1 /*
  2  * Copyright (c) 2016, 2019, Red Hat, Inc. All rights reserved.
  3  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
  4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  5  *
  6  * This code is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
  9  *
 10  * This code is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 13  * version 2 for more details (a copy is included in the LICENSE file that
 14  * accompanied this code).
 15  *
 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGIONCOUNTERS_HPP
 27 #define SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGIONCOUNTERS_HPP
 28 
 29 #include "memory/allocation.hpp"
 30 #include "logging/logFileStreamOutput.hpp"
 31 
 32 /**
 33  * This provides the following in JVMStat:
 34  *
 35  * constants:
 36  * - sun.gc.shenandoah.regions.timestamp    the timestamp for this sample
 37  * - sun.gc.shenandoah.regions.max_regions  maximum number of regions
 38  * - sun.gc.shenandoah.regions.region_size  size per region, in kilobytes
 39  *
 40  * variables:
 41  * - sun.gc.shenandoah.regions.status       current GC status:
 42  *   | global | old   | young | mode |
 43  *   |  0..1  | 2..3  | 4..5  | 6..7 |
 44  *
 45  *   For each generation:
 46  *   0 = idle, 1 = marking, 2 = evacuating, 3 = updating refs
 47  *
 48  *   For mode:
 49  *   0 = concurrent, 1 = degenerated, 2 = full
 50  *
 51  * two variable counters per region, with $max_regions (see above) counters:
 52  * - sun.gc.shenandoah.regions.region.$i.data
 53  * where $ is the region number from 0 <= i < $max_regions
 54  *
 55  * .data is in the following format:
 56  * - bits 0-6    used memory in percent
 57  * - bits 7-13   live memory in percent
 58  * - bits 14-20  tlab allocated memory in percent
 59  * - bits 21-27  gclab allocated memory in percent
 60  * - bits 28-34  shared allocated memory in percent
 61  * - bits 35-41  plab allocated memory in percent
 62  * - bits 42-50  <reserved>
 63  * - bits 51-55  age
 64  * - bits 56-57  affiliation: 0 = free, young = 1, old = 2
 65  * - bits 58-63  status
 66  *      - bits describe the state as recorded in ShenandoahHeapRegion
 67  */
 68 class ShenandoahHeapRegionCounters : public CHeapObj<mtGC>  {
 69 private:
 70   static const jlong PERCENT_MASK      = 0x7f;
 71   static const jlong AGE_MASK          = 0x1f;
 72   static const jlong AFFILIATION_MASK  = 0x03;
 73   static const jlong STATUS_MASK       = 0x3f;
 74 
 75   static const jlong USED_SHIFT        = 0;
 76   static const jlong LIVE_SHIFT        = 7;
 77   static const jlong TLAB_SHIFT        = 14;
 78   static const jlong GCLAB_SHIFT       = 21;
 79   static const jlong SHARED_SHIFT      = 28;
 80   static const jlong PLAB_SHIFT        = 35;
 81   static const jlong AGE_SHIFT         = 51;
 82   static const jlong AFFILIATION_SHIFT = 56;
 83   static const jlong STATUS_SHIFT      = 58;
 84 
 85   static const jlong VERSION_NUMBER    = 2;
 86 
 87   char* _name_space;
 88   PerfLongVariable** _regions_data;
 89   PerfLongVariable* _timestamp;
 90   PerfLongVariable* _status;
 91   volatile jlong _last_sample_millis;
 92 
 93   void write_snapshot(PerfLongVariable** regions,
 94                       PerfLongVariable* ts,
 95                       PerfLongVariable* status,
 96                       size_t num_regions,
 97                       size_t region_size, size_t protocolVersion);
 98 
 99   uint _count = 0;
100 public:
101   ShenandoahHeapRegionCounters();
102   ~ShenandoahHeapRegionCounters();
103   void update();
104 
105 private:
106   static jlong encode_heap_status(ShenandoahHeap* heap) ;
107 };
108 
109 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHHEAPREGIONCOUNTERS_HPP