8306833: Change CardTable::_covered to static array

Reviewed-by: tschatzl, kbarrett

Author: albertnetymk

src/hotspot/share/gc/shared/cardTable.cpp

@@ -74,17 +74,12 @@ CardTable::CardTable(MemRegion whole_heap) :
   _byte_map_size(0),
   _byte_map(nullptr),
   _byte_map_base(nullptr),
-  _covered(MemRegion::create_array(max_covered_regions, mtGC)),
   _guard_region()
 {
   assert((uintptr_t(_whole_heap.start())  & (_card_size - 1))  == 0, "heap must start at card boundary");
   assert((uintptr_t(_whole_heap.end()) & (_card_size - 1))  == 0, "heap must end at card boundary");
 }
 
-CardTable::~CardTable() {
-  MemRegion::destroy_array(_covered, max_covered_regions);
-}
-
 void CardTable::initialize(void* region0_start, void* region1_start) {
   size_t num_cards = cards_required(_whole_heap.word_size());
 

src/hotspot/share/gc/shared/cardTable.hpp

@@ -57,7 +57,7 @@ class CardTable: public CHeapObj<mtGC> {
   static constexpr int max_covered_regions = 2;
 
   // The covered regions should be in address order.
-  MemRegion* _covered;
+  MemRegion _covered[max_covered_regions];
 
   // The last card is a guard card; never committed.
   MemRegion _guard_region;
@@ -82,13 +82,15 @@ class CardTable: public CHeapObj<mtGC> {
   size_t last_valid_index() const {
     return cards_required(_whole_heap.word_size()) - 1;
   }
+
 private:
   void initialize_covered_region(void* region0_start, void* region1_start);
 
   MemRegion committed_for(const MemRegion mr) const;
 public:
   CardTable(MemRegion whole_heap);
-  virtual ~CardTable();
+  virtual ~CardTable() = default;
+
   void initialize(void* region0_start, void* region1_start);
 
   // *** Barrier set functions.

src/hotspot/share/gc/shared/cardTableBarrierSet.hpp

@@ -60,9 +60,9 @@ class CardTableBarrierSet: public ModRefBarrierSet {
                       CardTable* card_table,
                       const BarrierSet::FakeRtti& fake_rtti);
 
- public:
+public:
   CardTableBarrierSet(CardTable* card_table);
-  ~CardTableBarrierSet();
+  virtual ~CardTableBarrierSet();
 
   CardTable* card_table() const { return _card_table; }
 

src/hotspot/share/gc/shared/vmStructs_gc.hpp

@@ -89,10 +89,9 @@
   nonstatic_field(CardTable,                   _whole_heap,                                   const MemRegion)                       \
   nonstatic_field(CardTable,                   _page_size,                                    const size_t)                          \
   nonstatic_field(CardTable,                   _byte_map_size,                                const size_t)                          \
-  nonstatic_field(CardTable,                   _byte_map,                                     CardTable::CardValue*)                                \
-  nonstatic_field(CardTable,                   _covered,                                      MemRegion*)                            \
+  nonstatic_field(CardTable,                   _byte_map,                                     CardTable::CardValue*)                 \
   nonstatic_field(CardTable,                   _guard_region,                                 MemRegion)                             \
-  nonstatic_field(CardTable,                   _byte_map_base,                                CardTable::CardValue*)                                \
+  nonstatic_field(CardTable,                   _byte_map_base,                                CardTable::CardValue*)                 \
   nonstatic_field(CardTableBarrierSet,         _defer_initial_card_mark,                      bool)                                  \
   nonstatic_field(CardTableBarrierSet,         _card_table,                                   CardTable*)                            \
                                                                                                                                      \