/*

 * Copyright (c) 2013, 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/shenandoahMemoryPool.hpp"

ShenandoahMemoryPool::ShenandoahMemoryPool(ShenandoahHeap* heap) :

        CollectedMemoryPool("Shenandoah",

                            heap->initial_capacity(),

                            heap->max_capacity(),

                            true /* support_usage_threshold */),

                            _heap(heap) {}

MemoryUsage ShenandoahMemoryPool::get_memory_usage() {

  size_t initial   = initial_size();

  size_t max       = max_size();

  size_t used      = used_in_bytes();

  size_t committed = _heap->committed();

  // These asserts can never fail: max is stable, and all updates to other values never overflow max.

  assert(initial <= max,    "initial: "   SIZE_FORMAT ", max: "       SIZE_FORMAT, initial,   max);

  assert(used <= max,       "used: "      SIZE_FORMAT ", max: "       SIZE_FORMAT, used,      max);

  assert(committed <= max,  "committed: " SIZE_FORMAT ", max: "       SIZE_FORMAT, committed, max);

  // Committed and used are updated concurrently and independently. They can momentarily break

  // the assert below, which would also fail in downstream code. To avoid that, adjust values

  // to make sense under the race. See JDK-8207200.

  committed = MAX2(used, committed);

  assert(used <= committed, "used: "      SIZE_FORMAT ", committed: " SIZE_FORMAT, used,      committed);

  return MemoryUsage(initial, used, committed, max);

}