/*

 * Copyright (c) 2019, 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.

 *

 * 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/g1/g1DirtyCardQueue.hpp"

#include "gc/g1/g1SharedDirtyCardQueue.hpp"

#include "gc/shared/ptrQueue.hpp"

#include "runtime/mutex.hpp"

#include "runtime/mutexLocker.hpp"

G1SharedDirtyCardQueue::G1SharedDirtyCardQueue(G1DirtyCardQueueSet* qset) :

  _qset(qset),

  _buffer(NULL),

  _index(0)

{}

G1SharedDirtyCardQueue::~G1SharedDirtyCardQueue() {

  flush();

}

void G1SharedDirtyCardQueue::enqueue(void* card_ptr) {

  MutexLocker ml(Shared_DirtyCardQ_lock, Mutex::_no_safepoint_check_flag);

  if (_index == 0) {

    flush();

    _buffer = _qset->allocate_buffer();

    _index = _qset->buffer_size();

    assert(_index != 0, "invariant");

  }

  _buffer[--_index] = card_ptr;

}

void G1SharedDirtyCardQueue::flush() {

  if (_buffer != NULL) {

    BufferNode* node = BufferNode::make_node_from_buffer(_buffer, _index);

    _buffer = NULL;

    _index = 0;

    if (node->index() == _qset->buffer_size()) {

      _qset->deallocate_buffer(node);

    } else {

      _qset->enqueue_completed_buffer(node);

    }

  }

  assert(_index == 0, "invariant");

}

void G1SharedDirtyCardQueue::reset() {

  if (_buffer == NULL) {

    _index = 0;

  } else {

    _index = _qset->buffer_size();

  }

}