1 /*
   2  * Copyright (c) 2001, 2014, 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   int gclocker_stalled_count = 0;
 264 
 265   while (result == NULL) {
 266     // We don't want to have multiple collections for a single filled generation.
 267     // To prevent this, each thread tracks the total_collections() value, and if
 268     // the count has changed, does not do a new collection.
 269     //
 270     // The collection count must be read only while holding the heap lock. VM
 271     // operations also hold the heap lock during collections. There is a lock
 272     // contention case where thread A blocks waiting on the Heap_lock, while
 273     // thread B is holding it doing a collection. When thread A gets the lock,
 274     // the collection count has already changed. To prevent duplicate collections,
 275     // The policy MUST attempt allocations during the same period it reads the
 276     // total_collections() value!
 277     {
 278       MutexLocker ml(Heap_lock);
 279       gc_count = Universe::heap()->total_collections();
 280 
 281       result = young_gen()->allocate(size);
 282       if (result != NULL) {
 283         return result;
 284       }
 285 
 286       // If certain conditions hold, try allocating from the old gen.
 287       result = mem_allocate_old_gen(size);
 288       if (result != NULL) {
 289         return result;
 290       }
 291 
 292       if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
 293         return NULL;
 294       }
 295 
 296       // Failed to allocate without a gc.
 297       if (GC_locker::is_active_and_needs_gc()) {
 298         // If this thread is not in a jni critical section, we stall
 299         // the requestor until the critical section has cleared and
 300         // GC allowed. When the critical section clears, a GC is
 301         // initiated by the last thread exiting the critical section; so
 302         // we retry the allocation sequence from the beginning of the loop,
 303         // rather than causing more, now probably unnecessary, GC attempts.
 304         JavaThread* jthr = JavaThread::current();
 305         if (!jthr->in_critical()) {
 306           MutexUnlocker mul(Heap_lock);
 307           GC_locker::stall_until_clear();
 308           gclocker_stalled_count += 1;
 309           continue;
 310         } else {
 311           if (CheckJNICalls) {
 312             fatal("Possible deadlock due to allocating while"
 313                   " in jni critical section");
 314           }
 315           return NULL;
 316         }
 317       }
 318     }
 319 
 320     if (result == NULL) {
 321       // Generate a VM operation
 322       VM_ParallelGCFailedAllocation op(size, gc_count);
 323       VMThread::execute(&op);
 324 
 325       // Did the VM operation execute? If so, return the result directly.
 326       // This prevents us from looping until time out on requests that can
 327       // not be satisfied.
 328       if (op.prologue_succeeded()) {
 329         assert(Universe::heap()->is_in_or_null(op.result()),
 330           "result not in heap");
 331 
 332         // If GC was locked out during VM operation then retry allocation
 333         // and/or stall as necessary.
 334         if (op.gc_locked()) {
 335           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
 336           continue;  // retry and/or stall as necessary
 337         }
 338 
 339         // Exit the loop if the gc time limit has been exceeded.
 340         // The allocation must have failed above ("result" guarding
 341         // this path is NULL) and the most recent collection has exceeded the
 342         // gc overhead limit (although enough may have been collected to
 343         // satisfy the allocation).  Exit the loop so that an out-of-memory
 344         // will be thrown (return a NULL ignoring the contents of
 345         // op.result()),
 346         // but clear gc_overhead_limit_exceeded so that the next collection
 347         // starts with a clean slate (i.e., forgets about previous overhead
 348         // excesses).  Fill op.result() with a filler object so that the
 349         // heap remains parsable.
 350         const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
 351         const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
 352 
 353         if (limit_exceeded && softrefs_clear) {
 354           *gc_overhead_limit_was_exceeded = true;
 355           size_policy()->set_gc_overhead_limit_exceeded(false);
 356           if (PrintGCDetails && Verbose) {
 357             gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
 358               "return NULL because gc_overhead_limit_exceeded is set");
 359           }
 360           if (op.result() != NULL) {
 361             CollectedHeap::fill_with_object(op.result(), size);
 362           }
 363           return NULL;
 364         }
 365 
 366         return op.result();
 367       }
 368     }
 369 
 370     // The policy object will prevent us from looping forever. If the
 371     // time spent in gc crosses a threshold, we will bail out.
 372     loop_count++;
 373     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
 374         (loop_count % QueuedAllocationWarningCount == 0)) {
 375       warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t"
 376               " size=" SIZE_FORMAT, loop_count, size);
 377     }
 378   }
 379 
 380   return result;
 381 }
 382 
 383 // A "death march" is a series of ultra-slow allocations in which a full gc is
 384 // done before each allocation, and after the full gc the allocation still
 385 // cannot be satisfied from the young gen.  This routine detects that condition;
 386 // it should be called after a full gc has been done and the allocation
 387 // attempted from the young gen. The parameter 'addr' should be the result of
 388 // that young gen allocation attempt.
 389 void
 390 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
 391   if (addr != NULL) {
 392     _death_march_count = 0;  // death march has ended
 393   } else if (_death_march_count == 0) {
 394     if (should_alloc_in_eden(size)) {
 395       _death_march_count = 1;    // death march has started
 396     }
 397   }
 398 }
 399 
 400 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
 401   if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) {
 402     // Size is too big for eden, or gc is locked out.
 403     return old_gen()->allocate(size);
 404   }
 405 
 406   // If a "death march" is in progress, allocate from the old gen a limited
 407   // number of times before doing a GC.
 408   if (_death_march_count > 0) {
 409     if (_death_march_count < 64) {
 410       ++_death_march_count;
 411       return old_gen()->allocate(size);
 412     } else {
 413       _death_march_count = 0;
 414     }
 415   }
 416   return NULL;
 417 }
 418 
 419 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
 420   if (UseParallelOldGC) {
 421     // The do_full_collection() parameter clear_all_soft_refs
 422     // is interpreted here as maximum_compaction which will
 423     // cause SoftRefs to be cleared.
 424     bool maximum_compaction = clear_all_soft_refs;
 425     PSParallelCompact::invoke(maximum_compaction);
 426   } else {
 427     PSMarkSweep::invoke(clear_all_soft_refs);
 428   }
 429 }
 430 
 431 // Failed allocation policy. Must be called from the VM thread, and
 432 // only at a safepoint! Note that this method has policy for allocation
 433 // flow, and NOT collection policy. So we do not check for gc collection
 434 // time over limit here, that is the responsibility of the heap specific
 435 // collection methods. This method decides where to attempt allocations,
 436 // and when to attempt collections, but no collection specific policy.
 437 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
 438   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
 439   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
 440   assert(!Universe::heap()->is_gc_active(), "not reentrant");
 441   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 442 
 443   // We assume that allocation in eden will fail unless we collect.
 444 
 445   // First level allocation failure, scavenge and allocate in young gen.
 446   GCCauseSetter gccs(this, GCCause::_allocation_failure);
 447   const bool invoked_full_gc = PSScavenge::invoke();
 448   HeapWord* result = young_gen()->allocate(size);
 449 
 450   // Second level allocation failure.
 451   //   Mark sweep and allocate in young generation.
 452   if (result == NULL && !invoked_full_gc) {
 453     do_full_collection(false);
 454     result = young_gen()->allocate(size);
 455   }
 456 
 457   death_march_check(result, size);
 458 
 459   // Third level allocation failure.
 460   //   After mark sweep and young generation allocation failure,
 461   //   allocate in old generation.
 462   if (result == NULL) {
 463     result = old_gen()->allocate(size);
 464   }
 465 
 466   // Fourth level allocation failure. We're running out of memory.
 467   //   More complete mark sweep and allocate in young generation.
 468   if (result == NULL) {
 469     do_full_collection(true);
 470     result = young_gen()->allocate(size);
 471   }
 472 
 473   // Fifth level allocation failure.
 474   //   After more complete mark sweep, allocate in old generation.
 475   if (result == NULL) {
 476     result = old_gen()->allocate(size);
 477   }
 478 
 479   return result;
 480 }
 481 
 482 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
 483   CollectedHeap::ensure_parsability(retire_tlabs);
 484   young_gen()->eden_space()->ensure_parsability();
 485 }
 486 
 487 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
 488   return young_gen()->eden_space()->tlab_capacity(thr);
 489 }
 490 
 491 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
 492   return young_gen()->eden_space()->tlab_used(thr);
 493 }
 494 
 495 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
 496   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
 497 }
 498 
 499 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
 500   return young_gen()->allocate(size);
 501 }
 502 
 503 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
 504   CollectedHeap::accumulate_statistics_all_tlabs();
 505 }
 506 
 507 void ParallelScavengeHeap::resize_all_tlabs() {
 508   CollectedHeap::resize_all_tlabs();
 509 }
 510 
 511 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) {
 512   // We don't need barriers for stores to objects in the
 513   // young gen and, a fortiori, for initializing stores to
 514   // objects therein.
 515   return is_in_young(new_obj);
 516 }
 517 
 518 // This method is used by System.gc() and JVMTI.
 519 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
 520   assert(!Heap_lock->owned_by_self(),
 521     "this thread should not own the Heap_lock");
 522 
 523   unsigned int gc_count      = 0;
 524   unsigned int full_gc_count = 0;
 525   {
 526     MutexLocker ml(Heap_lock);
 527     // This value is guarded by the Heap_lock
 528     gc_count      = Universe::heap()->total_collections();
 529     full_gc_count = Universe::heap()->total_full_collections();
 530   }
 531 
 532   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
 533   VMThread::execute(&op);
 534 }
 535 
 536 void ParallelScavengeHeap::oop_iterate(ExtendedOopClosure* cl) {
 537   Unimplemented();
 538 }
 539 
 540 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
 541   young_gen()->object_iterate(cl);
 542   old_gen()->object_iterate(cl);
 543 }
 544 
 545 
 546 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
 547   if (young_gen()->is_in_reserved(addr)) {
 548     assert(young_gen()->is_in(addr),
 549            "addr should be in allocated part of young gen");
 550     // called from os::print_location by find or VMError
 551     if (Debugging || VMError::fatal_error_in_progress())  return NULL;
 552     Unimplemented();
 553   } else if (old_gen()->is_in_reserved(addr)) {
 554     assert(old_gen()->is_in(addr),
 555            "addr should be in allocated part of old gen");
 556     return old_gen()->start_array()->object_start((HeapWord*)addr);
 557   }
 558   return 0;
 559 }
 560 
 561 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
 562   return oop(addr)->size();
 563 }
 564 
 565 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
 566   return block_start(addr) == addr;
 567 }
 568 
 569 jlong ParallelScavengeHeap::millis_since_last_gc() {
 570   return UseParallelOldGC ?
 571     PSParallelCompact::millis_since_last_gc() :
 572     PSMarkSweep::millis_since_last_gc();
 573 }
 574 
 575 void ParallelScavengeHeap::prepare_for_verify() {
 576   ensure_parsability(false);  // no need to retire TLABs for verification
 577 }
 578 
 579 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
 580   PSOldGen* old = old_gen();
 581   HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
 582   VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
 583   SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
 584 
 585   PSYoungGen* young = young_gen();
 586   VirtualSpaceSummary young_summary(young->reserved().start(),
 587     (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
 588 
 589   MutableSpace* eden = young_gen()->eden_space();
 590   SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
 591 
 592   MutableSpace* from = young_gen()->from_space();
 593   SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
 594 
 595   MutableSpace* to = young_gen()->to_space();
 596   SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
 597 
 598   VirtualSpaceSummary heap_summary = create_heap_space_summary();
 599   return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
 600 }
 601 
 602 void ParallelScavengeHeap::print_on(outputStream* st) const {
 603   young_gen()->print_on(st);
 604   old_gen()->print_on(st);
 605   MetaspaceAux::print_on(st);
 606 }
 607 
 608 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
 609   this->CollectedHeap::print_on_error(st);
 610 
 611   if (UseParallelOldGC) {
 612     st->cr();
 613     PSParallelCompact::print_on_error(st);
 614   }
 615 }
 616 
 617 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
 618   PSScavenge::gc_task_manager()->threads_do(tc);
 619 }
 620 
 621 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
 622   PSScavenge::gc_task_manager()->print_threads_on(st);
 623 }
 624 
 625 void ParallelScavengeHeap::print_tracing_info() const {
 626   if (TraceYoungGenTime) {
 627     double time = PSScavenge::accumulated_time()->seconds();
 628     tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
 629   }
 630   if (TraceOldGenTime) {
 631     double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds();
 632     tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
 633   }
 634 }
 635 
 636 
 637 void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) {
 638   // Why do we need the total_collections()-filter below?
 639   if (total_collections() > 0) {
 640     if (!silent) {
 641       gclog_or_tty->print("tenured ");
 642     }
 643     old_gen()->verify();
 644 
 645     if (!silent) {
 646       gclog_or_tty->print("eden ");
 647     }
 648     young_gen()->verify();
 649   }
 650 }
 651 
 652 void ParallelScavengeHeap::print_heap_change(size_t prev_used) {
 653   if (PrintGCDetails && Verbose) {
 654     gclog_or_tty->print(" "  SIZE_FORMAT
 655                         "->" SIZE_FORMAT
 656                         "("  SIZE_FORMAT ")",
 657                         prev_used, used(), capacity());
 658   } else {
 659     gclog_or_tty->print(" "  SIZE_FORMAT "K"
 660                         "->" SIZE_FORMAT "K"
 661                         "("  SIZE_FORMAT "K)",
 662                         prev_used / K, used() / K, capacity() / K);
 663   }
 664 }
 665 
 666 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
 667   const PSHeapSummary& heap_summary = create_ps_heap_summary();
 668   gc_tracer->report_gc_heap_summary(when, heap_summary);
 669 
 670   const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
 671   gc_tracer->report_metaspace_summary(when, metaspace_summary);
 672 }
 673 
 674 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
 675   assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
 676   assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap");
 677   return _psh;
 678 }
 679 
 680 // Before delegating the resize to the young generation,
 681 // the reserved space for the young and old generations
 682 // may be changed to accommodate the desired resize.
 683 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
 684     size_t survivor_size) {
 685   if (UseAdaptiveGCBoundary) {
 686     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 687       size_policy()->reset_bytes_absorbed_from_eden();
 688       return;  // The generation changed size already.
 689     }
 690     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
 691   }
 692 
 693   // Delegate the resize to the generation.
 694   _young_gen->resize(eden_size, survivor_size);
 695 }
 696 
 697 // Before delegating the resize to the old generation,
 698 // the reserved space for the young and old generations
 699 // may be changed to accommodate the desired resize.
 700 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
 701   if (UseAdaptiveGCBoundary) {
 702     if (size_policy()->bytes_absorbed_from_eden() != 0) {
 703       size_policy()->reset_bytes_absorbed_from_eden();
 704       return;  // The generation changed size already.
 705     }
 706     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
 707   }
 708 
 709   // Delegate the resize to the generation.
 710   _old_gen->resize(desired_free_space);
 711 }
 712 
 713 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
 714   // nothing particular
 715 }
 716 
 717 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
 718   // nothing particular
 719 }
 720 
 721 #ifndef PRODUCT
 722 void ParallelScavengeHeap::record_gen_tops_before_GC() {
 723   if (ZapUnusedHeapArea) {
 724     young_gen()->record_spaces_top();
 725     old_gen()->record_spaces_top();
 726   }
 727 }
 728 
 729 void ParallelScavengeHeap::gen_mangle_unused_area() {
 730   if (ZapUnusedHeapArea) {
 731     young_gen()->eden_space()->mangle_unused_area();
 732     young_gen()->to_space()->mangle_unused_area();
 733     young_gen()->from_space()->mangle_unused_area();
 734     old_gen()->object_space()->mangle_unused_area();
 735   }
 736 }
 737 #endif