/*

 * Copyright (c) 2016, 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 "memory/allocation.hpp"

/**

 * This provides the following in JVMStat:

 *

 * constants:

 * - sun.gc.shenandoah.regions.timestamp    the timestamp for this sample

 * - sun.gc.shenandoah.regions.max_regions  maximum number of regions

 * - sun.gc.shenandoah.regions.region_size  size per region, in kilobytes

 *

 * variables:

 * - sun.gc.shenandoah.regions.status       current GC status:

 *     - bit 0 set when marking in progress

 *     - bit 1 set when evacuation in progress

 *     - bit 2 set when update refs in progress

 *     - bit 3 set when traversal in progress

 *

 * two variable counters per region, with $max_regions (see above) counters:

 * - sun.gc.shenandoah.regions.region.$i.data

 * where $ is the region number from 0 <= i < $max_regions

 *

 * .data is in the following format:

 * - bits 0-6    used memory in percent

 * - bits 7-13   live memory in percent

 * - bits 14-20  tlab allocated memory in percent

 * - bits 21-27  gclab allocated memory in percent

 * - bits 28-34  shared allocated memory in percent

 * - bits 35-41  <reserved>

 * - bits 42-50  <reserved>

 * - bits 51-57  <reserved>

 * - bits 58-63  status

 *      - bits describe the state as recorded in ShenandoahHeapRegion

 */

class ShenandoahHeapRegionCounters : public CHeapObj<mtGC>  {

private:

  static const jlong PERCENT_MASK = 0x7f;

  static const jlong STATUS_MASK  = 0x3f;

  static const jlong USED_SHIFT   = 0;

  static const jlong LIVE_SHIFT   = 7;

  static const jlong TLAB_SHIFT   = 14;

  static const jlong GCLAB_SHIFT  = 21;

  static const jlong SHARED_SHIFT = 28;

  static const jlong STATUS_SHIFT = 58;

  char* _name_space;

  PerfLongVariable** _regions_data;

  PerfLongVariable* _timestamp;

  PerfLongVariable* _status;

  volatile jlong _last_sample_millis;

public:

  ShenandoahHeapRegionCounters();

  ~ShenandoahHeapRegionCounters();

  void update();

};