jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp@df6caf649ff7 (annotated)

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp@df6caf649ff7 (annotated)

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

Tue, 14 Jul 2009 15:40:39 -0700

author: ysr
date: Tue, 14 Jul 2009 15:40:39 -0700
changeset 1280: df6caf649ff7
parent 1229: 315a5d70b295
child 1325: 6cb8e9df7174
permissions: -rw-r--r--

6700789: G1: Enable use of compressed oops with G1 heaps
Summary: Modifications to G1 so as to allow the use of compressed oops.
Reviewed-by: apetrusenko, coleenp, jmasa, kvn, never, phh, 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@df6caf649ff7 (annotated)

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