/*

 * Copyright (c) 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 "precompiled.hpp"

#include "gc/shenandoah/shenandoahHeap.inline.hpp"

#include "gc/shenandoah/shenandoahSATBMarkQueueSet.hpp"

#include "gc/shenandoah/shenandoahThreadLocalData.hpp"

ShenandoahSATBMarkQueueSet::ShenandoahSATBMarkQueueSet() :

  _heap(NULL),

  _satb_mark_queue_buffer_allocator(ShenandoahSATBBufferSize, SATB_Q_FL_lock)

{}

void ShenandoahSATBMarkQueueSet::initialize(ShenandoahHeap* const heap,

                                            Monitor* cbl_mon,

                                            int process_completed_threshold,

                                            uint buffer_enqueue_threshold_percentage,

                                            Mutex* lock) {

  SATBMarkQueueSet::initialize(cbl_mon,

                               &_satb_mark_queue_buffer_allocator,

                               process_completed_threshold,

                               buffer_enqueue_threshold_percentage,

                               lock);

  _heap = heap;

}

SATBMarkQueue& ShenandoahSATBMarkQueueSet::satb_queue_for_thread(JavaThread* const t) const {

  return ShenandoahThreadLocalData::satb_mark_queue(t);

}

static inline bool discard_entry(const void* entry, ShenandoahHeap* heap) {

  return !heap->requires_marking(entry);

}

class ShenandoahSATBMarkQueueFilterFn {

  ShenandoahHeap* _heap;

public:

  ShenandoahSATBMarkQueueFilterFn(ShenandoahHeap* heap) : _heap(heap) {}

  // Return true if entry should be filtered out (removed), false if

  // it should be retained.

  bool operator()(const void* entry) const {

    return discard_entry(entry, _heap);

  }

};

void ShenandoahSATBMarkQueueSet::filter(SATBMarkQueue* queue) {

  assert(_heap != NULL, "SATB queue set not initialized");

  apply_filter(ShenandoahSATBMarkQueueFilterFn(_heap), queue);

}

bool ShenandoahSATBMarkQueue::should_enqueue_buffer() {

  bool should_enqueue = SATBMarkQueue::should_enqueue_buffer();

  size_t cap = capacity();

  Thread* t = Thread::current();

  if (ShenandoahThreadLocalData::is_force_satb_flush(t)) {

    if (!should_enqueue && cap != index()) {

      // Non-empty buffer is compacted, and we decided not to enqueue it.

      // We still want to know about leftover work in that buffer eventually.

      // This avoid dealing with these leftovers during the final-mark, after

      // the buffers are drained completely. See JDK-8205353 for more discussion.

      should_enqueue = true;

    }

    ShenandoahThreadLocalData::set_force_satb_flush(t, false);

  }

  return should_enqueue;

}