1 /*
   2  * Copyright (c) 2001, 2017, 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/adjoiningVirtualSpaces.hpp"
  29 #include "gc/parallel/cardTableExtension.hpp"
  30 #include "gc/parallel/gcTaskManager.hpp"
  31 #include "gc/parallel/generationSizer.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/psMarkSweep.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/vmPSOperations.hpp"
  41 #include "gc/shared/gcHeapSummary.hpp"
  42 #include "gc/shared/gcLocker.inline.hpp"
  43 #include "gc/shared/gcWhen.hpp"
  44 #include "logging/log.hpp"
  45 #include "memory/metaspaceCounters.hpp"
  46 #include "oops/oop.inline.hpp"
  47 #include "runtime/handles.inline.hpp"
  48 #include "runtime/java.hpp"
  49 #include "runtime/vmThread.hpp"
  50 #include "services/memoryManager.hpp"
  51 #include "services/memTracker.hpp"
  52 #include "utilities/vmError.hpp"
  53 
  54 PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
  55 PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
  56 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
  57 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
  58 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
  59 
  60 jint ParallelScavengeHeap::initialize() {
  61   CollectedHeap::pre_initialize();
  62 
  63   const size_t heap_size = _collector_policy->max_heap_byte_size();
  64 
  65   ReservedSpace heap_rs = Universe::reserve_heap(heap_size, _collector_policy->heap_alignment());
  66 
  67   os::trace_page_sizes("Heap",
  68                        _collector_policy->min_heap_byte_size(),
  69                        heap_size,
  70                        generation_alignment(),
  71                        heap_rs.base(),
  72                        heap_rs.size());
  73 
  74   initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
  75 
  76   CardTableExtension* const barrier_set = new CardTableExtension(reserved_region());
  77   barrier_set->initialize();
  78   set_barrier_set(barrier_set);
  79 
  80   // Make up the generations
  81   // Calculate the maximum size that a generation can grow.  This
  82   // includes growth into the other generation.  Note that the
  83   // parameter _max_gen_size is kept as the maximum
  84   // size of the generation as the boundaries currently stand.
  85   // _max_gen_size is still used as that value.
  86   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
  87   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
  88 
  89   _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
  90 
  91   _old_gen = _gens->old_gen();
  92   _young_gen = _gens->young_gen();
  93 
  94   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
  95   const size_t old_capacity = _old_gen->capacity_in_bytes();
  96   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
  97   _size_policy =
  98     new PSAdaptiveSizePolicy(eden_capacity,
  99                              initial_promo_size,
 100                              young_gen()->to_space()->capacity_in_bytes(),
 101                              _collector_policy->gen_alignment(),
 102                              max_gc_pause_sec,
 103                              max_gc_minor_pause_sec,
 104                              GCTimeRatio
 105                              );
 106 
 107   assert(!UseAdaptiveGCBoundary ||
 108     (old_gen()->virtual_space()->high_boundary() ==
 109      young_gen()->virtual_space()->low_boundary()),
 110     "Boundaries must meet");
 111   // initialize the policy counters - 2 collectors, 2 generations
 112   _gc_policy_counters =
 113     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
 114 
 115   // Set up the GCTaskManager
 116   _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
 117 
 118   if (UseParallelOldGC && !PSParallelCompact::initialize()) {
 119     return JNI_ENOMEM;
 120   }
 121 
 122   return JNI_OK;
 123 }
 124 
 125 void ParallelScavengeHeap::initialize_serviceability() {
 126 
 127   _eden_pool = new EdenMutableSpacePool(_young_gen,
 128                                         _young_gen->eden_space(),
 129                                         "PS Eden Space",
 130                                         false /* support_usage_threshold */);
 131 
 132   _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
 133                                                 "PS Survivor Space",
 134                                                 false /* support_usage_threshold */);
 135 
 136   _old_pool = new PSGenerationPool(_old_gen,
 137                                    "PS Old Gen",
 138                                    true /* support_usage_threshold */);
 139 
 140   _young_manager = new GCMemoryManager("PS Scavenge", "end of minor GC");
 141   _old_manager = new GCMemoryManager("PS MarkSweep", "end of major GC");
 142 
 143   _old_manager->add_pool(_eden_pool);
 144   _old_manager->add_pool(_survivor_pool);
 145   _old_manager->add_pool(_old_pool);
 146 
 147   _young_manager->add_pool(_eden_pool);
 148   _young_manager->add_pool(_survivor_pool);
 149 
 150 }
 151 
 152 void ParallelScavengeHeap::post_initialize() {
 153   CollectedHeap::post_initialize();
 154   // Need to init the tenuring threshold
 155   PSScavenge::initialize();
 156   if (UseParallelOldGC) {
 157     PSParallelCompact::post_initialize();
 158   } else {
 159     PSMarkSweep::initialize();
 160   }
 161   PSPromotionManager::initialize();
 162 }
 163 
 164 void ParallelScavengeHeap::update_counters() {
 165   young_gen()->update_counters();
 166   old_gen()->update_counters();
 167   MetaspaceCounters::update_performance_counters();
 168   CompressedClassSpaceCounters::update_performance_counters();
 169 }
 170 
 171 size_t ParallelScavengeHeap::capacity() const {
 172   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
 173   return value;
 174 }
 175 
 176 size_t ParallelScavengeHeap::used() const {
 177   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
 178   return value;
 179 }
 180 
 181 bool ParallelScavengeHeap::is_maximal_no_gc() const {
 182   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
 183 }
 184 
 185 
 186 size_t ParallelScavengeHeap::max_capacity() const {
 187   size_t estimated = reserved_region().byte_size();
 188   if (UseAdaptiveSizePolicy) {
 189     estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
 190   } else {
 191     estimated -= young_gen()->to_space()->capacity_in_bytes();
 192   }
 193   return MAX2(estimated, capacity());
 194 }
 195 
 196 bool ParallelScavengeHeap::is_in(const void* p) const {
 197   return young_gen()->is_in(p) || old_gen()->is_in(p);
 198 }
 199 
 200 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
 201   return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
 202 }
 203 
 204 // There are two levels of allocation policy here.
 205 //
 206 // When an allocation request fails, the requesting thread must invoke a VM
 207 // operation, transfer control to the VM thread, and await the results of a
 208 // garbage collection. That is quite expensive, and we should avoid doing it
 209 // multiple times if possible.
 210 //
 211 // To accomplish this, we have a basic allocation policy, and also a
 212 // failed allocation policy.
 213 //
 214 // The basic allocation policy controls how you allocate memory without
 215 // attempting garbage collection. It is okay to grab locks and
 216 // expand the heap, if that can be done without coming to a safepoint.
 217 // It is likely that the basic allocation policy will not be very
 218 // aggressive.
 219 //
 220 // The failed allocation policy is invoked from the VM thread after
 221 // the basic allocation policy is unable to satisfy a mem_allocate
 222 // request. This policy needs to cover the entire range of collection,
 223 // heap expansion, and out-of-memory conditions. It should make every
 224 // attempt to allocate the requested memory.
 225 
 226 // Basic allocation policy. Should never be called at a safepoint, or
 227 // from the VM thread.
 228 //
 229 // This method must handle cases where many mem_allocate requests fail
 230 // simultaneously. When that happens, only one VM operation will succeed,
 231 // and the rest will not be executed. For that reason, this method loops
 232 // during failed allocation attempts. If the java heap becomes exhausted,
 233 // we rely on the size_policy object to force a bail out.
 234 HeapWord* ParallelScavengeHeap::mem_allocate(
 235                                      size_t size,
 236                                      bool* gc_overhead_limit_was_exceeded) {
 237   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
 238   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
 239   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 240 
 241   // In general gc_overhead_limit_was_exceeded should be false so
 242   // set it so here and reset it to true only if the gc time
 243   // limit is being exceeded as checked below.
 244   *gc_overhead_limit_was_exceeded = false;
 245 
 246   HeapWord* result = young_gen()->allocate(size);
 247 
 248   uint loop_count = 0;
 249   uint gc_count = 0;
 250   uint gclocker_stalled_count = 0;
 251 
 252   while (result == NULL) {
 253     // We don't want to have multiple collections for a single filled generation.
 254     // To prevent this, each thread tracks the total_collections() value, and if
 255     // the count has changed, does not do a new collection.
 256     //
 257     // The collection count must be read only while holding the heap lock. VM
 258     // operations also hold the heap lock during collections. There is a lock
 259     // contention case where thread A blocks waiting on the Heap_lock, while
 260     // thread B is holding it doing a collection. When thread A gets the lock,
 261     // the collection count has already changed. To prevent duplicate collections,
 262     // The policy MUST attempt allocations during the same period it reads the
 263     // total_collections() value!
 264     {
 265       MutexLocker ml(Heap_lock);
 266       gc_count = total_collections();
 267 
 268       result = young_gen()->allocate(size);
 269       if (result != NULL) {
 270         return result;
 271       }
 272 
 273       // If certain conditions hold, try allocating from the old gen.
 274       result = mem_allocate_old_gen(size);
 275       if (result != NULL) {
 276         return result;
 277       }
 278 
 279       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
 280         return NULL;
 281       }
 282 
 283       // Failed to allocate without a gc.
 284       if (GCLocker::is_active_and_needs_gc()) {
 285         // If this thread is not in a jni critical section, we stall
 286         // the requestor until the critical section has cleared and
 287         // GC allowed. When the critical section clears, a GC is
 288         // initiated by the last thread exiting the critical section; so
 289         // we retry the allocation sequence from the beginning of the loop,
 290         // rather than causing more, now probably unnecessary, GC attempts.
 291         JavaThread* jthr = JavaThread::current();
 292         if (!jthr->in_critical()) {
 293           MutexUnlocker mul(Heap_lock);
 294           GCLocker::stall_until_clear();
 295           gclocker_stalled_count += 1;
 296           continue;
 297         } else {
 298           if (CheckJNICalls) {
 299             fatal("Possible deadlock due to allocating while"
 300                   " in jni critical section");
 301           }
 302           return NULL;
 303         }
 304       }
 305     }
 306 
 307     if (result == NULL) {
 308       // Generate a VM operation
 309       VM_ParallelGCFailedAllocation op(size, gc_count);
 310       VMThread::execute(&op);
 311 
 312       // Did the VM operation execute? If so, return the result directly.
 313       // This prevents us from looping until time out on requests that can
 314       // not be satisfied.
 315       if (op.prologue_succeeded()) {
 316         assert(is_in_or_null(op.result()), "result not in heap");
 317 
 318         // If GC was locked out during VM operation then retry allocation
 319         // and/or stall as necessary.
 320         if (op.gc_locked()) {
 321           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 322           continue;  // retry and/or stall as necessary
 323         }
 324 
 325         // Exit the loop if the gc time limit has been exceeded.
 326         // The allocation must have failed above ("result" guarding
 327         // this path is NULL) and the most recent collection has exceeded the
 328         // gc overhead limit (although enough may have been collected to
 329         // satisfy the allocation).  Exit the loop so that an out-of-memory
 330         // will be thrown (return a NULL ignoring the contents of
 331         // op.result()),
 332         // but clear gc_overhead_limit_exceeded so that the next collection
 333         // starts with a clean slate (i.e., forgets about previous overhead
 334         // excesses).  Fill op.result() with a filler object so that the
 335         // heap remains parsable.
 336         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 337         const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
 338 
 339         if (limit_exceeded && softrefs_clear) {
 340           *gc_overhead_limit_was_exceeded = true;
 341           size_policy()->set_gc_overhead_limit_exceeded(false);
 342           log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
 343           if (op.result() != NULL) {
 344             CollectedHeap::fill_with_object(op.result(), size);
 345           }
 346           return NULL;
 347         }
 348 
 349         return op.result();
 350       }
 351     }
 352 
 353     // The policy object will prevent us from looping forever. If the
 354     // time spent in gc crosses a threshold, we will bail out.
 355     loop_count++;
 356     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 357         (loop_count % QueuedAllocationWarningCount == 0)) {
 358       log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
 359       log_warning(gc)("\tsize=" SIZE_FORMAT, size);
 360     }
 361   }
 362 
 363   return result;
 364 }
 365 
 366 // A "death march" is a series of ultra-slow allocations in which a full gc is
 367 // done before each allocation, and after the full gc the allocation still
 368 // cannot be satisfied from the young gen.  This routine detects that condition;
 369 // it should be called after a full gc has been done and the allocation
 370 // attempted from the young gen. The parameter 'addr' should be the result of
 371 // that young gen allocation attempt.
 372 void
 373 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 374   if (addr != NULL) {
 375     _death_march_count = 0;  // death march has ended
 376   } else if (_death_march_count == 0) {
 377     if (should_alloc_in_eden(size)) {
 378       _death_march_count = 1;    // death march has started
 379     }
 380   }
 381 }
 382 
 383 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 384   if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
 385     // Size is too big for eden, or gc is locked out.
 386     return old_gen()->allocate(size);
 387   }
 388 
 389   // If a "death march" is in progress, allocate from the old gen a limited
 390   // number of times before doing a GC.
 391   if (_death_march_count > 0) {
 392     if (_death_march_count < 64) {
 393       ++_death_march_count;
 394       return old_gen()->allocate(size);
 395     } else {
 396       _death_march_count = 0;
 397     }
 398   }
 399   return NULL;
 400 }
 401 
 402 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 403   if (UseParallelOldGC) {
 404     // The do_full_collection() parameter clear_all_soft_refs
 405     // is interpreted here as maximum_compaction which will
 406     // cause SoftRefs to be cleared.
 407     bool maximum_compaction = clear_all_soft_refs;
 408     PSParallelCompact::invoke(maximum_compaction);
 409   } else {
 410     PSMarkSweep::invoke(clear_all_soft_refs);
 411   }
 412 }
 413 
 414 // Failed allocation policy. Must be called from the VM thread, and
 415 // only at a safepoint! Note that this method has policy for allocation
 416 // flow, and NOT collection policy. So we do not check for gc collection
 417 // time over limit here, that is the responsibility of the heap specific
 418 // collection methods. This method decides where to attempt allocations,
 419 // and when to attempt collections, but no collection specific policy.
 420 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 421   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 422   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 423   assert(!is_gc_active(), "not reentrant");
 424   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 425 
 426   // We assume that allocation in eden will fail unless we collect.
 427 
 428   // First level allocation failure, scavenge and allocate in young gen.
 429   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 430   const bool invoked_full_gc = PSScavenge::invoke();
 431   HeapWord* result = young_gen()->allocate(size);
 432 
 433   // Second level allocation failure.
 434   //   Mark sweep and allocate in young generation.
 435   if (result == NULL && !invoked_full_gc) {
 436     do_full_collection(false);
 437     result = young_gen()->allocate(size);
 438   }
 439 
 440   death_march_check(result, size);
 441 
 442   // Third level allocation failure.
 443   //   After mark sweep and young generation allocation failure,
 444   //   allocate in old generation.
 445   if (result == NULL) {
 446     result = old_gen()->allocate(size);
 447   }
 448 
 449   // Fourth level allocation failure. We're running out of memory.
 450   //   More complete mark sweep and allocate in young generation.
 451   if (result == NULL) {
 452     do_full_collection(true);
 453     result = young_gen()->allocate(size);
 454   }
 455 
 456   // Fifth level allocation failure.
 457   //   After more complete mark sweep, allocate in old generation.
 458   if (result == NULL) {
 459     result = old_gen()->allocate(size);
 460   }
 461 
 462   return result;
 463 }
 464 
 465 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 466   CollectedHeap::ensure_parsability(retire_tlabs);
 467   young_gen()->eden_space()->ensure_parsability();
 468 }
 469 
 470 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 471   return young_gen()->eden_space()->tlab_capacity(thr);
 472 }
 473 
 474 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 475   return young_gen()->eden_space()->tlab_used(thr);
 476 }
 477 
 478 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 479   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 480 }
 481 
 482 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
 483   return young_gen()->allocate(size);
 484 }
 485 
 486 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
 487   CollectedHeap::accumulate_statistics_all_tlabs();
 488 }
 489 
 490 void ParallelScavengeHeap::resize_all_tlabs() {
 491   CollectedHeap::resize_all_tlabs();
 492 }
 493 
 494 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) {
 495   // We don't need barriers for stores to objects in the
 496   // young gen and, a fortiori, for initializing stores to
 497   // objects therein.
 498   return is_in_young(new_obj);
 499 }
 500 
 501 // This method is used by System.gc() and JVMTI.
 502 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 503   assert(!Heap_lock->owned_by_self(),
 504     "this thread should not own the Heap_lock");
 505 
 506   uint gc_count      = 0;
 507   uint full_gc_count = 0;
 508   {
 509     MutexLocker ml(Heap_lock);
 510     // This value is guarded by the Heap_lock
 511     gc_count      = total_collections();
 512     full_gc_count = total_full_collections();
 513   }
 514 
 515   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 516   VMThread::execute(&op);
 517 }
 518 
 519 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 520   young_gen()->object_iterate(cl);
 521   old_gen()->object_iterate(cl);
 522 }
 523 
 524 
 525 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 526   if (young_gen()->is_in_reserved(addr)) {
 527     assert(young_gen()->is_in(addr),
 528            "addr should be in allocated part of young gen");
 529     // called from os::print_location by find or VMError
 530     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 531     Unimplemented();
 532   } else if (old_gen()->is_in_reserved(addr)) {
 533     assert(old_gen()->is_in(addr),
 534            "addr should be in allocated part of old gen");
 535     return old_gen()->start_array()->object_start((HeapWord*)addr);
 536   }
 537   return 0;
 538 }
 539 
 540 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
 541   return oop(addr)->size();
 542 }
 543 
 544 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 545   return block_start(addr) == addr;
 546 }
 547 
 548 jlong ParallelScavengeHeap::millis_since_last_gc() {
 549   return UseParallelOldGC ?
 550     PSParallelCompact::millis_since_last_gc() :
 551     PSMarkSweep::millis_since_last_gc();
 552 }
 553 
 554 void ParallelScavengeHeap::prepare_for_verify() {
 555   ensure_parsability(false);  // no need to retire TLABs for verification
 556 }
 557 
 558 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 559   PSOldGen* old = old_gen();
 560   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 561   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 562   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 563 
 564   PSYoungGen* young = young_gen();
 565   VirtualSpaceSummary young_summary(young->reserved().start(),
 566     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 567 
 568   MutableSpace* eden = young_gen()->eden_space();
 569   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 570 
 571   MutableSpace* from = young_gen()->from_space();
 572   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 573 
 574   MutableSpace* to = young_gen()->to_space();
 575   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 576 
 577   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 578   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 579 }
 580 
 581 void ParallelScavengeHeap::print_on(outputStream* st) const {
 582   young_gen()->print_on(st);
 583   old_gen()->print_on(st);
 584   MetaspaceAux::print_on(st);
 585 }
 586 
 587 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 588   this->CollectedHeap::print_on_error(st);
 589 
 590   if (UseParallelOldGC) {
 591     st->cr();
 592     PSParallelCompact::print_on_error(st);
 593   }
 594 }
 595 
 596 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 597   PSScavenge::gc_task_manager()->threads_do(tc);
 598 }
 599 
 600 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
 601   PSScavenge::gc_task_manager()->print_threads_on(st);
 602 }
 603 
 604 void ParallelScavengeHeap::print_tracing_info() const {
 605   AdaptiveSizePolicyOutput::print();
 606   log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
 607   log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs",
 608       UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds());
 609 }
 610 
 611 
 612 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
 613   // Why do we need the total_collections()-filter below?
 614   if (total_collections() > 0) {
 615     log_debug(gc, verify)("Tenured");
 616     old_gen()->verify();
 617 
 618     log_debug(gc, verify)("Eden");
 619     young_gen()->verify();
 620   }
 621 }
 622 
 623 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 624   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 625   gc_tracer->report_gc_heap_summary(when, heap_summary);
 626 
 627   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 628   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 629 }
 630 
 631 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
 632   CollectedHeap* heap = Universe::heap();
 633   assert(heap != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
 634   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Not a ParallelScavengeHeap");
 635   return (ParallelScavengeHeap*)heap;
 636 }
 637 
 638 // Before delegating the resize to the young generation,
 639 // the reserved space for the young and old generations
 640 // may be changed to accommodate the desired resize.
 641 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 642     size_t survivor_size) {
 643   if (UseAdaptiveGCBoundary) {
 644     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 645       size_policy()->reset_bytes_absorbed_from_eden();
 646       return;  // The generation changed size already.
 647     }
 648     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
 649   }
 650 
 651   // Delegate the resize to the generation.
 652   _young_gen->resize(eden_size, survivor_size);
 653 }
 654 
 655 // Before delegating the resize to the old generation,
 656 // the reserved space for the young and old generations
 657 // may be changed to accommodate the desired resize.
 658 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 659   if (UseAdaptiveGCBoundary) {
 660     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 661       size_policy()->reset_bytes_absorbed_from_eden();
 662       return;  // The generation changed size already.
 663     }
 664     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
 665   }
 666 
 667   // Delegate the resize to the generation.
 668   _old_gen->resize(desired_free_space);
 669 }
 670 
 671 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 672   // nothing particular
 673 }
 674 
 675 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 676   // nothing particular
 677 }
 678 
 679 #ifndef PRODUCT
 680 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 681   if (ZapUnusedHeapArea) {
 682     young_gen()->record_spaces_top();
 683     old_gen()->record_spaces_top();
 684   }
 685 }
 686 
 687 void ParallelScavengeHeap::gen_mangle_unused_area() {
 688   if (ZapUnusedHeapArea) {
 689     young_gen()->eden_space()->mangle_unused_area();
 690     young_gen()->to_space()->mangle_unused_area();
 691     young_gen()->from_space()->mangle_unused_area();
 692     old_gen()->object_space()->mangle_unused_area();
 693   }
 694 }
 695 #endif
 696 
 697 bool ParallelScavengeHeap::is_scavengable(oop obj) {
 698   return is_in_young(obj);
 699 }
 700 
 701 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
 702   CodeCache::register_scavenge_root_nmethod(nm);
 703 }
 704 
 705 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
 706   CodeCache::verify_scavenge_root_nmethod(nm);
 707 }
 708 
 709 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
 710   GrowableArray<GCMemoryManager*> memory_managers(2);
 711   memory_managers.append(_young_manager);
 712   memory_managers.append(_old_manager);
 713   return memory_managers;
 714 }
 715 
 716 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
 717   GrowableArray<MemoryPool*> memory_pools(3);
 718   memory_pools.append(_eden_pool);
 719   memory_pools.append(_survivor_pool);
 720   memory_pools.append(_old_pool);
 721   return memory_pools;
 722 }
 723 
--- EOF ---