1 /*
   2  * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "code/codeCache.hpp"
  27 #include "gc/parallel/parallelArguments.hpp"
  28 #include "gc/parallel/objectStartArray.inline.hpp"
  29 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
  30 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
  31 #include "gc/parallel/psMemoryPool.hpp"
  32 #include "gc/parallel/psParallelCompact.inline.hpp"
  33 #include "gc/parallel/psPromotionManager.hpp"
  34 #include "gc/parallel/psScavenge.hpp"
  35 #include "gc/parallel/psVMOperations.hpp"
  36 #include "gc/shared/gcHeapSummary.hpp"
  37 #include "gc/shared/gcLocker.hpp"
  38 #include "gc/shared/gcWhen.hpp"
  39 #include "gc/shared/genArguments.hpp"
  40 #include "gc/shared/gcInitLogger.hpp"
  41 #include "gc/shared/locationPrinter.inline.hpp"
  42 #include "gc/shared/scavengableNMethods.hpp"
  43 #include "logging/log.hpp"
  44 #include "memory/iterator.hpp"
  45 #include "memory/metaspaceCounters.hpp"
  46 #include "memory/universe.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "runtime/handles.inline.hpp"
  49 #include "runtime/java.hpp"
  50 #include "runtime/vmThread.hpp"
  51 #include "services/memoryManager.hpp"
  52 #include "services/memTracker.hpp"
  53 #include "utilities/macros.hpp"
  54 #include "utilities/vmError.hpp"
  55 
  56 PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
  57 PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
  58 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
  59 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
  60 
  61 jint ParallelScavengeHeap::initialize() {
  62   const size_t reserved_heap_size = ParallelArguments::heap_reserved_size_bytes();
  63 
  64   ReservedHeapSpace heap_rs = Universe::reserve_heap(reserved_heap_size, HeapAlignment);
  65 
  66   os::trace_page_sizes("Heap",
  67                        MinHeapSize,
  68                        reserved_heap_size,
  69                        GenAlignment,
  70                        heap_rs.base(),
  71                        heap_rs.size());
  72 
  73   initialize_reserved_region(heap_rs);
  74 
  75   PSCardTable* card_table = new PSCardTable(heap_rs.region());
  76   card_table->initialize();
  77   CardTableBarrierSet* const barrier_set = new CardTableBarrierSet(card_table);
  78   barrier_set->initialize();
  79   BarrierSet::set_barrier_set(barrier_set);
  80 
  81   // Make up the generations
  82   assert(MinOldSize <= OldSize && OldSize <= MaxOldSize, "Parameter check");
  83   assert(MinNewSize <= NewSize && NewSize <= MaxNewSize, "Parameter check");
  84 
  85   // Layout the reserved space for the generations.
  86   // If OldGen is allocated on nv-dimm, we need to split the reservation (this is required for windows).
  87   ReservedSpace old_rs   = heap_rs.first_part(MaxOldSize, ParallelArguments::is_heterogeneous_heap() /* split */);
  88   ReservedSpace young_rs = heap_rs.last_part(MaxOldSize);
  89   assert(young_rs.size() == MaxNewSize, "Didn't reserve all of the heap");
  90 
  91   // Create and initialize the generations.
  92   _young_gen = new PSYoungGen(
  93       young_rs,
  94       NewSize,
  95       MinNewSize,
  96       MaxNewSize);
  97   _old_gen = new PSOldGen(
  98       old_rs,
  99       OldSize,
 100       MinOldSize,
 101       MaxOldSize,
 102       "old", 1);
 103 
 104   assert(young_gen()->max_gen_size() == young_rs.size(),"Consistency check");
 105   assert(old_gen()->max_gen_size() == old_rs.size(), "Consistency check");
 106 
 107   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
 108   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
 109 
 110   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
 111   const size_t old_capacity = _old_gen->capacity_in_bytes();
 112   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
 113   _size_policy =
 114     new PSAdaptiveSizePolicy(eden_capacity,
 115                              initial_promo_size,
 116                              young_gen()->to_space()->capacity_in_bytes(),
 117                              GenAlignment,
 118                              max_gc_pause_sec,
 119                              max_gc_minor_pause_sec,
 120                              GCTimeRatio
 121                              );
 122 
 123   assert(ParallelArguments::is_heterogeneous_heap() ||
 124          (old_gen()->virtual_space()->high_boundary() ==
 125           young_gen()->virtual_space()->low_boundary()),
 126          "Boundaries must meet");
 127   // initialize the policy counters - 2 collectors, 2 generations
 128   _gc_policy_counters =
 129     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
 130 
 131   if (!PSParallelCompact::initialize()) {
 132     return JNI_ENOMEM;
 133   }
 134 
 135   // Set up WorkGang
 136   _workers.initialize_workers();
 137 
 138   GCInitLogger::print();
 139 
 140   return JNI_OK;
 141 }
 142 
 143 void ParallelScavengeHeap::initialize_serviceability() {
 144 
 145   _eden_pool = new EdenMutableSpacePool(_young_gen,
 146                                         _young_gen->eden_space(),
 147                                         "PS Eden Space",
 148                                         false /* support_usage_threshold */);
 149 
 150   _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
 151                                                 "PS Survivor Space",
 152                                                 false /* support_usage_threshold */);
 153 
 154   _old_pool = new PSGenerationPool(_old_gen,
 155                                    "PS Old Gen",
 156                                    true /* support_usage_threshold */);
 157 
 158   _young_manager = new GCMemoryManager("PS Scavenge", "end of minor GC");
 159   _old_manager = new GCMemoryManager("PS MarkSweep", "end of major GC");
 160 
 161   _old_manager->add_pool(_eden_pool);
 162   _old_manager->add_pool(_survivor_pool);
 163   _old_manager->add_pool(_old_pool);
 164 
 165   _young_manager->add_pool(_eden_pool);
 166   _young_manager->add_pool(_survivor_pool);
 167 
 168 }
 169 
 170 class PSIsScavengable : public BoolObjectClosure {
 171   bool do_object_b(oop obj) {
 172     return ParallelScavengeHeap::heap()->is_in_young(obj);
 173   }
 174 };
 175 
 176 static PSIsScavengable _is_scavengable;
 177 
 178 void ParallelScavengeHeap::post_initialize() {
 179   CollectedHeap::post_initialize();
 180   // Need to init the tenuring threshold
 181   PSScavenge::initialize();
 182   PSParallelCompact::post_initialize();
 183   PSPromotionManager::initialize();
 184 
 185   ScavengableNMethods::initialize(&_is_scavengable);
 186 }
 187 
 188 void ParallelScavengeHeap::update_counters() {
 189   young_gen()->update_counters();
 190   old_gen()->update_counters();
 191   MetaspaceCounters::update_performance_counters();
 192   CompressedClassSpaceCounters::update_performance_counters();
 193 }
 194 
 195 size_t ParallelScavengeHeap::capacity() const {
 196   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
 197   return value;
 198 }
 199 
 200 size_t ParallelScavengeHeap::used() const {
 201   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
 202   return value;
 203 }
 204 
 205 bool ParallelScavengeHeap::is_maximal_no_gc() const {
 206   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
 207 }
 208 
 209 
 210 size_t ParallelScavengeHeap::max_capacity() const {
 211   size_t estimated = reserved_region().byte_size();
 212   if (UseAdaptiveSizePolicy) {
 213     estimated -= _size_policy->max_survivor_size(young_gen()->max_gen_size());
 214   } else {
 215     estimated -= young_gen()->to_space()->capacity_in_bytes();
 216   }
 217   return MAX2(estimated, capacity());
 218 }
 219 
 220 bool ParallelScavengeHeap::is_in(const void* p) const {
 221   return young_gen()->is_in(p) || old_gen()->is_in(p);
 222 }
 223 
 224 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
 225   return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
 226 }
 227 
 228 // There are two levels of allocation policy here.
 229 //
 230 // When an allocation request fails, the requesting thread must invoke a VM
 231 // operation, transfer control to the VM thread, and await the results of a
 232 // garbage collection. That is quite expensive, and we should avoid doing it
 233 // multiple times if possible.
 234 //
 235 // To accomplish this, we have a basic allocation policy, and also a
 236 // failed allocation policy.
 237 //
 238 // The basic allocation policy controls how you allocate memory without
 239 // attempting garbage collection. It is okay to grab locks and
 240 // expand the heap, if that can be done without coming to a safepoint.
 241 // It is likely that the basic allocation policy will not be very
 242 // aggressive.
 243 //
 244 // The failed allocation policy is invoked from the VM thread after
 245 // the basic allocation policy is unable to satisfy a mem_allocate
 246 // request. This policy needs to cover the entire range of collection,
 247 // heap expansion, and out-of-memory conditions. It should make every
 248 // attempt to allocate the requested memory.
 249 
 250 // Basic allocation policy. Should never be called at a safepoint, or
 251 // from the VM thread.
 252 //
 253 // This method must handle cases where many mem_allocate requests fail
 254 // simultaneously. When that happens, only one VM operation will succeed,
 255 // and the rest will not be executed. For that reason, this method loops
 256 // during failed allocation attempts. If the java heap becomes exhausted,
 257 // we rely on the size_policy object to force a bail out.
 258 HeapWord* ParallelScavengeHeap::mem_allocate(
 259                                      size_t size,
 260                                      bool* gc_overhead_limit_was_exceeded) {
 261   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
 262   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
 263   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 264 
 265   // In general gc_overhead_limit_was_exceeded should be false so
 266   // set it so here and reset it to true only if the gc time
 267   // limit is being exceeded as checked below.
 268   *gc_overhead_limit_was_exceeded = false;
 269 
 270   HeapWord* result = young_gen()->allocate(size);
 271 
 272   uint loop_count = 0;
 273   uint gc_count = 0;
 274   uint gclocker_stalled_count = 0;
 275 
 276   while (result == NULL) {
 277     // We don't want to have multiple collections for a single filled generation.
 278     // To prevent this, each thread tracks the total_collections() value, and if
 279     // the count has changed, does not do a new collection.
 280     //
 281     // The collection count must be read only while holding the heap lock. VM
 282     // operations also hold the heap lock during collections. There is a lock
 283     // contention case where thread A blocks waiting on the Heap_lock, while
 284     // thread B is holding it doing a collection. When thread A gets the lock,
 285     // the collection count has already changed. To prevent duplicate collections,
 286     // The policy MUST attempt allocations during the same period it reads the
 287     // total_collections() value!
 288     {
 289       MutexLocker ml(Heap_lock);
 290       gc_count = total_collections();
 291 
 292       result = young_gen()->allocate(size);
 293       if (result != NULL) {
 294         return result;
 295       }
 296 
 297       // If certain conditions hold, try allocating from the old gen.
 298       result = mem_allocate_old_gen(size);
 299       if (result != NULL) {
 300         return result;
 301       }
 302 
 303       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
 304         return NULL;
 305       }
 306 
 307       // Failed to allocate without a gc.
 308       if (GCLocker::is_active_and_needs_gc()) {
 309         // If this thread is not in a jni critical section, we stall
 310         // the requestor until the critical section has cleared and
 311         // GC allowed. When the critical section clears, a GC is
 312         // initiated by the last thread exiting the critical section; so
 313         // we retry the allocation sequence from the beginning of the loop,
 314         // rather than causing more, now probably unnecessary, GC attempts.
 315         JavaThread* jthr = JavaThread::current();
 316         if (!jthr->in_critical()) {
 317           MutexUnlocker mul(Heap_lock);
 318           GCLocker::stall_until_clear();
 319           gclocker_stalled_count += 1;
 320           continue;
 321         } else {
 322           if (CheckJNICalls) {
 323             fatal("Possible deadlock due to allocating while"
 324                   " in jni critical section");
 325           }
 326           return NULL;
 327         }
 328       }
 329     }
 330 
 331     if (result == NULL) {
 332       // Generate a VM operation
 333       VM_ParallelGCFailedAllocation op(size, gc_count);
 334       VMThread::execute(&op);
 335 
 336       // Did the VM operation execute? If so, return the result directly.
 337       // This prevents us from looping until time out on requests that can
 338       // not be satisfied.
 339       if (op.prologue_succeeded()) {
 340         assert(is_in_or_null(op.result()), "result not in heap");
 341 
 342         // If GC was locked out during VM operation then retry allocation
 343         // and/or stall as necessary.
 344         if (op.gc_locked()) {
 345           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 346           continue;  // retry and/or stall as necessary
 347         }
 348 
 349         // Exit the loop if the gc time limit has been exceeded.
 350         // The allocation must have failed above ("result" guarding
 351         // this path is NULL) and the most recent collection has exceeded the
 352         // gc overhead limit (although enough may have been collected to
 353         // satisfy the allocation).  Exit the loop so that an out-of-memory
 354         // will be thrown (return a NULL ignoring the contents of
 355         // op.result()),
 356         // but clear gc_overhead_limit_exceeded so that the next collection
 357         // starts with a clean slate (i.e., forgets about previous overhead
 358         // excesses).  Fill op.result() with a filler object so that the
 359         // heap remains parsable.
 360         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 361         const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
 362 
 363         if (limit_exceeded && softrefs_clear) {
 364           *gc_overhead_limit_was_exceeded = true;
 365           size_policy()->set_gc_overhead_limit_exceeded(false);
 366           log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
 367           if (op.result() != NULL) {
 368             CollectedHeap::fill_with_object(op.result(), size);
 369           }
 370           return NULL;
 371         }
 372 
 373         return op.result();
 374       }
 375     }
 376 
 377     // The policy object will prevent us from looping forever. If the
 378     // time spent in gc crosses a threshold, we will bail out.
 379     loop_count++;
 380     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 381         (loop_count % QueuedAllocationWarningCount == 0)) {
 382       log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
 383       log_warning(gc)("\tsize=" SIZE_FORMAT, size);
 384     }
 385   }
 386 
 387   return result;
 388 }
 389 
 390 // A "death march" is a series of ultra-slow allocations in which a full gc is
 391 // done before each allocation, and after the full gc the allocation still
 392 // cannot be satisfied from the young gen.  This routine detects that condition;
 393 // it should be called after a full gc has been done and the allocation
 394 // attempted from the young gen. The parameter 'addr' should be the result of
 395 // that young gen allocation attempt.
 396 void
 397 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 398   if (addr != NULL) {
 399     _death_march_count = 0;  // death march has ended
 400   } else if (_death_march_count == 0) {
 401     if (should_alloc_in_eden(size)) {
 402       _death_march_count = 1;    // death march has started
 403     }
 404   }
 405 }
 406 
 407 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 408   if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
 409     // Size is too big for eden, or gc is locked out.
 410     return old_gen()->allocate(size);
 411   }
 412 
 413   // If a "death march" is in progress, allocate from the old gen a limited
 414   // number of times before doing a GC.
 415   if (_death_march_count > 0) {
 416     if (_death_march_count < 64) {
 417       ++_death_march_count;
 418       return old_gen()->allocate(size);
 419     } else {
 420       _death_march_count = 0;
 421     }
 422   }
 423   return NULL;
 424 }
 425 
 426 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 427   // The do_full_collection() parameter clear_all_soft_refs
 428   // is interpreted here as maximum_compaction which will
 429   // cause SoftRefs to be cleared.
 430   bool maximum_compaction = clear_all_soft_refs;
 431   PSParallelCompact::invoke(maximum_compaction);
 432 }
 433 
 434 // Failed allocation policy. Must be called from the VM thread, and
 435 // only at a safepoint! Note that this method has policy for allocation
 436 // flow, and NOT collection policy. So we do not check for gc collection
 437 // time over limit here, that is the responsibility of the heap specific
 438 // collection methods. This method decides where to attempt allocations,
 439 // and when to attempt collections, but no collection specific policy.
 440 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 441   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 442   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 443   assert(!is_gc_active(), "not reentrant");
 444   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 445 
 446   // We assume that allocation in eden will fail unless we collect.
 447 
 448   // First level allocation failure, scavenge and allocate in young gen.
 449   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 450   const bool invoked_full_gc = PSScavenge::invoke();
 451   HeapWord* result = young_gen()->allocate(size);
 452 
 453   // Second level allocation failure.
 454   //   Mark sweep and allocate in young generation.
 455   if (result == NULL && !invoked_full_gc) {
 456     do_full_collection(false);
 457     result = young_gen()->allocate(size);
 458   }
 459 
 460   death_march_check(result, size);
 461 
 462   // Third level allocation failure.
 463   //   After mark sweep and young generation allocation failure,
 464   //   allocate in old generation.
 465   if (result == NULL) {
 466     result = old_gen()->allocate(size);
 467   }
 468 
 469   // Fourth level allocation failure. We're running out of memory.
 470   //   More complete mark sweep and allocate in young generation.
 471   if (result == NULL) {
 472     do_full_collection(true);
 473     result = young_gen()->allocate(size);
 474   }
 475 
 476   // Fifth level allocation failure.
 477   //   After more complete mark sweep, allocate in old generation.
 478   if (result == NULL) {
 479     result = old_gen()->allocate(size);
 480   }
 481 
 482   return result;
 483 }
 484 
 485 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 486   CollectedHeap::ensure_parsability(retire_tlabs);
 487   young_gen()->eden_space()->ensure_parsability();
 488 }
 489 
 490 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 491   return young_gen()->eden_space()->tlab_capacity(thr);
 492 }
 493 
 494 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 495   return young_gen()->eden_space()->tlab_used(thr);
 496 }
 497 
 498 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 499   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 500 }
 501 
 502 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
 503   HeapWord* result = young_gen()->allocate(requested_size);
 504   if (result != NULL) {
 505     *actual_size = requested_size;
 506   }
 507 
 508   return result;
 509 }
 510 
 511 void ParallelScavengeHeap::resize_all_tlabs() {
 512   CollectedHeap::resize_all_tlabs();
 513 }
 514 
 515 // This method is used by System.gc() and JVMTI.
 516 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 517   assert(!Heap_lock->owned_by_self(),
 518     "this thread should not own the Heap_lock");
 519 
 520   uint gc_count      = 0;
 521   uint full_gc_count = 0;
 522   {
 523     MutexLocker ml(Heap_lock);
 524     // This value is guarded by the Heap_lock
 525     gc_count      = total_collections();
 526     full_gc_count = total_full_collections();
 527   }
 528 
 529   if (GCLocker::should_discard(cause, gc_count)) {
 530     return;
 531   }
 532 
 533   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 534   VMThread::execute(&op);
 535 }
 536 
 537 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 538   young_gen()->object_iterate(cl);
 539   old_gen()->object_iterate(cl);
 540 }
 541 
 542 
 543 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 544   if (young_gen()->is_in_reserved(addr)) {
 545     assert(young_gen()->is_in(addr),
 546            "addr should be in allocated part of young gen");
 547     // called from os::print_location by find or VMError
 548     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 549     Unimplemented();
 550   } else if (old_gen()->is_in_reserved(addr)) {
 551     assert(old_gen()->is_in(addr),
 552            "addr should be in allocated part of old gen");
 553     return old_gen()->start_array()->object_start((HeapWord*)addr);
 554   }
 555   return 0;
 556 }
 557 
 558 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 559   return block_start(addr) == addr;
 560 }
 561 
 562 jlong ParallelScavengeHeap::millis_since_last_gc() {
 563   return PSParallelCompact::millis_since_last_gc();
 564 }
 565 
 566 void ParallelScavengeHeap::prepare_for_verify() {
 567   ensure_parsability(false);  // no need to retire TLABs for verification
 568 }
 569 
 570 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 571   PSOldGen* old = old_gen();
 572   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 573   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 574   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 575 
 576   PSYoungGen* young = young_gen();
 577   VirtualSpaceSummary young_summary(young->reserved().start(),
 578     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 579 
 580   MutableSpace* eden = young_gen()->eden_space();
 581   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 582 
 583   MutableSpace* from = young_gen()->from_space();
 584   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 585 
 586   MutableSpace* to = young_gen()->to_space();
 587   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 588 
 589   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 590   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 591 }
 592 
 593 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
 594   return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
 595 }
 596 
 597 void ParallelScavengeHeap::print_on(outputStream* st) const {
 598   if (young_gen() != NULL) {
 599     young_gen()->print_on(st);
 600   }
 601   if (old_gen() != NULL) {
 602     old_gen()->print_on(st);
 603   }
 604   MetaspaceUtils::print_on(st);
 605 }
 606 
 607 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 608   this->CollectedHeap::print_on_error(st);
 609 
 610   st->cr();
 611   PSParallelCompact::print_on_error(st);
 612 }
 613 
 614 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 615   ParallelScavengeHeap::heap()->workers().threads_do(tc);
 616 }
 617 
 618 void ParallelScavengeHeap::print_tracing_info() const {
 619   AdaptiveSizePolicyOutput::print();
 620   log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
 621   log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
 622 }
 623 
 624 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
 625   const PSYoungGen* const young = young_gen();
 626   const MutableSpace* const eden = young->eden_space();
 627   const MutableSpace* const from = young->from_space();
 628   const PSOldGen* const old = old_gen();
 629 
 630   return PreGenGCValues(young->used_in_bytes(),
 631                         young->capacity_in_bytes(),
 632                         eden->used_in_bytes(),
 633                         eden->capacity_in_bytes(),
 634                         from->used_in_bytes(),
 635                         from->capacity_in_bytes(),
 636                         old->used_in_bytes(),
 637                         old->capacity_in_bytes());
 638 }
 639 
 640 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
 641   const PSYoungGen* const young = young_gen();
 642   const MutableSpace* const eden = young->eden_space();
 643   const MutableSpace* const from = young->from_space();
 644   const PSOldGen* const old = old_gen();
 645 
 646   log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
 647                      HEAP_CHANGE_FORMAT" "
 648                      HEAP_CHANGE_FORMAT,
 649                      HEAP_CHANGE_FORMAT_ARGS(young->name(),
 650                                              pre_gc_values.young_gen_used(),
 651                                              pre_gc_values.young_gen_capacity(),
 652                                              young->used_in_bytes(),
 653                                              young->capacity_in_bytes()),
 654                      HEAP_CHANGE_FORMAT_ARGS("Eden",
 655                                              pre_gc_values.eden_used(),
 656                                              pre_gc_values.eden_capacity(),
 657                                              eden->used_in_bytes(),
 658                                              eden->capacity_in_bytes()),
 659                      HEAP_CHANGE_FORMAT_ARGS("From",
 660                                              pre_gc_values.from_used(),
 661                                              pre_gc_values.from_capacity(),
 662                                              from->used_in_bytes(),
 663                                              from->capacity_in_bytes()));
 664   log_info(gc, heap)(HEAP_CHANGE_FORMAT,
 665                      HEAP_CHANGE_FORMAT_ARGS(old->name(),
 666                                              pre_gc_values.old_gen_used(),
 667                                              pre_gc_values.old_gen_capacity(),
 668                                              old->used_in_bytes(),
 669                                              old->capacity_in_bytes()));
 670   MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
 671 }
 672 
 673 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
 674   // Why do we need the total_collections()-filter below?
 675   if (total_collections() > 0) {
 676     log_debug(gc, verify)("Tenured");
 677     old_gen()->verify();
 678 
 679     log_debug(gc, verify)("Eden");
 680     young_gen()->verify();
 681   }
 682 }
 683 
 684 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 685   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 686   gc_tracer->report_gc_heap_summary(when, heap_summary);
 687 
 688   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 689   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 690 }
 691 
 692 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
 693   return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
 694 }
 695 
 696 PSCardTable* ParallelScavengeHeap::card_table() {
 697   return static_cast<PSCardTable*>(barrier_set()->card_table());
 698 }
 699 
 700 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 701                                             size_t survivor_size) {
 702   // Delegate the resize to the generation.
 703   _young_gen->resize(eden_size, survivor_size);
 704 }
 705 
 706 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 707   // Delegate the resize to the generation.
 708   _old_gen->resize(desired_free_space);
 709 }
 710 
 711 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 712   // nothing particular
 713 }
 714 
 715 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 716   // nothing particular
 717 }
 718 
 719 #ifndef PRODUCT
 720 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 721   if (ZapUnusedHeapArea) {
 722     young_gen()->record_spaces_top();
 723     old_gen()->record_spaces_top();
 724   }
 725 }
 726 
 727 void ParallelScavengeHeap::gen_mangle_unused_area() {
 728   if (ZapUnusedHeapArea) {
 729     young_gen()->eden_space()->mangle_unused_area();
 730     young_gen()->to_space()->mangle_unused_area();
 731     young_gen()->from_space()->mangle_unused_area();
 732     old_gen()->object_space()->mangle_unused_area();
 733   }
 734 }
 735 #endif
 736 
 737 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
 738   ScavengableNMethods::register_nmethod(nm);
 739 }
 740 
 741 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
 742   ScavengableNMethods::unregister_nmethod(nm);
 743 }
 744 
 745 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
 746   ScavengableNMethods::verify_nmethod(nm);
 747 }
 748 
 749 void ParallelScavengeHeap::flush_nmethod(nmethod* nm) {
 750   // nothing particular
 751 }
 752 
 753 void ParallelScavengeHeap::prune_scavengable_nmethods() {
 754   ScavengableNMethods::prune_nmethods();
 755 }
 756 
 757 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
 758   GrowableArray<GCMemoryManager*> memory_managers(2);
 759   memory_managers.append(_young_manager);
 760   memory_managers.append(_old_manager);
 761   return memory_managers;
 762 }
 763 
 764 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
 765   GrowableArray<MemoryPool*> memory_pools(3);
 766   memory_pools.append(_eden_pool);
 767   memory_pools.append(_survivor_pool);
 768   memory_pools.append(_old_pool);
 769   return memory_pools;
 770 }