1 /*
   2  * Copyright (c) 2001, 2018, 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/adjoiningGenerations.hpp"
  28 #include "gc/parallel/adjoiningGenerationsForHeteroHeap.hpp"
  29 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
  30 #include "gc/parallel/parallelArguments.hpp"
  31 #include "gc/parallel/gcTaskManager.hpp"
  32 #include "gc/parallel/objectStartArray.inline.hpp"
  33 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
  34 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
  35 #include "gc/parallel/psMarkSweepProxy.hpp"
  36 #include "gc/parallel/psMemoryPool.hpp"
  37 #include "gc/parallel/psParallelCompact.inline.hpp"
  38 #include "gc/parallel/psPromotionManager.hpp"
  39 #include "gc/parallel/psScavenge.hpp"
  40 #include "gc/parallel/psVMOperations.hpp"
  41 #include "gc/shared/gcHeapSummary.hpp"
  42 #include "gc/shared/gcLocker.hpp"
  43 #include "gc/shared/gcWhen.hpp"
  44 #include "gc/shared/genArguments.hpp"
  45 #include "gc/shared/scavengableNMethods.hpp"
  46 #include "logging/log.hpp"
  47 #include "memory/metaspaceCounters.hpp"
  48 #include "memory/universe.hpp"
  49 #include "oops/oop.inline.hpp"
  50 #include "runtime/handles.inline.hpp"
  51 #include "runtime/java.hpp"
  52 #include "runtime/vmThread.hpp"
  53 #include "services/memoryManager.hpp"
  54 #include "services/memTracker.hpp"
  55 #include "utilities/macros.hpp"
  56 #include "utilities/vmError.hpp"
  57 
  58 PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
  59 PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
  60 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
  61 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
  62 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
  63 
  64 jint ParallelScavengeHeap::initialize() {
  65   const size_t reserved_heap_size = ParallelArguments::heap_reserved_size_bytes();
  66 
  67   ReservedSpace heap_rs = Universe::reserve_heap(reserved_heap_size, HeapAlignment);
  68 
  69   os::trace_page_sizes("Heap",
  70                        MinHeapSize,
  71                        reserved_heap_size,
  72                        GenAlignment,
  73                        heap_rs.base(),
  74                        heap_rs.size());
  75 
  76   initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
  77 
  78   PSCardTable* card_table = new PSCardTable(reserved_region());
  79   card_table->initialize();
  80   CardTableBarrierSet* const barrier_set = new CardTableBarrierSet(card_table);
  81   barrier_set->initialize();
  82   BarrierSet::set_barrier_set(barrier_set);
  83 
  84   // Make up the generations
  85   // Calculate the maximum size that a generation can grow.  This
  86   // includes growth into the other generation.  Note that the
  87   // parameter _max_gen_size is kept as the maximum
  88   // size of the generation as the boundaries currently stand.
  89   // _max_gen_size is still used as that value.
  90   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
  91   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
  92 
  93   _gens = AdjoiningGenerations::create_adjoining_generations(heap_rs);
  94 
  95   _old_gen = _gens->old_gen();
  96   _young_gen = _gens->young_gen();
  97 
  98   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
  99   const size_t old_capacity = _old_gen->capacity_in_bytes();
 100   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
 101   _size_policy =
 102     new PSAdaptiveSizePolicy(eden_capacity,
 103                              initial_promo_size,
 104                              young_gen()->to_space()->capacity_in_bytes(),
 105                              GenAlignment,
 106                              max_gc_pause_sec,
 107                              max_gc_minor_pause_sec,
 108                              GCTimeRatio
 109                              );
 110 
 111   assert(ParallelArguments::is_heterogeneous_heap() || !UseAdaptiveGCBoundary ||
 112     (old_gen()->virtual_space()->high_boundary() ==
 113      young_gen()->virtual_space()->low_boundary()),
 114     "Boundaries must meet");
 115   // initialize the policy counters - 2 collectors, 2 generations
 116   _gc_policy_counters =
 117     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
 118 
 119   // Set up the GCTaskManager
 120   _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
 121 
 122   if (UseParallelOldGC && !PSParallelCompact::initialize()) {
 123     return JNI_ENOMEM;
 124   }
 125 
 126   return JNI_OK;
 127 }
 128 
 129 void ParallelScavengeHeap::initialize_serviceability() {
 130 
 131   _eden_pool = new EdenMutableSpacePool(_young_gen,
 132                                         _young_gen->eden_space(),
 133                                         "PS Eden Space",
 134                                         false /* support_usage_threshold */);
 135 
 136   _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
 137                                                 "PS Survivor Space",
 138                                                 false /* support_usage_threshold */);
 139 
 140   _old_pool = new PSGenerationPool(_old_gen,
 141                                    "PS Old Gen",
 142                                    true /* support_usage_threshold */);
 143 
 144   _young_manager = new GCMemoryManager("PS Scavenge", "end of minor GC");
 145   _old_manager = new GCMemoryManager("PS MarkSweep", "end of major GC");
 146 
 147   _old_manager->add_pool(_eden_pool);
 148   _old_manager->add_pool(_survivor_pool);
 149   _old_manager->add_pool(_old_pool);
 150 
 151   _young_manager->add_pool(_eden_pool);
 152   _young_manager->add_pool(_survivor_pool);
 153 
 154 }
 155 
 156 class PSIsScavengable : public BoolObjectClosure {
 157   bool do_object_b(oop obj) {
 158     return ParallelScavengeHeap::heap()->is_in_young(obj);
 159   }
 160 };
 161 
 162 static PSIsScavengable _is_scavengable;
 163 
 164 void ParallelScavengeHeap::post_initialize() {
 165   CollectedHeap::post_initialize();
 166   // Need to init the tenuring threshold
 167   PSScavenge::initialize();
 168   if (UseParallelOldGC) {
 169     PSParallelCompact::post_initialize();
 170   } else {
 171     PSMarkSweepProxy::initialize();
 172   }
 173   PSPromotionManager::initialize();
 174 
 175   ScavengableNMethods::initialize(&_is_scavengable);
 176 }
 177 
 178 void ParallelScavengeHeap::update_counters() {
 179   young_gen()->update_counters();
 180   old_gen()->update_counters();
 181   MetaspaceCounters::update_performance_counters();
 182   CompressedClassSpaceCounters::update_performance_counters();
 183 }
 184 
 185 size_t ParallelScavengeHeap::capacity() const {
 186   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
 187   return value;
 188 }
 189 
 190 size_t ParallelScavengeHeap::used() const {
 191   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
 192   return value;
 193 }
 194 
 195 bool ParallelScavengeHeap::is_maximal_no_gc() const {
 196   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
 197 }
 198 
 199 
 200 size_t ParallelScavengeHeap::max_capacity() const {
 201   size_t estimated = reserved_region().byte_size();
 202   if (UseAdaptiveSizePolicy) {
 203     estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
 204   } else {
 205     estimated -= young_gen()->to_space()->capacity_in_bytes();
 206   }
 207   return MAX2(estimated, capacity());
 208 }
 209 
 210 bool ParallelScavengeHeap::is_in(const void* p) const {
 211   return young_gen()->is_in(p) || old_gen()->is_in(p);
 212 }
 213 
 214 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
 215   return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
 216 }
 217 
 218 // There are two levels of allocation policy here.
 219 //
 220 // When an allocation request fails, the requesting thread must invoke a VM
 221 // operation, transfer control to the VM thread, and await the results of a
 222 // garbage collection. That is quite expensive, and we should avoid doing it
 223 // multiple times if possible.
 224 //
 225 // To accomplish this, we have a basic allocation policy, and also a
 226 // failed allocation policy.
 227 //
 228 // The basic allocation policy controls how you allocate memory without
 229 // attempting garbage collection. It is okay to grab locks and
 230 // expand the heap, if that can be done without coming to a safepoint.
 231 // It is likely that the basic allocation policy will not be very
 232 // aggressive.
 233 //
 234 // The failed allocation policy is invoked from the VM thread after
 235 // the basic allocation policy is unable to satisfy a mem_allocate
 236 // request. This policy needs to cover the entire range of collection,
 237 // heap expansion, and out-of-memory conditions. It should make every
 238 // attempt to allocate the requested memory.
 239 
 240 // Basic allocation policy. Should never be called at a safepoint, or
 241 // from the VM thread.
 242 //
 243 // This method must handle cases where many mem_allocate requests fail
 244 // simultaneously. When that happens, only one VM operation will succeed,
 245 // and the rest will not be executed. For that reason, this method loops
 246 // during failed allocation attempts. If the java heap becomes exhausted,
 247 // we rely on the size_policy object to force a bail out.
 248 HeapWord* ParallelScavengeHeap::mem_allocate(
 249                                      size_t size,
 250                                      bool* gc_overhead_limit_was_exceeded) {
 251   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
 252   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
 253   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 254 
 255   // In general gc_overhead_limit_was_exceeded should be false so
 256   // set it so here and reset it to true only if the gc time
 257   // limit is being exceeded as checked below.
 258   *gc_overhead_limit_was_exceeded = false;
 259 
 260   HeapWord* result = young_gen()->allocate(size);
 261 
 262   uint loop_count = 0;
 263   uint gc_count = 0;
 264   uint gclocker_stalled_count = 0;
 265 
 266   while (result == NULL) {
 267     // We don't want to have multiple collections for a single filled generation.
 268     // To prevent this, each thread tracks the total_collections() value, and if
 269     // the count has changed, does not do a new collection.
 270     //
 271     // The collection count must be read only while holding the heap lock. VM
 272     // operations also hold the heap lock during collections. There is a lock
 273     // contention case where thread A blocks waiting on the Heap_lock, while
 274     // thread B is holding it doing a collection. When thread A gets the lock,
 275     // the collection count has already changed. To prevent duplicate collections,
 276     // The policy MUST attempt allocations during the same period it reads the
 277     // total_collections() value!
 278     {
 279       MutexLocker ml(Heap_lock);
 280       gc_count = total_collections();
 281 
 282       result = young_gen()->allocate(size);
 283       if (result != NULL) {
 284         return result;
 285       }
 286 
 287       // If certain conditions hold, try allocating from the old gen.
 288       result = mem_allocate_old_gen(size);
 289       if (result != NULL) {
 290         return result;
 291       }
 292 
 293       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
 294         return NULL;
 295       }
 296 
 297       // Failed to allocate without a gc.
 298       if (GCLocker::is_active_and_needs_gc()) {
 299         // If this thread is not in a jni critical section, we stall
 300         // the requestor until the critical section has cleared and
 301         // GC allowed. When the critical section clears, a GC is
 302         // initiated by the last thread exiting the critical section; so
 303         // we retry the allocation sequence from the beginning of the loop,
 304         // rather than causing more, now probably unnecessary, GC attempts.
 305         JavaThread* jthr = JavaThread::current();
 306         if (!jthr->in_critical()) {
 307           MutexUnlocker mul(Heap_lock);
 308           GCLocker::stall_until_clear();
 309           gclocker_stalled_count += 1;
 310           continue;
 311         } else {
 312           if (CheckJNICalls) {
 313             fatal("Possible deadlock due to allocating while"
 314                   " in jni critical section");
 315           }
 316           return NULL;
 317         }
 318       }
 319     }
 320 
 321     if (result == NULL) {
 322       // Generate a VM operation
 323       VM_ParallelGCFailedAllocation op(size, gc_count);
 324       VMThread::execute(&op);
 325 
 326       // Did the VM operation execute? If so, return the result directly.
 327       // This prevents us from looping until time out on requests that can
 328       // not be satisfied.
 329       if (op.prologue_succeeded()) {
 330         assert(is_in_or_null(op.result()), "result not in heap");
 331 
 332         // If GC was locked out during VM operation then retry allocation
 333         // and/or stall as necessary.
 334         if (op.gc_locked()) {
 335           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 336           continue;  // retry and/or stall as necessary
 337         }
 338 
 339         // Exit the loop if the gc time limit has been exceeded.
 340         // The allocation must have failed above ("result" guarding
 341         // this path is NULL) and the most recent collection has exceeded the
 342         // gc overhead limit (although enough may have been collected to
 343         // satisfy the allocation).  Exit the loop so that an out-of-memory
 344         // will be thrown (return a NULL ignoring the contents of
 345         // op.result()),
 346         // but clear gc_overhead_limit_exceeded so that the next collection
 347         // starts with a clean slate (i.e., forgets about previous overhead
 348         // excesses).  Fill op.result() with a filler object so that the
 349         // heap remains parsable.
 350         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 351         const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
 352 
 353         if (limit_exceeded && softrefs_clear) {
 354           *gc_overhead_limit_was_exceeded = true;
 355           size_policy()->set_gc_overhead_limit_exceeded(false);
 356           log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
 357           if (op.result() != NULL) {
 358             CollectedHeap::fill_with_object(op.result(), size);
 359           }
 360           return NULL;
 361         }
 362 
 363         return op.result();
 364       }
 365     }
 366 
 367     // The policy object will prevent us from looping forever. If the
 368     // time spent in gc crosses a threshold, we will bail out.
 369     loop_count++;
 370     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 371         (loop_count % QueuedAllocationWarningCount == 0)) {
 372       log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
 373       log_warning(gc)("\tsize=" SIZE_FORMAT, size);
 374     }
 375   }
 376 
 377   return result;
 378 }
 379 
 380 // A "death march" is a series of ultra-slow allocations in which a full gc is
 381 // done before each allocation, and after the full gc the allocation still
 382 // cannot be satisfied from the young gen.  This routine detects that condition;
 383 // it should be called after a full gc has been done and the allocation
 384 // attempted from the young gen. The parameter 'addr' should be the result of
 385 // that young gen allocation attempt.
 386 void
 387 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 388   if (addr != NULL) {
 389     _death_march_count = 0;  // death march has ended
 390   } else if (_death_march_count == 0) {
 391     if (should_alloc_in_eden(size)) {
 392       _death_march_count = 1;    // death march has started
 393     }
 394   }
 395 }
 396 
 397 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 398   if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
 399     // Size is too big for eden, or gc is locked out.
 400     return old_gen()->allocate(size);
 401   }
 402 
 403   // If a "death march" is in progress, allocate from the old gen a limited
 404   // number of times before doing a GC.
 405   if (_death_march_count > 0) {
 406     if (_death_march_count < 64) {
 407       ++_death_march_count;
 408       return old_gen()->allocate(size);
 409     } else {
 410       _death_march_count = 0;
 411     }
 412   }
 413   return NULL;
 414 }
 415 
 416 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 417   if (UseParallelOldGC) {
 418     // The do_full_collection() parameter clear_all_soft_refs
 419     // is interpreted here as maximum_compaction which will
 420     // cause SoftRefs to be cleared.
 421     bool maximum_compaction = clear_all_soft_refs;
 422     PSParallelCompact::invoke(maximum_compaction);
 423   } else {
 424     PSMarkSweepProxy::invoke(clear_all_soft_refs);
 425   }
 426 }
 427 
 428 // Failed allocation policy. Must be called from the VM thread, and
 429 // only at a safepoint! Note that this method has policy for allocation
 430 // flow, and NOT collection policy. So we do not check for gc collection
 431 // time over limit here, that is the responsibility of the heap specific
 432 // collection methods. This method decides where to attempt allocations,
 433 // and when to attempt collections, but no collection specific policy.
 434 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 435   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 436   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 437   assert(!is_gc_active(), "not reentrant");
 438   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 439 
 440   // We assume that allocation in eden will fail unless we collect.
 441 
 442   // First level allocation failure, scavenge and allocate in young gen.
 443   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 444   const bool invoked_full_gc = PSScavenge::invoke();
 445   HeapWord* result = young_gen()->allocate(size);
 446 
 447   // Second level allocation failure.
 448   //   Mark sweep and allocate in young generation.
 449   if (result == NULL && !invoked_full_gc) {
 450     do_full_collection(false);
 451     result = young_gen()->allocate(size);
 452   }
 453 
 454   death_march_check(result, size);
 455 
 456   // Third level allocation failure.
 457   //   After mark sweep and young generation allocation failure,
 458   //   allocate in old generation.
 459   if (result == NULL) {
 460     result = old_gen()->allocate(size);
 461   }
 462 
 463   // Fourth level allocation failure. We're running out of memory.
 464   //   More complete mark sweep and allocate in young generation.
 465   if (result == NULL) {
 466     do_full_collection(true);
 467     result = young_gen()->allocate(size);
 468   }
 469 
 470   // Fifth level allocation failure.
 471   //   After more complete mark sweep, allocate in old generation.
 472   if (result == NULL) {
 473     result = old_gen()->allocate(size);
 474   }
 475 
 476   return result;
 477 }
 478 
 479 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 480   CollectedHeap::ensure_parsability(retire_tlabs);
 481   young_gen()->eden_space()->ensure_parsability();
 482 }
 483 
 484 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 485   return young_gen()->eden_space()->tlab_capacity(thr);
 486 }
 487 
 488 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 489   return young_gen()->eden_space()->tlab_used(thr);
 490 }
 491 
 492 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 493   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 494 }
 495 
 496 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
 497   HeapWord* result = young_gen()->allocate(requested_size);
 498   if (result != NULL) {
 499     *actual_size = requested_size;
 500   }
 501 
 502   return result;
 503 }
 504 
 505 void ParallelScavengeHeap::resize_all_tlabs() {
 506   CollectedHeap::resize_all_tlabs();
 507 }
 508 
 509 // This method is used by System.gc() and JVMTI.
 510 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 511   assert(!Heap_lock->owned_by_self(),
 512     "this thread should not own the Heap_lock");
 513 
 514   uint gc_count      = 0;
 515   uint full_gc_count = 0;
 516   {
 517     MutexLocker ml(Heap_lock);
 518     // This value is guarded by the Heap_lock
 519     gc_count      = total_collections();
 520     full_gc_count = total_full_collections();
 521   }
 522 
 523   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 524   VMThread::execute(&op);
 525 }
 526 
 527 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 528   young_gen()->object_iterate(cl);
 529   old_gen()->object_iterate(cl);
 530 }
 531 
 532 
 533 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 534   if (young_gen()->is_in_reserved(addr)) {
 535     assert(young_gen()->is_in(addr),
 536            "addr should be in allocated part of young gen");
 537     // called from os::print_location by find or VMError
 538     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 539     Unimplemented();
 540   } else if (old_gen()->is_in_reserved(addr)) {
 541     assert(old_gen()->is_in(addr),
 542            "addr should be in allocated part of old gen");
 543     return old_gen()->start_array()->object_start((HeapWord*)addr);
 544   }
 545   return 0;
 546 }
 547 
 548 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 549   return block_start(addr) == addr;
 550 }
 551 
 552 jlong ParallelScavengeHeap::millis_since_last_gc() {
 553   return UseParallelOldGC ?
 554     PSParallelCompact::millis_since_last_gc() :
 555     PSMarkSweepProxy::millis_since_last_gc();
 556 }
 557 
 558 void ParallelScavengeHeap::prepare_for_verify() {
 559   ensure_parsability(false);  // no need to retire TLABs for verification
 560 }
 561 
 562 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 563   PSOldGen* old = old_gen();
 564   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 565   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 566   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 567 
 568   PSYoungGen* young = young_gen();
 569   VirtualSpaceSummary young_summary(young->reserved().start(),
 570     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 571 
 572   MutableSpace* eden = young_gen()->eden_space();
 573   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 574 
 575   MutableSpace* from = young_gen()->from_space();
 576   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 577 
 578   MutableSpace* to = young_gen()->to_space();
 579   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 580 
 581   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 582   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 583 }
 584 
 585 void ParallelScavengeHeap::print_on(outputStream* st) const {
 586   young_gen()->print_on(st);
 587   old_gen()->print_on(st);
 588   MetaspaceUtils::print_on(st);
 589 }
 590 
 591 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 592   this->CollectedHeap::print_on_error(st);
 593 
 594   if (UseParallelOldGC) {
 595     st->cr();
 596     PSParallelCompact::print_on_error(st);
 597   }
 598 }
 599 
 600 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 601   PSScavenge::gc_task_manager()->threads_do(tc);
 602 }
 603 
 604 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
 605   PSScavenge::gc_task_manager()->print_threads_on(st);
 606 }
 607 
 608 void ParallelScavengeHeap::print_tracing_info() const {
 609   AdaptiveSizePolicyOutput::print();
 610   log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
 611   log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs",
 612       UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweepProxy::accumulated_time()->seconds());
 613 }
 614 
 615 
 616 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
 617   // Why do we need the total_collections()-filter below?
 618   if (total_collections() > 0) {
 619     log_debug(gc, verify)("Tenured");
 620     old_gen()->verify();
 621 
 622     log_debug(gc, verify)("Eden");
 623     young_gen()->verify();
 624   }
 625 }
 626 
 627 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 628   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 629   gc_tracer->report_gc_heap_summary(when, heap_summary);
 630 
 631   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 632   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 633 }
 634 
 635 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
 636   CollectedHeap* heap = Universe::heap();
 637   assert(heap != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
 638   assert(heap->kind() == CollectedHeap::Parallel, "Invalid name");
 639   return (ParallelScavengeHeap*)heap;
 640 }
 641 
 642 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
 643   return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
 644 }
 645 
 646 PSCardTable* ParallelScavengeHeap::card_table() {
 647   return static_cast<PSCardTable*>(barrier_set()->card_table());
 648 }
 649 
 650 // Before delegating the resize to the young generation,
 651 // the reserved space for the young and old generations
 652 // may be changed to accommodate the desired resize.
 653 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 654     size_t survivor_size) {
 655   if (UseAdaptiveGCBoundary) {
 656     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 657       size_policy()->reset_bytes_absorbed_from_eden();
 658       return;  // The generation changed size already.
 659     }
 660     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
 661   }
 662 
 663   // Delegate the resize to the generation.
 664   _young_gen->resize(eden_size, survivor_size);
 665 }
 666 
 667 // Before delegating the resize to the old generation,
 668 // the reserved space for the young and old generations
 669 // may be changed to accommodate the desired resize.
 670 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 671   if (UseAdaptiveGCBoundary) {
 672     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 673       size_policy()->reset_bytes_absorbed_from_eden();
 674       return;  // The generation changed size already.
 675     }
 676     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
 677   }
 678 
 679   // Delegate the resize to the generation.
 680   _old_gen->resize(desired_free_space);
 681 }
 682 
 683 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 684   // nothing particular
 685 }
 686 
 687 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 688   // nothing particular
 689 }
 690 
 691 #ifndef PRODUCT
 692 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 693   if (ZapUnusedHeapArea) {
 694     young_gen()->record_spaces_top();
 695     old_gen()->record_spaces_top();
 696   }
 697 }
 698 
 699 void ParallelScavengeHeap::gen_mangle_unused_area() {
 700   if (ZapUnusedHeapArea) {
 701     young_gen()->eden_space()->mangle_unused_area();
 702     young_gen()->to_space()->mangle_unused_area();
 703     young_gen()->from_space()->mangle_unused_area();
 704     old_gen()->object_space()->mangle_unused_area();
 705   }
 706 }
 707 #endif
 708 
 709 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
 710   ScavengableNMethods::register_nmethod(nm);
 711 }
 712 
 713 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
 714   ScavengableNMethods::unregister_nmethod(nm);
 715 }
 716 
 717 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
 718   ScavengableNMethods::verify_nmethod(nm);
 719 }
 720 
 721 void ParallelScavengeHeap::flush_nmethod(nmethod* nm) {
 722   // nothing particular
 723 }
 724 
 725 void ParallelScavengeHeap::prune_scavengable_nmethods() {
 726   ScavengableNMethods::prune_nmethods();
 727 }
 728 
 729 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
 730   GrowableArray<GCMemoryManager*> memory_managers(2);
 731   memory_managers.append(_young_manager);
 732   memory_managers.append(_old_manager);
 733   return memory_managers;
 734 }
 735 
 736 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
 737   GrowableArray<MemoryPool*> memory_pools(3);
 738   memory_pools.append(_eden_pool);
 739   memory_pools.append(_survivor_pool);
 740   memory_pools.append(_old_pool);
 741   return memory_pools;
 742 }