/*

 * Copyright (c) 2018, 2019, 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(BufferNode::Allocator* allocator) :

  SATBMarkQueueSet(allocator)

{}

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

  return ShenandoahThreadLocalData::satb_mark_queue(t);

}

template <bool RESOLVE>

class ShenandoahSATBMarkQueueFilterFn {

  ShenandoahHeap* const _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 !_heap->requires_marking<RESOLVE>(entry);

  }

};

void ShenandoahSATBMarkQueueSet::filter(SATBMarkQueue* queue) {

  ShenandoahHeap* heap = ShenandoahHeap::heap();

  if (heap->has_forwarded_objects()) {

    apply_filter(ShenandoahSATBMarkQueueFilterFn<true>(heap), queue);

  } else {

    apply_filter(ShenandoahSATBMarkQueueFilterFn<false>(heap), queue);

  }

}

void ShenandoahSATBMarkQueue::handle_completed_buffer() {

  SATBMarkQueue::handle_completed_buffer();

  if (!is_empty()) {

    Thread* t = Thread::current();

    if (ShenandoahThreadLocalData::is_force_satb_flush(t)) {

      // 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.

      ShenandoahThreadLocalData::set_force_satb_flush(t, false);

      enqueue_completed_buffer();

    }

  }

}