1 /*

     2  * Copyright (c) 2011, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #include "precompiled.hpp"

    26 #include "gc/g1/g1CollectedHeap.inline.hpp"

    27 #include "gc/g1/g1MonitoringSupport.hpp"

    28 #include "gc/g1/g1Policy.hpp"

    29 

    30 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm,

    31                                            const char* name,

    32                                            int ordinal, int spaces,

    33                                            size_t min_capacity,

    34                                            size_t max_capacity,

    35                                            size_t curr_capacity)

    36   : GenerationCounters(name, ordinal, spaces, min_capacity,

    37                        max_capacity, curr_capacity), _g1mm(g1mm) { }

    38 

    39 // We pad the capacity three times given that the young generation

    40 // contains three spaces (eden and two survivors).

    41 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm,

    42                                                      const char* name)

    43   : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */,

    44                G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */,

    45                G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3),

    46                G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) {

    47   if (UsePerfData) {

    48     update_all();

    49   }

    50 }

    51 

    52 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm,

    53                                                  const char* name)

    54   : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */,

    55                G1MonitoringSupport::pad_capacity(0) /* min_capacity */,

    56                G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()),

    57                G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) {

    58   if (UsePerfData) {

    59     update_all();

    60   }

    61 }

    62 

    63 void G1YoungGenerationCounters::update_all() {

    64   size_t committed =

    65             G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3);

    66   _current_size->set_value(committed);

    67 }

    68 

    69 void G1OldGenerationCounters::update_all() {

    70   size_t committed =

    71             G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed());

    72   _current_size->set_value(committed);

    73 }

    74 

    75 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) :

    76   _g1h(g1h),

    77   _incremental_collection_counters(NULL),

    78   _full_collection_counters(NULL),

    79   _old_collection_counters(NULL),

    80   _old_space_counters(NULL),

    81   _young_collection_counters(NULL),

    82   _eden_counters(NULL),

    83   _from_counters(NULL),

    84   _to_counters(NULL),

    85 

    86   _overall_reserved(0),

    87   _overall_committed(0),    _overall_used(0),

    88   _young_region_num(0),

    89   _young_gen_committed(0),

    90   _eden_committed(0),       _eden_used(0),

    91   _survivor_committed(0),   _survivor_used(0),

    92   _old_committed(0),        _old_used(0) {

    93 

    94   _overall_reserved = g1h->max_capacity();

    95   recalculate_sizes();

    96 

    97   // Counters for GC collections

    98   //

    99   //  name "collector.0".  In a generational collector this would be the

   100   // young generation collection.

   101   _incremental_collection_counters =

   102     new CollectorCounters("G1 incremental collections", 0);

   103   //   name "collector.1".  In a generational collector this would be the

   104   // old generation collection.

   105   _full_collection_counters =

   106     new CollectorCounters("G1 stop-the-world full collections", 1);

   107 

   108   // timer sampling for all counters supporting sampling only update the

   109   // used value.  See the take_sample() method.  G1 requires both used and

   110   // capacity updated so sampling is not currently used.  It might

   111   // be sufficient to update all counters in take_sample() even though

   112   // take_sample() only returns "used".  When sampling was used, there

   113   // were some anomolous values emitted which may have been the consequence

   114   // of not updating all values simultaneously (i.e., see the calculation done

   115   // in eden_space_used(), is it possible that the values used to

   116   // calculate either eden_used or survivor_used are being updated by

   117   // the collector when the sample is being done?).

   118   const bool sampled = false;

   119 

   120   // "Generation" and "Space" counters.

   121   //

   122   //  name "generation.1" This is logically the old generation in

   123   // generational GC terms.  The "1, 1" parameters are for

   124   // the n-th generation (=1) with 1 space.

   125   // Counters are created from minCapacity, maxCapacity, and capacity

   126   _old_collection_counters = new G1OldGenerationCounters(this, "old");

   127 

   128   //  name  "generation.1.space.0"

   129   // Counters are created from maxCapacity, capacity, initCapacity,

   130   // and used.

   131   _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */,

   132     pad_capacity(overall_reserved()) /* max_capacity */,

   133     pad_capacity(old_space_committed()) /* init_capacity */,

   134    _old_collection_counters);

   135 

   136   //   Young collection set

   137   //  name "generation.0".  This is logically the young generation.

   138   //  The "0, 3" are parameters for the n-th generation (=0) with 3 spaces.

   139   // See  _old_collection_counters for additional counters

   140   _young_collection_counters = new G1YoungGenerationCounters(this, "young");

   141 

   142   //  name "generation.0.space.0"

   143   // See _old_space_counters for additional counters

   144   _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */,

   145     pad_capacity(overall_reserved()) /* max_capacity */,

   146     pad_capacity(eden_space_committed()) /* init_capacity */,

   147     _young_collection_counters);

   148 

   149   //  name "generation.0.space.1"

   150   // See _old_space_counters for additional counters

   151   // Set the arguments to indicate that this survivor space is not used.

   152   _from_counters = new HSpaceCounters("s0", 1 /* ordinal */,

   153     pad_capacity(0) /* max_capacity */,

   154     pad_capacity(0) /* init_capacity */,

   155     _young_collection_counters);

   156 

   157   //  name "generation.0.space.2"

   158   // See _old_space_counters for additional counters

   159   _to_counters = new HSpaceCounters("s1", 2 /* ordinal */,

   160     pad_capacity(overall_reserved()) /* max_capacity */,

   161     pad_capacity(survivor_space_committed()) /* init_capacity */,

   162     _young_collection_counters);

   163 

   164   if (UsePerfData) {

   165     // Given that this survivor space is not used, we update it here

   166     // once to reflect that its used space is 0 so that we don't have to

   167     // worry about updating it again later.

   168     _from_counters->update_used(0);

   169   }

   170 }

   171 

   172 void G1MonitoringSupport::recalculate_sizes() {

   173   G1CollectedHeap* g1 = g1h();

   174 

   175   // Recalculate all the sizes from scratch. We assume that this is

   176   // called at a point where no concurrent updates to the various

   177   // values we read here are possible (i.e., at a STW phase at the end

   178   // of a GC).

   179 

   180   uint young_list_length = g1->young_regions_count();

   181   uint survivor_list_length = g1->survivor_regions_count();

   182   assert(young_list_length >= survivor_list_length, "invariant");

   183   uint eden_list_length = young_list_length - survivor_list_length;

   184   // Max length includes any potential extensions to the young gen

   185   // we'll do when the GC locker is active.

   186   uint young_list_max_length = g1->g1_policy()->young_list_max_length();

   187   assert(young_list_max_length >= survivor_list_length, "invariant");

   188   uint eden_list_max_length = young_list_max_length - survivor_list_length;

   189 

   190   _overall_used = g1->used_unlocked();

   191   _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes;

   192   _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes;

   193   _young_region_num = young_list_length;

   194   _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used);

   195 

   196   // First calculate the committed sizes that can be calculated independently.

   197   _survivor_committed = _survivor_used;

   198   _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used);

   199 

   200   // Next, start with the overall committed size.

   201   _overall_committed = g1->capacity();

   202   size_t committed = _overall_committed;

   203 

   204   // Remove the committed size we have calculated so far (for the

   205   // survivor and old space).

   206   assert(committed >= (_survivor_committed + _old_committed), "sanity");

   207   committed -= _survivor_committed + _old_committed;

   208 

   209   // Next, calculate and remove the committed size for the eden.

   210   _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes;

   211   // Somewhat defensive: be robust in case there are inaccuracies in

   212   // the calculations

   213   _eden_committed = MIN2(_eden_committed, committed);

   214   committed -= _eden_committed;

   215 

   216   // Finally, give the rest to the old space...

   217   _old_committed += committed;

   218   // ..and calculate the young gen committed.

   219   _young_gen_committed = _eden_committed + _survivor_committed;

   220 

   221   assert(_overall_committed ==

   222          (_eden_committed + _survivor_committed + _old_committed),

   223          "the committed sizes should add up");

   224   // Somewhat defensive: cap the eden used size to make sure it

   225   // never exceeds the committed size.

   226   _eden_used = MIN2(_eden_used, _eden_committed);

   227   // _survivor_committed and _old_committed are calculated in terms of

   228   // the corresponding _*_used value, so the next two conditions

   229   // should hold.

   230   assert(_survivor_used <= _survivor_committed, "post-condition");

   231   assert(_old_used <= _old_committed, "post-condition");

   232 }

   233 

   234 void G1MonitoringSupport::recalculate_eden_size() {

   235   G1CollectedHeap* g1 = g1h();

   236 

   237   // When a new eden region is allocated, only the eden_used size is

   238   // affected (since we have recalculated everything else at the last GC).

   239 

   240   uint young_region_num = g1h()->young_regions_count();

   241   if (young_region_num > _young_region_num) {

   242     uint diff = young_region_num - _young_region_num;

   243     _eden_used += (size_t) diff * HeapRegion::GrainBytes;

   244     // Somewhat defensive: cap the eden used size to make sure it

   245     // never exceeds the committed size.

   246     _eden_used = MIN2(_eden_used, _eden_committed);

   247     _young_region_num = young_region_num;

   248   }

   249 }

   250 

   251 void G1MonitoringSupport::update_sizes() {

   252   recalculate_sizes();

   253   if (UsePerfData) {

   254     eden_counters()->update_capacity(pad_capacity(eden_space_committed()));

   255     eden_counters()->update_used(eden_space_used());

   256     // only the to survivor space (s1) is active, so we don't need to

   257     // update the counters for the from survivor space (s0)

   258     to_counters()->update_capacity(pad_capacity(survivor_space_committed()));

   259     to_counters()->update_used(survivor_space_used());

   260     old_space_counters()->update_capacity(pad_capacity(old_space_committed()));

   261     old_space_counters()->update_used(old_space_used());

   262     old_collection_counters()->update_all();

   263     young_collection_counters()->update_all();

   264     MetaspaceCounters::update_performance_counters();

   265     CompressedClassSpaceCounters::update_performance_counters();

   266   }

   267 }

   268 

   269 void G1MonitoringSupport::update_eden_size() {

   270   recalculate_eden_size();

   271   if (UsePerfData) {

   272     eden_counters()->update_used(eden_space_used());

   273   }

   274 }