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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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#ifndef SHARE_VM_GC_G1_G1BARRIERSET_HPP
#define SHARE_VM_GC_G1_G1BARRIERSET_HPP

#include "gc/shared/cardTableModRefBS.hpp"

class CardTable;
class DirtyCardQueueSet;
class G1CardTable;
class SATBMarkQueueSet;

// This barrier is specialized to use a logging barrier to support
// snapshot-at-the-beginning marking.

class G1BarrierSet: public CardTableModRefBS {
  friend class VMStructs;
private:
  void write_ref_nmethod_pre(nmethod* nm, ptrdiff_t offset);
  void write_ref_nmethod_post(nmethod* nm, oop new_value);
  static bool is_referent_field(oop base, ptrdiff_t offset);

public:
  G1BarrierSet(CardTable* table);
  ~G1BarrierSet() { }

  static SATBMarkQueueSet& satb_mark_queue_set();
  static DirtyCardQueueSet& dirty_card_queue_set();

  // Add "pre_val" to a set of objects that may have been disconnected from the
  // pre-marking object graph.
  static void satb_enqueue(oop pre_val);
  static void card_enqueue(volatile jbyte* card);

  template <DecoratorSet decorators>
  void write_ref_field_pre(void* field);

  template <DecoratorSet decorators>
  void write_ref_field_post(void* field, oop new_val);

  void klass_update_barrier_set_pre(Klass* klass, oop* p);

  template <class T> void write_ref_array_pre_work(T* dst, int count);
  virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
  virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);

  // NB: if you do a whole-heap invalidation, the "usual invariant" defined
  // above no longer applies.
  void invalidate(MemRegion mr);

  virtual void write_region(MemRegion mr) { invalidate(mr); }

  virtual void write_ref_array_region(MemRegion mr) { invalidate(mr); }

  // This method initializes the SATB and dirty card queues before a
  // JavaThread is added to the Java thread list. Right now, we don't
  // have to do anything to the dirty card queue (it should have been
  // activated when the thread was created), but we have to activate
  // the SATB queue if the thread is created while a marking cycle is
  // in progress. The activation / de-activation of the SATB queues at
  // the beginning / end of a marking cycle is done during safepoints
  // so we have to make sure this method is called outside one to be
  // able to safely read the active field of the SATB queue set. Right
  // now, it is called just before the thread is added to the Java
  // thread list in the Threads::add() method. That method is holding
  // the Threads_lock which ensures we are outside a safepoint. We
  // cannot do the obvious and set the active field of the SATB queue
  // when the thread is created given that, in some cases, safepoints
  // might happen between the JavaThread constructor being called and the
  // thread being added to the Java thread list (an example of this is
  // when the structure for the DestroyJavaVM thread is created).
  virtual void on_add_thread(JavaThread* thread);

  virtual void on_destroy_thread(JavaThread* thread);

  virtual BarrierSetCodeGen *make_code_gen();
  virtual C1BarrierSetCodeGen* make_c1_code_gen();
  virtual C2BarrierSetCodeGen* make_c2_code_gen();

  // Runtime calls for generated code
  static void g1_wb_pre(oopDesc* orig, JavaThread *thread);
  static void g1_wb_post(void* card_addr, JavaThread* thread);

  // Callbacks for runtime accesses.
  template <DecoratorSet decorators>
  class AccessBarrier: public ModRefBarrierSet::AccessBarrier<decorators, G1BarrierSet> {
    typedef ModRefBarrierSet::AccessBarrier<decorators, G1BarrierSet> ModRef;
    typedef BarrierSet::AccessBarrier<decorators> Basic;

  public:
    typedef ModRef SuperAccessBarrier;

    // Needed for loads on weak references
    static oop oop_load(void* addr);

    // Needed for anonymous weak references
    static oop oop_load_at(oop base, ptrdiff_t offset);

    // Needed for stores in nmethods
    static void oop_store_at(nmethod* base, ptrdiff_t offset, oop new_value);
  };
};

template<>
struct BSTypeToName<G1BarrierSet> {
  static const BarrierSet::Name value = BarrierSet::G1BarrierSet;
};

template<>
struct BSNameToType<BarrierSet::G1BarrierSet> {
  typedef G1BarrierSet type;
};

#endif // SHARE_VM_GC_G1_G1BARRIERSET_HPP