jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

Mon, 03 Aug 2009 12:59:30 -0700

author: johnc
date: Mon, 03 Aug 2009 12:59:30 -0700
changeset 1324: 15c5903cf9e1
parent 1280: df6caf649ff7
child 1325: 6cb8e9df7174
permissions: -rw-r--r--

6865703: G1: Parallelize hot card cache cleanup
Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads.
Reviewed-by: jmasa, tonyp

 /*
  * Copyright 2001-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_g1CollectorPolicy.cpp.incl"
 #define PREDICTIONS_VERBOSE 0
 // <NEW PREDICTION>
 // Different defaults for different number of GC threads
 // They were chosen by running GCOld and SPECjbb on debris with different
 //   numbers of GC threads and choosing them based on the results
 // all the same
 static double rs_length_diff_defaults[] = {
 .0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
 };
 static double cost_per_card_ms_defaults[] = {
 .01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
 };
 static double cost_per_scan_only_region_ms_defaults[] = {
 .0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
 };
 // all the same
 static double fully_young_cards_per_entry_ratio_defaults[] = {
 .0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
 };
 static double cost_per_entry_ms_defaults[] = {
 .015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
 };
 static double cost_per_byte_ms_defaults[] = {
 .00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
 };
 // these should be pretty consistent
 static double constant_other_time_ms_defaults[] = {
 .0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
 };
 static double young_other_cost_per_region_ms_defaults[] = {
 .3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
 };
 static double non_young_other_cost_per_region_ms_defaults[] = {
 .0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
 };
 // </NEW PREDICTION>
 G1CollectorPolicy::G1CollectorPolicy() :
   _parallel_gc_threads((ParallelGCThreads > 0) ? ParallelGCThreads : 1),
   _n_pauses(0),
   _recent_CH_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_G1_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_evac_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _all_pause_times_ms(new NumberSeq()),
   _stop_world_start(0.0),
   _all_stop_world_times_ms(new NumberSeq()),
   _all_yield_times_ms(new NumberSeq()),
   _all_mod_union_times_ms(new NumberSeq()),
   _summary(new Summary()),
   _abandoned_summary(new AbandonedSummary()),
   _cur_clear_ct_time_ms(0.0),
   _region_num_young(0),
   _region_num_tenured(0),
   _prev_region_num_young(0),
   _prev_region_num_tenured(0),
   _aux_num(10),
   _all_aux_times_ms(new NumberSeq[_aux_num]),
   _cur_aux_start_times_ms(new double[_aux_num]),
   _cur_aux_times_ms(new double[_aux_num]),
   _cur_aux_times_set(new bool[_aux_num]),
   _concurrent_mark_init_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
   // <NEW PREDICTION>
   _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _prev_collection_pause_end_ms(0.0),
   _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
   _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
   _partially_young_cards_per_entry_ratio_seq(
                                          new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
   _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _non_young_other_cost_per_region_ms_seq(
                                          new TruncatedSeq(TruncatedSeqLength)),
   _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
   _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
   _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
   _pause_time_target_ms((double) MaxGCPauseMillis),
   // </NEW PREDICTION>
   _in_young_gc_mode(false),
   _full_young_gcs(true),
   _full_young_pause_num(0),
   _partial_young_pause_num(0),
   _during_marking(false),
   _in_marking_window(false),
   _in_marking_window_im(false),
   _known_garbage_ratio(0.0),
   _known_garbage_bytes(0),
   _young_gc_eff_seq(new TruncatedSeq(TruncatedSeqLength)),
   _target_pause_time_ms(-1.0),
    _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)),
   _recent_avg_pause_time_ratio(0.0),
   _num_markings(0),
   _n_marks(0),
   _n_pauses_at_mark_end(0),
   _all_full_gc_times_ms(new NumberSeq()),
   // G1PausesBtwnConcMark defaults to -1
   // so the hack is to do the cast  QQQ FIXME
   _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark),
   _n_marks_since_last_pause(0),
   _conc_mark_initiated(false),
   _should_initiate_conc_mark(false),
   _should_revert_to_full_young_gcs(false),
   _last_full_young_gc(false),
   _prev_collection_pause_used_at_end_bytes(0),
   _collection_set(NULL),
 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
 #endif // _MSC_VER
   _short_lived_surv_rate_group(new SurvRateGroup(this, "Short Lived",
                                                  G1YoungSurvRateNumRegionsSummary)),
   _survivor_surv_rate_group(new SurvRateGroup(this, "Survivor",
                                               G1YoungSurvRateNumRegionsSummary)),
   // add here any more surv rate groups
   _recorded_survivor_regions(0),
   _recorded_survivor_head(NULL),
   _recorded_survivor_tail(NULL),
   _survivors_age_table(true)
 {
   _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
   _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
   _par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads];
   _par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads];
   _par_last_scan_only_times_ms = new double[_parallel_gc_threads];
   _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads];
   _par_last_update_rs_start_times_ms = new double[_parallel_gc_threads];
   _par_last_update_rs_times_ms = new double[_parallel_gc_threads];
   _par_last_update_rs_processed_buffers = new double[_parallel_gc_threads];
   _par_last_scan_rs_start_times_ms = new double[_parallel_gc_threads];
   _par_last_scan_rs_times_ms = new double[_parallel_gc_threads];
   _par_last_scan_new_refs_times_ms = new double[_parallel_gc_threads];
   _par_last_obj_copy_times_ms = new double[_parallel_gc_threads];
   _par_last_termination_times_ms = new double[_parallel_gc_threads];
   // start conservatively
   _expensive_region_limit_ms = 0.5 * (double) MaxGCPauseMillis;
   // <NEW PREDICTION>
   int index;
   if (ParallelGCThreads == 0)
     index = 0;
   else if (ParallelGCThreads > 8)
     index = 7;
   else
     index = ParallelGCThreads - 1;
   _pending_card_diff_seq->add(0.0);
   _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
   _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
   _cost_per_scan_only_region_ms_seq->add(
                                  cost_per_scan_only_region_ms_defaults[index]);
   _fully_young_cards_per_entry_ratio_seq->add(
                             fully_young_cards_per_entry_ratio_defaults[index]);
   _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
   _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
   _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
   _young_other_cost_per_region_ms_seq->add(
                                young_other_cost_per_region_ms_defaults[index]);
   _non_young_other_cost_per_region_ms_seq->add(
                            non_young_other_cost_per_region_ms_defaults[index]);
   // </NEW PREDICTION>
   double time_slice  = (double) GCPauseIntervalMillis / 1000.0;
   double max_gc_time = (double) MaxGCPauseMillis / 1000.0;
   guarantee(max_gc_time < time_slice,
             "Max GC time should not be greater than the time slice");
   _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time);
   _sigma = (double) G1ConfidencePercent / 100.0;
   // start conservatively (around 50ms is about right)
   _concurrent_mark_init_times_ms->add(0.05);
   _concurrent_mark_remark_times_ms->add(0.05);
   _concurrent_mark_cleanup_times_ms->add(0.20);
   _tenuring_threshold = MaxTenuringThreshold;
   if (G1UseSurvivorSpaces) {
     // if G1FixedSurvivorSpaceSize is 0 which means the size is not
     // fixed, then _max_survivor_regions will be calculated at
     // calculate_young_list_target_config during initialization
     _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
   } else {
     _max_survivor_regions = 0;
   }
   initialize_all();
 }
 // Increment "i", mod "len"
 static void inc_mod(int& i, int len) {
   i++; if (i == len) i = 0;
 }
 void G1CollectorPolicy::initialize_flags() {
   set_min_alignment(HeapRegion::GrainBytes);
   set_max_alignment(GenRemSet::max_alignment_constraint(rem_set_name()));
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }
   CollectorPolicy::initialize_flags();
 }
 void G1CollectorPolicy::init() {
   // Set aside an initial future to_space.
   _g1 = G1CollectedHeap::heap();
   size_t regions = Universe::heap()->capacity() / HeapRegion::GrainBytes;
   assert(Heap_lock->owned_by_self(), "Locking discipline.");
   if (G1SteadyStateUsed < 50) {
     vm_exit_during_initialization("G1SteadyStateUsed must be at least 50%.");
   }
   initialize_gc_policy_counters();
   if (G1Gen) {
     _in_young_gc_mode = true;
     if (G1YoungGenSize == 0) {
       set_adaptive_young_list_length(true);
       _young_list_fixed_length = 0;
     } else {
       set_adaptive_young_list_length(false);
       _young_list_fixed_length = (G1YoungGenSize / HeapRegion::GrainBytes);
     }
      _free_regions_at_end_of_collection = _g1->free_regions();
      _scan_only_regions_at_end_of_collection = 0;
      calculate_young_list_min_length();
      guarantee( _young_list_min_length == 0, "invariant, not enough info" );
      calculate_young_list_target_config();
    } else {
      _young_list_fixed_length = 0;
     _in_young_gc_mode = false;
   }
 }
 // Create the jstat counters for the policy.
 void G1CollectorPolicy::initialize_gc_policy_counters()
 {
   _gc_policy_counters = new GCPolicyCounters("GarbageFirst", 1, 2 + G1Gen);
 }
 void G1CollectorPolicy::calculate_young_list_min_length() {
   _young_list_min_length = 0;
   if (!adaptive_young_list_length())
     return;
   if (_alloc_rate_ms_seq->num() > 3) {
     double now_sec = os::elapsedTime();
     double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
     double alloc_rate_ms = predict_alloc_rate_ms();
     int min_regions = (int) ceil(alloc_rate_ms * when_ms);
     int current_region_num = (int) _g1->young_list_length();
     _young_list_min_length = min_regions + current_region_num;
   }
 }
 void G1CollectorPolicy::calculate_young_list_target_config() {
   if (adaptive_young_list_length()) {
     size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
     calculate_young_list_target_config(rs_lengths);
   } else {
     if (full_young_gcs())
       _young_list_target_length = _young_list_fixed_length;
     else
       _young_list_target_length = _young_list_fixed_length / 2;
     _young_list_target_length = MAX2(_young_list_target_length, (size_t)1);
     size_t so_length = calculate_optimal_so_length(_young_list_target_length);
     guarantee( so_length < _young_list_target_length, "invariant" );
     _young_list_so_prefix_length = so_length;
   }
   calculate_survivors_policy();
 }
 // This method calculate the optimal scan-only set for a fixed young
 // gen size. I couldn't work out how to reuse the more elaborate one,
 // i.e. calculate_young_list_target_config(rs_length), as the loops are
 // fundamentally different (the other one finds a config for different
 // S-O lengths, whereas here we need to do the opposite).
 size_t G1CollectorPolicy::calculate_optimal_so_length(
                                                     size_t young_list_length) {
   if (!G1UseScanOnlyPrefix)
     return 0;
   if (_all_pause_times_ms->num() < 3) {
     // we won't use a scan-only set at the beginning to allow the rest
     // of the predictors to warm up
     return 0;
   }
   if (_cost_per_scan_only_region_ms_seq->num() < 3) {
     // then, we'll only set the S-O set to 1 for a little bit of time,
     // to get enough information on the scanning cost
     return 1;
   }
   size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
   size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
   size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
   size_t scanned_cards;
   if (full_young_gcs())
     scanned_cards = predict_young_card_num(adj_rs_lengths);
   else
     scanned_cards = predict_non_young_card_num(adj_rs_lengths);
   double base_time_ms = predict_base_elapsed_time_ms(pending_cards,
                                                      scanned_cards);
   size_t so_length = 0;
   double max_gc_eff = 0.0;
   for (size_t i = 0; i < young_list_length; ++i) {
     double gc_eff = 0.0;
     double pause_time_ms = 0.0;
     predict_gc_eff(young_list_length, i, base_time_ms,
                    &gc_eff, &pause_time_ms);
     if (gc_eff > max_gc_eff) {
       max_gc_eff = gc_eff;
       so_length = i;
     }
   }
   // set it to 95% of the optimal to make sure we sample the "area"
   // around the optimal length to get up-to-date survival rate data
   return so_length * 950 / 1000;
 }
 // This is a really cool piece of code! It finds the best
 // target configuration (young length / scan-only prefix length) so
 // that GC efficiency is maximized and that we also meet a pause
 // time. It's a triple nested loop. These loops are explained below
 // from the inside-out :-)
 //
 // (a) The innermost loop will try to find the optimal young length
 // for a fixed S-O length. It uses a binary search to speed up the
 // process. We assume that, for a fixed S-O length, as we add more
 // young regions to the CSet, the GC efficiency will only go up (I'll
 // skip the proof). So, using a binary search to optimize this process
 // makes perfect sense.
 //
 // (b) The middle loop will fix the S-O length before calling the
 // innermost one. It will vary it between two parameters, increasing
 // it by a given increment.
 //
 // (c) The outermost loop will call the middle loop three times.
 //   (1) The first time it will explore all possible S-O length values
 //   from 0 to as large as it can get, using a coarse increment (to
 //   quickly "home in" to where the optimal seems to be).
 //   (2) The second time it will explore the values around the optimal
 //   that was found by the first iteration using a fine increment.
 //   (3) Once the optimal config has been determined by the second
 //   iteration, we'll redo the calculation, but setting the S-O length
 //   to 95% of the optimal to make sure we sample the "area"
 //   around the optimal length to get up-to-date survival rate data
 //
 // Termination conditions for the iterations are several: the pause
 // time is over the limit, we do not have enough to-space, etc.
 void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) {
   guarantee( adaptive_young_list_length(), "pre-condition" );
   double start_time_sec = os::elapsedTime();
   size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1MinReservePercent);
   min_reserve_perc = MIN2((size_t) 50, min_reserve_perc);
   size_t reserve_regions =
     (size_t) ((double) min_reserve_perc * (double) _g1->n_regions() / 100.0);
   if (full_young_gcs() && _free_regions_at_end_of_collection > 0) {
     // we are in fully-young mode and there are free regions in the heap
     double survivor_regions_evac_time =
         predict_survivor_regions_evac_time();
     size_t min_so_length = 0;
     size_t max_so_length = 0;
     if (G1UseScanOnlyPrefix) {
       if (_all_pause_times_ms->num() < 3) {
         // we won't use a scan-only set at the beginning to allow the rest
         // of the predictors to warm up
         min_so_length = 0;
         max_so_length = 0;
       } else if (_cost_per_scan_only_region_ms_seq->num() < 3) {
         // then, we'll only set the S-O set to 1 for a little bit of time,
         // to get enough information on the scanning cost
         min_so_length = 1;
         max_so_length = 1;
       } else if (_in_marking_window || _last_full_young_gc) {
         // no S-O prefix during a marking phase either, as at the end
         // of the marking phase we'll have to use a very small young
         // length target to fill up the rest of the CSet with
         // non-young regions and, if we have lots of scan-only regions
         // left-over, we will not be able to add any more non-young
         // regions.
         min_so_length = 0;
         max_so_length = 0;
       } else {
         // this is the common case; we'll never reach the maximum, we
         // one of the end conditions will fire well before that
         // (hopefully!)
         min_so_length = 0;
         max_so_length = _free_regions_at_end_of_collection - 1;
       }
     } else {
       // no S-O prefix, as the switch is not set, but we still need to
       // do one iteration to calculate the best young target that
       // meets the pause time; this way we reuse the same code instead
       // of replicating it
       min_so_length = 0;
       max_so_length = 0;
     }
     double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
     size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
     size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
     size_t scanned_cards;
     if (full_young_gcs())
       scanned_cards = predict_young_card_num(adj_rs_lengths);
     else
       scanned_cards = predict_non_young_card_num(adj_rs_lengths);
     // calculate this once, so that we don't have to recalculate it in
     // the innermost loop
     double base_time_ms = predict_base_elapsed_time_ms(pending_cards, scanned_cards)
                           + survivor_regions_evac_time;
     // the result
     size_t final_young_length = 0;
     size_t final_so_length = 0;
     double final_gc_eff = 0.0;
     // we'll also keep track of how many times we go into the inner loop
     // this is for profiling reasons
     size_t calculations = 0;
     // this determines which of the three iterations the outer loop is in
     typedef enum {
       pass_type_coarse,
       pass_type_fine,
       pass_type_final
     } pass_type_t;
     // range of the outer loop's iteration
     size_t from_so_length   = min_so_length;
     size_t to_so_length     = max_so_length;
     guarantee( from_so_length <= to_so_length, "invariant" );
     // this will keep the S-O length that's found by the second
     // iteration of the outer loop; we'll keep it just in case the third
     // iteration fails to find something
     size_t fine_so_length   = 0;
     // the increment step for the coarse (first) iteration
     size_t so_coarse_increments = 5;
     // the common case, we'll start with the coarse iteration
     pass_type_t pass = pass_type_coarse;
     size_t so_length_incr = so_coarse_increments;
     if (from_so_length == to_so_length) {
       // not point in doing the coarse iteration, we'll go directly into
       // the fine one (we essentially trying to find the optimal young
       // length for a fixed S-O length).
       so_length_incr = 1;
       pass = pass_type_final;
     } else if (to_so_length - from_so_length < 3 * so_coarse_increments) {
       // again, the range is too short so no point in foind the coarse
       // iteration either
       so_length_incr = 1;
       pass = pass_type_fine;
     }
     bool done = false;
     // this is the outermost loop
     while (!done) {
 #ifdef TRACE_CALC_YOUNG_CONFIG
       // leave this in for debugging, just in case
       gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT
                              ", incr " SIZE_FORMAT ", pass %s",
                              from_so_length, to_so_length, so_length_incr,
                              (pass == pass_type_coarse) ? "coarse" :
                              (pass == pass_type_fine) ? "fine" : "final");
 #endif // TRACE_CALC_YOUNG_CONFIG
       size_t so_length = from_so_length;
       size_t init_free_regions =
         MAX2((size_t)0,
              _free_regions_at_end_of_collection +
              _scan_only_regions_at_end_of_collection - reserve_regions);
       // this determines whether a configuration was found
       bool gc_eff_set = false;
       // this is the middle loop
       while (so_length <= to_so_length) {
         // base time, which excludes region-related time; again we
         // calculate it once to avoid recalculating it in the
         // innermost loop
         double base_time_with_so_ms =
                            base_time_ms + predict_scan_only_time_ms(so_length);
         // it's already over the pause target, go around
         if (base_time_with_so_ms > target_pause_time_ms)
           break;
         size_t starting_young_length = so_length+1;
         // we make sure that the short young length that makes sense
         // (one more than the S-O length) is feasible
         size_t min_young_length = starting_young_length;
         double min_gc_eff;
         bool min_ok;
         ++calculations;
         min_ok = predict_gc_eff(min_young_length, so_length,
                                 base_time_with_so_ms,
                                 init_free_regions, target_pause_time_ms,
                                 &min_gc_eff);
         if (min_ok) {
           // the shortest young length is indeed feasible; we'll know
           // set up the max young length and we'll do a binary search
           // between min_young_length and max_young_length
           size_t max_young_length = _free_regions_at_end_of_collection - 1;
           double max_gc_eff = 0.0;
           bool max_ok = false;
           // the innermost loop! (finally!)
           while (max_young_length > min_young_length) {
             // we'll make sure that min_young_length is always at a
             // feasible config
             guarantee( min_ok, "invariant" );
             ++calculations;
             max_ok = predict_gc_eff(max_young_length, so_length,
                                     base_time_with_so_ms,
                                     init_free_regions, target_pause_time_ms,
                                     &max_gc_eff);
             size_t diff = (max_young_length - min_young_length) / 2;
             if (max_ok) {
               min_young_length = max_young_length;
               min_gc_eff = max_gc_eff;
               min_ok = true;
             }
             max_young_length = min_young_length + diff;
           }
           // the innermost loop found a config
           guarantee( min_ok, "invariant" );
           if (min_gc_eff > final_gc_eff) {
             // it's the best config so far, so we'll keep it
             final_gc_eff = min_gc_eff;
             final_young_length = min_young_length;
             final_so_length = so_length;
             gc_eff_set = true;
           }
         }
         // incremental the fixed S-O length and go around
         so_length += so_length_incr;
       }
       // this is the end of the outermost loop and we need to decide
       // what to do during the next iteration
       if (pass == pass_type_coarse) {
         // we just did the coarse pass (first iteration)
         if (!gc_eff_set)
           // we didn't find a feasible config so we'll just bail out; of
           // course, it might be the case that we missed it; but I'd say
           // it's a bit unlikely
           done = true;
         else {
           // We did find a feasible config with optimal GC eff during
           // the first pass. So the second pass we'll only consider the
           // S-O lengths around that config with a fine increment.
           guarantee( so_length_incr == so_coarse_increments, "invariant" );
           guarantee( final_so_length >= min_so_length, "invariant" );
 #ifdef TRACE_CALC_YOUNG_CONFIG
           // leave this in for debugging, just in case
           gclog_or_tty->print_cr("  coarse pass: SO length " SIZE_FORMAT,
                                  final_so_length);
 #endif // TRACE_CALC_YOUNG_CONFIG
           from_so_length =
             (final_so_length - min_so_length > so_coarse_increments) ?
             final_so_length - so_coarse_increments + 1 : min_so_length;
           to_so_length =
             (max_so_length - final_so_length > so_coarse_increments) ?
             final_so_length + so_coarse_increments - 1 : max_so_length;
           pass = pass_type_fine;
           so_length_incr = 1;
         }
       } else if (pass == pass_type_fine) {
         // we just finished the second pass
         if (!gc_eff_set) {
           // we didn't find a feasible config (yes, it's possible;
           // notice that, sometimes, we go directly into the fine
           // iteration and skip the coarse one) so we bail out
           done = true;
         } else {
           // We did find a feasible config with optimal GC eff
           guarantee( so_length_incr == 1, "invariant" );
           if (final_so_length == 0) {
             // The config is of an empty S-O set, so we'll just bail out
             done = true;
           } else {
             // we'll go around once more, setting the S-O length to 95%
             // of the optimal
             size_t new_so_length = 950 * final_so_length / 1000;
 #ifdef TRACE_CALC_YOUNG_CONFIG
             // leave this in for debugging, just in case
             gclog_or_tty->print_cr("  fine pass: SO length " SIZE_FORMAT
                                    ", setting it to " SIZE_FORMAT,
                                     final_so_length, new_so_length);
 #endif // TRACE_CALC_YOUNG_CONFIG
             from_so_length = new_so_length;
             to_so_length = new_so_length;
             fine_so_length = final_so_length;
             pass = pass_type_final;
           }
         }
       } else if (pass == pass_type_final) {
         // we just finished the final (third) pass
         if (!gc_eff_set)
           // we didn't find a feasible config, so we'll just use the one
           // we found during the second pass, which we saved
           final_so_length = fine_so_length;
         // and we're done!
         done = true;
       } else {
         guarantee( false, "should never reach here" );
       }
       // we now go around the outermost loop
     }
     // we should have at least one region in the target young length
     _young_list_target_length =
         MAX2((size_t) 1, final_young_length + _recorded_survivor_regions);
     if (final_so_length >= final_young_length)
       // and we need to ensure that the S-O length is not greater than
       // the target young length (this is being a bit careful)
       final_so_length = 0;
     _young_list_so_prefix_length = final_so_length;
     guarantee( !_in_marking_window || !_last_full_young_gc ||
                _young_list_so_prefix_length == 0, "invariant" );
     // let's keep an eye of how long we spend on this calculation
     // right now, I assume that we'll print it when we need it; we
     // should really adde it to the breakdown of a pause
     double end_time_sec = os::elapsedTime();
     double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0;
 #ifdef TRACE_CALC_YOUNG_CONFIG
     // leave this in for debugging, just in case
     gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT
                            ", SO = " SIZE_FORMAT ", "
                            "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) "
                            SIZE_FORMAT SIZE_FORMAT,
                            target_pause_time_ms,
                            _young_list_target_length - _young_list_so_prefix_length,
                            _young_list_so_prefix_length,
                            elapsed_time_ms,
                            calculations,
                            full_young_gcs() ? "full" : "partial",
                            should_initiate_conc_mark() ? " i-m" : "",
                            _in_marking_window,
                            _in_marking_window_im);
 #endif // TRACE_CALC_YOUNG_CONFIG
     if (_young_list_target_length < _young_list_min_length) {
       // bummer; this means that, if we do a pause when the optimal
       // config dictates, we'll violate the pause spacing target (the
       // min length was calculate based on the application's current
       // alloc rate);
       // so, we have to bite the bullet, and allocate the minimum
       // number. We'll violate our target, but we just can't meet it.
       size_t so_length = 0;
       // a note further up explains why we do not want an S-O length
       // during marking
       if (!_in_marking_window && !_last_full_young_gc)
         // but we can still try to see whether we can find an optimal
         // S-O length
         so_length = calculate_optimal_so_length(_young_list_min_length);
 #ifdef TRACE_CALC_YOUNG_CONFIG
       // leave this in for debugging, just in case
       gclog_or_tty->print_cr("adjusted target length from "
                              SIZE_FORMAT " to " SIZE_FORMAT
                              ", SO " SIZE_FORMAT,
                              _young_list_target_length, _young_list_min_length,
                              so_length);
 #endif // TRACE_CALC_YOUNG_CONFIG
       _young_list_target_length =
         MAX2(_young_list_min_length, (size_t)1);
       _young_list_so_prefix_length = so_length;
     }
   } else {
     // we are in a partially-young mode or we've run out of regions (due
     // to evacuation failure)
 #ifdef TRACE_CALC_YOUNG_CONFIG
     // leave this in for debugging, just in case
     gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT
                            ", SO " SIZE_FORMAT,
                            _young_list_min_length, 0);
 #endif // TRACE_CALC_YOUNG_CONFIG
     // we'll do the pause as soon as possible and with no S-O prefix
     // (see above for the reasons behind the latter)
     _young_list_target_length =
       MAX2(_young_list_min_length, (size_t) 1);
     _young_list_so_prefix_length = 0;
   }
   _rs_lengths_prediction = rs_lengths;
 }
 // This is used by: calculate_optimal_so_length(length). It returns
 // the GC eff and predicted pause time for a particular config
 void
 G1CollectorPolicy::predict_gc_eff(size_t young_length,
                                   size_t so_length,
                                   double base_time_ms,
                                   double* ret_gc_eff,
                                   double* ret_pause_time_ms) {
   double so_time_ms = predict_scan_only_time_ms(so_length);
   double accum_surv_rate_adj = 0.0;
   if (so_length > 0)
     accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
   double accum_surv_rate =
     accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
   size_t bytes_to_copy =
     (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
   double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
   double young_other_time_ms =
                        predict_young_other_time_ms(young_length - so_length);
   double pause_time_ms =
                 base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms;
   size_t reclaimed_bytes =
     (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
   double gc_eff = (double) reclaimed_bytes / pause_time_ms;
   *ret_gc_eff = gc_eff;
   *ret_pause_time_ms = pause_time_ms;
 }
 // This is used by: calculate_young_list_target_config(rs_length). It
 // returns the GC eff of a particular config. It returns false if that
 // config violates any of the end conditions of the search in the
 // calling method, or true upon success. The end conditions were put
 // here since it's called twice and it was best not to replicate them
 // in the caller. Also, passing the parameteres avoids having to
 // recalculate them in the innermost loop.
 bool
 G1CollectorPolicy::predict_gc_eff(size_t young_length,
                                   size_t so_length,
                                   double base_time_with_so_ms,
                                   size_t init_free_regions,
                                   double target_pause_time_ms,
                                   double* ret_gc_eff) {
   *ret_gc_eff = 0.0;
   if (young_length >= init_free_regions)
     // end condition 1: not enough space for the young regions
     return false;
   double accum_surv_rate_adj = 0.0;
   if (so_length > 0)
     accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
   double accum_surv_rate =
     accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
   size_t bytes_to_copy =
     (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
   double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
   double young_other_time_ms =
                        predict_young_other_time_ms(young_length - so_length);
   double pause_time_ms =
                    base_time_with_so_ms + copy_time_ms + young_other_time_ms;
   if (pause_time_ms > target_pause_time_ms)
     // end condition 2: over the target pause time
     return false;
   size_t reclaimed_bytes =
     (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
   size_t free_bytes =
                  (init_free_regions - young_length) * HeapRegion::GrainBytes;
   if ((2.0 + sigma()) * (double) bytes_to_copy > (double) free_bytes)
     // end condition 3: out of to-space (conservatively)
     return false;
   // success!
   double gc_eff = (double) reclaimed_bytes / pause_time_ms;
   *ret_gc_eff = gc_eff;
   return true;
 }
 double G1CollectorPolicy::predict_survivor_regions_evac_time() {
   double survivor_regions_evac_time = 0.0;
   for (HeapRegion * r = _recorded_survivor_head;
        r != NULL && r != _recorded_survivor_tail->get_next_young_region();
        r = r->get_next_young_region()) {
     survivor_regions_evac_time += predict_region_elapsed_time_ms(r, true);
   }
   return survivor_regions_evac_time;
 }
 void G1CollectorPolicy::check_prediction_validity() {
   guarantee( adaptive_young_list_length(), "should not call this otherwise" );
   size_t rs_lengths = _g1->young_list_sampled_rs_lengths();
   if (rs_lengths > _rs_lengths_prediction) {
     // add 10% to avoid having to recalculate often
     size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
     calculate_young_list_target_config(rs_lengths_prediction);
   }
 }
 HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size,
                                                bool is_tlab,
                                                bool* gc_overhead_limit_was_exceeded) {
   guarantee(false, "Not using this policy feature yet.");
   return NULL;
 }
 // This method controls how a collector handles one or more
 // of its generations being fully allocated.
 HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size,
                                                        bool is_tlab) {
   guarantee(false, "Not using this policy feature yet.");
   return NULL;
 }
 #ifndef PRODUCT
 bool G1CollectorPolicy::verify_young_ages() {
   HeapRegion* head = _g1->young_list_first_region();
   return
     verify_young_ages(head, _short_lived_surv_rate_group);
   // also call verify_young_ages on any additional surv rate groups
 }
 bool
 G1CollectorPolicy::verify_young_ages(HeapRegion* head,
                                      SurvRateGroup *surv_rate_group) {
   guarantee( surv_rate_group != NULL, "pre-condition" );
   const char* name = surv_rate_group->name();
   bool ret = true;
   int prev_age = -1;
   for (HeapRegion* curr = head;
        curr != NULL;
        curr = curr->get_next_young_region()) {
     SurvRateGroup* group = curr->surv_rate_group();
     if (group == NULL && !curr->is_survivor()) {
       gclog_or_tty->print_cr("## %s: encountered NULL surv_rate_group", name);
       ret = false;
     }
     if (surv_rate_group == group) {
       int age = curr->age_in_surv_rate_group();
       if (age < 0) {
         gclog_or_tty->print_cr("## %s: encountered negative age", name);
         ret = false;
       }
       if (age <= prev_age) {
         gclog_or_tty->print_cr("## %s: region ages are not strictly increasing "
                                "(%d, %d)", name, age, prev_age);
         ret = false;
       }
       prev_age = age;
     }
   }
   return ret;
 }
 #endif // PRODUCT
 void G1CollectorPolicy::record_full_collection_start() {
   _cur_collection_start_sec = os::elapsedTime();
   // Release the future to-space so that it is available for compaction into.
   _g1->set_full_collection();
 }
 void G1CollectorPolicy::record_full_collection_end() {
   // Consider this like a collection pause for the purposes of allocation
   // since last pause.
   double end_sec = os::elapsedTime();
   double full_gc_time_sec = end_sec - _cur_collection_start_sec;
   double full_gc_time_ms = full_gc_time_sec * 1000.0;
   checkpoint_conc_overhead();
   _all_full_gc_times_ms->add(full_gc_time_ms);
   update_recent_gc_times(end_sec, full_gc_time_ms);
   _g1->clear_full_collection();
   // "Nuke" the heuristics that control the fully/partially young GC
   // transitions and make sure we start with fully young GCs after the
   // Full GC.
   set_full_young_gcs(true);
   _last_full_young_gc = false;
   _should_revert_to_full_young_gcs = false;
   _should_initiate_conc_mark = false;
   _known_garbage_bytes = 0;
   _known_garbage_ratio = 0.0;
   _in_marking_window = false;
   _in_marking_window_im = false;
   _short_lived_surv_rate_group->record_scan_only_prefix(0);
   _short_lived_surv_rate_group->start_adding_regions();
   // also call this on any additional surv rate groups
   record_survivor_regions(0, NULL, NULL);
   _prev_region_num_young   = _region_num_young;
   _prev_region_num_tenured = _region_num_tenured;
   _free_regions_at_end_of_collection = _g1->free_regions();
   _scan_only_regions_at_end_of_collection = 0;
   // Reset survivors SurvRateGroup.
   _survivor_surv_rate_group->reset();
   calculate_young_list_min_length();
   calculate_young_list_target_config();
  }
 void G1CollectorPolicy::record_before_bytes(size_t bytes) {
   _bytes_in_to_space_before_gc += bytes;
 }
 void G1CollectorPolicy::record_after_bytes(size_t bytes) {
   _bytes_in_to_space_after_gc += bytes;
 }
 void G1CollectorPolicy::record_stop_world_start() {
   _stop_world_start = os::elapsedTime();
 }
 void G1CollectorPolicy::record_collection_pause_start(double start_time_sec,
                                                       size_t start_used) {
   if (PrintGCDetails) {
     gclog_or_tty->stamp(PrintGCTimeStamps);
     gclog_or_tty->print("[GC pause");
     if (in_young_gc_mode())
       gclog_or_tty->print(" (%s)", full_young_gcs() ? "young" : "partial");
   }
   assert(_g1->used_regions() == _g1->recalculate_used_regions(),
          "sanity");
   assert(_g1->used() == _g1->recalculate_used(), "sanity");
   double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
   _all_stop_world_times_ms->add(s_w_t_ms);
   _stop_world_start = 0.0;
   _cur_collection_start_sec = start_time_sec;
   _cur_collection_pause_used_at_start_bytes = start_used;
   _cur_collection_pause_used_regions_at_start = _g1->used_regions();
   _pending_cards = _g1->pending_card_num();
   _max_pending_cards = _g1->max_pending_card_num();
   _bytes_in_to_space_before_gc = 0;
   _bytes_in_to_space_after_gc = 0;
   _bytes_in_collection_set_before_gc = 0;
 #ifdef DEBUG
   // initialise these to something well known so that we can spot
   // if they are not set properly
   for (int i = 0; i < _parallel_gc_threads; ++i) {
     _par_last_ext_root_scan_times_ms[i] = -666.0;
     _par_last_mark_stack_scan_times_ms[i] = -666.0;
     _par_last_scan_only_times_ms[i] = -666.0;
     _par_last_scan_only_regions_scanned[i] = -666.0;
     _par_last_update_rs_start_times_ms[i] = -666.0;
     _par_last_update_rs_times_ms[i] = -666.0;
     _par_last_update_rs_processed_buffers[i] = -666.0;
     _par_last_scan_rs_start_times_ms[i] = -666.0;
     _par_last_scan_rs_times_ms[i] = -666.0;
     _par_last_scan_new_refs_times_ms[i] = -666.0;
     _par_last_obj_copy_times_ms[i] = -666.0;
     _par_last_termination_times_ms[i] = -666.0;
   }
 #endif
   for (int i = 0; i < _aux_num; ++i) {
     _cur_aux_times_ms[i] = 0.0;
     _cur_aux_times_set[i] = false;
   }
   _satb_drain_time_set = false;
   _last_satb_drain_processed_buffers = -1;
   if (in_young_gc_mode())
     _last_young_gc_full = false;
   // do that for any other surv rate groups
   _short_lived_surv_rate_group->stop_adding_regions();
   size_t short_lived_so_length = _young_list_so_prefix_length;
   _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length);
   tag_scan_only(short_lived_so_length);
   if (G1UseSurvivorSpaces) {
     _survivors_age_table.clear();
   }
   assert( verify_young_ages(), "region age verification" );
 }
 void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) {
   // done in a way that it can be extended for other surv rate groups too...
   HeapRegion* head = _g1->young_list_first_region();
   bool finished_short_lived = (short_lived_scan_only_length == 0);
   if (finished_short_lived)
     return;
   for (HeapRegion* curr = head;
        curr != NULL;
        curr = curr->get_next_young_region()) {
     SurvRateGroup* surv_rate_group = curr->surv_rate_group();
     int age = curr->age_in_surv_rate_group();
     if (surv_rate_group == _short_lived_surv_rate_group) {
       if ((size_t)age < short_lived_scan_only_length)
         curr->set_scan_only();
       else
         finished_short_lived = true;
     }
     if (finished_short_lived)
       return;
   }
   guarantee( false, "we should never reach here" );
 }
 void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
   _mark_closure_time_ms = mark_closure_time_ms;
 }
 void G1CollectorPolicy::record_concurrent_mark_init_start() {
   _mark_init_start_sec = os::elapsedTime();
   guarantee(!in_young_gc_mode(), "should not do be here in young GC mode");
 }
 void G1CollectorPolicy::record_concurrent_mark_init_end_pre(double
                                                    mark_init_elapsed_time_ms) {
   _during_marking = true;
   _should_initiate_conc_mark = false;
   _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms;
 }
 void G1CollectorPolicy::record_concurrent_mark_init_end() {
   double end_time_sec = os::elapsedTime();
   double elapsed_time_ms = (end_time_sec - _mark_init_start_sec) * 1000.0;
   _concurrent_mark_init_times_ms->add(elapsed_time_ms);
   checkpoint_conc_overhead();
   record_concurrent_mark_init_end_pre(elapsed_time_ms);
   _mmu_tracker->add_pause(_mark_init_start_sec, end_time_sec, true);
 }
 void G1CollectorPolicy::record_concurrent_mark_remark_start() {
   _mark_remark_start_sec = os::elapsedTime();
   _during_marking = false;
 }
 void G1CollectorPolicy::record_concurrent_mark_remark_end() {
   double end_time_sec = os::elapsedTime();
   double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0;
   checkpoint_conc_overhead();
   _concurrent_mark_remark_times_ms->add(elapsed_time_ms);
   _cur_mark_stop_world_time_ms += elapsed_time_ms;
   _prev_collection_pause_end_ms += elapsed_time_ms;
   _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec, true);
 }
 void G1CollectorPolicy::record_concurrent_mark_cleanup_start() {
   _mark_cleanup_start_sec = os::elapsedTime();
 }
 void
 G1CollectorPolicy::record_concurrent_mark_cleanup_end(size_t freed_bytes,
                                                       size_t max_live_bytes) {
   record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
   record_concurrent_mark_cleanup_end_work2();
 }
 void
 G1CollectorPolicy::
 record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
                                          size_t max_live_bytes) {
   if (_n_marks < 2) _n_marks++;
   if (G1PolicyVerbose > 0)
     gclog_or_tty->print_cr("At end of marking, max_live is " SIZE_FORMAT " MB "
                            " (of " SIZE_FORMAT " MB heap).",
                            max_live_bytes/M, _g1->capacity()/M);
 }
 // The important thing about this is that it includes "os::elapsedTime".
 void G1CollectorPolicy::record_concurrent_mark_cleanup_end_work2() {
   checkpoint_conc_overhead();
   double end_time_sec = os::elapsedTime();
   double elapsed_time_ms = (end_time_sec - _mark_cleanup_start_sec)*1000.0;
   _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
   _cur_mark_stop_world_time_ms += elapsed_time_ms;
   _prev_collection_pause_end_ms += elapsed_time_ms;
   _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_time_sec, true);
   _num_markings++;
   // We did a marking, so reset the "since_last_mark" variables.
   double considerConcMarkCost = 1.0;
   // If there are available processors, concurrent activity is free...
   if (Threads::number_of_non_daemon_threads() * 2 <
       os::active_processor_count()) {
     considerConcMarkCost = 0.0;
   }
   _n_pauses_at_mark_end = _n_pauses;
   _n_marks_since_last_pause++;
   _conc_mark_initiated = false;
 }
 void
 G1CollectorPolicy::record_concurrent_mark_cleanup_completed() {
   if (in_young_gc_mode()) {
     _should_revert_to_full_young_gcs = false;
     _last_full_young_gc = true;
     _in_marking_window = false;
     if (adaptive_young_list_length())
       calculate_young_list_target_config();
   }
 }
 void G1CollectorPolicy::record_concurrent_pause() {
   if (_stop_world_start > 0.0) {
     double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
     _all_yield_times_ms->add(yield_ms);
   }
 }
 void G1CollectorPolicy::record_concurrent_pause_end() {
 }
 void G1CollectorPolicy::record_collection_pause_end_CH_strong_roots() {
   _cur_CH_strong_roots_end_sec = os::elapsedTime();
   _cur_CH_strong_roots_dur_ms =
     (_cur_CH_strong_roots_end_sec - _cur_collection_start_sec) * 1000.0;
 }
 void G1CollectorPolicy::record_collection_pause_end_G1_strong_roots() {
   _cur_G1_strong_roots_end_sec = os::elapsedTime();
   _cur_G1_strong_roots_dur_ms =
     (_cur_G1_strong_roots_end_sec - _cur_CH_strong_roots_end_sec) * 1000.0;
 }
 template<class T>
 T sum_of(T* sum_arr, int start, int n, int N) {
   T sum = (T)0;
   for (int i = 0; i < n; i++) {
     int j = (start + i) % N;
     sum += sum_arr[j];
   }
   return sum;
 }
 void G1CollectorPolicy::print_par_stats (int level,
                                          const char* str,
                                          double* data,
                                          bool summary) {
   double min = data[0], max = data[0];
   double total = 0.0;
   int j;
   for (j = 0; j < level; ++j)
     gclog_or_tty->print("   ");
   gclog_or_tty->print("[%s (ms):", str);
   for (uint i = 0; i < ParallelGCThreads; ++i) {
     double val = data[i];
     if (val < min)
       min = val;
     if (val > max)
       max = val;
     total += val;
     gclog_or_tty->print("  %3.1lf", val);
   }
   if (summary) {
     gclog_or_tty->print_cr("");
     double avg = total / (double) ParallelGCThreads;
     gclog_or_tty->print(" ");
     for (j = 0; j < level; ++j)
       gclog_or_tty->print("   ");
     gclog_or_tty->print("Avg: %5.1lf, Min: %5.1lf, Max: %5.1lf",
                         avg, min, max);
   }
   gclog_or_tty->print_cr("]");
 }
 void G1CollectorPolicy::print_par_buffers (int level,
                                          const char* str,
                                          double* data,
                                          bool summary) {
   double min = data[0], max = data[0];
   double total = 0.0;
   int j;
   for (j = 0; j < level; ++j)
     gclog_or_tty->print("   ");
   gclog_or_tty->print("[%s :", str);
   for (uint i = 0; i < ParallelGCThreads; ++i) {
     double val = data[i];
     if (val < min)
       min = val;
     if (val > max)
       max = val;
     total += val;
     gclog_or_tty->print(" %d", (int) val);
   }
   if (summary) {
     gclog_or_tty->print_cr("");
     double avg = total / (double) ParallelGCThreads;
     gclog_or_tty->print(" ");
     for (j = 0; j < level; ++j)
       gclog_or_tty->print("   ");
     gclog_or_tty->print("Sum: %d, Avg: %d, Min: %d, Max: %d",
                (int)total, (int)avg, (int)min, (int)max);
   }
   gclog_or_tty->print_cr("]");
 }
 void G1CollectorPolicy::print_stats (int level,
                                      const char* str,
                                      double value) {
   for (int j = 0; j < level; ++j)
     gclog_or_tty->print("   ");
   gclog_or_tty->print_cr("[%s: %5.1lf ms]", str, value);
 }
 void G1CollectorPolicy::print_stats (int level,
                                      const char* str,
                                      int value) {
   for (int j = 0; j < level; ++j)
     gclog_or_tty->print("   ");
   gclog_or_tty->print_cr("[%s: %d]", str, value);
 }
 double G1CollectorPolicy::avg_value (double* data) {
   if (ParallelGCThreads > 0) {
     double ret = 0.0;
     for (uint i = 0; i < ParallelGCThreads; ++i)
       ret += data[i];
     return ret / (double) ParallelGCThreads;
   } else {
     return data[0];
   }
 }
 double G1CollectorPolicy::max_value (double* data) {
   if (ParallelGCThreads > 0) {
     double ret = data[0];
     for (uint i = 1; i < ParallelGCThreads; ++i)
       if (data[i] > ret)
         ret = data[i];
     return ret;
   } else {
     return data[0];
   }
 }
 double G1CollectorPolicy::sum_of_values (double* data) {
   if (ParallelGCThreads > 0) {
     double sum = 0.0;
     for (uint i = 0; i < ParallelGCThreads; i++)
       sum += data[i];
     return sum;
   } else {
     return data[0];
   }
 }
 double G1CollectorPolicy::max_sum (double* data1,
                                    double* data2) {
   double ret = data1[0] + data2[0];
   if (ParallelGCThreads > 0) {
     for (uint i = 1; i < ParallelGCThreads; ++i) {
       double data = data1[i] + data2[i];
       if (data > ret)
         ret = data;
     }
   }
   return ret;
 }
 // Anything below that is considered to be zero
 #define MIN_TIMER_GRANULARITY 0.0000001
 void G1CollectorPolicy::record_collection_pause_end(bool abandoned) {
   double end_time_sec = os::elapsedTime();
   double elapsed_ms = _last_pause_time_ms;
   bool parallel = ParallelGCThreads > 0;
   double evac_ms = (end_time_sec - _cur_G1_strong_roots_end_sec) * 1000.0;
   size_t rs_size =
     _cur_collection_pause_used_regions_at_start - collection_set_size();
   size_t cur_used_bytes = _g1->used();
   assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
   bool last_pause_included_initial_mark = false;
   bool update_stats = !abandoned && !_g1->evacuation_failed();
 #ifndef PRODUCT
   if (G1YoungSurvRateVerbose) {
     gclog_or_tty->print_cr("");
     _short_lived_surv_rate_group->print();
     // do that for any other surv rate groups too
   }
 #endif // PRODUCT
   checkpoint_conc_overhead();
   if (in_young_gc_mode()) {
     last_pause_included_initial_mark = _should_initiate_conc_mark;
     if (last_pause_included_initial_mark)
       record_concurrent_mark_init_end_pre(0.0);
     size_t min_used_targ =
       (_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta);
     if (cur_used_bytes > min_used_targ) {
       if (cur_used_bytes <= _prev_collection_pause_used_at_end_bytes) {
       } else if (!_g1->mark_in_progress() && !_last_full_young_gc) {
         _should_initiate_conc_mark = true;
       }
     }
     _prev_collection_pause_used_at_end_bytes = cur_used_bytes;
   }
   _mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0,
                           end_time_sec, false);
   guarantee(_cur_collection_pause_used_regions_at_start >=
             collection_set_size(),
             "Negative RS size?");
   // This assert is exempted when we're doing parallel collection pauses,
   // because the fragmentation caused by the parallel GC allocation buffers
   // can lead to more memory being used during collection than was used
   // before. Best leave this out until the fragmentation problem is fixed.
   // Pauses in which evacuation failed can also lead to negative
   // collections, since no space is reclaimed from a region containing an
   // object whose evacuation failed.
   // Further, we're now always doing parallel collection.  But I'm still
   // leaving this here as a placeholder for a more precise assertion later.
   // (DLD, 10/05.)
   assert((true || parallel) // Always using GC LABs now.
          || _g1->evacuation_failed()
          || _cur_collection_pause_used_at_start_bytes >= cur_used_bytes,
          "Negative collection");
   size_t freed_bytes =
     _cur_collection_pause_used_at_start_bytes - cur_used_bytes;
   size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes;
   double survival_fraction =
     (double)surviving_bytes/
     (double)_collection_set_bytes_used_before;
   _n_pauses++;
   if (update_stats) {
     _recent_CH_strong_roots_times_ms->add(_cur_CH_strong_roots_dur_ms);
     _recent_G1_strong_roots_times_ms->add(_cur_G1_strong_roots_dur_ms);
     _recent_evac_times_ms->add(evac_ms);
     _recent_pause_times_ms->add(elapsed_ms);
     _recent_rs_sizes->add(rs_size);
     // We exempt parallel collection from this check because Alloc Buffer
     // fragmentation can produce negative collections.  Same with evac
     // failure.
     // Further, we're now always doing parallel collection.  But I'm still
     // leaving this here as a placeholder for a more precise assertion later.
     // (DLD, 10/05.
     assert((true || parallel)
            || _g1->evacuation_failed()
            || surviving_bytes <= _collection_set_bytes_used_before,
            "Or else negative collection!");
     _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before);
     _recent_CS_bytes_surviving->add(surviving_bytes);
     // this is where we update the allocation rate of the application
     double app_time_ms =
       (_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms);
     if (app_time_ms < MIN_TIMER_GRANULARITY) {
       // This usually happens due to the timer not having the required
       // granularity. Some Linuxes are the usual culprits.
       // We'll just set it to something (arbitrarily) small.
       app_time_ms = 1.0;
     }
     size_t regions_allocated =
       (_region_num_young - _prev_region_num_young) +
       (_region_num_tenured - _prev_region_num_tenured);
     double alloc_rate_ms = (double) regions_allocated / app_time_ms;
     _alloc_rate_ms_seq->add(alloc_rate_ms);
     _prev_region_num_young   = _region_num_young;
     _prev_region_num_tenured = _region_num_tenured;
     double interval_ms =
       (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
     update_recent_gc_times(end_time_sec, elapsed_ms);
     _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms;
     assert(recent_avg_pause_time_ratio() < 1.00, "All GC?");
   }
   if (G1PolicyVerbose > 1) {
     gclog_or_tty->print_cr("   Recording collection pause(%d)", _n_pauses);
   }
   PauseSummary* summary;
   if (abandoned) {
     summary = _abandoned_summary;
   } else {
     summary = _summary;
   }
   double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
   double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms);
   double scan_only_time = avg_value(_par_last_scan_only_times_ms);
   double scan_only_regions_scanned =
     sum_of_values(_par_last_scan_only_regions_scanned);
   double update_rs_time = avg_value(_par_last_update_rs_times_ms);
   double update_rs_processed_buffers =
     sum_of_values(_par_last_update_rs_processed_buffers);
   double scan_rs_time = avg_value(_par_last_scan_rs_times_ms);
   double obj_copy_time = avg_value(_par_last_obj_copy_times_ms);
   double termination_time = avg_value(_par_last_termination_times_ms);
   double parallel_other_time = _cur_collection_par_time_ms -
     (update_rs_time + ext_root_scan_time + mark_stack_scan_time +
      scan_only_time + scan_rs_time + obj_copy_time + termination_time);
   if (update_stats) {
     MainBodySummary* body_summary = summary->main_body_summary();
     guarantee(body_summary != NULL, "should not be null!");
     if (_satb_drain_time_set)
       body_summary->record_satb_drain_time_ms(_cur_satb_drain_time_ms);
     else
       body_summary->record_satb_drain_time_ms(0.0);
     body_summary->record_ext_root_scan_time_ms(ext_root_scan_time);
     body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time);
     body_summary->record_scan_only_time_ms(scan_only_time);
     body_summary->record_update_rs_time_ms(update_rs_time);
     body_summary->record_scan_rs_time_ms(scan_rs_time);
     body_summary->record_obj_copy_time_ms(obj_copy_time);
     if (parallel) {
       body_summary->record_parallel_time_ms(_cur_collection_par_time_ms);
       body_summary->record_clear_ct_time_ms(_cur_clear_ct_time_ms);
       body_summary->record_termination_time_ms(termination_time);
       body_summary->record_parallel_other_time_ms(parallel_other_time);
     }
     body_summary->record_mark_closure_time_ms(_mark_closure_time_ms);
   }
   if (G1PolicyVerbose > 1) {
     gclog_or_tty->print_cr("      ET: %10.6f ms           (avg: %10.6f ms)\n"
                            "        CH Strong: %10.6f ms    (avg: %10.6f ms)\n"
                            "        G1 Strong: %10.6f ms    (avg: %10.6f ms)\n"
                            "        Evac:      %10.6f ms    (avg: %10.6f ms)\n"
                            "       ET-RS:  %10.6f ms      (avg: %10.6f ms)\n"
                            "      |RS|: " SIZE_FORMAT,
                            elapsed_ms, recent_avg_time_for_pauses_ms(),
                            _cur_CH_strong_roots_dur_ms, recent_avg_time_for_CH_strong_ms(),
                            _cur_G1_strong_roots_dur_ms, recent_avg_time_for_G1_strong_ms(),
                            evac_ms, recent_avg_time_for_evac_ms(),
                            scan_rs_time,
                            recent_avg_time_for_pauses_ms() -
                            recent_avg_time_for_G1_strong_ms(),
                            rs_size);
     gclog_or_tty->print_cr("       Used at start: " SIZE_FORMAT"K"
                            "       At end " SIZE_FORMAT "K\n"
                            "       garbage      : " SIZE_FORMAT "K"
                            "       of     " SIZE_FORMAT "K\n"
                            "       survival     : %6.2f%%  (%6.2f%% avg)",
                            _cur_collection_pause_used_at_start_bytes/K,
                            _g1->used()/K, freed_bytes/K,
                            _collection_set_bytes_used_before/K,
                            survival_fraction*100.0,
                            recent_avg_survival_fraction()*100.0);
     gclog_or_tty->print_cr("       Recent %% gc pause time: %6.2f",
                            recent_avg_pause_time_ratio() * 100.0);
   }
   double other_time_ms = elapsed_ms;
   if (!abandoned) {
     if (_satb_drain_time_set)
       other_time_ms -= _cur_satb_drain_time_ms;
     if (parallel)
       other_time_ms -= _cur_collection_par_time_ms + _cur_clear_ct_time_ms;
     else
       other_time_ms -=
         update_rs_time +
         ext_root_scan_time + mark_stack_scan_time + scan_only_time +
         scan_rs_time + obj_copy_time;
   }
   if (PrintGCDetails) {
     gclog_or_tty->print_cr("%s%s, %1.8lf secs]",
                            abandoned ? " (abandoned)" : "",
                            (last_pause_included_initial_mark) ? " (initial-mark)" : "",
                            elapsed_ms / 1000.0);
     if (!abandoned) {
       if (_satb_drain_time_set) {
         print_stats(1, "SATB Drain Time", _cur_satb_drain_time_ms);
       }
       if (_last_satb_drain_processed_buffers >= 0) {
         print_stats(2, "Processed Buffers", _last_satb_drain_processed_buffers);
       }
       if (parallel) {
         print_stats(1, "Parallel Time", _cur_collection_par_time_ms);
         print_par_stats(2, "Update RS (Start)", _par_last_update_rs_start_times_ms, false);
         print_par_stats(2, "Update RS", _par_last_update_rs_times_ms);
         print_par_buffers(3, "Processed Buffers",
                           _par_last_update_rs_processed_buffers, true);
         print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
         print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms);
         print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms);
         print_par_buffers(3, "Scan-Only Regions",
                           _par_last_scan_only_regions_scanned, true);
         print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
         print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
         print_par_stats(2, "Termination", _par_last_termination_times_ms);
         print_stats(2, "Other", parallel_other_time);
         print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
       } else {
         print_stats(1, "Update RS", update_rs_time);
         print_stats(2, "Processed Buffers",
                     (int)update_rs_processed_buffers);
         print_stats(1, "Ext Root Scanning", ext_root_scan_time);
         print_stats(1, "Mark Stack Scanning", mark_stack_scan_time);
         print_stats(1, "Scan-Only Scanning", scan_only_time);
         print_stats(1, "Scan RS", scan_rs_time);
         print_stats(1, "Object Copying", obj_copy_time);
       }
     }
     print_stats(1, "Other", other_time_ms);
     for (int i = 0; i < _aux_num; ++i) {
       if (_cur_aux_times_set[i]) {
         char buffer[96];
         sprintf(buffer, "Aux%d", i);
         print_stats(1, buffer, _cur_aux_times_ms[i]);
       }
     }
   }
   if (PrintGCDetails)
     gclog_or_tty->print("   [");
   if (PrintGC || PrintGCDetails)
     _g1->print_size_transition(gclog_or_tty,
                                _cur_collection_pause_used_at_start_bytes,
                                _g1->used(), _g1->capacity());
   if (PrintGCDetails)
     gclog_or_tty->print_cr("]");
   _all_pause_times_ms->add(elapsed_ms);
   if (update_stats) {
     summary->record_total_time_ms(elapsed_ms);
     summary->record_other_time_ms(other_time_ms);
   }
   for (int i = 0; i < _aux_num; ++i)
     if (_cur_aux_times_set[i])
       _all_aux_times_ms[i].add(_cur_aux_times_ms[i]);
   // Reset marks-between-pauses counter.
   _n_marks_since_last_pause = 0;
   // Update the efficiency-since-mark vars.
   double proc_ms = elapsed_ms * (double) _parallel_gc_threads;
   if (elapsed_ms < MIN_TIMER_GRANULARITY) {
     // This usually happens due to the timer not having the required
     // granularity. Some Linuxes are the usual culprits.
     // We'll just set it to something (arbitrarily) small.
     proc_ms = 1.0;
   }
   double cur_efficiency = (double) freed_bytes / proc_ms;
   bool new_in_marking_window = _in_marking_window;
   bool new_in_marking_window_im = false;
   if (_should_initiate_conc_mark) {
     new_in_marking_window = true;
     new_in_marking_window_im = true;
   }
   if (in_young_gc_mode()) {
     if (_last_full_young_gc) {
       set_full_young_gcs(false);
       _last_full_young_gc = false;
     }
     if ( !_last_young_gc_full ) {
       if ( _should_revert_to_full_young_gcs ||
            _known_garbage_ratio < 0.05 ||
            (adaptive_young_list_length() &&
            (get_gc_eff_factor() * cur_efficiency < predict_young_gc_eff())) ) {
         set_full_young_gcs(true);
       }
     }
     _should_revert_to_full_young_gcs = false;
     if (_last_young_gc_full && !_during_marking)
       _young_gc_eff_seq->add(cur_efficiency);
   }
   _short_lived_surv_rate_group->start_adding_regions();
   // do that for any other surv rate groupsx
   // <NEW PREDICTION>
   if (update_stats) {
     double pause_time_ms = elapsed_ms;
     size_t diff = 0;
     if (_max_pending_cards >= _pending_cards)
       diff = _max_pending_cards - _pending_cards;
     _pending_card_diff_seq->add((double) diff);
     double cost_per_card_ms = 0.0;
     if (_pending_cards > 0) {
       cost_per_card_ms = update_rs_time / (double) _pending_cards;
       _cost_per_card_ms_seq->add(cost_per_card_ms);
     }
     double cost_per_scan_only_region_ms = 0.0;
     if (scan_only_regions_scanned > 0.0) {
       cost_per_scan_only_region_ms =
         scan_only_time / scan_only_regions_scanned;
       if (_in_marking_window_im)
         _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms);
       else
         _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms);
     }
     size_t cards_scanned = _g1->cards_scanned();
     double cost_per_entry_ms = 0.0;
     if (cards_scanned > 10) {
       cost_per_entry_ms = scan_rs_time / (double) cards_scanned;
       if (_last_young_gc_full)
         _cost_per_entry_ms_seq->add(cost_per_entry_ms);
       else
         _partially_young_cost_per_entry_ms_seq->add(cost_per_entry_ms);
     }
     if (_max_rs_lengths > 0) {
       double cards_per_entry_ratio =
         (double) cards_scanned / (double) _max_rs_lengths;
       if (_last_young_gc_full)
         _fully_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
       else
         _partially_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
     }
     size_t rs_length_diff = _max_rs_lengths - _recorded_rs_lengths;
     if (rs_length_diff >= 0)
       _rs_length_diff_seq->add((double) rs_length_diff);
     size_t copied_bytes = surviving_bytes;
     double cost_per_byte_ms = 0.0;
     if (copied_bytes > 0) {
       cost_per_byte_ms = obj_copy_time / (double) copied_bytes;
       if (_in_marking_window)
         _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
       else
         _cost_per_byte_ms_seq->add(cost_per_byte_ms);
     }
     double all_other_time_ms = pause_time_ms -
       (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time +
        _mark_closure_time_ms + termination_time);
     double young_other_time_ms = 0.0;
     if (_recorded_young_regions > 0) {
       young_other_time_ms =
         _recorded_young_cset_choice_time_ms +
         _recorded_young_free_cset_time_ms;
       _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
                                              (double) _recorded_young_regions);
     }
     double non_young_other_time_ms = 0.0;
     if (_recorded_non_young_regions > 0) {
       non_young_other_time_ms =
         _recorded_non_young_cset_choice_time_ms +
         _recorded_non_young_free_cset_time_ms;
       _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
                                          (double) _recorded_non_young_regions);
     }
     double constant_other_time_ms = all_other_time_ms -
       (young_other_time_ms + non_young_other_time_ms);
     _constant_other_time_ms_seq->add(constant_other_time_ms);
     double survival_ratio = 0.0;
     if (_bytes_in_collection_set_before_gc > 0) {
       survival_ratio = (double) bytes_in_to_space_during_gc() /
         (double) _bytes_in_collection_set_before_gc;
     }
     _pending_cards_seq->add((double) _pending_cards);
     _scanned_cards_seq->add((double) cards_scanned);
     _rs_lengths_seq->add((double) _max_rs_lengths);
     double expensive_region_limit_ms =
       (double) MaxGCPauseMillis - predict_constant_other_time_ms();
     if (expensive_region_limit_ms < 0.0) {
       // this means that the other time was predicted to be longer than
       // than the max pause time
       expensive_region_limit_ms = (double) MaxGCPauseMillis;
     }
     _expensive_region_limit_ms = expensive_region_limit_ms;
     if (PREDICTIONS_VERBOSE) {
       gclog_or_tty->print_cr("");
       gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
                     "REGIONS %d %d %d %d "
                     "PENDING_CARDS %d %d "
                     "CARDS_SCANNED %d %d "
                     "RS_LENGTHS %d %d "
                     "SCAN_ONLY_SCAN %1.6lf %1.6lf "
                     "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
                     "SURVIVAL_RATIO %1.6lf %1.6lf "
                     "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
                     "OTHER_YOUNG %1.6lf %1.6lf "
                     "OTHER_NON_YOUNG %1.6lf %1.6lf "
                     "VTIME_DIFF %1.6lf TERMINATION %1.6lf "
                     "ELAPSED %1.6lf %1.6lf ",
                     _cur_collection_start_sec,
                     (!_last_young_gc_full) ? 2 :
                     (last_pause_included_initial_mark) ? 1 : 0,
                     _recorded_region_num,
                     _recorded_young_regions,
                     _recorded_scan_only_regions,
                     _recorded_non_young_regions,
                     _predicted_pending_cards, _pending_cards,
                     _predicted_cards_scanned, cards_scanned,
                     _predicted_rs_lengths, _max_rs_lengths,
                     _predicted_scan_only_scan_time_ms, scan_only_time,
                     _predicted_rs_update_time_ms, update_rs_time,
                     _predicted_rs_scan_time_ms, scan_rs_time,
                     _predicted_survival_ratio, survival_ratio,
                     _predicted_object_copy_time_ms, obj_copy_time,
                     _predicted_constant_other_time_ms, constant_other_time_ms,
                     _predicted_young_other_time_ms, young_other_time_ms,
                     _predicted_non_young_other_time_ms,
                     non_young_other_time_ms,
                     _vtime_diff_ms, termination_time,
                     _predicted_pause_time_ms, elapsed_ms);
     }
     if (G1PolicyVerbose > 0) {
       gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms",
                     _predicted_pause_time_ms,
                     (_within_target) ? "within" : "outside",
                     elapsed_ms);
     }
   }
   _in_marking_window = new_in_marking_window;
   _in_marking_window_im = new_in_marking_window_im;
   _free_regions_at_end_of_collection = _g1->free_regions();
   _scan_only_regions_at_end_of_collection = _g1->young_list_length();
   calculate_young_list_min_length();
   calculate_young_list_target_config();
   // </NEW PREDICTION>
   _target_pause_time_ms = -1.0;
 }
 // <NEW PREDICTION>
 double
 G1CollectorPolicy::
 predict_young_collection_elapsed_time_ms(size_t adjustment) {
   guarantee( adjustment == 0 || adjustment == 1, "invariant" );
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   size_t young_num = g1h->young_list_length();
   if (young_num == 0)
     return 0.0;
   young_num += adjustment;
   size_t pending_cards = predict_pending_cards();
   size_t rs_lengths = g1h->young_list_sampled_rs_lengths() +
                       predict_rs_length_diff();
   size_t card_num;
   if (full_young_gcs())
     card_num = predict_young_card_num(rs_lengths);
   else
     card_num = predict_non_young_card_num(rs_lengths);
   size_t young_byte_size = young_num * HeapRegion::GrainBytes;
   double accum_yg_surv_rate =
     _short_lived_surv_rate_group->accum_surv_rate(adjustment);
   size_t bytes_to_copy =
     (size_t) (accum_yg_surv_rate * (double) HeapRegion::GrainBytes);
   return
     predict_rs_update_time_ms(pending_cards) +
     predict_rs_scan_time_ms(card_num) +
     predict_object_copy_time_ms(bytes_to_copy) +
     predict_young_other_time_ms(young_num) +
     predict_constant_other_time_ms();
 }
 double
 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) {
   size_t rs_length = predict_rs_length_diff();
   size_t card_num;
   if (full_young_gcs())
     card_num = predict_young_card_num(rs_length);
   else
     card_num = predict_non_young_card_num(rs_length);
   return predict_base_elapsed_time_ms(pending_cards, card_num);
 }
 double
 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards,
                                                 size_t scanned_cards) {
   return
     predict_rs_update_time_ms(pending_cards) +
     predict_rs_scan_time_ms(scanned_cards) +
     predict_constant_other_time_ms();
 }
 double
 G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr,
                                                   bool young) {
   size_t rs_length = hr->rem_set()->occupied();
   size_t card_num;
   if (full_young_gcs())
     card_num = predict_young_card_num(rs_length);
   else
     card_num = predict_non_young_card_num(rs_length);
   size_t bytes_to_copy = predict_bytes_to_copy(hr);
   double region_elapsed_time_ms =
     predict_rs_scan_time_ms(card_num) +
     predict_object_copy_time_ms(bytes_to_copy);
   if (young)
     region_elapsed_time_ms += predict_young_other_time_ms(1);
   else
     region_elapsed_time_ms += predict_non_young_other_time_ms(1);
   return region_elapsed_time_ms;
 }
 size_t
 G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) {
   size_t bytes_to_copy;
   if (hr->is_marked())
     bytes_to_copy = hr->max_live_bytes();
   else {
     guarantee( hr->is_young() && hr->age_in_surv_rate_group() != -1,
                "invariant" );
     int age = hr->age_in_surv_rate_group();
     double yg_surv_rate = predict_yg_surv_rate(age, hr->surv_rate_group());
     bytes_to_copy = (size_t) ((double) hr->used() * yg_surv_rate);
   }
   return bytes_to_copy;
 }
 void
 G1CollectorPolicy::start_recording_regions() {
   _recorded_rs_lengths            = 0;
   _recorded_scan_only_regions     = 0;
   _recorded_young_regions         = 0;
   _recorded_non_young_regions     = 0;
 #if PREDICTIONS_VERBOSE
   _predicted_rs_lengths           = 0;
   _predicted_cards_scanned        = 0;
   _recorded_marked_bytes          = 0;
   _recorded_young_bytes           = 0;
   _predicted_bytes_to_copy        = 0;
 #endif // PREDICTIONS_VERBOSE
 }
 void
 G1CollectorPolicy::record_cset_region(HeapRegion* hr, bool young) {
   if (young) {
     ++_recorded_young_regions;
   } else {
     ++_recorded_non_young_regions;
   }
 #if PREDICTIONS_VERBOSE
   if (young) {
     _recorded_young_bytes += hr->used();
   } else {
     _recorded_marked_bytes += hr->max_live_bytes();
   }
   _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
 #endif // PREDICTIONS_VERBOSE
   size_t rs_length = hr->rem_set()->occupied();
   _recorded_rs_lengths += rs_length;
 }
 void
 G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) {
   _recorded_scan_only_regions = scan_only_length;
 }
 void
 G1CollectorPolicy::end_recording_regions() {
 #if PREDICTIONS_VERBOSE
   _predicted_pending_cards = predict_pending_cards();
   _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
   if (full_young_gcs())
     _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths);
   else
     _predicted_cards_scanned +=
       predict_non_young_card_num(_predicted_rs_lengths);
   _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
   _predicted_scan_only_scan_time_ms =
     predict_scan_only_time_ms(_recorded_scan_only_regions);
   _predicted_rs_update_time_ms =
     predict_rs_update_time_ms(_g1->pending_card_num());
   _predicted_rs_scan_time_ms =
     predict_rs_scan_time_ms(_predicted_cards_scanned);
   _predicted_object_copy_time_ms =
     predict_object_copy_time_ms(_predicted_bytes_to_copy);
   _predicted_constant_other_time_ms =
     predict_constant_other_time_ms();
   _predicted_young_other_time_ms =
     predict_young_other_time_ms(_recorded_young_regions);
   _predicted_non_young_other_time_ms =
     predict_non_young_other_time_ms(_recorded_non_young_regions);
   _predicted_pause_time_ms =
     _predicted_scan_only_scan_time_ms +
     _predicted_rs_update_time_ms +
     _predicted_rs_scan_time_ms +
     _predicted_object_copy_time_ms +
     _predicted_constant_other_time_ms +
     _predicted_young_other_time_ms +
     _predicted_non_young_other_time_ms;
 #endif // PREDICTIONS_VERBOSE
 }
 void G1CollectorPolicy::check_if_region_is_too_expensive(double
                                                            predicted_time_ms) {
   // I don't think we need to do this when in young GC mode since
   // marking will be initiated next time we hit the soft limit anyway...
   if (predicted_time_ms > _expensive_region_limit_ms) {
     if (!in_young_gc_mode()) {
         set_full_young_gcs(true);
       _should_initiate_conc_mark = true;
     } else
       // no point in doing another partial one
       _should_revert_to_full_young_gcs = true;
   }
 }
 // </NEW PREDICTION>
 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
                                                double elapsed_ms) {
   _recent_gc_times_ms->add(elapsed_ms);
   _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
   _prev_collection_pause_end_ms = end_time_sec * 1000.0;
 }
 double G1CollectorPolicy::recent_avg_time_for_pauses_ms() {
   if (_recent_pause_times_ms->num() == 0) return (double) MaxGCPauseMillis;
   else return _recent_pause_times_ms->avg();
 }
 double G1CollectorPolicy::recent_avg_time_for_CH_strong_ms() {
   if (_recent_CH_strong_roots_times_ms->num() == 0)
     return (double)MaxGCPauseMillis/3.0;
   else return _recent_CH_strong_roots_times_ms->avg();
 }
 double G1CollectorPolicy::recent_avg_time_for_G1_strong_ms() {
   if (_recent_G1_strong_roots_times_ms->num() == 0)
     return (double)MaxGCPauseMillis/3.0;
   else return _recent_G1_strong_roots_times_ms->avg();
 }
 double G1CollectorPolicy::recent_avg_time_for_evac_ms() {
   if (_recent_evac_times_ms->num() == 0) return (double)MaxGCPauseMillis/3.0;
   else return _recent_evac_times_ms->avg();
 }
 int G1CollectorPolicy::number_of_recent_gcs() {
   assert(_recent_CH_strong_roots_times_ms->num() ==
          _recent_G1_strong_roots_times_ms->num(), "Sequence out of sync");
   assert(_recent_G1_strong_roots_times_ms->num() ==
          _recent_evac_times_ms->num(), "Sequence out of sync");
   assert(_recent_evac_times_ms->num() ==
          _recent_pause_times_ms->num(), "Sequence out of sync");
   assert(_recent_pause_times_ms->num() ==
          _recent_CS_bytes_used_before->num(), "Sequence out of sync");
   assert(_recent_CS_bytes_used_before->num() ==
          _recent_CS_bytes_surviving->num(), "Sequence out of sync");
   return _recent_pause_times_ms->num();
 }
 double G1CollectorPolicy::recent_avg_survival_fraction() {
   return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving,
                                            _recent_CS_bytes_used_before);
 }
 double G1CollectorPolicy::last_survival_fraction() {
   return last_survival_fraction_work(_recent_CS_bytes_surviving,
                                      _recent_CS_bytes_used_before);
 }
 double
 G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving,
                                                      TruncatedSeq* before) {
   assert(surviving->num() == before->num(), "Sequence out of sync");
   if (before->sum() > 0.0) {
       double recent_survival_rate = surviving->sum() / before->sum();
       // We exempt parallel collection from this check because Alloc Buffer
       // fragmentation can produce negative collections.
       // Further, we're now always doing parallel collection.  But I'm still
       // leaving this here as a placeholder for a more precise assertion later.
       // (DLD, 10/05.)
       assert((true || ParallelGCThreads > 0) ||
              _g1->evacuation_failed() ||
              recent_survival_rate <= 1.0, "Or bad frac");
       return recent_survival_rate;
   } else {
     return 1.0; // Be conservative.
   }
 }
 double
 G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving,
                                                TruncatedSeq* before) {
   assert(surviving->num() == before->num(), "Sequence out of sync");
   if (surviving->num() > 0 && before->last() > 0.0) {
     double last_survival_rate = surviving->last() / before->last();
     // We exempt parallel collection from this check because Alloc Buffer
     // fragmentation can produce negative collections.
     // Further, we're now always doing parallel collection.  But I'm still
     // leaving this here as a placeholder for a more precise assertion later.
     // (DLD, 10/05.)
     assert((true || ParallelGCThreads > 0) ||
            last_survival_rate <= 1.0, "Or bad frac");
     return last_survival_rate;
   } else {
     return 1.0;
   }
 }
 static const int survival_min_obs = 5;
 static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 };
 static const double min_survival_rate = 0.1;
 double
 G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg,
                                                            double latest) {
   double res = avg;
   if (number_of_recent_gcs() < survival_min_obs) {
     res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]);
   }
   res = MAX2(res, latest);
   res = MAX2(res, min_survival_rate);
   // In the parallel case, LAB fragmentation can produce "negative
   // collections"; so can evac failure.  Cap at 1.0
   res = MIN2(res, 1.0);
   return res;
 }
 size_t G1CollectorPolicy::expansion_amount() {
   if ((int)(recent_avg_pause_time_ratio() * 100.0) > G1GCPercent) {
     // We will double the existing space, or take
     // G1ExpandByPercentOfAvailable % of the available expansion
     // space, whichever is smaller, bounded below by a minimum
     // expansion (unless that's all that's left.)
     const size_t min_expand_bytes = 1*M;
     size_t reserved_bytes = _g1->g1_reserved_obj_bytes();
     size_t committed_bytes = _g1->capacity();
     size_t uncommitted_bytes = reserved_bytes - committed_bytes;
     size_t expand_bytes;
     size_t expand_bytes_via_pct =
       uncommitted_bytes * G1ExpandByPercentOfAvailable / 100;
     expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes);
     expand_bytes = MAX2(expand_bytes, min_expand_bytes);
     expand_bytes = MIN2(expand_bytes, uncommitted_bytes);
     if (G1PolicyVerbose > 1) {
       gclog_or_tty->print("Decided to expand: ratio = %5.2f, "
                  "committed = %d%s, uncommited = %d%s, via pct = %d%s.\n"
                  "                   Answer = %d.\n",
                  recent_avg_pause_time_ratio(),
                  byte_size_in_proper_unit(committed_bytes),
                  proper_unit_for_byte_size(committed_bytes),
                  byte_size_in_proper_unit(uncommitted_bytes),
                  proper_unit_for_byte_size(uncommitted_bytes),
                  byte_size_in_proper_unit(expand_bytes_via_pct),
                  proper_unit_for_byte_size(expand_bytes_via_pct),
                  byte_size_in_proper_unit(expand_bytes),
                  proper_unit_for_byte_size(expand_bytes));
     }
     return expand_bytes;
   } else {
     return 0;
   }
 }
 void G1CollectorPolicy::note_start_of_mark_thread() {
   _mark_thread_startup_sec = os::elapsedTime();
 }
 class CountCSClosure: public HeapRegionClosure {
   G1CollectorPolicy* _g1_policy;
 public:
   CountCSClosure(G1CollectorPolicy* g1_policy) :
     _g1_policy(g1_policy) {}
   bool doHeapRegion(HeapRegion* r) {
     _g1_policy->_bytes_in_collection_set_before_gc += r->used();
     return false;
   }
 };
 void G1CollectorPolicy::count_CS_bytes_used() {
   CountCSClosure cs_closure(this);
   _g1->collection_set_iterate(&cs_closure);
 }
 static void print_indent(int level) {
   for (int j = 0; j < level+1; ++j)
     gclog_or_tty->print("   ");
 }
 void G1CollectorPolicy::print_summary (int level,
                                        const char* str,
                                        NumberSeq* seq) const {
   double sum = seq->sum();
   print_indent(level);
   gclog_or_tty->print_cr("%-24s = %8.2lf s (avg = %8.2lf ms)",
                 str, sum / 1000.0, seq->avg());
 }
 void G1CollectorPolicy::print_summary_sd (int level,
                                           const char* str,
                                           NumberSeq* seq) const {
   print_summary(level, str, seq);
   print_indent(level + 5);
   gclog_or_tty->print_cr("(num = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
                 seq->num(), seq->sd(), seq->maximum());
 }
 void G1CollectorPolicy::check_other_times(int level,
                                         NumberSeq* other_times_ms,
                                         NumberSeq* calc_other_times_ms) const {
   bool should_print = false;
   double max_sum = MAX2(fabs(other_times_ms->sum()),
                         fabs(calc_other_times_ms->sum()));
   double min_sum = MIN2(fabs(other_times_ms->sum()),
                         fabs(calc_other_times_ms->sum()));
   double sum_ratio = max_sum / min_sum;
   if (sum_ratio > 1.1) {
     should_print = true;
     print_indent(level + 1);
     gclog_or_tty->print_cr("## CALCULATED OTHER SUM DOESN'T MATCH RECORDED ###");
   }
   double max_avg = MAX2(fabs(other_times_ms->avg()),
                         fabs(calc_other_times_ms->avg()));
   double min_avg = MIN2(fabs(other_times_ms->avg()),
                         fabs(calc_other_times_ms->avg()));
   double avg_ratio = max_avg / min_avg;
   if (avg_ratio > 1.1) {
     should_print = true;
     print_indent(level + 1);
     gclog_or_tty->print_cr("## CALCULATED OTHER AVG DOESN'T MATCH RECORDED ###");
   }
   if (other_times_ms->sum() < -0.01) {
     print_indent(level + 1);
     gclog_or_tty->print_cr("## RECORDED OTHER SUM IS NEGATIVE ###");
   }
   if (other_times_ms->avg() < -0.01) {
     print_indent(level + 1);
     gclog_or_tty->print_cr("## RECORDED OTHER AVG IS NEGATIVE ###");
   }
   if (calc_other_times_ms->sum() < -0.01) {
     should_print = true;
     print_indent(level + 1);
     gclog_or_tty->print_cr("## CALCULATED OTHER SUM IS NEGATIVE ###");
   }
   if (calc_other_times_ms->avg() < -0.01) {
     should_print = true;
     print_indent(level + 1);
     gclog_or_tty->print_cr("## CALCULATED OTHER AVG IS NEGATIVE ###");
   }
   if (should_print)
     print_summary(level, "Other(Calc)", calc_other_times_ms);
 }
 void G1CollectorPolicy::print_summary(PauseSummary* summary) const {
   bool parallel = ParallelGCThreads > 0;
   MainBodySummary*    body_summary = summary->main_body_summary();
   if (summary->get_total_seq()->num() > 0) {
     print_summary_sd(0, "Evacuation Pauses", summary->get_total_seq());
     if (body_summary != NULL) {
       print_summary(1, "SATB Drain", body_summary->get_satb_drain_seq());
       if (parallel) {
         print_summary(1, "Parallel Time", body_summary->get_parallel_seq());
         print_summary(2, "Update RS", body_summary->get_update_rs_seq());
         print_summary(2, "Ext Root Scanning",
                       body_summary->get_ext_root_scan_seq());
         print_summary(2, "Mark Stack Scanning",
                       body_summary->get_mark_stack_scan_seq());
         print_summary(2, "Scan-Only Scanning",
                       body_summary->get_scan_only_seq());
         print_summary(2, "Scan RS", body_summary->get_scan_rs_seq());
         print_summary(2, "Object Copy", body_summary->get_obj_copy_seq());
         print_summary(2, "Termination", body_summary->get_termination_seq());
         print_summary(2, "Other", body_summary->get_parallel_other_seq());
         {
           NumberSeq* other_parts[] = {
             body_summary->get_update_rs_seq(),
             body_summary->get_ext_root_scan_seq(),
             body_summary->get_mark_stack_scan_seq(),
             body_summary->get_scan_only_seq(),
             body_summary->get_scan_rs_seq(),
             body_summary->get_obj_copy_seq(),
             body_summary->get_termination_seq()
           };
           NumberSeq calc_other_times_ms(body_summary->get_parallel_seq(),
 , other_parts);
           check_other_times(2, body_summary->get_parallel_other_seq(),
                             &calc_other_times_ms);
         }
         print_summary(1, "Mark Closure", body_summary->get_mark_closure_seq());
         print_summary(1, "Clear CT", body_summary->get_clear_ct_seq());
       } else {
         print_summary(1, "Update RS", body_summary->get_update_rs_seq());
         print_summary(1, "Ext Root Scanning",
                       body_summary->get_ext_root_scan_seq());
         print_summary(1, "Mark Stack Scanning",
                       body_summary->get_mark_stack_scan_seq());
         print_summary(1, "Scan-Only Scanning",
                       body_summary->get_scan_only_seq());
         print_summary(1, "Scan RS", body_summary->get_scan_rs_seq());
         print_summary(1, "Object Copy", body_summary->get_obj_copy_seq());
       }
     }
     print_summary(1, "Other", summary->get_other_seq());
     {
       NumberSeq calc_other_times_ms;
       if (body_summary != NULL) {
         // not abandoned
         if (parallel) {
           // parallel
           NumberSeq* other_parts[] = {
             body_summary->get_satb_drain_seq(),
             body_summary->get_parallel_seq(),
             body_summary->get_clear_ct_seq()
           };
           calc_other_times_ms = NumberSeq(summary->get_total_seq(),
 , other_parts);
         } else {
           // serial
           NumberSeq* other_parts[] = {
             body_summary->get_satb_drain_seq(),
             body_summary->get_update_rs_seq(),
             body_summary->get_ext_root_scan_seq(),
             body_summary->get_mark_stack_scan_seq(),
             body_summary->get_scan_only_seq(),
             body_summary->get_scan_rs_seq(),
             body_summary->get_obj_copy_seq()
           };
           calc_other_times_ms = NumberSeq(summary->get_total_seq(),
 , other_parts);
         }
       } else {
         // abandoned
         calc_other_times_ms = NumberSeq();
       }
       check_other_times(1,  summary->get_other_seq(), &calc_other_times_ms);
     }
   } else {
     print_indent(0);
     gclog_or_tty->print_cr("none");
   }
   gclog_or_tty->print_cr("");
 }
 void
 G1CollectorPolicy::print_abandoned_summary(PauseSummary* summary) const {
   bool printed = false;
   if (summary->get_total_seq()->num() > 0) {
     printed = true;
     print_summary(summary);
   }
   if (!printed) {
     print_indent(0);
     gclog_or_tty->print_cr("none");
     gclog_or_tty->print_cr("");
   }
 }
 void G1CollectorPolicy::print_tracing_info() const {
   if (TraceGen0Time) {
     gclog_or_tty->print_cr("ALL PAUSES");
     print_summary_sd(0, "Total", _all_pause_times_ms);
     gclog_or_tty->print_cr("");
     gclog_or_tty->print_cr("");
     gclog_or_tty->print_cr("   Full Young GC Pauses:    %8d", _full_young_pause_num);
     gclog_or_tty->print_cr("   Partial Young GC Pauses: %8d", _partial_young_pause_num);
     gclog_or_tty->print_cr("");
     gclog_or_tty->print_cr("EVACUATION PAUSES");
     print_summary(_summary);
     gclog_or_tty->print_cr("ABANDONED PAUSES");
     print_abandoned_summary(_abandoned_summary);
     gclog_or_tty->print_cr("MISC");
     print_summary_sd(0, "Stop World", _all_stop_world_times_ms);
     print_summary_sd(0, "Yields", _all_yield_times_ms);
     for (int i = 0; i < _aux_num; ++i) {
       if (_all_aux_times_ms[i].num() > 0) {
         char buffer[96];
         sprintf(buffer, "Aux%d", i);
         print_summary_sd(0, buffer, &_all_aux_times_ms[i]);
       }
     }
     size_t all_region_num = _region_num_young + _region_num_tenured;
     gclog_or_tty->print_cr("   New Regions %8d, Young %8d (%6.2lf%%), "
                "Tenured %8d (%6.2lf%%)",
                all_region_num,
                _region_num_young,
                (double) _region_num_young / (double) all_region_num * 100.0,
                _region_num_tenured,
                (double) _region_num_tenured / (double) all_region_num * 100.0);
   }
   if (TraceGen1Time) {
     if (_all_full_gc_times_ms->num() > 0) {
       gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s",
                  _all_full_gc_times_ms->num(),
                  _all_full_gc_times_ms->sum() / 1000.0);
       gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times_ms->avg());
       gclog_or_tty->print_cr("                     [std. dev = %8.2f ms, max = %8.2f ms]",
                     _all_full_gc_times_ms->sd(),
                     _all_full_gc_times_ms->maximum());
     }
   }
 }
 void G1CollectorPolicy::print_yg_surv_rate_info() const {
 #ifndef PRODUCT
   _short_lived_surv_rate_group->print_surv_rate_summary();
   // add this call for any other surv rate groups
 #endif // PRODUCT
 }
 bool
 G1CollectorPolicy::should_add_next_region_to_young_list() {
   assert(in_young_gc_mode(), "should be in young GC mode");
   bool ret;
   size_t young_list_length = _g1->young_list_length();
   size_t young_list_max_length = _young_list_target_length;
   if (G1FixedEdenSize) {
     young_list_max_length -= _max_survivor_regions;
   }
   if (young_list_length < young_list_max_length) {
     ret = true;
     ++_region_num_young;
   } else {
     ret = false;
     ++_region_num_tenured;
   }
   return ret;
 }
 #ifndef PRODUCT
 // for debugging, bit of a hack...
 static char*
 region_num_to_mbs(int length) {
   static char buffer[64];
   double bytes = (double) (length * HeapRegion::GrainBytes);
   double mbs = bytes / (double) (1024 * 1024);
   sprintf(buffer, "%7.2lfMB", mbs);
   return buffer;
 }
 #endif // PRODUCT
 void
 G1CollectorPolicy::checkpoint_conc_overhead() {
   double conc_overhead = 0.0;
   if (G1AccountConcurrentOverhead)
     conc_overhead = COTracker::totalPredConcOverhead();
   _mmu_tracker->update_conc_overhead(conc_overhead);
 #if 0
   gclog_or_tty->print(" CO %1.4lf TARGET %1.4lf",
              conc_overhead, _mmu_tracker->max_gc_time());
 #endif
 }
 size_t G1CollectorPolicy::max_regions(int purpose) {
   switch (purpose) {
     case GCAllocForSurvived:
       return _max_survivor_regions;
     case GCAllocForTenured:
       return REGIONS_UNLIMITED;
     default:
       ShouldNotReachHere();
       return REGIONS_UNLIMITED;
   };
 }
 // Calculates survivor space parameters.
 void G1CollectorPolicy::calculate_survivors_policy()
 {
   if (!G1UseSurvivorSpaces) {
     return;
   }
   if (G1FixedSurvivorSpaceSize == 0) {
     _max_survivor_regions = _young_list_target_length / SurvivorRatio;
   } else {
     _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
   }
   if (G1FixedTenuringThreshold) {
     _tenuring_threshold = MaxTenuringThreshold;
   } else {
     _tenuring_threshold = _survivors_age_table.compute_tenuring_threshold(
         HeapRegion::GrainWords * _max_survivor_regions);
   }
 }
 bool
 G1CollectorPolicy_BestRegionsFirst::should_do_collection_pause(size_t
                                                                word_size) {
   assert(_g1->regions_accounted_for(), "Region leakage!");
   // Initiate a pause when we reach the steady-state "used" target.
   size_t used_hard = (_g1->capacity() / 100) * G1SteadyStateUsed;
   size_t used_soft =
    MAX2((_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta),
         used_hard/2);
   size_t used = _g1->used();
   double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
   size_t young_list_length = _g1->young_list_length();
   size_t young_list_max_length = _young_list_target_length;
   if (G1FixedEdenSize) {
     young_list_max_length -= _max_survivor_regions;
   }
   bool reached_target_length = young_list_length >= young_list_max_length;
   if (in_young_gc_mode()) {
     if (reached_target_length) {
       assert( young_list_length > 0 && _g1->young_list_length() > 0,
               "invariant" );
       _target_pause_time_ms = max_pause_time_ms;
       return true;
     }
   } else {
     guarantee( false, "should not reach here" );
   }
   return false;
 }
 #ifndef PRODUCT
 class HRSortIndexIsOKClosure: public HeapRegionClosure {
   CollectionSetChooser* _chooser;
 public:
   HRSortIndexIsOKClosure(CollectionSetChooser* chooser) :
     _chooser(chooser) {}
   bool doHeapRegion(HeapRegion* r) {
     if (!r->continuesHumongous()) {
       assert(_chooser->regionProperlyOrdered(r), "Ought to be.");
     }
     return false;
   }
 };
 bool G1CollectorPolicy_BestRegionsFirst::assertMarkedBytesDataOK() {
   HRSortIndexIsOKClosure cl(_collectionSetChooser);
   _g1->heap_region_iterate(&cl);
   return true;
 }
 #endif
 void
 G1CollectorPolicy_BestRegionsFirst::
 record_collection_pause_start(double start_time_sec, size_t start_used) {
   G1CollectorPolicy::record_collection_pause_start(start_time_sec, start_used);
 }
 class NextNonCSElemFinder: public HeapRegionClosure {
   HeapRegion* _res;
 public:
   NextNonCSElemFinder(): _res(NULL) {}
   bool doHeapRegion(HeapRegion* r) {
     if (!r->in_collection_set()) {
       _res = r;
       return true;
     } else {
       return false;
     }
   }
   HeapRegion* res() { return _res; }
 };
 class KnownGarbageClosure: public HeapRegionClosure {
   CollectionSetChooser* _hrSorted;
 public:
   KnownGarbageClosure(CollectionSetChooser* hrSorted) :
     _hrSorted(hrSorted)
   {}
   bool doHeapRegion(HeapRegion* r) {
     // We only include humongous regions in collection
     // sets when concurrent mark shows that their contained object is
     // unreachable.
     // Do we have any marking information for this region?
     if (r->is_marked()) {
       // We don't include humongous regions in collection
       // sets because we collect them immediately at the end of a marking
       // cycle.  We also don't include young regions because we *must*
       // include them in the next collection pause.
       if (!r->isHumongous() && !r->is_young()) {
         _hrSorted->addMarkedHeapRegion(r);
       }
     }
     return false;
   }
 };
 class ParKnownGarbageHRClosure: public HeapRegionClosure {
   CollectionSetChooser* _hrSorted;
   jint _marked_regions_added;
   jint _chunk_size;
   jint _cur_chunk_idx;
   jint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end)
   int _worker;
   int _invokes;
   void get_new_chunk() {
     _cur_chunk_idx = _hrSorted->getParMarkedHeapRegionChunk(_chunk_size);
     _cur_chunk_end = _cur_chunk_idx + _chunk_size;
   }
   void add_region(HeapRegion* r) {
     if (_cur_chunk_idx == _cur_chunk_end) {
       get_new_chunk();
     }
     assert(_cur_chunk_idx < _cur_chunk_end, "postcondition");
     _hrSorted->setMarkedHeapRegion(_cur_chunk_idx, r);
     _marked_regions_added++;
     _cur_chunk_idx++;
   }
 public:
   ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
                            jint chunk_size,
                            int worker) :
     _hrSorted(hrSorted), _chunk_size(chunk_size), _worker(worker),
     _marked_regions_added(0), _cur_chunk_idx(0), _cur_chunk_end(0),
     _invokes(0)
   {}
   bool doHeapRegion(HeapRegion* r) {
     // We only include humongous regions in collection
     // sets when concurrent mark shows that their contained object is
     // unreachable.
     _invokes++;
     // Do we have any marking information for this region?
     if (r->is_marked()) {
       // We don't include humongous regions in collection
       // sets because we collect them immediately at the end of a marking
       // cycle.
       // We also do not include young regions in collection sets
       if (!r->isHumongous() && !r->is_young()) {
         add_region(r);
       }
     }
     return false;
   }
   jint marked_regions_added() { return _marked_regions_added; }
   int invokes() { return _invokes; }
 };
 class ParKnownGarbageTask: public AbstractGangTask {
   CollectionSetChooser* _hrSorted;
   jint _chunk_size;
   G1CollectedHeap* _g1;
 public:
   ParKnownGarbageTask(CollectionSetChooser* hrSorted, jint chunk_size) :
     AbstractGangTask("ParKnownGarbageTask"),
     _hrSorted(hrSorted), _chunk_size(chunk_size),
     _g1(G1CollectedHeap::heap())
   {}
   void work(int i) {
     ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size, i);
     // Back to zero for the claim value.
     _g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, i,
                                          HeapRegion::InitialClaimValue);
     jint regions_added = parKnownGarbageCl.marked_regions_added();
     _hrSorted->incNumMarkedHeapRegions(regions_added);
     if (G1PrintParCleanupStats) {
       gclog_or_tty->print("     Thread %d called %d times, added %d regions to list.\n",
                  i, parKnownGarbageCl.invokes(), regions_added);
     }
   }
 };
 void
 G1CollectorPolicy_BestRegionsFirst::
 record_concurrent_mark_cleanup_end(size_t freed_bytes,
                                    size_t max_live_bytes) {
   double start;
   if (G1PrintParCleanupStats) start = os::elapsedTime();
   record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
   _collectionSetChooser->clearMarkedHeapRegions();
   double clear_marked_end;
   if (G1PrintParCleanupStats) {
     clear_marked_end = os::elapsedTime();
     gclog_or_tty->print_cr("  clear marked regions + work1: %8.3f ms.",
                   (clear_marked_end - start)*1000.0);
   }
   if (ParallelGCThreads > 0) {
     const size_t OverpartitionFactor = 4;
     const size_t MinChunkSize = 8;
     const size_t ChunkSize =
       MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor),
            MinChunkSize);
     _collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(),
                                                              ChunkSize);
     ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser,
                                             (int) ChunkSize);
     _g1->workers()->run_task(&parKnownGarbageTask);
     assert(_g1->check_heap_region_claim_values(HeapRegion::InitialClaimValue),
            "sanity check");
   } else {
     KnownGarbageClosure knownGarbagecl(_collectionSetChooser);
     _g1->heap_region_iterate(&knownGarbagecl);
   }
   double known_garbage_end;
   if (G1PrintParCleanupStats) {
     known_garbage_end = os::elapsedTime();
     gclog_or_tty->print_cr("  compute known garbage: %8.3f ms.",
                   (known_garbage_end - clear_marked_end)*1000.0);
   }
   _collectionSetChooser->sortMarkedHeapRegions();
   double sort_end;
   if (G1PrintParCleanupStats) {
     sort_end = os::elapsedTime();
     gclog_or_tty->print_cr("  sorting: %8.3f ms.",
                   (sort_end - known_garbage_end)*1000.0);
   }
   record_concurrent_mark_cleanup_end_work2();
   double work2_end;
   if (G1PrintParCleanupStats) {
     work2_end = os::elapsedTime();
     gclog_or_tty->print_cr("  work2: %8.3f ms.",
                   (work2_end - sort_end)*1000.0);
   }
 }
 // Add the heap region to the collection set and return the conservative
 // estimate of the number of live bytes.
 void G1CollectorPolicy::
 add_to_collection_set(HeapRegion* hr) {
   if (G1PrintRegions) {
     gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], "
                   "top "PTR_FORMAT", young %s",
                   hr->hrs_index(), hr->bottom(), hr->end(),
                   hr->top(), (hr->is_young()) ? "YES" : "NO");
   }
   if (_g1->mark_in_progress())
     _g1->concurrent_mark()->registerCSetRegion(hr);
   assert(!hr->in_collection_set(),
               "should not already be in the CSet");
   hr->set_in_collection_set(true);
   hr->set_next_in_collection_set(_collection_set);
   _collection_set = hr;
   _collection_set_size++;
   _collection_set_bytes_used_before += hr->used();
   _g1->register_region_with_in_cset_fast_test(hr);
 }
 void
 G1CollectorPolicy_BestRegionsFirst::
 choose_collection_set() {
   double non_young_start_time_sec;
   start_recording_regions();
   guarantee(_target_pause_time_ms > -1.0,
             "_target_pause_time_ms should have been set!");
   assert(_collection_set == NULL, "Precondition");
   double base_time_ms = predict_base_elapsed_time_ms(_pending_cards);
   double predicted_pause_time_ms = base_time_ms;
   double target_time_ms = _target_pause_time_ms;
   double time_remaining_ms = target_time_ms - base_time_ms;
   // the 10% and 50% values are arbitrary...
   if (time_remaining_ms < 0.10*target_time_ms) {
     time_remaining_ms = 0.50 * target_time_ms;
     _within_target = false;
   } else {
     _within_target = true;
   }
   // We figure out the number of bytes available for future to-space.
   // For new regions without marking information, we must assume the
   // worst-case of complete survival.  If we have marking information for a
   // region, we can bound the amount of live data.  We can add a number of
   // such regions, as long as the sum of the live data bounds does not
   // exceed the available evacuation space.
   size_t max_live_bytes = _g1->free_regions() * HeapRegion::GrainBytes;
   size_t expansion_bytes =
     _g1->expansion_regions() * HeapRegion::GrainBytes;
   _collection_set_bytes_used_before = 0;
   _collection_set_size = 0;
   // Adjust for expansion and slop.
   max_live_bytes = max_live_bytes + expansion_bytes;
   assert(_g1->regions_accounted_for(), "Region leakage!");
   HeapRegion* hr;
   if (in_young_gc_mode()) {
     double young_start_time_sec = os::elapsedTime();
     if (G1PolicyVerbose > 0) {
       gclog_or_tty->print_cr("Adding %d young regions to the CSet",
                     _g1->young_list_length());
     }
     _young_cset_length  = 0;
     _last_young_gc_full = full_young_gcs() ? true : false;
     if (_last_young_gc_full)
       ++_full_young_pause_num;
     else
       ++_partial_young_pause_num;
     hr = _g1->pop_region_from_young_list();
     while (hr != NULL) {
       assert( hr->young_index_in_cset() == -1, "invariant" );
       assert( hr->age_in_surv_rate_group() != -1, "invariant" );
       hr->set_young_index_in_cset((int) _young_cset_length);
       ++_young_cset_length;
       double predicted_time_ms = predict_region_elapsed_time_ms(hr, true);
       time_remaining_ms -= predicted_time_ms;
       predicted_pause_time_ms += predicted_time_ms;
       assert(!hr->in_collection_set(), "invariant");
       add_to_collection_set(hr);
       record_cset_region(hr, true);
       max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
       if (G1PolicyVerbose > 0) {
         gclog_or_tty->print_cr("  Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.",
                       hr->bottom(), hr->end());
         gclog_or_tty->print_cr("    (" SIZE_FORMAT " KB left in heap.)",
                       max_live_bytes/K);
       }
       hr = _g1->pop_region_from_young_list();
     }
     record_scan_only_regions(_g1->young_list_scan_only_length());
     double young_end_time_sec = os::elapsedTime();
     _recorded_young_cset_choice_time_ms =
       (young_end_time_sec - young_start_time_sec) * 1000.0;
     non_young_start_time_sec = os::elapsedTime();
     if (_young_cset_length > 0 && _last_young_gc_full) {
       // don't bother adding more regions...
       goto choose_collection_set_end;
     }
   }
   if (!in_young_gc_mode() || !full_young_gcs()) {
     bool should_continue = true;
     NumberSeq seq;
     double avg_prediction = 100000000000000000.0; // something very large
     do {
       hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
                                                       avg_prediction);
       if (hr != NULL) {
         double predicted_time_ms = predict_region_elapsed_time_ms(hr, false);
         time_remaining_ms -= predicted_time_ms;
         predicted_pause_time_ms += predicted_time_ms;
         add_to_collection_set(hr);
         record_cset_region(hr, false);
         max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
         if (G1PolicyVerbose > 0) {
           gclog_or_tty->print_cr("    (" SIZE_FORMAT " KB left in heap.)",
                         max_live_bytes/K);
         }
         seq.add(predicted_time_ms);
         avg_prediction = seq.avg() + seq.sd();
       }
       should_continue =
         ( hr != NULL) &&
         ( (adaptive_young_list_length()) ? time_remaining_ms > 0.0
           : _collection_set_size < _young_list_fixed_length );
     } while (should_continue);
     if (!adaptive_young_list_length() &&
         _collection_set_size < _young_list_fixed_length)
       _should_revert_to_full_young_gcs  = true;
   }
 choose_collection_set_end:
   count_CS_bytes_used();
   end_recording_regions();
   double non_young_end_time_sec = os::elapsedTime();
   _recorded_non_young_cset_choice_time_ms =
     (non_young_end_time_sec - non_young_start_time_sec) * 1000.0;
 }
 void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() {
   G1CollectorPolicy::record_full_collection_end();
   _collectionSetChooser->updateAfterFullCollection();
 }
 void G1CollectorPolicy_BestRegionsFirst::
 expand_if_possible(size_t numRegions) {
   size_t expansion_bytes = numRegions * HeapRegion::GrainBytes;
   _g1->expand(expansion_bytes);
 }
 void G1CollectorPolicy_BestRegionsFirst::
 record_collection_pause_end(bool abandoned) {
   G1CollectorPolicy::record_collection_pause_end(abandoned);
   assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
 }
 // Local Variables: ***
 // c-indentation-style: gnu ***
 // End: ***

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp