/*

 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "gc/shared/workgroup.hpp"

#include "gc/shenandoah/shenandoahTaskqueue.hpp"

#include "memory/allocation.hpp"

class ShenandoahObjToScanQueueSet;

class ShenandoahWorkerScope : public StackObj {

private:

  uint      _n_workers;

  WorkGang* _workers;

public:

  ShenandoahWorkerScope(WorkGang* workers, uint nworkers, const char* msg, bool do_check = true);

  ~ShenandoahWorkerScope();

};

class ShenandoahPushWorkerScope : StackObj {

protected:

  uint      _n_workers;

  uint      _old_workers;

  WorkGang* _workers;

public:

  ShenandoahPushWorkerScope(WorkGang* workers, uint nworkers, bool do_check = true);

  ~ShenandoahPushWorkerScope();

};

class ShenandoahPushWorkerQueuesScope : public ShenandoahPushWorkerScope {

private:

  ShenandoahObjToScanQueueSet* _queues;

public:

  ShenandoahPushWorkerQueuesScope(WorkGang* workers, ShenandoahObjToScanQueueSet* queues, uint nworkers, bool do_check = true);

  ~ShenandoahPushWorkerQueuesScope();

};

class ShenandoahWorkGang : public WorkGang {

private:

  bool     _initialize_gclab;

public:

  ShenandoahWorkGang(const char* name,

           uint workers,

           bool are_GC_task_threads,

           bool are_ConcurrentGC_threads) :

    WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads), _initialize_gclab(false) {

    }

  // Create a GC worker and install it into the work gang.

  // We need to initialize gclab for dynamic allocated workers

  AbstractGangWorker* install_worker(uint which);

  // We allow _active_workers < _total_workers when UseDynamicNumberOfGCThreads is off.

  // We use the same WorkGang for concurrent and parallel processing, and honor

  // ConcGCThreads and ParallelGCThreads settings

  virtual uint active_workers() const {

    assert(_active_workers > 0, "no active worker");

    assert(_active_workers <= _total_workers,

           "_active_workers: %u > _total_workers: %u", _active_workers, _total_workers);

    return _active_workers;

  }

  void set_initialize_gclab() { assert(!_initialize_gclab, "Can only enable once"); _initialize_gclab = true; }

};