view src/share/vm/gc/shared/modRefBarrierSet.hpp @ 12338:a3ee61047501

8166898: G1SATBCardTableLoggingModRefBS::invalidate() incorrect with whole_heap == true Reviewed-by: tschatzl, kbarrett
author lmesnik
date Thu, 24 Nov 2016 16:48:22 +0300
parents d487a586ed9c
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 * published by the Free Software Foundation.
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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#include "gc/shared/barrierSet.hpp"

// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
// enumerate ref fields that have been modified (since the last
// enumeration), using a card table.

class OopClosure;
class Generation;

class ModRefBarrierSet: public BarrierSet {

  // Barriers only on ref writes.
  bool has_read_ref_barrier() { return false; }
  bool has_read_prim_barrier() { return false; }
  bool has_write_ref_barrier() { return true; }
  bool has_write_prim_barrier() { return false; }

  bool read_ref_needs_barrier(void* field) { return false; }
  bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
  bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
                                juint val1, juint val2) { return false; }

  void write_prim_field(oop obj, size_t offset, size_t bytes,
                        juint val1, juint val2) {}

  void read_ref_field(void* field) {}
  void read_prim_field(HeapWord* field, size_t bytes) {}


  ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)
    : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }
  ~ModRefBarrierSet() { }

  void write_prim_field(HeapWord* field, size_t bytes,
                        juint val1, juint val2) {}

  bool has_read_ref_array_opt() { return false; }
  bool has_read_prim_array_opt() { return false; }
  bool has_write_prim_array_opt() { return false; }

  bool has_read_region_opt() { return false; }

  // These operations should assert false unless the corresponding operation
  // above returns true.
  void read_ref_array(MemRegion mr) {
    assert(false, "can't call");
  void read_prim_array(MemRegion mr) {
    assert(false, "can't call");
  void write_prim_array(MemRegion mr) {
    assert(false, "can't call");
  void read_region(MemRegion mr) {
    assert(false, "can't call");

  // Causes all refs in "mr" to be assumed to be modified.
  virtual void invalidate(MemRegion mr) = 0;

  // The caller guarantees that "mr" contains no references.  (Perhaps it's
  // objects have been moved elsewhere.)
  virtual void clear(MemRegion mr) = 0;

struct BarrierSet::GetName<ModRefBarrierSet> {
  static const BarrierSet::Name value = BarrierSet::ModRef;