/*

 * Copyright 2002-2007 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;

#define PS_PM_STATS         0

class PSPromotionManager : public CHeapObj {

  friend class PSScavenge;

  friend class PSRefProcTaskExecutor;

 private:

  static PSPromotionManager**         _manager_array;

  static OopStarTaskQueueSet*         _stack_array_depth;

  static OopTaskQueueSet*             _stack_array_breadth;

  static PSOldGen*                    _old_gen;

  static MutableSpace*                _young_space;

#if PS_PM_STATS

  uint                                _total_pushes;

  uint                                _masked_pushes;

  uint                                _overflow_pushes;

  uint                                _max_overflow_length;

  uint                                _arrays_chunked;

  uint                                _array_chunks_processed;

  uint                                _total_steals;

  uint                                _masked_steals;

  void print_stats(uint i);

  static void print_stats();

#endif // PS_PM_STATS

  PSYoungPromotionLAB                 _young_lab;

  PSOldPromotionLAB                   _old_lab;

  bool                                _young_gen_is_full;

  bool                                _old_gen_is_full;

  PrefetchQueue                       _prefetch_queue;

  OopStarTaskQueue                    _claimed_stack_depth;

  OopTaskQueue                        _claimed_stack_breadth;

  GrowableArray<oop>*                 _overflow_stack_breadth;

  bool                                _depth_first;

  bool                                _totally_drain;

  uint                                _target_stack_size;

  uint                                _array_chunk_size;

  uint                                _min_array_size_for_chunking;

  // Accessors

  inline static PSPromotionManager* manager_array(int index);

  // On the task queues we push reference locations as well as

  // partially-scanned arrays (in the latter case, we push an oop to

  // the from-space image of the array and the length on the

  // from-space image indicates how many entries on the array we still

  // need to scan; this is basically how ParNew does partial array

  // scanning too). To be able to distinguish between reference

  // locations and partially-scanned array oops we simply mask the

  // latter oops with 0x01. The next three methods do the masking,

  // unmasking, and checking whether the oop is masked or not. Notice

  // that the signature of the mask and unmask methods looks a bit

  // strange, as they accept and return different types (oop and

  // oop*). This is because of the difference in types between what

  // the task queue holds (oop*) and oops to partially-scanned arrays

  // (oop). We do all the necessary casting in the mask / unmask

  // methods to avoid sprinkling the rest of the code with more casts.

  }

  oop* mask_chunked_array_oop(oop obj) {

    assert(!is_oop_masked((oop*) obj), "invariant");

    assert(is_oop_masked(ret), "invariant");

    return ret;

  }

    assert(is_oop_masked(p), "invariant");

    assert(!is_oop_masked((oop*) ret), "invariant");

    return ret;

  }

  void process_array_chunk(oop old);

    assert(depth_first(), "pre-condition");

#if PS_PM_STATS

    ++_total_pushes;

#endif // PS_PM_STATS

    if (!claimed_stack_depth()->push(p)) {

      overflow_stack_depth()->push(p);

#if PS_PM_STATS

      ++_overflow_pushes;

      uint stack_length = (uint) overflow_stack_depth()->length();

      if (stack_length > _max_overflow_length) {

        _max_overflow_length = stack_length;

      }

#endif // PS_PM_STATS

    }

  }

  void push_breadth(oop o) {

    assert(!depth_first(), "pre-condition");

#if PS_PM_STATS

    ++_total_pushes;

#endif // PS_PM_STATS

    if(!claimed_stack_breadth()->push(o)) {

      overflow_stack_breadth()->push(o);

#if PS_PM_STATS

      ++_overflow_pushes;

      uint stack_length = (uint) overflow_stack_breadth()->length();

      if (stack_length > _max_overflow_length) {

        _max_overflow_length = stack_length;

      }

#endif // PS_PM_STATS

    }

  }

 protected:

  static OopTaskQueueSet*     stack_array_breadth() { return _stack_array_breadth; }

 public:

  // Static

  static void initialize();

  static void pre_scavenge();

  static void post_scavenge();

  static PSPromotionManager* gc_thread_promotion_manager(int index);

  static PSPromotionManager* vm_thread_promotion_manager();

  static bool steal_depth(int queue_num, int* seed, StarTask& t) {

    assert(stack_array_depth() != NULL, "invariant");

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

  }

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

    assert(stack_array_breadth() != NULL, "invariant");

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

  }

  PSPromotionManager();

  // Accessors

  OopStarTaskQueue* claimed_stack_depth() {

    return &_claimed_stack_depth;

  }

  OopTaskQueue* claimed_stack_breadth() {

    return &_claimed_stack_breadth;

  }

  bool young_gen_is_full()             { return _young_gen_is_full; }

  bool old_gen_is_full()               { return _old_gen_is_full; }

  void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }

  // Promotion methods

  oop copy_to_survivor_space(oop o, bool depth_first);

  oop oop_promotion_failed(oop obj, markOop obj_mark);

  void reset();

  void flush_labs();

  void drain_stacks(bool totally_drain) {

    if (depth_first()) {

      drain_stacks_depth(totally_drain);

    } else {

      drain_stacks_breadth(totally_drain);

    }

  }

  void drain_stacks_cond_depth() {

    if (claimed_stack_depth()->size() > _target_stack_size) {

      drain_stacks_depth(false);

    }

  }

  void drain_stacks_depth(bool totally_drain);

  void drain_stacks_breadth(bool totally_drain);

  bool claimed_stack_empty() {

    if (depth_first()) {

      return claimed_stack_depth()->size() <= 0;

    } else {

      return claimed_stack_breadth()->size() <= 0;

    }

  }

  bool overflow_stack_empty() {

    if (depth_first()) {

      return overflow_stack_depth()->length() <= 0;

    } else {

      return overflow_stack_breadth()->length() <= 0;

    }

  }

  bool stacks_empty() {

    return claimed_stack_empty() && overflow_stack_empty();

  }

  bool depth_first() {

    return _depth_first;

  }

  inline void flush_prefetch_queue();

#if PS_PM_STATS

  void increment_steals(oop* p = NULL) {

    _total_steals += 1;

    if (p != NULL && is_oop_masked(p)) {

      _masked_steals += 1;

    }

  }

#endif // PS_PM_STATS

};