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   _barrier_set = barrier_set;
  82   oopDesc::set_bs(_barrier_set);
  83   if (_barrier_set == NULL) {
  84     vm_shutdown_during_initialization(
  85       "Could not reserve enough space for barrier set");
  86     return JNI_ENOMEM;
  87   }
  88 
  89   // Make up the generations
  90   // Calculate the maximum size that a generation can grow.  This
  91   // includes growth into the other generation.  Note that the
  92   // parameter _max_gen_size is kept as the maximum
  93   // size of the generation as the boundaries currently stand.
  94   // _max_gen_size is still used as that value.
  95   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
  96   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
  97 
  98   _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
  99 
 100   _old_gen = _gens->old_gen();
 101   _young_gen = _gens->young_gen();
 102 
 103   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
 104   const size_t old_capacity = _old_gen->capacity_in_bytes();
 105   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
 106   _size_policy =
 107     new PSAdaptiveSizePolicy(eden_capacity,
 108                              initial_promo_size,
 109                              young_gen()->to_space()->capacity_in_bytes(),
 110                              _collector_policy->gen_alignment(),
 111                              max_gc_pause_sec,
 112                              max_gc_minor_pause_sec,
 113                              GCTimeRatio
 114                              );
 115 
 116   assert(!UseAdaptiveGCBoundary ||
 117     (old_gen()->virtual_space()->high_boundary() ==
 118      young_gen()->virtual_space()->low_boundary()),
 119     "Boundaries must meet");
 120   // initialize the policy counters - 2 collectors, 3 generations
 121   _gc_policy_counters =
 122     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy);
 123   _psh = this;
 124 
 125   // Set up the GCTaskManager
 126   _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
 127 
 128   if (UseParallelOldGC && !PSParallelCompact::initialize()) {
 129     return JNI_ENOMEM;
 130   }
 131 
 132   return JNI_OK;
 133 }
 134 
 135 void ParallelScavengeHeap::post_initialize() {
 136   // Need to init the tenuring threshold
 137   PSScavenge::initialize();
 138   if (UseParallelOldGC) {
 139     PSParallelCompact::post_initialize();
 140   } else {
 141     PSMarkSweep::initialize();
 142   }
 143   PSPromotionManager::initialize();
 144 }
 145 
 146 void ParallelScavengeHeap::update_counters() {
 147   young_gen()->update_counters();
 148   old_gen()->update_counters();
 149   MetaspaceCounters::update_performance_counters();
 150   CompressedClassSpaceCounters::update_performance_counters();
 151 }
 152 
 153 size_t ParallelScavengeHeap::capacity() const {
 154   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
 155   return value;
 156 }
 157 
 158 size_t ParallelScavengeHeap::used() const {
 159   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
 160   return value;
 161 }
 162 
 163 bool ParallelScavengeHeap::is_maximal_no_gc() const {
 164   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
 165 }
 166 
 167 
 168 size_t ParallelScavengeHeap::max_capacity() const {
 169   size_t estimated = reserved_region().byte_size();
 170   if (UseAdaptiveSizePolicy) {
 171     estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
 172   } else {
 173     estimated -= young_gen()->to_space()->capacity_in_bytes();
 174   }
 175   return MAX2(estimated, capacity());
 176 }
 177 
 178 bool ParallelScavengeHeap::is_in(const void* p) const {
 179   if (young_gen()->is_in(p)) {
 180     return true;
 181   }
 182 
 183   if (old_gen()->is_in(p)) {
 184     return true;
 185   }
 186 
 187   return false;
 188 }
 189 
 190 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
 191   if (young_gen()->is_in_reserved(p)) {
 192     return true;
 193   }
 194 
 195   if (old_gen()->is_in_reserved(p)) {
 196     return true;
 197   }
 198 
 199   return false;
 200 }
 201 
 202 bool ParallelScavengeHeap::is_scavengable(const void* addr) {
 203   return is_in_young((oop)addr);
 204 }
 205 
 206 #ifdef ASSERT
 207 // Don't implement this by using is_in_young().  This method is used
 208 // in some cases to check that is_in_young() is correct.
 209 bool ParallelScavengeHeap::is_in_partial_collection(const void *p) {
 210   assert(is_in_reserved(p) || p == NULL,
 211     "Does not work if address is non-null and outside of the heap");
 212   // The order of the generations is old (low addr), young (high addr)
 213   return p >= old_gen()->reserved().end();
 214 }
 215 #endif
 216 
 217 // There are two levels of allocation policy here.
 218 //
 219 // When an allocation request fails, the requesting thread must invoke a VM
 220 // operation, transfer control to the VM thread, and await the results of a
 221 // garbage collection. That is quite expensive, and we should avoid doing it
 222 // multiple times if possible.
 223 //
 224 // To accomplish this, we have a basic allocation policy, and also a
 225 // failed allocation policy.
 226 //
 227 // The basic allocation policy controls how you allocate memory without
 228 // attempting garbage collection. It is okay to grab locks and
 229 // expand the heap, if that can be done without coming to a safepoint.
 230 // It is likely that the basic allocation policy will not be very
 231 // aggressive.
 232 //
 233 // The failed allocation policy is invoked from the VM thread after
 234 // the basic allocation policy is unable to satisfy a mem_allocate
 235 // request. This policy needs to cover the entire range of collection,
 236 // heap expansion, and out-of-memory conditions. It should make every
 237 // attempt to allocate the requested memory.
 238 
 239 // Basic allocation policy. Should never be called at a safepoint, or
 240 // from the VM thread.
 241 //
 242 // This method must handle cases where many mem_allocate requests fail
 243 // simultaneously. When that happens, only one VM operation will succeed,
 244 // and the rest will not be executed. For that reason, this method loops
 245 // during failed allocation attempts. If the java heap becomes exhausted,
 246 // we rely on the size_policy object to force a bail out.
 247 HeapWord* ParallelScavengeHeap::mem_allocate(
 248                                      size_t size,
 249                                      bool* gc_overhead_limit_was_exceeded) {
 250   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
 251   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
 252   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 253 
 254   // In general gc_overhead_limit_was_exceeded should be false so
 255   // set it so here and reset it to true only if the gc time
 256   // limit is being exceeded as checked below.
 257   *gc_overhead_limit_was_exceeded = false;
 258 
 259   HeapWord* result = young_gen()->allocate(size);
 260 
 261   uint loop_count = 0;
 262   uint gc_count = 0;
 263   uint gclocker_stalled_count = 0;
 264   uint gc_attempt = 1;
 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 = Universe::heap()->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 (GC_locker::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           GC_locker::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, gc_attempt++);
 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(Universe::heap()->is_in_or_null(op.result()),
 331           "result not in heap");
 332 
 333         // If GC was locked out during VM operation then retry allocation
 334         // and/or stall as necessary.
 335         if (op.gc_locked()) {
 336           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 337           continue;  // retry and/or stall as necessary
 338         }
 339 
 340         // Exit the loop if the gc time limit has been exceeded.
 341         // The allocation must have failed above ("result" guarding
 342         // this path is NULL) and the most recent collection has exceeded the
 343         // gc overhead limit (although enough may have been collected to
 344         // satisfy the allocation).  Exit the loop so that an out-of-memory
 345         // will be thrown (return a NULL ignoring the contents of
 346         // op.result()),
 347         // but clear gc_overhead_limit_exceeded so that the next collection
 348         // starts with a clean slate (i.e., forgets about previous overhead
 349         // excesses).  Fill op.result() with a filler object so that the
 350         // heap remains parsable.
 351         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 352         const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
 353 
 354         if (limit_exceeded && softrefs_clear) {
 355           *gc_overhead_limit_was_exceeded = true;
 356           size_policy()->set_gc_overhead_limit_exceeded(false);
 357           if (PrintGCDetails && Verbose) {
 358             gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
 359               "return NULL because gc_overhead_limit_exceeded is set");
 360           }
 361           if (op.result() != NULL) {
 362             CollectedHeap::fill_with_object(op.result(), size);
 363           }
 364           return NULL;
 365         }
 366 
 367         return op.result();
 368       }
 369     }
 370 
 371     // The policy object will prevent us from looping forever. If the
 372     // time spent in gc crosses a threshold, we will bail out.
 373     loop_count++;
 374     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 375         (loop_count % QueuedAllocationWarningCount == 0)) {
 376       warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t"
 377               " size=" SIZE_FORMAT, loop_count, size);
 378     }
 379   }
 380 
 381   return result;
 382 }
 383 
 384 // A "death march" is a series of ultra-slow allocations in which a full gc is
 385 // done before each allocation, and after the full gc the allocation still
 386 // cannot be satisfied from the young gen.  This routine detects that condition;
 387 // it should be called after a full gc has been done and the allocation
 388 // attempted from the young gen. The parameter 'addr' should be the result of
 389 // that young gen allocation attempt.
 390 void
 391 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 392   if (addr != NULL) {
 393     _death_march_count = 0;  // death march has ended
 394   } else if (_death_march_count == 0) {
 395     if (should_alloc_in_eden(size)) {
 396       _death_march_count = 1;    // death march has started
 397     }
 398   }
 399 }
 400 
 401 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 402   if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) {
 403     // Size is too big for eden, or gc is locked out.
 404     return old_gen()->allocate(size);
 405   }
 406 
 407   // If a "death march" is in progress, allocate from the old gen a limited
 408   // number of times before doing a GC.
 409   if (_death_march_count > 0) {
 410     if (_death_march_count < 64) {
 411       ++_death_march_count;
 412       return old_gen()->allocate(size);
 413     } else {
 414       _death_march_count = 0;
 415     }
 416   }
 417   return NULL;
 418 }
 419 
 420 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 421   if (UseParallelOldGC) {
 422     // The do_full_collection() parameter clear_all_soft_refs
 423     // is interpreted here as maximum_compaction which will
 424     // cause SoftRefs to be cleared.
 425     bool maximum_compaction = clear_all_soft_refs;
 426     PSParallelCompact::invoke(maximum_compaction);
 427   } else {
 428     PSMarkSweep::invoke(clear_all_soft_refs);
 429   }
 430 }
 431 
 432 // Failed allocation policy. Must be called from the VM thread, and
 433 // only at a safepoint! Note that this method has policy for allocation
 434 // flow, and NOT collection policy. So we do not check for gc collection
 435 // time over limit here, that is the responsibility of the heap specific
 436 // collection methods. This method decides where to attempt allocations,
 437 // and when to attempt collections, but no collection specific policy.
 438 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 439   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 440   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 441   assert(!Universe::heap()->is_gc_active(), "not reentrant");
 442   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 443 
 444   // We assume that allocation in eden will fail unless we collect.
 445 
 446   // First level allocation failure, scavenge and allocate in young gen.
 447   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 448   const bool invoked_full_gc = PSScavenge::invoke();
 449   HeapWord* result = young_gen()->allocate(size);
 450 
 451   // Second level allocation failure.
 452   //   Mark sweep and allocate in young generation.
 453   if (result == NULL && !invoked_full_gc) {
 454     do_full_collection(false);
 455     result = young_gen()->allocate(size);
 456   }
 457 
 458   death_march_check(result, size);
 459 
 460   // Third level allocation failure.
 461   //   After mark sweep and young generation allocation failure,
 462   //   allocate in old generation.
 463   if (result == NULL) {
 464     result = old_gen()->allocate(size);
 465   }
 466 
 467   // Fourth level allocation failure. We're running out of memory.
 468   //   More complete mark sweep and allocate in young generation.
 469   if (result == NULL) {
 470     do_full_collection(true);
 471     result = young_gen()->allocate(size);
 472   }
 473 
 474   // Fifth level allocation failure.
 475   //   After more complete mark sweep, allocate in old generation.
 476   if (result == NULL) {
 477     result = old_gen()->allocate(size);
 478   }
 479 
 480   return result;
 481 }
 482 
 483 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 484   CollectedHeap::ensure_parsability(retire_tlabs);
 485   young_gen()->eden_space()->ensure_parsability();
 486 }
 487 
 488 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 489   return young_gen()->eden_space()->tlab_capacity(thr);
 490 }
 491 
 492 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 493   return young_gen()->eden_space()->tlab_used(thr);
 494 }
 495 
 496 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 497   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 498 }
 499 
 500 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
 501   return young_gen()->allocate(size);
 502 }
 503 
 504 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
 505   CollectedHeap::accumulate_statistics_all_tlabs();
 506 }
 507 
 508 void ParallelScavengeHeap::resize_all_tlabs() {
 509   CollectedHeap::resize_all_tlabs();
 510 }
 511 
 512 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) {
 513   // We don't need barriers for stores to objects in the
 514   // young gen and, a fortiori, for initializing stores to
 515   // objects therein.
 516   return is_in_young(new_obj);
 517 }
 518 
 519 // This method is used by System.gc() and JVMTI.
 520 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 521   assert(!Heap_lock->owned_by_self(),
 522     "this thread should not own the Heap_lock");
 523 
 524   uint gc_count      = 0;
 525   uint full_gc_count = 0;
 526   {
 527     MutexLocker ml(Heap_lock);
 528     // This value is guarded by the Heap_lock
 529     gc_count      = Universe::heap()->total_collections();
 530     full_gc_count = Universe::heap()->total_full_collections();
 531   }
 532 
 533   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 534   VMThread::execute(&op);
 535 }
 536 
 537 void ParallelScavengeHeap::oop_iterate(ExtendedOopClosure* cl) {
 538   Unimplemented();
 539 }
 540 
 541 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 542   young_gen()->object_iterate(cl);
 543   old_gen()->object_iterate(cl);
 544 }
 545 
 546 
 547 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 548   if (young_gen()->is_in_reserved(addr)) {
 549     assert(young_gen()->is_in(addr),
 550            "addr should be in allocated part of young gen");
 551     // called from os::print_location by find or VMError
 552     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 553     Unimplemented();
 554   } else if (old_gen()->is_in_reserved(addr)) {
 555     assert(old_gen()->is_in(addr),
 556            "addr should be in allocated part of old gen");
 557     return old_gen()->start_array()->object_start((HeapWord*)addr);
 558   }
 559   return 0;
 560 }
 561 
 562 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
 563   return oop(addr)->size();
 564 }
 565 
 566 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 567   return block_start(addr) == addr;
 568 }
 569 
 570 jlong ParallelScavengeHeap::millis_since_last_gc() {
 571   return UseParallelOldGC ?
 572     PSParallelCompact::millis_since_last_gc() :
 573     PSMarkSweep::millis_since_last_gc();
 574 }
 575 
 576 void ParallelScavengeHeap::prepare_for_verify() {
 577   ensure_parsability(false);  // no need to retire TLABs for verification
 578 }
 579 
 580 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 581   PSOldGen* old = old_gen();
 582   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 583   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 584   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 585 
 586   PSYoungGen* young = young_gen();
 587   VirtualSpaceSummary young_summary(young->reserved().start(),
 588     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 589 
 590   MutableSpace* eden = young_gen()->eden_space();
 591   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 592 
 593   MutableSpace* from = young_gen()->from_space();
 594   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 595 
 596   MutableSpace* to = young_gen()->to_space();
 597   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 598 
 599   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 600   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 601 }
 602 
 603 void ParallelScavengeHeap::print_on(outputStream* st) const {
 604   young_gen()->print_on(st);
 605   old_gen()->print_on(st);
 606   MetaspaceAux::print_on(st);
 607 }
 608 
 609 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 610   this->CollectedHeap::print_on_error(st);
 611 
 612   if (UseParallelOldGC) {
 613     st->cr();
 614     PSParallelCompact::print_on_error(st);
 615   }
 616 }
 617 
 618 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 619   PSScavenge::gc_task_manager()->threads_do(tc);
 620 }
 621 
 622 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
 623   PSScavenge::gc_task_manager()->print_threads_on(st);
 624 }
 625 
 626 void ParallelScavengeHeap::print_tracing_info() const {
 627   if (TraceYoungGenTime) {
 628     double time = PSScavenge::accumulated_time()->seconds();
 629     tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
 630   }
 631   if (TraceOldGenTime) {
 632     double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds();
 633     tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
 634   }
 635 }
 636 
 637 
 638 void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) {
 639   // Why do we need the total_collections()-filter below?
 640   if (total_collections() > 0) {
 641     if (!silent) {
 642       gclog_or_tty->print("tenured ");
 643     }
 644     old_gen()->verify();
 645 
 646     if (!silent) {
 647       gclog_or_tty->print("eden ");
 648     }
 649     young_gen()->verify();
 650   }
 651 }
 652 
 653 void ParallelScavengeHeap::print_heap_change(size_t prev_used) {
 654   if (PrintGCDetails && Verbose) {
 655     gclog_or_tty->print(" "  SIZE_FORMAT
 656                         "->" SIZE_FORMAT
 657                         "("  SIZE_FORMAT ")",
 658                         prev_used, used(), capacity());
 659   } else {
 660     gclog_or_tty->print(" "  SIZE_FORMAT "K"
 661                         "->" SIZE_FORMAT "K"
 662                         "("  SIZE_FORMAT "K)",
 663                         prev_used / K, used() / K, capacity() / K);
 664   }
 665 }
 666 
 667 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 668   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 669   gc_tracer->report_gc_heap_summary(when, heap_summary);
 670 
 671   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 672   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 673 }
 674 
 675 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
 676   assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
 677   assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap");
 678   return _psh;
 679 }
 680 
 681 // Before delegating the resize to the young generation,
 682 // the reserved space for the young and old generations
 683 // may be changed to accommodate the desired resize.
 684 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 685     size_t survivor_size) {
 686   if (UseAdaptiveGCBoundary) {
 687     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 688       size_policy()->reset_bytes_absorbed_from_eden();
 689       return;  // The generation changed size already.
 690     }
 691     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
 692   }
 693 
 694   // Delegate the resize to the generation.
 695   _young_gen->resize(eden_size, survivor_size);
 696 }
 697 
 698 // Before delegating the resize to the old generation,
 699 // the reserved space for the young and old generations
 700 // may be changed to accommodate the desired resize.
 701 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 702   if (UseAdaptiveGCBoundary) {
 703     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 704       size_policy()->reset_bytes_absorbed_from_eden();
 705       return;  // The generation changed size already.
 706     }
 707     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
 708   }
 709 
 710   // Delegate the resize to the generation.
 711   _old_gen->resize(desired_free_space);
 712 }
 713 
 714 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 715   // nothing particular
 716 }
 717 
 718 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 719   // nothing particular
 720 }
 721 
 722 #ifndef PRODUCT
 723 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 724   if (ZapUnusedHeapArea) {
 725     young_gen()->record_spaces_top();
 726     old_gen()->record_spaces_top();
 727   }
 728 }
 729 
 730 void ParallelScavengeHeap::gen_mangle_unused_area() {
 731   if (ZapUnusedHeapArea) {
 732     young_gen()->eden_space()->mangle_unused_area();
 733     young_gen()->to_space()->mangle_unused_area();
 734     young_gen()->from_space()->mangle_unused_area();
 735     old_gen()->object_space()->mangle_unused_area();
 736   }
 737 }
 738 #endif