/*

 * Copyright 2005-2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

//

// psPromotionManager is used by a single thread to manage object survival

// during a scavenge. The promotion manager contains thread local data only.

//

// NOTE! Be carefull when allocating the stacks on cheap. If you are going

// to use a promotion manager in more than one thread, the stacks MUST be

// on cheap. This can lead to memory leaks, though, as they are not auto

// deallocated.

//

// FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate!

//

// Move to some global location

#define HAS_BEEN_MOVED 0x1501d01d

// End move to some global location

class MutableSpace;

class PSOldGen;

class ParCompactionManager;

class ObjectStartArray;

class ParallelCompactData;

class ParMarkBitMap;

// Move to it's own file if this works out.

class ParCompactionManager : public CHeapObj {

  friend class ParallelTaskTerminator;

  friend class ParMarkBitMap;

  friend class PSParallelCompact;

  friend class StealChunkCompactionTask;

  friend class UpdateAndFillClosure;

  friend class RefProcTaskExecutor;

 public:

// ------------------------  Don't putback if not needed

  // Actions that the compaction manager should take.

  enum Action {

    Update,

    Copy,

    UpdateAndCopy,

    CopyAndUpdate,

    VerifyUpdate,

    ResetObjects,

    NotValid

  };

// ------------------------  End don't putback if not needed

 private:

  static ParCompactionManager**  _manager_array;

  static OopTaskQueueSet*      _stack_array;

  static ObjectStartArray*     _start_array;

  static ChunkTaskQueueSet*    _chunk_array;

  static PSOldGen*             _old_gen;

  OopTaskQueue                 _marking_stack;

  GrowableArray<oop>*          _overflow_stack;

  // Is there a way to reuse the _marking_stack for the

  // saving empty chunks?  For now just create a different

  // type of TaskQueue.

#ifdef USE_ChunkTaskQueueWithOverflow

  ChunkTaskQueueWithOverflow   _chunk_stack;

#else

  ChunkTaskQueue               _chunk_stack;

  GrowableArray<size_t>*       _chunk_overflow_stack;

#endif

#if 1  // does this happen enough to need a per thread stack?

  GrowableArray<Klass*>*       _revisit_klass_stack;

#endif

  static ParMarkBitMap* _mark_bitmap;

  Action _action;

  static PSOldGen* old_gen()             { return _old_gen; }

  static ObjectStartArray* start_array() { return _start_array; }

  static OopTaskQueueSet* stack_array()   { return _stack_array; }

  static void initialize(ParMarkBitMap* mbm);

 protected:

  // Array of tasks.  Needed by the ParallelTaskTerminator.

  static ChunkTaskQueueSet* chunk_array()   { return _chunk_array; }

  OopTaskQueue*  marking_stack()          { return &_marking_stack; }

  GrowableArray<oop>* overflow_stack()    { return _overflow_stack; }

#ifdef USE_ChunkTaskQueueWithOverflow

  ChunkTaskQueueWithOverflow* chunk_stack() { return &_chunk_stack; }

#else

  ChunkTaskQueue*  chunk_stack()          { return &_chunk_stack; }

  GrowableArray<size_t>* chunk_overflow_stack() { return _chunk_overflow_stack; }

#endif

  // Pushes onto the marking stack.  If the marking stack is full,

  // pushes onto the overflow stack.

  void stack_push(oop obj);

  // Do not implement an equivalent stack_pop.  Deal with the

  // marking stack and overflow stack directly.

  // Pushes onto the chunk stack.  If the chunk stack is full,

  // pushes onto the chunk overflow stack.

  void chunk_stack_push(size_t chunk_index);

 public:

  Action action() { return _action; }

  void set_action(Action v) { _action = v; }

  inline static ParCompactionManager* manager_array(int index);

  ParCompactionManager();

  ~ParCompactionManager();

  void allocate_stacks();

  void deallocate_stacks();

  ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }

  // Take actions in preparation for a compaction.

  static void reset();

  // void drain_stacks();

  bool should_update();

  bool should_copy();

  bool should_verify_only();

  bool should_reset_only();

#if 1

  // Probably stays as a growable array

  GrowableArray<Klass*>* revisit_klass_stack() { return _revisit_klass_stack; }

#endif

  // Save oop for later processing.  Must not fail.

  void save_for_scanning(oop m);

  // Get a oop for scanning.  If returns null, no oop were found.

  oop retrieve_for_scanning();

  // Save chunk for later processing.  Must not fail.

  void save_for_processing(size_t chunk_index);

  // Get a chunk for processing.  If returns null, no chunk were found.

  bool retrieve_for_processing(size_t& chunk_index);

  // Access function for compaction managers

  static ParCompactionManager* gc_thread_compaction_manager(int index);

  static bool steal(int queue_num, int* seed, Task& t) {

    return stack_array()->steal(queue_num, seed, t);

  }

  static bool steal(int queue_num, int* seed, ChunkTask& t) {

    return chunk_array()->steal(queue_num, seed, t);

  }

  // Process tasks remaining on any stack

  void drain_marking_stacks(OopClosure *blk);

  // Process tasks remaining on any stack

  void drain_chunk_stacks();

  // Process tasks remaining on any stack

  void drain_chunk_overflow_stack();

  // Debugging support

#ifdef ASSERT

  bool stacks_have_been_allocated();

#endif

};

inline ParCompactionManager* ParCompactionManager::manager_array(int index) {

  assert(_manager_array != NULL, "access of NULL manager_array");

  assert(index >= 0 && index <= (int)ParallelGCThreads,

    "out of range manager_array access");

  return _manager_array[index];

}