1 /*
  2  * Copyright (c) 2001, 2021, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "precompiled.hpp"
 26 #include "code/codeCache.hpp"
 27 #include "gc/parallel/parallelArguments.hpp"
 28 #include "gc/parallel/objectStartArray.inline.hpp"
 29 #include "gc/parallel/parallelInitLogger.hpp"
 30 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
 31 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
 32 #include "gc/parallel/psMemoryPool.hpp"
 33 #include "gc/parallel/psParallelCompact.inline.hpp"
 34 #include "gc/parallel/psPromotionManager.hpp"
 35 #include "gc/parallel/psScavenge.hpp"
 36 #include "gc/parallel/psVMOperations.hpp"
 37 #include "gc/shared/gcHeapSummary.hpp"
 38 #include "gc/shared/gcLocker.hpp"
 39 #include "gc/shared/gcWhen.hpp"
 40 #include "gc/shared/genArguments.hpp"
 41 #include "gc/shared/gcInitLogger.hpp"
 42 #include "gc/shared/locationPrinter.inline.hpp"
 43 #include "gc/shared/scavengableNMethods.hpp"
 44 #include "gc/shared/suspendibleThreadSet.hpp"
 45 #include "logging/log.hpp"
 46 #include "memory/iterator.hpp"
 47 #include "memory/metaspaceCounters.hpp"
 48 #include "memory/metaspaceUtils.hpp"
 49 #include "memory/universe.hpp"
 50 #include "oops/oop.inline.hpp"
 51 #include "runtime/handles.inline.hpp"
 52 #include "runtime/java.hpp"
 53 #include "runtime/vmThread.hpp"
 54 #include "services/memoryManager.hpp"
 55 #include "services/memTracker.hpp"
 56 #include "utilities/macros.hpp"
 57 #include "utilities/vmError.hpp"
 58 
 59 PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
 60 PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
 61 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
 62 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
 63 
 64 jint ParallelScavengeHeap::initialize() {
 65   const size_t reserved_heap_size = ParallelArguments::heap_reserved_size_bytes();
 66 
 67   ReservedHeapSpace heap_rs = Universe::reserve_heap(reserved_heap_size, HeapAlignment);
 68 
 69   trace_actual_reserved_page_size(reserved_heap_size, heap_rs);
 70 
 71   initialize_reserved_region(heap_rs);
 72 
 73   PSCardTable* card_table = new PSCardTable(heap_rs.region());
 74   card_table->initialize();
 75   CardTableBarrierSet* const barrier_set = new CardTableBarrierSet(card_table);
 76   barrier_set->initialize();
 77   BarrierSet::set_barrier_set(barrier_set);
 78 
 79   // Make up the generations
 80   assert(MinOldSize <= OldSize && OldSize <= MaxOldSize, "Parameter check");
 81   assert(MinNewSize <= NewSize && NewSize <= MaxNewSize, "Parameter check");
 82 
 83   // Layout the reserved space for the generations.
 84   ReservedSpace old_rs   = heap_rs.first_part(MaxOldSize);
 85   ReservedSpace young_rs = heap_rs.last_part(MaxOldSize);
 86   assert(young_rs.size() == MaxNewSize, "Didn't reserve all of the heap");
 87 
 88   // Set up WorkerThreads
 89   _workers.initialize_workers();
 90 
 91   // Create and initialize the generations.
 92   _young_gen = new PSYoungGen(
 93       young_rs,
 94       NewSize,
 95       MinNewSize,
 96       MaxNewSize);
 97   _old_gen = new PSOldGen(
 98       old_rs,
 99       OldSize,
100       MinOldSize,
101       MaxOldSize,
102       "old", 1);
103 
104   assert(young_gen()->max_gen_size() == young_rs.size(),"Consistency check");
105   assert(old_gen()->max_gen_size() == old_rs.size(), "Consistency check");
106 
107   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
108   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
109 
110   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
111   const size_t old_capacity = _old_gen->capacity_in_bytes();
112   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
113   _size_policy =
114     new PSAdaptiveSizePolicy(eden_capacity,
115                              initial_promo_size,
116                              young_gen()->to_space()->capacity_in_bytes(),
117                              GenAlignment,
118                              max_gc_pause_sec,
119                              max_gc_minor_pause_sec,
120                              GCTimeRatio
121                              );
122 
123   assert((old_gen()->virtual_space()->high_boundary() ==
124           young_gen()->virtual_space()->low_boundary()),
125          "Boundaries must meet");
126   // initialize the policy counters - 2 collectors, 2 generations
127   _gc_policy_counters =
128     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
129 
130   if (!PSParallelCompact::initialize()) {
131     return JNI_ENOMEM;
132   }
133 
134   ParallelInitLogger::print();
135 
136   return JNI_OK;
137 }
138 
139 void ParallelScavengeHeap::initialize_serviceability() {
140 
141   _eden_pool = new EdenMutableSpacePool(_young_gen,
142                                         _young_gen->eden_space(),
143                                         "PS Eden Space",
144                                         false /* support_usage_threshold */);
145 
146   _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
147                                                 "PS Survivor Space",
148                                                 false /* support_usage_threshold */);
149 
150   _old_pool = new PSGenerationPool(_old_gen,
151                                    "PS Old Gen",
152                                    true /* support_usage_threshold */);
153 
154   _young_manager = new GCMemoryManager("PS Scavenge", "end of minor GC");
155   _old_manager = new GCMemoryManager("PS MarkSweep", "end of major GC");
156 
157   _old_manager->add_pool(_eden_pool);
158   _old_manager->add_pool(_survivor_pool);
159   _old_manager->add_pool(_old_pool);
160 
161   _young_manager->add_pool(_eden_pool);
162   _young_manager->add_pool(_survivor_pool);
163 
164 }
165 
166 void ParallelScavengeHeap::safepoint_synchronize_begin() {
167   if (UseStringDeduplication) {
168     SuspendibleThreadSet::synchronize();
169   }
170 }
171 
172 void ParallelScavengeHeap::safepoint_synchronize_end() {
173   if (UseStringDeduplication) {
174     SuspendibleThreadSet::desynchronize();
175   }
176 }
177 class PSIsScavengable : public BoolObjectClosure {
178   bool do_object_b(oop obj) {
179     return ParallelScavengeHeap::heap()->is_in_young(obj);
180   }
181 };
182 
183 static PSIsScavengable _is_scavengable;
184 
185 void ParallelScavengeHeap::post_initialize() {
186   CollectedHeap::post_initialize();
187   // Need to init the tenuring threshold
188   PSScavenge::initialize();
189   PSParallelCompact::post_initialize();
190   PSPromotionManager::initialize();
191 
192   ScavengableNMethods::initialize(&_is_scavengable);
193 }
194 
195 void ParallelScavengeHeap::update_counters() {
196   young_gen()->update_counters();
197   old_gen()->update_counters();
198   MetaspaceCounters::update_performance_counters();
199 }
200 
201 size_t ParallelScavengeHeap::capacity() const {
202   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
203   return value;
204 }
205 
206 size_t ParallelScavengeHeap::used() const {
207   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
208   return value;
209 }
210 
211 bool ParallelScavengeHeap::is_maximal_no_gc() const {
212   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
213 }
214 
215 
216 size_t ParallelScavengeHeap::max_capacity() const {
217   size_t estimated = reserved_region().byte_size();
218   if (UseAdaptiveSizePolicy) {
219     estimated -= _size_policy->max_survivor_size(young_gen()->max_gen_size());
220   } else {
221     estimated -= young_gen()->to_space()->capacity_in_bytes();
222   }
223   return MAX2(estimated, capacity());
224 }
225 
226 bool ParallelScavengeHeap::is_in(const void* p) const {
227   return young_gen()->is_in(p) || old_gen()->is_in(p);
228 }
229 
230 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
231   return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
232 }
233 
234 bool ParallelScavengeHeap::requires_barriers(oop p) const {
235   return !is_in_young(p);
236 }
237 
238 // There are two levels of allocation policy here.
239 //
240 // When an allocation request fails, the requesting thread must invoke a VM
241 // operation, transfer control to the VM thread, and await the results of a
242 // garbage collection. That is quite expensive, and we should avoid doing it
243 // multiple times if possible.
244 //
245 // To accomplish this, we have a basic allocation policy, and also a
246 // failed allocation policy.
247 //
248 // The basic allocation policy controls how you allocate memory without
249 // attempting garbage collection. It is okay to grab locks and
250 // expand the heap, if that can be done without coming to a safepoint.
251 // It is likely that the basic allocation policy will not be very
252 // aggressive.
253 //
254 // The failed allocation policy is invoked from the VM thread after
255 // the basic allocation policy is unable to satisfy a mem_allocate
256 // request. This policy needs to cover the entire range of collection,
257 // heap expansion, and out-of-memory conditions. It should make every
258 // attempt to allocate the requested memory.
259 
260 // Basic allocation policy. Should never be called at a safepoint, or
261 // from the VM thread.
262 //
263 // This method must handle cases where many mem_allocate requests fail
264 // simultaneously. When that happens, only one VM operation will succeed,
265 // and the rest will not be executed. For that reason, this method loops
266 // during failed allocation attempts. If the java heap becomes exhausted,
267 // we rely on the size_policy object to force a bail out.
268 HeapWord* ParallelScavengeHeap::mem_allocate(
269                                      size_t size,
270                                      bool* gc_overhead_limit_was_exceeded) {
271   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
272   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
273   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
274 
275   // In general gc_overhead_limit_was_exceeded should be false so
276   // set it so here and reset it to true only if the gc time
277   // limit is being exceeded as checked below.
278   *gc_overhead_limit_was_exceeded = false;
279 
280   HeapWord* result = young_gen()->allocate(size);
281 
282   uint loop_count = 0;
283   uint gc_count = 0;
284   uint gclocker_stalled_count = 0;
285 
286   while (result == NULL) {
287     // We don't want to have multiple collections for a single filled generation.
288     // To prevent this, each thread tracks the total_collections() value, and if
289     // the count has changed, does not do a new collection.
290     //
291     // The collection count must be read only while holding the heap lock. VM
292     // operations also hold the heap lock during collections. There is a lock
293     // contention case where thread A blocks waiting on the Heap_lock, while
294     // thread B is holding it doing a collection. When thread A gets the lock,
295     // the collection count has already changed. To prevent duplicate collections,
296     // The policy MUST attempt allocations during the same period it reads the
297     // total_collections() value!
298     {
299       MutexLocker ml(Heap_lock);
300       gc_count = total_collections();
301 
302       result = young_gen()->allocate(size);
303       if (result != NULL) {
304         return result;
305       }
306 
307       // If certain conditions hold, try allocating from the old gen.
308       result = mem_allocate_old_gen(size);
309       if (result != NULL) {
310         return result;
311       }
312 
313       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
314         return NULL;
315       }
316 
317       // Failed to allocate without a gc.
318       if (GCLocker::is_active_and_needs_gc()) {
319         // If this thread is not in a jni critical section, we stall
320         // the requestor until the critical section has cleared and
321         // GC allowed. When the critical section clears, a GC is
322         // initiated by the last thread exiting the critical section; so
323         // we retry the allocation sequence from the beginning of the loop,
324         // rather than causing more, now probably unnecessary, GC attempts.
325         JavaThread* jthr = JavaThread::current();
326         if (!jthr->in_critical()) {
327           MutexUnlocker mul(Heap_lock);
328           GCLocker::stall_until_clear();
329           gclocker_stalled_count += 1;
330           continue;
331         } else {
332           if (CheckJNICalls) {
333             fatal("Possible deadlock due to allocating while"
334                   " in jni critical section");
335           }
336           return NULL;
337         }
338       }
339     }
340 
341     if (result == NULL) {
342       // Generate a VM operation
343       VM_ParallelGCFailedAllocation op(size, gc_count);
344       VMThread::execute(&op);
345 
346       // Did the VM operation execute? If so, return the result directly.
347       // This prevents us from looping until time out on requests that can
348       // not be satisfied.
349       if (op.prologue_succeeded()) {
350         assert(is_in_or_null(op.result()), "result not in heap");
351 
352         // If GC was locked out during VM operation then retry allocation
353         // and/or stall as necessary.
354         if (op.gc_locked()) {
355           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
356           continue;  // retry and/or stall as necessary
357         }
358 
359         // Exit the loop if the gc time limit has been exceeded.
360         // The allocation must have failed above ("result" guarding
361         // this path is NULL) and the most recent collection has exceeded the
362         // gc overhead limit (although enough may have been collected to
363         // satisfy the allocation).  Exit the loop so that an out-of-memory
364         // will be thrown (return a NULL ignoring the contents of
365         // op.result()),
366         // but clear gc_overhead_limit_exceeded so that the next collection
367         // starts with a clean slate (i.e., forgets about previous overhead
368         // excesses).  Fill op.result() with a filler object so that the
369         // heap remains parsable.
370         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
371         const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
372 
373         if (limit_exceeded && softrefs_clear) {
374           *gc_overhead_limit_was_exceeded = true;
375           size_policy()->set_gc_overhead_limit_exceeded(false);
376           log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
377           if (op.result() != NULL) {
378             CollectedHeap::fill_with_object(op.result(), size);
379           }
380           return NULL;
381         }
382 
383         return op.result();
384       }
385     }
386 
387     // The policy object will prevent us from looping forever. If the
388     // time spent in gc crosses a threshold, we will bail out.
389     loop_count++;
390     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
391         (loop_count % QueuedAllocationWarningCount == 0)) {
392       log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
393       log_warning(gc)("\tsize=" SIZE_FORMAT, size);
394     }
395   }
396 
397   return result;
398 }
399 
400 // A "death march" is a series of ultra-slow allocations in which a full gc is
401 // done before each allocation, and after the full gc the allocation still
402 // cannot be satisfied from the young gen.  This routine detects that condition;
403 // it should be called after a full gc has been done and the allocation
404 // attempted from the young gen. The parameter 'addr' should be the result of
405 // that young gen allocation attempt.
406 void
407 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
408   if (addr != NULL) {
409     _death_march_count = 0;  // death march has ended
410   } else if (_death_march_count == 0) {
411     if (should_alloc_in_eden(size)) {
412       _death_march_count = 1;    // death march has started
413     }
414   }
415 }
416 
417 HeapWord* ParallelScavengeHeap::allocate_old_gen_and_record(size_t size) {
418   assert_locked_or_safepoint(Heap_lock);
419   HeapWord* res = old_gen()->allocate(size);
420   if (res != NULL) {
421     _size_policy->tenured_allocation(size * HeapWordSize);
422   }
423   return res;
424 }
425 
426 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
427   if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
428     // Size is too big for eden, or gc is locked out.
429     return allocate_old_gen_and_record(size);
430   }
431 
432   // If a "death march" is in progress, allocate from the old gen a limited
433   // number of times before doing a GC.
434   if (_death_march_count > 0) {
435     if (_death_march_count < 64) {
436       ++_death_march_count;
437       return allocate_old_gen_and_record(size);
438     } else {
439       _death_march_count = 0;
440     }
441   }
442   return NULL;
443 }
444 
445 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
446   // The do_full_collection() parameter clear_all_soft_refs
447   // is interpreted here as maximum_compaction which will
448   // cause SoftRefs to be cleared.
449   bool maximum_compaction = clear_all_soft_refs;
450   PSParallelCompact::invoke(maximum_compaction);
451 }
452 
453 // Failed allocation policy. Must be called from the VM thread, and
454 // only at a safepoint! Note that this method has policy for allocation
455 // flow, and NOT collection policy. So we do not check for gc collection
456 // time over limit here, that is the responsibility of the heap specific
457 // collection methods. This method decides where to attempt allocations,
458 // and when to attempt collections, but no collection specific policy.
459 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
460   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
461   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
462   assert(!is_gc_active(), "not reentrant");
463   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
464 
465   // We assume that allocation in eden will fail unless we collect.
466 
467   // First level allocation failure, scavenge and allocate in young gen.
468   GCCauseSetter gccs(this, GCCause::_allocation_failure);
469   const bool invoked_full_gc = PSScavenge::invoke();
470   HeapWord* result = young_gen()->allocate(size);
471 
472   // Second level allocation failure.
473   //   Mark sweep and allocate in young generation.
474   if (result == NULL && !invoked_full_gc) {
475     do_full_collection(false);
476     result = young_gen()->allocate(size);
477   }
478 
479   death_march_check(result, size);
480 
481   // Third level allocation failure.
482   //   After mark sweep and young generation allocation failure,
483   //   allocate in old generation.
484   if (result == NULL) {
485     result = allocate_old_gen_and_record(size);
486   }
487 
488   // Fourth level allocation failure. We're running out of memory.
489   //   More complete mark sweep and allocate in young generation.
490   if (result == NULL) {
491     do_full_collection(true);
492     result = young_gen()->allocate(size);
493   }
494 
495   // Fifth level allocation failure.
496   //   After more complete mark sweep, allocate in old generation.
497   if (result == NULL) {
498     result = allocate_old_gen_and_record(size);
499   }
500 
501   return result;
502 }
503 
504 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
505   CollectedHeap::ensure_parsability(retire_tlabs);
506   young_gen()->eden_space()->ensure_parsability();
507 }
508 
509 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
510   return young_gen()->eden_space()->tlab_capacity(thr);
511 }
512 
513 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
514   return young_gen()->eden_space()->tlab_used(thr);
515 }
516 
517 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
518   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
519 }
520 
521 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
522   HeapWord* result = young_gen()->allocate(requested_size);
523   if (result != NULL) {
524     *actual_size = requested_size;
525   }
526 
527   return result;
528 }
529 
530 void ParallelScavengeHeap::resize_all_tlabs() {
531   CollectedHeap::resize_all_tlabs();
532 }
533 
534 // This method is used by System.gc() and JVMTI.
535 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
536   assert(!Heap_lock->owned_by_self(),
537     "this thread should not own the Heap_lock");
538 
539   uint gc_count      = 0;
540   uint full_gc_count = 0;
541   {
542     MutexLocker ml(Heap_lock);
543     // This value is guarded by the Heap_lock
544     gc_count      = total_collections();
545     full_gc_count = total_full_collections();
546   }
547 
548   if (GCLocker::should_discard(cause, gc_count)) {
549     return;
550   }
551 
552   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
553   VMThread::execute(&op);
554 }
555 
556 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
557   young_gen()->object_iterate(cl);
558   old_gen()->object_iterate(cl);
559 }
560 
561 // The HeapBlockClaimer is used during parallel iteration over the heap,
562 // allowing workers to claim heap areas ("blocks"), gaining exclusive rights to these.
563 // The eden and survivor spaces are treated as single blocks as it is hard to divide
564 // these spaces.
565 // The old space is divided into fixed-size blocks.
566 class HeapBlockClaimer : public StackObj {
567   size_t _claimed_index;
568 
569 public:
570   static const size_t InvalidIndex = SIZE_MAX;
571   static const size_t EdenIndex = 0;
572   static const size_t SurvivorIndex = 1;
573   static const size_t NumNonOldGenClaims = 2;
574 
575   HeapBlockClaimer() : _claimed_index(EdenIndex) { }
576   // Claim the block and get the block index.
577   size_t claim_and_get_block() {
578     size_t block_index;
579     block_index = Atomic::fetch_and_add(&_claimed_index, 1u);
580 
581     PSOldGen* old_gen = ParallelScavengeHeap::heap()->old_gen();
582     size_t num_claims = old_gen->num_iterable_blocks() + NumNonOldGenClaims;
583 
584     return block_index < num_claims ? block_index : InvalidIndex;
585   }
586 };
587 
588 void ParallelScavengeHeap::object_iterate_parallel(ObjectClosure* cl,
589                                                    HeapBlockClaimer* claimer) {
590   size_t block_index = claimer->claim_and_get_block();
591   // Iterate until all blocks are claimed
592   if (block_index == HeapBlockClaimer::EdenIndex) {
593     young_gen()->eden_space()->object_iterate(cl);
594     block_index = claimer->claim_and_get_block();
595   }
596   if (block_index == HeapBlockClaimer::SurvivorIndex) {
597     young_gen()->from_space()->object_iterate(cl);
598     young_gen()->to_space()->object_iterate(cl);
599     block_index = claimer->claim_and_get_block();
600   }
601   while (block_index != HeapBlockClaimer::InvalidIndex) {
602     old_gen()->object_iterate_block(cl, block_index - HeapBlockClaimer::NumNonOldGenClaims);
603     block_index = claimer->claim_and_get_block();
604   }
605 }
606 
607 class PSScavengeParallelObjectIterator : public ParallelObjectIterator {
608 private:
609   ParallelScavengeHeap*  _heap;
610   HeapBlockClaimer      _claimer;
611 
612 public:
613   PSScavengeParallelObjectIterator() :
614       _heap(ParallelScavengeHeap::heap()),
615       _claimer() {}
616 
617   virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
618     _heap->object_iterate_parallel(cl, &_claimer);
619   }
620 };
621 
622 ParallelObjectIterator* ParallelScavengeHeap::parallel_object_iterator(uint thread_num) {
623   return new PSScavengeParallelObjectIterator();
624 }
625 
626 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
627   if (young_gen()->is_in_reserved(addr)) {
628     assert(young_gen()->is_in(addr),
629            "addr should be in allocated part of young gen");
630     // called from os::print_location by find or VMError
631     if (Debugging || VMError::is_error_reported())  return NULL;
632     Unimplemented();
633   } else if (old_gen()->is_in_reserved(addr)) {
634     assert(old_gen()->is_in(addr),
635            "addr should be in allocated part of old gen");
636     return old_gen()->start_array()->object_start((HeapWord*)addr);
637   }
638   return 0;
639 }
640 
641 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
642   return block_start(addr) == addr;
643 }
644 
645 void ParallelScavengeHeap::prepare_for_verify() {
646   ensure_parsability(false);  // no need to retire TLABs for verification
647 }
648 
649 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
650   PSOldGen* old = old_gen();
651   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
652   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
653   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
654 
655   PSYoungGen* young = young_gen();
656   VirtualSpaceSummary young_summary(young->reserved().start(),
657     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
658 
659   MutableSpace* eden = young_gen()->eden_space();
660   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
661 
662   MutableSpace* from = young_gen()->from_space();
663   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
664 
665   MutableSpace* to = young_gen()->to_space();
666   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
667 
668   VirtualSpaceSummary heap_summary = create_heap_space_summary();
669   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
670 }
671 
672 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
673   return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
674 }
675 
676 void ParallelScavengeHeap::print_on(outputStream* st) const {
677   if (young_gen() != NULL) {
678     young_gen()->print_on(st);
679   }
680   if (old_gen() != NULL) {
681     old_gen()->print_on(st);
682   }
683   MetaspaceUtils::print_on(st);
684 }
685 
686 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
687   this->CollectedHeap::print_on_error(st);
688 
689   st->cr();
690   PSParallelCompact::print_on_error(st);
691 }
692 
693 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
694   ParallelScavengeHeap::heap()->workers().threads_do(tc);
695 }
696 
697 void ParallelScavengeHeap::print_tracing_info() const {
698   AdaptiveSizePolicyOutput::print();
699   log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
700   log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
701 }
702 
703 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
704   const PSYoungGen* const young = young_gen();
705   const MutableSpace* const eden = young->eden_space();
706   const MutableSpace* const from = young->from_space();
707   const PSOldGen* const old = old_gen();
708 
709   return PreGenGCValues(young->used_in_bytes(),
710                         young->capacity_in_bytes(),
711                         eden->used_in_bytes(),
712                         eden->capacity_in_bytes(),
713                         from->used_in_bytes(),
714                         from->capacity_in_bytes(),
715                         old->used_in_bytes(),
716                         old->capacity_in_bytes());
717 }
718 
719 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
720   const PSYoungGen* const young = young_gen();
721   const MutableSpace* const eden = young->eden_space();
722   const MutableSpace* const from = young->from_space();
723   const PSOldGen* const old = old_gen();
724 
725   log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
726                      HEAP_CHANGE_FORMAT" "
727                      HEAP_CHANGE_FORMAT,
728                      HEAP_CHANGE_FORMAT_ARGS(young->name(),
729                                              pre_gc_values.young_gen_used(),
730                                              pre_gc_values.young_gen_capacity(),
731                                              young->used_in_bytes(),
732                                              young->capacity_in_bytes()),
733                      HEAP_CHANGE_FORMAT_ARGS("Eden",
734                                              pre_gc_values.eden_used(),
735                                              pre_gc_values.eden_capacity(),
736                                              eden->used_in_bytes(),
737                                              eden->capacity_in_bytes()),
738                      HEAP_CHANGE_FORMAT_ARGS("From",
739                                              pre_gc_values.from_used(),
740                                              pre_gc_values.from_capacity(),
741                                              from->used_in_bytes(),
742                                              from->capacity_in_bytes()));
743   log_info(gc, heap)(HEAP_CHANGE_FORMAT,
744                      HEAP_CHANGE_FORMAT_ARGS(old->name(),
745                                              pre_gc_values.old_gen_used(),
746                                              pre_gc_values.old_gen_capacity(),
747                                              old->used_in_bytes(),
748                                              old->capacity_in_bytes()));
749   MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
750 }
751 
752 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
753   // Why do we need the total_collections()-filter below?
754   if (total_collections() > 0) {
755     log_debug(gc, verify)("Tenured");
756     old_gen()->verify();
757 
758     log_debug(gc, verify)("Eden");
759     young_gen()->verify();
760   }
761 }
762 
763 void ParallelScavengeHeap::trace_actual_reserved_page_size(const size_t reserved_heap_size, const ReservedSpace rs) {
764   // Check if Info level is enabled, since os::trace_page_sizes() logs on Info level.
765   if(log_is_enabled(Info, pagesize)) {
766     const size_t page_size = rs.page_size();
767     os::trace_page_sizes("Heap",
768                          MinHeapSize,
769                          reserved_heap_size,
770                          page_size,
771                          rs.base(),
772                          rs.size());
773   }
774 }
775 
776 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
777   const PSHeapSummary& heap_summary = create_ps_heap_summary();
778   gc_tracer->report_gc_heap_summary(when, heap_summary);
779 
780   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
781   gc_tracer->report_metaspace_summary(when, metaspace_summary);
782 }
783 
784 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
785   return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
786 }
787 
788 PSCardTable* ParallelScavengeHeap::card_table() {
789   return static_cast<PSCardTable*>(barrier_set()->card_table());
790 }
791 
792 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
793                                             size_t survivor_size) {
794   // Delegate the resize to the generation.
795   _young_gen->resize(eden_size, survivor_size);
796 }
797 
798 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
799   // Delegate the resize to the generation.
800   _old_gen->resize(desired_free_space);
801 }
802 
803 #ifndef PRODUCT
804 void ParallelScavengeHeap::record_gen_tops_before_GC() {
805   if (ZapUnusedHeapArea) {
806     young_gen()->record_spaces_top();
807     old_gen()->record_spaces_top();
808   }
809 }
810 
811 void ParallelScavengeHeap::gen_mangle_unused_area() {
812   if (ZapUnusedHeapArea) {
813     young_gen()->eden_space()->mangle_unused_area();
814     young_gen()->to_space()->mangle_unused_area();
815     young_gen()->from_space()->mangle_unused_area();
816     old_gen()->object_space()->mangle_unused_area();
817   }
818 }
819 #endif
820 
821 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
822   ScavengableNMethods::register_nmethod(nm);
823 }
824 
825 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
826   ScavengableNMethods::unregister_nmethod(nm);
827 }
828 
829 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
830   ScavengableNMethods::verify_nmethod(nm);
831 }
832 
833 void ParallelScavengeHeap::flush_nmethod(nmethod* nm) {
834   // nothing particular
835 }
836 
837 void ParallelScavengeHeap::prune_scavengable_nmethods() {
838   ScavengableNMethods::prune_nmethods();
839 }
840 
841 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
842   GrowableArray<GCMemoryManager*> memory_managers(2);
843   memory_managers.append(_young_manager);
844   memory_managers.append(_old_manager);
845   return memory_managers;
846 }
847 
848 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
849   GrowableArray<MemoryPool*> memory_pools(3);
850   memory_pools.append(_eden_pool);
851   memory_pools.append(_survivor_pool);
852   memory_pools.append(_old_pool);
853   return memory_pools;
854 }
--- EOF ---