Mercurial > jdk8-mips64-public > hotspot / changeset

     1.1 --- a/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp	Thu Dec 08 15:12:58 2016 +0300
     1.2 +++ b/src/share/vm/gc_implementation/parNew/parCardTableModRefBS.cpp	Fri Dec 02 11:07:27 2016 +0100
     1.3 @@ -452,9 +452,13 @@
     1.4    // event lock and do the read again in case some other thread had already
     1.5    // succeeded and done the resize.
     1.6    int cur_collection = Universe::heap()->total_collections();
     1.7 -  if (_last_LNC_resizing_collection[i] != cur_collection) {
     1.8 +  // Updated _last_LNC_resizing_collection[i] must not be visible before
     1.9 +  // _lowest_non_clean and friends are visible. Therefore use acquire/release
    1.10 +  // to guarantee this on non TSO architecures.
    1.11 +  if (OrderAccess::load_acquire(&_last_LNC_resizing_collection[i]) != cur_collection) {
    1.12      MutexLocker x(ParGCRareEvent_lock);
    1.13 -    if (_last_LNC_resizing_collection[i] != cur_collection) {
    1.14 +    // This load_acquire is here for clarity only. The MutexLocker already fences.
    1.15 +    if (OrderAccess::load_acquire(&_last_LNC_resizing_collection[i]) != cur_collection) {
    1.16        if (_lowest_non_clean[i] == NULL ||
    1.17            n_chunks != _lowest_non_clean_chunk_size[i]) {
    1.18  
    1.19 @@ -474,7 +478,8 @@
    1.20              _lowest_non_clean[i][j] = NULL;
    1.21          }
    1.22        }
    1.23 -      _last_LNC_resizing_collection[i] = cur_collection;
    1.24 +      // Make sure this gets visible only after _lowest_non_clean* was initialized
    1.25 +      OrderAccess::release_store(&_last_LNC_resizing_collection[i], cur_collection);
    1.26      }
    1.27    }
    1.28    // In any case, now do the initialization.

     2.1 --- a/src/share/vm/memory/cardTableModRefBS.hpp	Thu Dec 08 15:12:58 2016 +0300
     2.2 +++ b/src/share/vm/memory/cardTableModRefBS.hpp	Fri Dec 02 11:07:27 2016 +0100
     2.3 @@ -217,7 +217,7 @@
     2.4    CardArr* _lowest_non_clean;
     2.5    size_t*  _lowest_non_clean_chunk_size;
     2.6    uintptr_t* _lowest_non_clean_base_chunk_index;
     2.7 -  int* _last_LNC_resizing_collection;
     2.8 +  volatile int* _last_LNC_resizing_collection;
     2.9  
    2.10    // Initializes "lowest_non_clean" to point to the array for the region
    2.11    // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk