/*

 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. 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.

 *

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 */

#ifndef SHARE_VM_GC_G1_CONCURRENTG1REFINE_HPP

#define SHARE_VM_GC_G1_CONCURRENTG1REFINE_HPP

#include "gc/g1/g1HotCardCache.hpp"

#include "memory/allocation.hpp"

#include "runtime/thread.hpp"

#include "utilities/globalDefinitions.hpp"

// Forward decl

class ConcurrentG1RefineThread;

class G1CollectedHeap;

class G1HotCardCache;

class G1RegionToSpaceMapper;

class G1RemSet;

class DirtyCardQueue;

class ConcurrentG1Refine: public CHeapObj<mtGC> {

  ConcurrentG1RefineThread** _threads;

  uint _n_worker_threads;

 /*

  * The value of the update buffer queue length falls into one of 3 zones:

  * green, yellow, red. If the value is in [0, green) nothing is

  * done, the buffers are left unprocessed to enable the caching effect of the

  * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement

  * threads are gradually activated. In [yellow, red) all threads are

  * running. If the length becomes red (max queue length) the mutators start

  * processing the buffers.

  *

  * There are some interesting cases (when G1UseAdaptiveConcRefinement

  * is turned off):

  * 1) green = yellow = red = 0. In this case the mutator will process all

  *    buffers. Except for those that are created by the deferred updates

  *    machinery during a collection.

  * 2) green = 0. Means no caching. Can be a good way to minimize the

  *    amount of time spent updating rsets during a collection.

  */

  int _green_zone;

  int _yellow_zone;

  int _red_zone;

  int _thread_threshold_step;

  // We delay the refinement of 'hot' cards using the hot card cache.

  G1HotCardCache _hot_card_cache;

  // Reset the threshold step value based of the current zone boundaries.

  void reset_threshold_step();

  ConcurrentG1Refine(G1CollectedHeap* g1h);

 public:

  ~ConcurrentG1Refine();

  // Returns ConcurrentG1Refine instance if succeeded to create/initialize ConcurrentG1Refine and ConcurrentG1RefineThread.

  // Otherwise, returns NULL with error code.

  static ConcurrentG1Refine* create(G1CollectedHeap* g1h, CardTableEntryClosure* refine_closure, jint* ecode);

  void init(G1RegionToSpaceMapper* card_counts_storage);

  void stop();

  void reinitialize_threads();

  // Iterate over all concurrent refinement threads

  void threads_do(ThreadClosure *tc);

  // Iterate over all worker refinement threads

  void worker_threads_do(ThreadClosure * tc);

  static uint thread_num();

  void print_worker_threads_on(outputStream* st) const;

  void set_green_zone(int x)  { _green_zone = x;  }

  void set_yellow_zone(int x) { _yellow_zone = x; }

  void set_red_zone(int x)    { _red_zone = x;    }

  int green_zone() const      { return _green_zone;  }

  int yellow_zone() const     { return _yellow_zone; }

  int red_zone() const        { return _red_zone;    }

  uint worker_thread_num() const { return _n_worker_threads; }

  int thread_threshold_step() const { return _thread_threshold_step; }

  G1HotCardCache* hot_card_cache() { return &_hot_card_cache; }

  static bool hot_card_cache_enabled() { return G1HotCardCache::default_use_cache(); }

};

#endif // SHARE_VM_GC_G1_CONCURRENTG1REFINE_HPP