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src/hotspot/share/gc/g1/g1CollectionSet.cpp

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rev 52675 : 8213890: Implementation of JEP 344: Abortable Mixed Collections for G1
Reviewed-by:
Contributed-by: erik.helin@oracle.com, stefan.johansson@oracle.com
rev 52676 : imported patch AMGC-impl
rev 52677 : imported patch AMGC-tsch-rev1
rev 52678 : imported patch AMGC-tsch-rev1-optcset
rev 52680 : [mq]: AMGC-tsch-rev2


   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/g1/g1CollectedHeap.hpp"
  27 #include "gc/g1/g1CollectionSet.hpp"
  28 #include "gc/g1/g1CollectorState.hpp"
  29 #include "gc/g1/g1Policy.hpp"
  30 #include "gc/g1/heapRegion.inline.hpp"
  31 #include "gc/g1/heapRegionRemSet.hpp"
  32 #include "gc/g1/heapRegionSet.hpp"
  33 #include "logging/logStream.hpp"
  34 #include "utilities/debug.hpp"

  35 #include "utilities/quickSort.hpp"
  36 
  37 G1CollectorState* G1CollectionSet::collector_state() {
  38   return _g1h->collector_state();
  39 }
  40 
  41 G1GCPhaseTimes* G1CollectionSet::phase_times() {
  42   return _policy->phase_times();
  43 }
  44 
  45 CollectionSetChooser* G1CollectionSet::cset_chooser() {
  46   return _cset_chooser;
  47 }
  48 
  49 double G1CollectionSet::predict_region_elapsed_time_ms(HeapRegion* hr) {
  50   return _policy->predict_region_elapsed_time_ms(hr, collector_state()->in_young_only_phase());
  51 }
  52 
  53 G1CollectionSet::G1CollectionSet(G1CollectedHeap* g1h, G1Policy* policy) :
  54   _g1h(g1h),
  55   _policy(policy),
  56   _cset_chooser(new CollectionSetChooser()),
  57   _eden_region_length(0),
  58   _survivor_region_length(0),
  59   _old_region_length(0),
  60   _collection_set_regions(NULL),
  61   _collection_set_cur_length(0),
  62   _collection_set_max_length(0),



  63   _bytes_used_before(0),
  64   _recorded_rs_lengths(0),
  65   _inc_build_state(Inactive),
  66   _inc_bytes_used_before(0),
  67   _inc_recorded_rs_lengths(0),
  68   _inc_recorded_rs_lengths_diffs(0),
  69   _inc_predicted_elapsed_time_ms(0.0),
  70   _inc_predicted_elapsed_time_ms_diffs(0.0) {
  71 }
  72 
  73 G1CollectionSet::~G1CollectionSet() {
  74   if (_collection_set_regions != NULL) {
  75     FREE_C_HEAP_ARRAY(uint, _collection_set_regions);
  76   }

  77   delete _cset_chooser;
  78 }
  79 
  80 void G1CollectionSet::init_region_lengths(uint eden_cset_region_length,
  81                                           uint survivor_cset_region_length) {
  82   assert_at_safepoint_on_vm_thread();
  83 
  84   _eden_region_length     = eden_cset_region_length;
  85   _survivor_region_length = survivor_cset_region_length;
  86 
  87   assert((size_t) young_region_length() == _collection_set_cur_length,
  88          "Young region length %u should match collection set length " SIZE_FORMAT, young_region_length(), _collection_set_cur_length);
  89 
  90   _old_region_length      = 0;

  91 }
  92 
  93 void G1CollectionSet::initialize(uint max_region_length) {
  94   guarantee(_collection_set_regions == NULL, "Must only initialize once.");
  95   _collection_set_max_length = max_region_length;
  96   _collection_set_regions = NEW_C_HEAP_ARRAY(uint, max_region_length, mtGC);
  97 }
  98 















  99 void G1CollectionSet::set_recorded_rs_lengths(size_t rs_lengths) {
 100   _recorded_rs_lengths = rs_lengths;
 101 }
 102 
 103 // Add the heap region at the head of the non-incremental collection set
 104 void G1CollectionSet::add_old_region(HeapRegion* hr) {
 105   assert_at_safepoint_on_vm_thread();
 106 
 107   assert(_inc_build_state == Active, "Precondition");

 108   assert(hr->is_old(), "the region should be old");
 109 
 110   assert(!hr->in_collection_set(), "should not already be in the CSet");
 111   _g1h->register_old_region_with_cset(hr);
 112 
 113   _collection_set_regions[_collection_set_cur_length++] = hr->hrm_index();
 114   assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set now larger than maximum size.");
 115 
 116   _bytes_used_before += hr->used();
 117   size_t rs_length = hr->rem_set()->occupied();
 118   _recorded_rs_lengths += rs_length;
 119   _old_region_length += 1;
















 120 }
 121 
 122 // Initialize the per-collection-set information
 123 void G1CollectionSet::start_incremental_building() {
 124   assert(_collection_set_cur_length == 0, "Collection set must be empty before starting a new collection set.");
 125   assert(_inc_build_state == Inactive, "Precondition");
 126 
 127   _inc_bytes_used_before = 0;
 128 
 129   _inc_recorded_rs_lengths = 0;
 130   _inc_recorded_rs_lengths_diffs = 0;
 131   _inc_predicted_elapsed_time_ms = 0.0;
 132   _inc_predicted_elapsed_time_ms_diffs = 0.0;
 133   _inc_build_state = Active;
 134 }
 135 
 136 void G1CollectionSet::finalize_incremental_building() {
 137   assert(_inc_build_state == Active, "Precondition");
 138   assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint");
 139 


 151     // as RSets can only grow between GCs. However, given that we
 152     // sample their size concurrently with other threads updating them
 153     // it's possible that we might get the wrong size back, which
 154     // could make the calculations somewhat inaccurate.
 155     size_t diffs = (size_t) (-_inc_recorded_rs_lengths_diffs);
 156     if (_inc_recorded_rs_lengths >= diffs) {
 157       _inc_recorded_rs_lengths -= diffs;
 158     } else {
 159       _inc_recorded_rs_lengths = 0;
 160     }
 161   }
 162   _inc_predicted_elapsed_time_ms += _inc_predicted_elapsed_time_ms_diffs;
 163 
 164   _inc_recorded_rs_lengths_diffs = 0;
 165   _inc_predicted_elapsed_time_ms_diffs = 0.0;
 166 }
 167 
 168 void G1CollectionSet::clear() {
 169   assert_at_safepoint_on_vm_thread();
 170   _collection_set_cur_length = 0;

 171 }
 172 
 173 void G1CollectionSet::iterate(HeapRegionClosure* cl) const {
 174   iterate_from(cl, 0, 1);
 175 }
 176 
 177 void G1CollectionSet::iterate_from(HeapRegionClosure* cl, uint worker_id, uint total_workers) const {
 178   size_t len = _collection_set_cur_length;
 179   OrderAccess::loadload();
 180   if (len == 0) {
 181     return;
 182   }
 183   size_t start_pos = (worker_id * len) / total_workers;
 184   size_t cur_pos = start_pos;
 185 
 186   do {
 187     HeapRegion* r = _g1h->region_at(_collection_set_regions[cur_pos]);
 188     bool result = cl->do_heap_region(r);
 189     if (result) {
 190       cl->set_incomplete();


 379 
 380   // Clear the fields that point to the survivor list - they are all young now.
 381   survivors->convert_to_eden();
 382 
 383   _bytes_used_before = _inc_bytes_used_before;
 384   time_remaining_ms = MAX2(time_remaining_ms - _inc_predicted_elapsed_time_ms, 0.0);
 385 
 386   log_trace(gc, ergo, cset)("Add young regions to CSet. eden: %u regions, survivors: %u regions, predicted young region time: %1.2fms, target pause time: %1.2fms",
 387                             eden_region_length, survivor_region_length, _inc_predicted_elapsed_time_ms, target_pause_time_ms);
 388 
 389   // The number of recorded young regions is the incremental
 390   // collection set's current size
 391   set_recorded_rs_lengths(_inc_recorded_rs_lengths);
 392 
 393   double young_end_time_sec = os::elapsedTime();
 394   phase_times()->record_young_cset_choice_time_ms((young_end_time_sec - young_start_time_sec) * 1000.0);
 395 
 396   return time_remaining_ms;
 397 }
 398 























 399 static int compare_region_idx(const uint a, const uint b) {
 400   if (a > b) {
 401     return 1;
 402   } else if (a == b) {
 403     return 0;
 404   } else {
 405     return -1;
 406   }
 407 }
 408 
 409 void G1CollectionSet::finalize_old_part(double time_remaining_ms) {
 410   double non_young_start_time_sec = os::elapsedTime();
 411   double predicted_old_time_ms = 0.0;



 412 
 413   if (collector_state()->in_mixed_phase()) {
 414     cset_chooser()->verify();
 415     const uint min_old_cset_length = _policy->calc_min_old_cset_length();
 416     const uint max_old_cset_length = _policy->calc_max_old_cset_length();
 417 
 418     uint expensive_region_num = 0;
 419     bool check_time_remaining = _policy->adaptive_young_list_length();
 420 





 421     HeapRegion* hr = cset_chooser()->peek();
 422     while (hr != NULL) {
 423       if (old_region_length() >= max_old_cset_length) {
 424         // Added maximum number of old regions to the CSet.
 425         log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached max). old %u regions, max %u regions",
 426                                   old_region_length(), max_old_cset_length);

 427         break;
 428       }
 429 
 430       // Stop adding regions if the remaining reclaimable space is
 431       // not above G1HeapWastePercent.
 432       size_t reclaimable_bytes = cset_chooser()->remaining_reclaimable_bytes();
 433       double reclaimable_percent = _policy->reclaimable_bytes_percent(reclaimable_bytes);
 434       double threshold = (double) G1HeapWastePercent;
 435       if (reclaimable_percent <= threshold) {
 436         // We've added enough old regions that the amount of uncollected
 437         // reclaimable space is at or below the waste threshold. Stop
 438         // adding old regions to the CSet.
 439         log_debug(gc, ergo, cset)("Finish adding old regions to CSet (reclaimable percentage not over threshold). "
 440                                   "old %u regions, max %u regions, reclaimable: " SIZE_FORMAT "B (%1.2f%%) threshold: " UINTX_FORMAT "%%",
 441                                   old_region_length(), max_old_cset_length, reclaimable_bytes, reclaimable_percent, G1HeapWastePercent);

 442         break;
 443       }
 444 
 445       double predicted_time_ms = predict_region_elapsed_time_ms(hr);
 446       if (check_time_remaining) {
 447         if (predicted_time_ms > time_remaining_ms) {
 448           // Too expensive for the current CSet.
 449 
 450           if (old_region_length() >= min_old_cset_length) {
 451             // We have added the minimum number of old regions to the CSet,
 452             // we are done with this CSet.
 453             log_debug(gc, ergo, cset)("Finish adding old regions to CSet (predicted time is too high). "
 454                                       "predicted time: %1.2fms, remaining time: %1.2fms old %u regions, min %u regions",
 455                                       predicted_time_ms, time_remaining_ms, old_region_length(), min_old_cset_length);
 456             break;
 457           }
 458 
 459           // We'll add it anyway given that we haven't reached the
 460           // minimum number of old regions.
 461           expensive_region_num += 1;
 462         }
 463       } else {
 464         if (old_region_length() >= min_old_cset_length) {
 465           // In the non-auto-tuning case, we'll finish adding regions
 466           // to the CSet if we reach the minimum.
 467 
 468           log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached min). old %u regions, min %u regions",
 469                                     old_region_length(), min_old_cset_length);
 470           break;
 471         }
 472       }
 473 
 474       // We will add this region to the CSet.
 475       time_remaining_ms = MAX2(time_remaining_ms - predicted_time_ms, 0.0);
 476       predicted_old_time_ms += predicted_time_ms;
 477       cset_chooser()->pop(); // already have region via peek()
 478       _g1h->old_set_remove(hr);
 479       add_old_region(hr);
 480 











 481       hr = cset_chooser()->peek();
 482     }
 483     if (hr == NULL) {
 484       log_debug(gc, ergo, cset)("Finish adding old regions to CSet (candidate old regions not available)");
 485     }
 486 
 487     if (expensive_region_num > 0) {
 488       // We print the information once here at the end, predicated on
 489       // whether we added any apparently expensive regions or not, to
 490       // avoid generating output per region.
 491       log_debug(gc, ergo, cset)("Added expensive regions to CSet (old CSet region num not reached min)."
 492                                 "old: %u regions, expensive: %u regions, min: %u regions, remaining time: %1.2fms",
 493                                 old_region_length(), expensive_region_num, min_old_cset_length, time_remaining_ms);
 494     }
 495 
 496     cset_chooser()->verify();
 497   }
 498 
 499   stop_incremental_building();
 500 
 501   log_debug(gc, ergo, cset)("Finish choosing CSet. old: %u regions, predicted old region time: %1.2fms, time remaining: %1.2f",
 502                             old_region_length(), predicted_old_time_ms, time_remaining_ms);






 503 
 504   double non_young_end_time_sec = os::elapsedTime();
 505   phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0);
 506 
 507   QuickSort::sort(_collection_set_regions, _collection_set_cur_length, compare_region_idx, true);















































































 508 }
 509 
 510 #ifdef ASSERT
 511 class G1VerifyYoungCSetIndicesClosure : public HeapRegionClosure {
 512 private:
 513   size_t _young_length;
 514   int* _heap_region_indices;
 515 public:
 516   G1VerifyYoungCSetIndicesClosure(size_t young_length) : HeapRegionClosure(), _young_length(young_length) {
 517     _heap_region_indices = NEW_C_HEAP_ARRAY(int, young_length, mtGC);
 518     for (size_t i = 0; i < young_length; i++) {
 519       _heap_region_indices[i] = -1;
 520     }
 521   }
 522   ~G1VerifyYoungCSetIndicesClosure() {
 523     FREE_C_HEAP_ARRAY(int, _heap_region_indices);
 524   }
 525 
 526   virtual bool do_heap_region(HeapRegion* r) {
 527     const int idx = r->young_index_in_cset();




   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/g1/g1CollectedHeap.inline.hpp"
  27 #include "gc/g1/g1CollectionSet.hpp"
  28 #include "gc/g1/g1CollectorState.hpp"
  29 #include "gc/g1/g1Policy.hpp"
  30 #include "gc/g1/heapRegion.inline.hpp"
  31 #include "gc/g1/heapRegionRemSet.hpp"
  32 #include "gc/g1/heapRegionSet.hpp"
  33 #include "logging/logStream.hpp"
  34 #include "utilities/debug.hpp"
  35 #include "utilities/globalDefinitions.hpp"
  36 #include "utilities/quickSort.hpp"
  37 
  38 G1CollectorState* G1CollectionSet::collector_state() {
  39   return _g1h->collector_state();
  40 }
  41 
  42 G1GCPhaseTimes* G1CollectionSet::phase_times() {
  43   return _policy->phase_times();
  44 }
  45 
  46 CollectionSetChooser* G1CollectionSet::cset_chooser() {
  47   return _cset_chooser;
  48 }
  49 
  50 double G1CollectionSet::predict_region_elapsed_time_ms(HeapRegion* hr) {
  51   return _policy->predict_region_elapsed_time_ms(hr, collector_state()->in_young_only_phase());
  52 }
  53 
  54 G1CollectionSet::G1CollectionSet(G1CollectedHeap* g1h, G1Policy* policy) :
  55   _g1h(g1h),
  56   _policy(policy),
  57   _cset_chooser(new CollectionSetChooser()),
  58   _eden_region_length(0),
  59   _survivor_region_length(0),
  60   _old_region_length(0),
  61   _collection_set_regions(NULL),
  62   _collection_set_cur_length(0),
  63   _collection_set_max_length(0),
  64   _optional_regions(NULL),
  65   _optional_region_length(0),
  66   _optional_region_max_length(0),
  67   _bytes_used_before(0),
  68   _recorded_rs_lengths(0),
  69   _inc_build_state(Inactive),
  70   _inc_bytes_used_before(0),
  71   _inc_recorded_rs_lengths(0),
  72   _inc_recorded_rs_lengths_diffs(0),
  73   _inc_predicted_elapsed_time_ms(0.0),
  74   _inc_predicted_elapsed_time_ms_diffs(0.0) {
  75 }
  76 
  77 G1CollectionSet::~G1CollectionSet() {
  78   if (_collection_set_regions != NULL) {
  79     FREE_C_HEAP_ARRAY(uint, _collection_set_regions);
  80   }
  81   free_optional_regions();
  82   delete _cset_chooser;
  83 }
  84 
  85 void G1CollectionSet::init_region_lengths(uint eden_cset_region_length,
  86                                           uint survivor_cset_region_length) {
  87   assert_at_safepoint_on_vm_thread();
  88 
  89   _eden_region_length     = eden_cset_region_length;
  90   _survivor_region_length = survivor_cset_region_length;
  91 
  92   assert((size_t) young_region_length() == _collection_set_cur_length,
  93          "Young region length %u should match collection set length " SIZE_FORMAT, young_region_length(), _collection_set_cur_length);
  94 
  95   _old_region_length      = 0;
  96   _optional_region_length = 0;
  97 }
  98 
  99 void G1CollectionSet::initialize(uint max_region_length) {
 100   guarantee(_collection_set_regions == NULL, "Must only initialize once.");
 101   _collection_set_max_length = max_region_length;
 102   _collection_set_regions = NEW_C_HEAP_ARRAY(uint, max_region_length, mtGC);
 103 }
 104 
 105 void G1CollectionSet::initialize_optional(uint max_length) {
 106   assert(_optional_regions == NULL, "Already initialized");
 107   _optional_region_max_length = max_length;
 108   _optional_regions = NEW_C_HEAP_ARRAY(HeapRegion*, _optional_region_max_length, mtGC);
 109 }
 110 
 111 void G1CollectionSet::free_optional_regions() {
 112   _optional_region_length = 0;
 113   _optional_region_max_length = 0;
 114   if (_optional_regions != NULL) {
 115     FREE_C_HEAP_ARRAY(HeapRegion*, _optional_regions);
 116     _optional_regions = NULL;
 117   }
 118 }
 119 
 120 void G1CollectionSet::set_recorded_rs_lengths(size_t rs_lengths) {
 121   _recorded_rs_lengths = rs_lengths;
 122 }
 123 
 124 // Add the heap region at the head of the non-incremental collection set
 125 void G1CollectionSet::add_old_region(HeapRegion* hr) {
 126   assert_at_safepoint_on_vm_thread();
 127 
 128   assert(_inc_build_state == Active || hr->index_in_opt_cset() != G1OptionalCSet::InvalidCSetIndex,
 129          "Precondition, actively building cset or adding optional later on");
 130   assert(hr->is_old(), "the region should be old");
 131 
 132   assert(!hr->in_collection_set(), "should not already be in the CSet");
 133   _g1h->register_old_region_with_cset(hr);
 134 
 135   _collection_set_regions[_collection_set_cur_length++] = hr->hrm_index();
 136   assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set now larger than maximum size.");
 137 
 138   _bytes_used_before += hr->used();
 139   size_t rs_length = hr->rem_set()->occupied();
 140   _recorded_rs_lengths += rs_length;
 141   _old_region_length += 1;
 142 
 143   log_trace(gc, cset)("Added old region %d to collection set", hr->hrm_index());
 144 }
 145 
 146 void G1CollectionSet::add_optional_region(HeapRegion* hr) {
 147   assert(!optional_is_full(), "Precondition, must have room left for this region");
 148   assert(hr->is_old(), "the region should be old");
 149   assert(!hr->in_collection_set(), "should not already be in the CSet");
 150 
 151   _g1h->register_optional_region_with_cset(hr);
 152 
 153   _optional_regions[_optional_region_length] = hr;
 154   uint index = _optional_region_length++;
 155   hr->set_index_in_opt_cset(index);
 156 
 157   log_trace(gc, cset)("Added region %d to optional collection set (%u)", hr->hrm_index(), _optional_region_length);
 158 }
 159 
 160 // Initialize the per-collection-set information
 161 void G1CollectionSet::start_incremental_building() {
 162   assert(_collection_set_cur_length == 0, "Collection set must be empty before starting a new collection set.");
 163   assert(_inc_build_state == Inactive, "Precondition");
 164 
 165   _inc_bytes_used_before = 0;
 166 
 167   _inc_recorded_rs_lengths = 0;
 168   _inc_recorded_rs_lengths_diffs = 0;
 169   _inc_predicted_elapsed_time_ms = 0.0;
 170   _inc_predicted_elapsed_time_ms_diffs = 0.0;
 171   _inc_build_state = Active;
 172 }
 173 
 174 void G1CollectionSet::finalize_incremental_building() {
 175   assert(_inc_build_state == Active, "Precondition");
 176   assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint");
 177 


 189     // as RSets can only grow between GCs. However, given that we
 190     // sample their size concurrently with other threads updating them
 191     // it's possible that we might get the wrong size back, which
 192     // could make the calculations somewhat inaccurate.
 193     size_t diffs = (size_t) (-_inc_recorded_rs_lengths_diffs);
 194     if (_inc_recorded_rs_lengths >= diffs) {
 195       _inc_recorded_rs_lengths -= diffs;
 196     } else {
 197       _inc_recorded_rs_lengths = 0;
 198     }
 199   }
 200   _inc_predicted_elapsed_time_ms += _inc_predicted_elapsed_time_ms_diffs;
 201 
 202   _inc_recorded_rs_lengths_diffs = 0;
 203   _inc_predicted_elapsed_time_ms_diffs = 0.0;
 204 }
 205 
 206 void G1CollectionSet::clear() {
 207   assert_at_safepoint_on_vm_thread();
 208   _collection_set_cur_length = 0;
 209   _optional_region_length = 0;
 210 }
 211 
 212 void G1CollectionSet::iterate(HeapRegionClosure* cl) const {
 213   iterate_from(cl, 0, 1);
 214 }
 215 
 216 void G1CollectionSet::iterate_from(HeapRegionClosure* cl, uint worker_id, uint total_workers) const {
 217   size_t len = _collection_set_cur_length;
 218   OrderAccess::loadload();
 219   if (len == 0) {
 220     return;
 221   }
 222   size_t start_pos = (worker_id * len) / total_workers;
 223   size_t cur_pos = start_pos;
 224 
 225   do {
 226     HeapRegion* r = _g1h->region_at(_collection_set_regions[cur_pos]);
 227     bool result = cl->do_heap_region(r);
 228     if (result) {
 229       cl->set_incomplete();


 418 
 419   // Clear the fields that point to the survivor list - they are all young now.
 420   survivors->convert_to_eden();
 421 
 422   _bytes_used_before = _inc_bytes_used_before;
 423   time_remaining_ms = MAX2(time_remaining_ms - _inc_predicted_elapsed_time_ms, 0.0);
 424 
 425   log_trace(gc, ergo, cset)("Add young regions to CSet. eden: %u regions, survivors: %u regions, predicted young region time: %1.2fms, target pause time: %1.2fms",
 426                             eden_region_length, survivor_region_length, _inc_predicted_elapsed_time_ms, target_pause_time_ms);
 427 
 428   // The number of recorded young regions is the incremental
 429   // collection set's current size
 430   set_recorded_rs_lengths(_inc_recorded_rs_lengths);
 431 
 432   double young_end_time_sec = os::elapsedTime();
 433   phase_times()->record_young_cset_choice_time_ms((young_end_time_sec - young_start_time_sec) * 1000.0);
 434 
 435   return time_remaining_ms;
 436 }
 437 
 438 void G1CollectionSet::add_as_old(HeapRegion* hr) {
 439   cset_chooser()->pop(); // already have region via peek()
 440   _g1h->old_set_remove(hr);
 441   add_old_region(hr);
 442 }
 443 
 444 void G1CollectionSet::add_as_optional(HeapRegion* hr) {
 445   assert(_optional_regions != NULL, "Must not be called before array is allocated");
 446   cset_chooser()->pop(); // already have region via peek()
 447   _g1h->old_set_remove(hr);
 448   add_optional_region(hr);
 449 }
 450 
 451 bool G1CollectionSet::optional_is_full() {
 452   return _optional_region_length == _optional_region_max_length;
 453 }
 454 
 455 void G1CollectionSet::clear_optional_region(const HeapRegion* hr) {
 456   assert(_optional_regions != NULL, "Must not be called before array is allocated");
 457   uint index = hr->index_in_opt_cset();
 458   _optional_regions[index] = NULL;
 459 }
 460 
 461 static int compare_region_idx(const uint a, const uint b) {
 462   if (a > b) {
 463     return 1;
 464   } else if (a == b) {
 465     return 0;
 466   } else {
 467     return -1;
 468   }
 469 }
 470 
 471 void G1CollectionSet::finalize_old_part(double time_remaining_ms) {
 472   double non_young_start_time_sec = os::elapsedTime();
 473   double predicted_old_time_ms = 0.0;
 474   double predicted_optional_time_ms = 0.0;
 475   double optional_threshold_ms = time_remaining_ms * _policy->optional_prediction_fraction();
 476   uint expensive_region_num = 0;
 477 
 478   if (collector_state()->in_mixed_phase()) {
 479     cset_chooser()->verify();
 480     const uint min_old_cset_length = _policy->calc_min_old_cset_length();
 481     const uint max_old_cset_length = MAX2(min_old_cset_length, _policy->calc_max_old_cset_length());


 482     bool check_time_remaining = _policy->adaptive_young_list_length();
 483 
 484     initialize_optional(max_old_cset_length - min_old_cset_length);
 485     log_debug(gc, ergo, cset)("Start adding old regions for mixed gc. min %u regions, max %u regions, "
 486                               "time remaining %1.2fms, optional threshold %1.2fms",
 487                               min_old_cset_length, max_old_cset_length, time_remaining_ms, optional_threshold_ms);
 488 
 489     HeapRegion* hr = cset_chooser()->peek();
 490     while (hr != NULL) {
 491       if (old_region_length() + optional_region_length() >= max_old_cset_length) {
 492         // Added maximum number of old regions to the CSet.
 493         log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached max). "
 494                                   "old %u regions, optional %u regions",
 495                                   old_region_length(), optional_region_length());
 496         break;
 497       }
 498 
 499       // Stop adding regions if the remaining reclaimable space is
 500       // not above G1HeapWastePercent.
 501       size_t reclaimable_bytes = cset_chooser()->remaining_reclaimable_bytes();
 502       double reclaimable_percent = _policy->reclaimable_bytes_percent(reclaimable_bytes);
 503       double threshold = (double) G1HeapWastePercent;
 504       if (reclaimable_percent <= threshold) {
 505         // We've added enough old regions that the amount of uncollected
 506         // reclaimable space is at or below the waste threshold. Stop
 507         // adding old regions to the CSet.
 508         log_debug(gc, ergo, cset)("Finish adding old regions to CSet (reclaimable percentage not over threshold). "
 509                                   "reclaimable: " SIZE_FORMAT "%s (%1.2f%%) threshold: " UINTX_FORMAT "%%",
 510                                   byte_size_in_proper_unit(reclaimable_bytes), proper_unit_for_byte_size(reclaimable_bytes),
 511                                   reclaimable_percent, G1HeapWastePercent);
 512         break;
 513       }
 514 
 515       double predicted_time_ms = predict_region_elapsed_time_ms(hr);
 516       time_remaining_ms = MAX2(time_remaining_ms - predicted_time_ms, 0.0);
 517       // Add regions to old set until we reach minimum amount
 518       if (old_region_length() < min_old_cset_length) {
 519         predicted_old_time_ms += predicted_time_ms;
 520         add_as_old(hr);
 521         // Record the number of regions added when no time remaining
 522         if (time_remaining_ms == 0.0) {
 523           expensive_region_num++;








 524         }
 525       } else {

 526         // In the non-auto-tuning case, we'll finish adding regions
 527         // to the CSet if we reach the minimum.
 528         if (!check_time_remaining) {
 529           log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached min).");

 530           break;
 531         }
 532         // Keep adding regions to old set until we reach optional threshold
 533         if (time_remaining_ms > optional_threshold_ms) {


 534           predicted_old_time_ms += predicted_time_ms;
 535           add_as_old(hr);
 536         } else if (time_remaining_ms > 0) {
 537           // Keep adding optional regions until time is up
 538           if (!optional_is_full()) {
 539             predicted_optional_time_ms += predicted_time_ms;
 540             add_as_optional(hr);
 541           } else {
 542             log_debug(gc, ergo, cset)("Finish adding old regions to CSet (optional set full).");
 543             break;
 544           }
 545         } else {
 546           log_debug(gc, ergo, cset)("Finish adding old regions to CSet (predicted time is too high).");
 547           break;
 548         }
 549       }
 550       hr = cset_chooser()->peek();
 551     }
 552     if (hr == NULL) {
 553       log_debug(gc, ergo, cset)("Finish adding old regions to CSet (candidate old regions not available)");
 554     }
 555 









 556     cset_chooser()->verify();
 557   }
 558 
 559   stop_incremental_building();
 560 
 561   log_debug(gc, ergo, cset)("Finish choosing CSet regions old: %u, optional: %u, "
 562                             "predicted old time: %1.2fms, predicted optional time: %1.2fms, time remaining: %1.2f",
 563                             old_region_length(), optional_region_length(),
 564                             predicted_old_time_ms, predicted_optional_time_ms, time_remaining_ms);
 565   if (expensive_region_num > 0) {
 566     log_debug(gc, ergo, cset)("CSet contains %u old regions that were added although the predicted time was too high.",
 567                               expensive_region_num);
 568   }
 569 
 570   double non_young_end_time_sec = os::elapsedTime();
 571   phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0);
 572 
 573   QuickSort::sort(_collection_set_regions, _collection_set_cur_length, compare_region_idx, true);
 574 }
 575 
 576 HeapRegion* G1OptionalCSet::region_at(uint index) {
 577   return _cset->optional_region_at(index);
 578 }
 579 
 580 void G1OptionalCSet::prepare_evacuation(double time_limit) {
 581   assert(_current_index == _current_limit, "Before prepare no regions should be ready for evac");
 582 
 583   uint prepared_regions = 0;
 584   double prediction_ms = 0;
 585 
 586   _prepare_failed = true;
 587   for (uint i = _current_index; i < _cset->optional_region_length(); i++) {
 588     HeapRegion* hr = region_at(i);
 589     prediction_ms += _cset->predict_region_elapsed_time_ms(hr);
 590     if (prediction_ms > time_limit) {
 591       log_debug(gc, cset)("Prepared %u regions for optional evacuation. Predicted time: %.3fms", prepared_regions, prediction_ms);
 592       return;
 593     }
 594 
 595     // This region will be included in the next optional evacuation.
 596     prepare_to_evacuate_optional_region(hr);
 597     prepared_regions++;
 598     _current_limit++;
 599     _prepare_failed = false;
 600   }
 601 
 602   log_debug(gc, cset)("Prepared all %u regions for optional evacuation. Predicted time: %.3fms",
 603                       prepared_regions, prediction_ms);
 604 }
 605 
 606 bool G1OptionalCSet::prepare_failed() {
 607   return _prepare_failed;
 608 }
 609 
 610 void G1OptionalCSet::complete_evacuation() {
 611   _evacuation_failed = false;
 612   for (uint i = _current_index; i < _current_limit; i++) {
 613     HeapRegion* hr = region_at(i);
 614     _cset->clear_optional_region(hr);
 615     if (hr->evacuation_failed()){
 616       _evacuation_failed = true;
 617     }
 618   }
 619   _current_index = _current_limit;
 620 }
 621 
 622 bool G1OptionalCSet::evacuation_failed() {
 623   return _evacuation_failed;
 624 }
 625 
 626 G1OptionalCSet::~G1OptionalCSet() {
 627   G1CollectedHeap* g1h = G1CollectedHeap::heap();
 628   while (!is_empty()) {
 629     // We want to return regions not evacuated to the
 630     // chooser in reverse order to maintain the old order.
 631     HeapRegion* hr = _cset->remove_last_optional_region();
 632     assert(hr != NULL, "Should be valid region left");
 633     g1h->old_set_add(hr);
 634     g1h->clear_in_cset(hr);
 635     hr->set_index_in_opt_cset(InvalidCSetIndex);
 636     _cset->cset_chooser()->push(hr);
 637   }
 638   _cset->free_optional_regions();
 639 }
 640 
 641 uint G1OptionalCSet::size() {
 642   return _cset->optional_region_length() - _current_index;
 643 }
 644 
 645 bool G1OptionalCSet::is_empty() {
 646   return size() == 0;
 647 }
 648 
 649 void G1OptionalCSet::prepare_to_evacuate_optional_region(HeapRegion* hr) {
 650   log_trace(gc, cset)("Adding region %u for optional evacuation", hr->hrm_index());
 651   G1CollectedHeap::heap()->clear_in_cset(hr);
 652   _cset->add_old_region(hr);
 653 }
 654 
 655 #ifdef ASSERT
 656 class G1VerifyYoungCSetIndicesClosure : public HeapRegionClosure {
 657 private:
 658   size_t _young_length;
 659   int* _heap_region_indices;
 660 public:
 661   G1VerifyYoungCSetIndicesClosure(size_t young_length) : HeapRegionClosure(), _young_length(young_length) {
 662     _heap_region_indices = NEW_C_HEAP_ARRAY(int, young_length, mtGC);
 663     for (size_t i = 0; i < young_length; i++) {
 664       _heap_region_indices[i] = -1;
 665     }
 666   }
 667   ~G1VerifyYoungCSetIndicesClosure() {
 668     FREE_C_HEAP_ARRAY(int, _heap_region_indices);
 669   }
 670 
 671   virtual bool do_heap_region(HeapRegion* r) {
 672     const int idx = r->young_index_in_cset();


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