[ind], prt);
1.17 _n_fine_entries++;
1.18
1.19 if (G1HRRSUseSparseTable) {
