1 /*
   2  * Copyright (c) 2001, 2015, 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 "gc_implementation/parallelScavenge/adjoiningGenerations.hpp"
  27 #include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp"
  28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
  29 #include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
  30 #include "gc_implementation/parallelScavenge/generationSizer.hpp"
  31 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
  32 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
  33 #include "gc_implementation/parallelScavenge/psMarkSweep.hpp"
  34 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
  35 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
  36 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
  37 #include "gc_implementation/parallelScavenge/vmPSOperations.hpp"
  38 #include "gc_implementation/shared/gcHeapSummary.hpp"
  39 #include "gc_implementation/shared/gcWhen.hpp"
  40 #include "memory/gcLocker.inline.hpp"
  41 #include "oops/oop.inline.hpp"
  42 #include "runtime/handles.inline.hpp"
  43 #include "runtime/java.hpp"
  44 #include "runtime/vmThread.hpp"
  45 #include "services/memTracker.hpp"
  46 #include "utilities/vmError.hpp"
  47 
  48 PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
  49 PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
  50 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
  51 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
  52 ParallelScavengeHeap* ParallelScavengeHeap::_psh = NULL;
  53 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
  54 
  55 jint ParallelScavengeHeap::initialize() {
  56   CollectedHeap::pre_initialize();
  57 
  58   // Initialize collector policy
  59   _collector_policy = new GenerationSizer();
  60   _collector_policy->initialize_all();
  61 
  62   const size_t heap_size = _collector_policy->max_heap_byte_size();
  63 
  64   ReservedSpace heap_rs = Universe::reserve_heap(heap_size, _collector_policy->heap_alignment());
  65   MemTracker::record_virtual_memory_type((address)heap_rs.base(), mtJavaHeap);
  66 
  67   os::trace_page_sizes("ps main", _collector_policy->min_heap_byte_size(),
  68                        heap_size, generation_alignment(),
  69                        heap_rs.base(),
  70                        heap_rs.size());
  71   if (!heap_rs.is_reserved()) {
  72     vm_shutdown_during_initialization(
  73       "Could not reserve enough space for object heap");
  74     return JNI_ENOMEM;
  75   }
  76 
  77   initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
  78 
  79   CardTableExtension* const barrier_set = new CardTableExtension(reserved_region());
  80   barrier_set->initialize();
  81   set_barrier_set(barrier_set);
  82 
  83   // Make up the generations
  84   // Calculate the maximum size that a generation can grow.  This
  85   // includes growth into the other generation.  Note that the
  86   // parameter _max_gen_size is kept as the maximum
  87   // size of the generation as the boundaries currently stand.
  88   // _max_gen_size is still used as that value.
  89   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
  90   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
  91 
  92   _psh = this;
  93   _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
  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                              _collector_policy->gen_alignment(),
 106                              max_gc_pause_sec,
 107                              max_gc_minor_pause_sec,
 108                              GCTimeRatio
 109                              );
 110 
 111   assert(!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, 3 generations
 116   _gc_policy_counters =
 117     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _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::post_initialize() {
 130   // Need to init the tenuring threshold
 131   PSScavenge::initialize();
 132   if (UseParallelOldGC) {
 133     PSParallelCompact::post_initialize();
 134   } else {
 135     PSMarkSweep::initialize();
 136   }
 137   PSPromotionManager::initialize();
 138 }
 139 
 140 void ParallelScavengeHeap::update_counters() {
 141   young_gen()->update_counters();
 142   old_gen()->update_counters();
 143   MetaspaceCounters::update_performance_counters();
 144   CompressedClassSpaceCounters::update_performance_counters();
 145 }
 146 
 147 size_t ParallelScavengeHeap::capacity() const {
 148   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
 149   return value;
 150 }
 151 
 152 size_t ParallelScavengeHeap::used() const {
 153   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
 154   return value;
 155 }
 156 
 157 bool ParallelScavengeHeap::is_maximal_no_gc() const {
 158   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
 159 }
 160 
 161 
 162 size_t ParallelScavengeHeap::max_capacity() const {
 163   size_t estimated = reserved_region().byte_size();
 164   if (UseAdaptiveSizePolicy) {
 165     estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
 166   } else {
 167     estimated -= young_gen()->to_space()->capacity_in_bytes();
 168   }
 169   return MAX2(estimated, capacity());
 170 }
 171 
 172 bool ParallelScavengeHeap::is_in(const void* p) const {
 173   if (young_gen()->is_in(p)) {
 174     return true;
 175   }
 176 
 177   if (old_gen()->is_in(p)) {
 178     return true;
 179   }
 180 
 181   return false;
 182 }
 183 
 184 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
 185   if (young_gen()->is_in_reserved(p)) {
 186     return true;
 187   }
 188 
 189   if (old_gen()->is_in_reserved(p)) {
 190     return true;
 191   }
 192 
 193   return false;
 194 }
 195 
 196 bool ParallelScavengeHeap::is_scavengable(const void* addr) {
 197   return is_in_young((oop)addr);
 198 }
 199 
 200 // There are two levels of allocation policy here.
 201 //
 202 // When an allocation request fails, the requesting thread must invoke a VM
 203 // operation, transfer control to the VM thread, and await the results of a
 204 // garbage collection. That is quite expensive, and we should avoid doing it
 205 // multiple times if possible.
 206 //
 207 // To accomplish this, we have a basic allocation policy, and also a
 208 // failed allocation policy.
 209 //
 210 // The basic allocation policy controls how you allocate memory without
 211 // attempting garbage collection. It is okay to grab locks and
 212 // expand the heap, if that can be done without coming to a safepoint.
 213 // It is likely that the basic allocation policy will not be very
 214 // aggressive.
 215 //
 216 // The failed allocation policy is invoked from the VM thread after
 217 // the basic allocation policy is unable to satisfy a mem_allocate
 218 // request. This policy needs to cover the entire range of collection,
 219 // heap expansion, and out-of-memory conditions. It should make every
 220 // attempt to allocate the requested memory.
 221 
 222 // Basic allocation policy. Should never be called at a safepoint, or
 223 // from the VM thread.
 224 //
 225 // This method must handle cases where many mem_allocate requests fail
 226 // simultaneously. When that happens, only one VM operation will succeed,
 227 // and the rest will not be executed. For that reason, this method loops
 228 // during failed allocation attempts. If the java heap becomes exhausted,
 229 // we rely on the size_policy object to force a bail out.
 230 HeapWord* ParallelScavengeHeap::mem_allocate(
 231                                      size_t size,
 232                                      bool* gc_overhead_limit_was_exceeded) {
 233   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
 234   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
 235   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 236 
 237   // In general gc_overhead_limit_was_exceeded should be false so
 238   // set it so here and reset it to true only if the gc time
 239   // limit is being exceeded as checked below.
 240   *gc_overhead_limit_was_exceeded = false;
 241 
 242   HeapWord* result = young_gen()->allocate(size);
 243 
 244   uint loop_count = 0;
 245   uint gc_count = 0;
 246   uint gclocker_stalled_count = 0;
 247 
 248   while (result == NULL) {
 249     // We don't want to have multiple collections for a single filled generation.
 250     // To prevent this, each thread tracks the total_collections() value, and if
 251     // the count has changed, does not do a new collection.
 252     //
 253     // The collection count must be read only while holding the heap lock. VM
 254     // operations also hold the heap lock during collections. There is a lock
 255     // contention case where thread A blocks waiting on the Heap_lock, while
 256     // thread B is holding it doing a collection. When thread A gets the lock,
 257     // the collection count has already changed. To prevent duplicate collections,
 258     // The policy MUST attempt allocations during the same period it reads the
 259     // total_collections() value!
 260     {
 261       MutexLocker ml(Heap_lock);
 262       gc_count = total_collections();
 263 
 264       result = young_gen()->allocate(size);
 265       if (result != NULL) {
 266         return result;
 267       }
 268 
 269       // If certain conditions hold, try allocating from the old gen.
 270       result = mem_allocate_old_gen(size);
 271       if (result != NULL) {
 272         return result;
 273       }
 274 
 275       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
 276         return NULL;
 277       }
 278 
 279       // Failed to allocate without a gc.
 280       if (GC_locker::is_active_and_needs_gc()) {
 281         // If this thread is not in a jni critical section, we stall
 282         // the requestor until the critical section has cleared and
 283         // GC allowed. When the critical section clears, a GC is
 284         // initiated by the last thread exiting the critical section; so
 285         // we retry the allocation sequence from the beginning of the loop,
 286         // rather than causing more, now probably unnecessary, GC attempts.
 287         JavaThread* jthr = JavaThread::current();
 288         if (!jthr->in_critical()) {
 289           MutexUnlocker mul(Heap_lock);
 290           GC_locker::stall_until_clear();
 291           gclocker_stalled_count += 1;
 292           continue;
 293         } else {
 294           if (CheckJNICalls) {
 295             fatal("Possible deadlock due to allocating while"
 296                   " in jni critical section");
 297           }
 298           return NULL;
 299         }
 300       }
 301     }
 302 
 303     if (result == NULL) {
 304       // Generate a VM operation
 305       VM_ParallelGCFailedAllocation op(size, gc_count);
 306       VMThread::execute(&op);
 307 
 308       // Did the VM operation execute? If so, return the result directly.
 309       // This prevents us from looping until time out on requests that can
 310       // not be satisfied.
 311       if (op.prologue_succeeded()) {
 312         assert(is_in_or_null(op.result()), "result not in heap");
 313 
 314         // If GC was locked out during VM operation then retry allocation
 315         // and/or stall as necessary.
 316         if (op.gc_locked()) {
 317           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 318           continue;  // retry and/or stall as necessary
 319         }
 320 
 321         // Exit the loop if the gc time limit has been exceeded.
 322         // The allocation must have failed above ("result" guarding
 323         // this path is NULL) and the most recent collection has exceeded the
 324         // gc overhead limit (although enough may have been collected to
 325         // satisfy the allocation).  Exit the loop so that an out-of-memory
 326         // will be thrown (return a NULL ignoring the contents of
 327         // op.result()),
 328         // but clear gc_overhead_limit_exceeded so that the next collection
 329         // starts with a clean slate (i.e., forgets about previous overhead
 330         // excesses).  Fill op.result() with a filler object so that the
 331         // heap remains parsable.
 332         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 333         const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
 334 
 335         if (limit_exceeded && softrefs_clear) {
 336           *gc_overhead_limit_was_exceeded = true;
 337           size_policy()->set_gc_overhead_limit_exceeded(false);
 338           if (PrintGCDetails && Verbose) {
 339             gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
 340               "return NULL because gc_overhead_limit_exceeded is set");
 341           }
 342           if (op.result() != NULL) {
 343             CollectedHeap::fill_with_object(op.result(), size);
 344           }
 345           return NULL;
 346         }
 347 
 348         return op.result();
 349       }
 350     }
 351 
 352     // The policy object will prevent us from looping forever. If the
 353     // time spent in gc crosses a threshold, we will bail out.
 354     loop_count++;
 355     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 356         (loop_count % QueuedAllocationWarningCount == 0)) {
 357       warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t"
 358               " size=" SIZE_FORMAT, loop_count, size);
 359     }
 360   }
 361 
 362   return result;
 363 }
 364 
 365 // A "death march" is a series of ultra-slow allocations in which a full gc is
 366 // done before each allocation, and after the full gc the allocation still
 367 // cannot be satisfied from the young gen.  This routine detects that condition;
 368 // it should be called after a full gc has been done and the allocation
 369 // attempted from the young gen. The parameter 'addr' should be the result of
 370 // that young gen allocation attempt.
 371 void
 372 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 373   if (addr != NULL) {
 374     _death_march_count = 0;  // death march has ended
 375   } else if (_death_march_count == 0) {
 376     if (should_alloc_in_eden(size)) {
 377       _death_march_count = 1;    // death march has started
 378     }
 379   }
 380 }
 381 
 382 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 383   if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) {
 384     // Size is too big for eden, or gc is locked out.
 385     return old_gen()->allocate(size);
 386   }
 387 
 388   // If a "death march" is in progress, allocate from the old gen a limited
 389   // number of times before doing a GC.
 390   if (_death_march_count > 0) {
 391     if (_death_march_count < 64) {
 392       ++_death_march_count;
 393       return old_gen()->allocate(size);
 394     } else {
 395       _death_march_count = 0;
 396     }
 397   }
 398   return NULL;
 399 }
 400 
 401 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 402   if (UseParallelOldGC) {
 403     // The do_full_collection() parameter clear_all_soft_refs
 404     // is interpreted here as maximum_compaction which will
 405     // cause SoftRefs to be cleared.
 406     bool maximum_compaction = clear_all_soft_refs;
 407     PSParallelCompact::invoke(maximum_compaction);
 408   } else {
 409     PSMarkSweep::invoke(clear_all_soft_refs);
 410   }
 411 }
 412 
 413 // Failed allocation policy. Must be called from the VM thread, and
 414 // only at a safepoint! Note that this method has policy for allocation
 415 // flow, and NOT collection policy. So we do not check for gc collection
 416 // time over limit here, that is the responsibility of the heap specific
 417 // collection methods. This method decides where to attempt allocations,
 418 // and when to attempt collections, but no collection specific policy.
 419 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 420   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 421   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 422   assert(!is_gc_active(), "not reentrant");
 423   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 424 
 425   // We assume that allocation in eden will fail unless we collect.
 426 
 427   // First level allocation failure, scavenge and allocate in young gen.
 428   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 429   const bool invoked_full_gc = PSScavenge::invoke();
 430   HeapWord* result = young_gen()->allocate(size);
 431 
 432   // Second level allocation failure.
 433   //   Mark sweep and allocate in young generation.
 434   if (result == NULL && !invoked_full_gc) {
 435     do_full_collection(false);
 436     result = young_gen()->allocate(size);
 437   }
 438 
 439   death_march_check(result, size);
 440 
 441   // Third level allocation failure.
 442   //   After mark sweep and young generation allocation failure,
 443   //   allocate in old generation.
 444   if (result == NULL) {
 445     result = old_gen()->allocate(size);
 446   }
 447 
 448   // Fourth level allocation failure. We're running out of memory.
 449   //   More complete mark sweep and allocate in young generation.
 450   if (result == NULL) {
 451     do_full_collection(true);
 452     result = young_gen()->allocate(size);
 453   }
 454 
 455   // Fifth level allocation failure.
 456   //   After more complete mark sweep, allocate in old generation.
 457   if (result == NULL) {
 458     result = old_gen()->allocate(size);
 459   }
 460 
 461   return result;
 462 }
 463 
 464 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 465   CollectedHeap::ensure_parsability(retire_tlabs);
 466   young_gen()->eden_space()->ensure_parsability();
 467 }
 468 
 469 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 470   return young_gen()->eden_space()->tlab_capacity(thr);
 471 }
 472 
 473 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 474   return young_gen()->eden_space()->tlab_used(thr);
 475 }
 476 
 477 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 478   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 479 }
 480 
 481 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
 482   return young_gen()->allocate(size);
 483 }
 484 
 485 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
 486   CollectedHeap::accumulate_statistics_all_tlabs();
 487 }
 488 
 489 void ParallelScavengeHeap::resize_all_tlabs() {
 490   CollectedHeap::resize_all_tlabs();
 491 }
 492 
 493 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) {
 494   // We don't need barriers for stores to objects in the
 495   // young gen and, a fortiori, for initializing stores to
 496   // objects therein.
 497   return is_in_young(new_obj);
 498 }
 499 
 500 // This method is used by System.gc() and JVMTI.
 501 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 502   assert(!Heap_lock->owned_by_self(),
 503     "this thread should not own the Heap_lock");
 504 
 505   uint gc_count      = 0;
 506   uint full_gc_count = 0;
 507   {
 508     MutexLocker ml(Heap_lock);
 509     // This value is guarded by the Heap_lock
 510     gc_count      = total_collections();
 511     full_gc_count = total_full_collections();
 512   }
 513 
 514   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 515   VMThread::execute(&op);
 516 }
 517 
 518 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 519   young_gen()->object_iterate(cl);
 520   old_gen()->object_iterate(cl);
 521 }
 522 
 523 
 524 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 525   if (young_gen()->is_in_reserved(addr)) {
 526     assert(young_gen()->is_in(addr),
 527            "addr should be in allocated part of young gen");
 528     // called from os::print_location by find or VMError
 529     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 530     Unimplemented();
 531   } else if (old_gen()->is_in_reserved(addr)) {
 532     assert(old_gen()->is_in(addr),
 533            "addr should be in allocated part of old gen");
 534     return old_gen()->start_array()->object_start((HeapWord*)addr);
 535   }
 536   return 0;
 537 }
 538 
 539 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
 540   return oop(addr)->size();
 541 }
 542 
 543 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 544   return block_start(addr) == addr;
 545 }
 546 
 547 jlong ParallelScavengeHeap::millis_since_last_gc() {
 548   return UseParallelOldGC ?
 549     PSParallelCompact::millis_since_last_gc() :
 550     PSMarkSweep::millis_since_last_gc();
 551 }
 552 
 553 void ParallelScavengeHeap::prepare_for_verify() {
 554   ensure_parsability(false);  // no need to retire TLABs for verification
 555 }
 556 
 557 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 558   PSOldGen* old = old_gen();
 559   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 560   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 561   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 562 
 563   PSYoungGen* young = young_gen();
 564   VirtualSpaceSummary young_summary(young->reserved().start(),
 565     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 566 
 567   MutableSpace* eden = young_gen()->eden_space();
 568   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 569 
 570   MutableSpace* from = young_gen()->from_space();
 571   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 572 
 573   MutableSpace* to = young_gen()->to_space();
 574   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 575 
 576   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 577   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 578 }
 579 
 580 void ParallelScavengeHeap::print_on(outputStream* st) const {
 581   young_gen()->print_on(st);
 582   old_gen()->print_on(st);
 583   MetaspaceAux::print_on(st);
 584 }
 585 
 586 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 587   this->CollectedHeap::print_on_error(st);
 588 
 589   if (UseParallelOldGC) {
 590     st->cr();
 591     PSParallelCompact::print_on_error(st);
 592   }
 593 }
 594 
 595 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 596   PSScavenge::gc_task_manager()->threads_do(tc);
 597 }
 598 
 599 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
 600   PSScavenge::gc_task_manager()->print_threads_on(st);
 601 }
 602 
 603 void ParallelScavengeHeap::print_tracing_info() const {
 604   if (TraceYoungGenTime) {
 605     double time = PSScavenge::accumulated_time()->seconds();
 606     tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
 607   }
 608   if (TraceOldGenTime) {
 609     double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds();
 610     tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
 611   }
 612 }
 613 
 614 
 615 void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) {
 616   // Why do we need the total_collections()-filter below?
 617   if (total_collections() > 0) {
 618     if (!silent) {
 619       gclog_or_tty->print("tenured ");
 620     }
 621     old_gen()->verify();
 622 
 623     if (!silent) {
 624       gclog_or_tty->print("eden ");
 625     }
 626     young_gen()->verify();
 627   }
 628 }
 629 
 630 void ParallelScavengeHeap::print_heap_change(size_t prev_used) {
 631   if (PrintGCDetails && Verbose) {
 632     gclog_or_tty->print(" "  SIZE_FORMAT
 633                         "->" SIZE_FORMAT
 634                         "("  SIZE_FORMAT ")",
 635                         prev_used, used(), capacity());
 636   } else {
 637     gclog_or_tty->print(" "  SIZE_FORMAT "K"
 638                         "->" SIZE_FORMAT "K"
 639                         "("  SIZE_FORMAT "K)",
 640                         prev_used / K, used() / K, capacity() / K);
 641   }
 642 }
 643 
 644 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 645   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 646   gc_tracer->report_gc_heap_summary(when, heap_summary);
 647 
 648   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 649   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 650 }
 651 
 652 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
 653   assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
 654   assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap");
 655   return _psh;
 656 }
 657 
 658 // Before delegating the resize to the young generation,
 659 // the reserved space for the young and old generations
 660 // may be changed to accommodate the desired resize.
 661 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 662     size_t survivor_size) {
 663   if (UseAdaptiveGCBoundary) {
 664     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 665       size_policy()->reset_bytes_absorbed_from_eden();
 666       return;  // The generation changed size already.
 667     }
 668     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
 669   }
 670 
 671   // Delegate the resize to the generation.
 672   _young_gen->resize(eden_size, survivor_size);
 673 }
 674 
 675 // Before delegating the resize to the old generation,
 676 // the reserved space for the young and old generations
 677 // may be changed to accommodate the desired resize.
 678 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 679   if (UseAdaptiveGCBoundary) {
 680     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 681       size_policy()->reset_bytes_absorbed_from_eden();
 682       return;  // The generation changed size already.
 683     }
 684     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
 685   }
 686 
 687   // Delegate the resize to the generation.
 688   _old_gen->resize(desired_free_space);
 689 }
 690 
 691 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 692   // nothing particular
 693 }
 694 
 695 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 696   // nothing particular
 697 }
 698 
 699 #ifndef PRODUCT
 700 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 701   if (ZapUnusedHeapArea) {
 702     young_gen()->record_spaces_top();
 703     old_gen()->record_spaces_top();
 704   }
 705 }
 706 
 707 void ParallelScavengeHeap::gen_mangle_unused_area() {
 708   if (ZapUnusedHeapArea) {
 709     young_gen()->eden_space()->mangle_unused_area();
 710     young_gen()->to_space()->mangle_unused_area();
 711     young_gen()->from_space()->mangle_unused_area();
 712     old_gen()->object_space()->mangle_unused_area();
 713   }
 714 }
 715 #endif