heap.cc revision f5b0e20b5b31f5f5465784adcf2a204dcd69c7fd
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <vector> 24#include <valgrind.h> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/space_bitmap-inl.h" 37#include "gc/collector/mark_sweep-inl.h" 38#include "gc/collector/partial_mark_sweep.h" 39#include "gc/collector/semi_space.h" 40#include "gc/collector/sticky_mark_sweep.h" 41#include "gc/space/bump_pointer_space.h" 42#include "gc/space/dlmalloc_space-inl.h" 43#include "gc/space/image_space.h" 44#include "gc/space/large_object_space.h" 45#include "gc/space/rosalloc_space-inl.h" 46#include "gc/space/space-inl.h" 47#include "gc/space/zygote_space.h" 48#include "heap-inl.h" 49#include "image.h" 50#include "invoke_arg_array_builder.h" 51#include "mirror/art_field-inl.h" 52#include "mirror/class-inl.h" 53#include "mirror/object.h" 54#include "mirror/object-inl.h" 55#include "mirror/object_array-inl.h" 56#include "object_utils.h" 57#include "os.h" 58#include "runtime.h" 59#include "ScopedLocalRef.h" 60#include "scoped_thread_state_change.h" 61#include "sirt_ref.h" 62#include "thread_list.h" 63#include "UniquePtr.h" 64#include "well_known_classes.h" 65 66namespace art { 67 68extern void SetQuickAllocEntryPointsAllocator(gc::AllocatorType allocator); 69 70namespace gc { 71 72static constexpr bool kGCALotMode = false; 73static constexpr size_t kGcAlotInterval = KB; 74// Minimum amount of remaining bytes before a concurrent GC is triggered. 75static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 76static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 77 78Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 79 double target_utilization, size_t capacity, const std::string& image_file_name, 80 CollectorType post_zygote_collector_type, CollectorType background_collector_type, 81 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 82 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 83 bool ignore_max_footprint, bool use_tlab, bool verify_pre_gc_heap, 84 bool verify_post_gc_heap, bool verify_pre_gc_rosalloc, 85 bool verify_post_gc_rosalloc) 86 : non_moving_space_(nullptr), 87 rosalloc_space_(nullptr), 88 dlmalloc_space_(nullptr), 89 main_space_(nullptr), 90 concurrent_gc_(false), 91 collector_type_(kCollectorTypeNone), 92 post_zygote_collector_type_(post_zygote_collector_type), 93 background_collector_type_(background_collector_type), 94 parallel_gc_threads_(parallel_gc_threads), 95 conc_gc_threads_(conc_gc_threads), 96 low_memory_mode_(low_memory_mode), 97 long_pause_log_threshold_(long_pause_log_threshold), 98 long_gc_log_threshold_(long_gc_log_threshold), 99 ignore_max_footprint_(ignore_max_footprint), 100 have_zygote_space_(false), 101 soft_reference_queue_(this), 102 weak_reference_queue_(this), 103 finalizer_reference_queue_(this), 104 phantom_reference_queue_(this), 105 cleared_references_(this), 106 collector_type_running_(kCollectorTypeNone), 107 last_gc_type_(collector::kGcTypeNone), 108 next_gc_type_(collector::kGcTypePartial), 109 capacity_(capacity), 110 growth_limit_(growth_limit), 111 max_allowed_footprint_(initial_size), 112 native_footprint_gc_watermark_(initial_size), 113 native_footprint_limit_(2 * initial_size), 114 native_need_to_run_finalization_(false), 115 // Initially assume we perceive jank in case the process state is never updated. 116 process_state_(kProcessStateJankPerceptible), 117 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 118 total_bytes_freed_ever_(0), 119 total_objects_freed_ever_(0), 120 num_bytes_allocated_(0), 121 native_bytes_allocated_(0), 122 gc_memory_overhead_(0), 123 verify_missing_card_marks_(false), 124 verify_system_weaks_(false), 125 verify_pre_gc_heap_(verify_pre_gc_heap), 126 verify_post_gc_heap_(verify_post_gc_heap), 127 verify_mod_union_table_(false), 128 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 129 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 130 last_trim_time_ms_(0), 131 allocation_rate_(0), 132 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 133 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 134 * verification is enabled, we limit the size of allocation stacks to speed up their 135 * searching. 136 */ 137 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 138 : (kDesiredHeapVerification > kVerifyAllFast) ? KB : MB), 139 current_allocator_(kAllocatorTypeDlMalloc), 140 current_non_moving_allocator_(kAllocatorTypeNonMoving), 141 bump_pointer_space_(nullptr), 142 temp_space_(nullptr), 143 reference_referent_offset_(0), 144 reference_queue_offset_(0), 145 reference_queueNext_offset_(0), 146 reference_pendingNext_offset_(0), 147 finalizer_reference_zombie_offset_(0), 148 min_free_(min_free), 149 max_free_(max_free), 150 target_utilization_(target_utilization), 151 total_wait_time_(0), 152 total_allocation_time_(0), 153 verify_object_mode_(kHeapVerificationNotPermitted), 154 disable_moving_gc_count_(0), 155 running_on_valgrind_(RUNNING_ON_VALGRIND), 156 use_tlab_(use_tlab) { 157 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 158 LOG(INFO) << "Heap() entering"; 159 } 160 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 161 // entrypoints. 162 if (!Runtime::Current()->IsZygote() || !kMovingCollector) { 163 ChangeCollector(post_zygote_collector_type_); 164 } else { 165 // We are the zygote, use bump pointer allocation + semi space collector. 166 ChangeCollector(kCollectorTypeSS); 167 } 168 169 live_bitmap_.reset(new accounting::HeapBitmap(this)); 170 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 171 // Requested begin for the alloc space, to follow the mapped image and oat files 172 byte* requested_alloc_space_begin = nullptr; 173 if (!image_file_name.empty()) { 174 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str()); 175 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 176 AddSpace(image_space); 177 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 178 // isn't going to get in the middle 179 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 180 CHECK_GT(oat_file_end_addr, image_space->End()); 181 if (oat_file_end_addr > requested_alloc_space_begin) { 182 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 183 } 184 } 185 const char* name = Runtime::Current()->IsZygote() ? "zygote space" : "alloc space"; 186 space::MallocSpace* malloc_space; 187 if (kUseRosAlloc) { 188 malloc_space = space::RosAllocSpace::Create(name, initial_size, growth_limit, capacity, 189 requested_alloc_space_begin, low_memory_mode_); 190 CHECK(malloc_space != nullptr) << "Failed to create rosalloc space"; 191 } else { 192 malloc_space = space::DlMallocSpace::Create(name, initial_size, growth_limit, capacity, 193 requested_alloc_space_begin); 194 CHECK(malloc_space != nullptr) << "Failed to create dlmalloc space"; 195 } 196 VLOG(heap) << "malloc_space : " << malloc_space; 197 if (kMovingCollector) { 198 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 199 // TODO: Having 3+ spaces as big as the large heap size can cause virtual memory fragmentation 200 // issues. 201 const size_t bump_pointer_space_size = std::min(malloc_space->Capacity(), 128 * MB); 202 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space", 203 bump_pointer_space_size, nullptr); 204 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 205 AddSpace(bump_pointer_space_); 206 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", bump_pointer_space_size, 207 nullptr); 208 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 209 AddSpace(temp_space_); 210 VLOG(heap) << "bump_pointer_space : " << bump_pointer_space_; 211 VLOG(heap) << "temp_space : " << temp_space_; 212 } 213 non_moving_space_ = malloc_space; 214 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 215 AddSpace(malloc_space); 216 217 // Allocate the large object space. 218 constexpr bool kUseFreeListSpaceForLOS = false; 219 if (kUseFreeListSpaceForLOS) { 220 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity); 221 } else { 222 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 223 } 224 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 225 AddSpace(large_object_space_); 226 227 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 228 CHECK(!continuous_spaces_.empty()); 229 230 // Relies on the spaces being sorted. 231 byte* heap_begin = continuous_spaces_.front()->Begin(); 232 byte* heap_end = continuous_spaces_.back()->Limit(); 233 if (Runtime::Current()->IsZygote()) { 234 std::string error_str; 235 post_zygote_non_moving_space_mem_map_.reset( 236 MemMap::MapAnonymous("post zygote non-moving space", nullptr, 64 * MB, 237 PROT_READ | PROT_WRITE, true, &error_str)); 238 CHECK(post_zygote_non_moving_space_mem_map_.get() != nullptr) << error_str; 239 heap_begin = std::min(post_zygote_non_moving_space_mem_map_->Begin(), heap_begin); 240 heap_end = std::max(post_zygote_non_moving_space_mem_map_->End(), heap_end); 241 } 242 size_t heap_capacity = heap_end - heap_begin; 243 244 // Allocate the card table. 245 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 246 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 247 248 // Card cache for now since it makes it easier for us to update the references to the copying 249 // spaces. 250 accounting::ModUnionTable* mod_union_table = 251 new accounting::ModUnionTableCardCache("Image mod-union table", this, GetImageSpace()); 252 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 253 AddModUnionTable(mod_union_table); 254 255 // TODO: Count objects in the image space here. 256 num_bytes_allocated_ = 0; 257 258 // Default mark stack size in bytes. 259 static const size_t default_mark_stack_size = 64 * KB; 260 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", default_mark_stack_size)); 261 allocation_stack_.reset(accounting::ObjectStack::Create("allocation stack", 262 max_allocation_stack_size_)); 263 live_stack_.reset(accounting::ObjectStack::Create("live stack", 264 max_allocation_stack_size_)); 265 266 // It's still too early to take a lock because there are no threads yet, but we can create locks 267 // now. We don't create it earlier to make it clear that you can't use locks during heap 268 // initialization. 269 gc_complete_lock_ = new Mutex("GC complete lock"); 270 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 271 *gc_complete_lock_)); 272 last_gc_time_ns_ = NanoTime(); 273 last_gc_size_ = GetBytesAllocated(); 274 275 if (ignore_max_footprint_) { 276 SetIdealFootprint(std::numeric_limits<size_t>::max()); 277 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 278 } 279 CHECK_NE(max_allowed_footprint_, 0U); 280 281 // Create our garbage collectors. 282 for (size_t i = 0; i < 2; ++i) { 283 const bool concurrent = i != 0; 284 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 285 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 286 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 287 } 288 if (kMovingCollector) { 289 // TODO: Clean this up. 290 bool generational = post_zygote_collector_type_ == kCollectorTypeGSS; 291 semi_space_collector_ = new collector::SemiSpace(this, generational); 292 garbage_collectors_.push_back(semi_space_collector_); 293 } 294 295 if (running_on_valgrind_) { 296 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 297 } 298 299 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 300 LOG(INFO) << "Heap() exiting"; 301 } 302} 303 304void Heap::ChangeAllocator(AllocatorType allocator) { 305 // These two allocators are only used internally and don't have any entrypoints. 306 DCHECK_NE(allocator, kAllocatorTypeLOS); 307 DCHECK_NE(allocator, kAllocatorTypeNonMoving); 308 if (current_allocator_ != allocator) { 309 current_allocator_ = allocator; 310 SetQuickAllocEntryPointsAllocator(current_allocator_); 311 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 312 } 313} 314 315bool Heap::IsCompilingBoot() const { 316 for (const auto& space : continuous_spaces_) { 317 if (space->IsImageSpace()) { 318 return false; 319 } else if (space->IsZygoteSpace()) { 320 return false; 321 } 322 } 323 return true; 324} 325 326bool Heap::HasImageSpace() const { 327 for (const auto& space : continuous_spaces_) { 328 if (space->IsImageSpace()) { 329 return true; 330 } 331 } 332 return false; 333} 334 335void Heap::IncrementDisableMovingGC(Thread* self) { 336 // Need to do this holding the lock to prevent races where the GC is about to run / running when 337 // we attempt to disable it. 338 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 339 MutexLock mu(self, *gc_complete_lock_); 340 ++disable_moving_gc_count_; 341 if (IsCompactingGC(collector_type_running_)) { 342 WaitForGcToCompleteLocked(self); 343 } 344} 345 346void Heap::DecrementDisableMovingGC(Thread* self) { 347 MutexLock mu(self, *gc_complete_lock_); 348 CHECK_GE(disable_moving_gc_count_, 0U); 349 --disable_moving_gc_count_; 350} 351 352void Heap::UpdateProcessState(ProcessState process_state) { 353 if (process_state_ != process_state) { 354 process_state_ = process_state; 355 if (process_state_ == kProcessStateJankPerceptible) { 356 TransitionCollector(post_zygote_collector_type_); 357 } else { 358 TransitionCollector(background_collector_type_); 359 } 360 } else { 361 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 362 } 363} 364 365void Heap::CreateThreadPool() { 366 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 367 if (num_threads != 0) { 368 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 369 } 370} 371 372void Heap::VisitObjects(ObjectCallback callback, void* arg) { 373 Thread* self = Thread::Current(); 374 // GCs can move objects, so don't allow this. 375 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 376 if (bump_pointer_space_ != nullptr) { 377 // Visit objects in bump pointer space. 378 bump_pointer_space_->Walk(callback, arg); 379 } 380 // TODO: Switch to standard begin and end to use ranged a based loop. 381 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 382 it < end; ++it) { 383 mirror::Object* obj = *it; 384 if (obj != nullptr && obj->GetClass() != nullptr) { 385 // Avoid the race condition caused by the object not yet being written into the allocation 386 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 387 // there can be nulls on the allocation stack. 388 callback(obj, arg); 389 } 390 } 391 GetLiveBitmap()->Walk(callback, arg); 392 self->EndAssertNoThreadSuspension(old_cause); 393} 394 395void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 396 space::ContinuousSpace* space1 = rosalloc_space_ != nullptr ? rosalloc_space_ : non_moving_space_; 397 space::ContinuousSpace* space2 = dlmalloc_space_ != nullptr ? dlmalloc_space_ : non_moving_space_; 398 // This is just logic to handle a case of either not having a rosalloc or dlmalloc space. 399 // TODO: Generalize this to n bitmaps? 400 if (space1 == nullptr) { 401 DCHECK(space2 != nullptr); 402 space1 = space2; 403 } 404 if (space2 == nullptr) { 405 DCHECK(space1 != nullptr); 406 space2 = space1; 407 } 408 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 409 large_object_space_->GetLiveObjects(), stack); 410} 411 412void Heap::DeleteThreadPool() { 413 thread_pool_.reset(nullptr); 414} 415 416void Heap::AddSpace(space::Space* space, bool set_as_default) { 417 DCHECK(space != nullptr); 418 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 419 if (space->IsContinuousSpace()) { 420 DCHECK(!space->IsDiscontinuousSpace()); 421 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 422 // Continuous spaces don't necessarily have bitmaps. 423 accounting::SpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 424 accounting::SpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 425 if (live_bitmap != nullptr) { 426 DCHECK(mark_bitmap != nullptr); 427 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 428 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 429 } 430 continuous_spaces_.push_back(continuous_space); 431 if (set_as_default) { 432 if (continuous_space->IsDlMallocSpace()) { 433 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 434 } else if (continuous_space->IsRosAllocSpace()) { 435 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 436 } 437 } 438 // Ensure that spaces remain sorted in increasing order of start address. 439 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 440 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 441 return a->Begin() < b->Begin(); 442 }); 443 } else { 444 DCHECK(space->IsDiscontinuousSpace()); 445 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 446 DCHECK(discontinuous_space->GetLiveObjects() != nullptr); 447 live_bitmap_->AddDiscontinuousObjectSet(discontinuous_space->GetLiveObjects()); 448 DCHECK(discontinuous_space->GetMarkObjects() != nullptr); 449 mark_bitmap_->AddDiscontinuousObjectSet(discontinuous_space->GetMarkObjects()); 450 discontinuous_spaces_.push_back(discontinuous_space); 451 } 452 if (space->IsAllocSpace()) { 453 alloc_spaces_.push_back(space->AsAllocSpace()); 454 } 455} 456 457void Heap::RemoveSpace(space::Space* space) { 458 DCHECK(space != nullptr); 459 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 460 if (space->IsContinuousSpace()) { 461 DCHECK(!space->IsDiscontinuousSpace()); 462 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 463 // Continuous spaces don't necessarily have bitmaps. 464 accounting::SpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 465 accounting::SpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 466 if (live_bitmap != nullptr) { 467 DCHECK(mark_bitmap != nullptr); 468 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 469 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 470 } 471 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 472 DCHECK(it != continuous_spaces_.end()); 473 continuous_spaces_.erase(it); 474 if (continuous_space == dlmalloc_space_) { 475 dlmalloc_space_ = nullptr; 476 } else if (continuous_space == rosalloc_space_) { 477 rosalloc_space_ = nullptr; 478 } 479 if (continuous_space == main_space_) { 480 main_space_ = nullptr; 481 } 482 } else { 483 DCHECK(space->IsDiscontinuousSpace()); 484 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 485 DCHECK(discontinuous_space->GetLiveObjects() != nullptr); 486 live_bitmap_->RemoveDiscontinuousObjectSet(discontinuous_space->GetLiveObjects()); 487 DCHECK(discontinuous_space->GetMarkObjects() != nullptr); 488 mark_bitmap_->RemoveDiscontinuousObjectSet(discontinuous_space->GetMarkObjects()); 489 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 490 discontinuous_space); 491 DCHECK(it != discontinuous_spaces_.end()); 492 discontinuous_spaces_.erase(it); 493 } 494 if (space->IsAllocSpace()) { 495 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 496 DCHECK(it != alloc_spaces_.end()); 497 alloc_spaces_.erase(it); 498 } 499} 500 501void Heap::RegisterGCAllocation(size_t bytes) { 502 if (this != nullptr) { 503 gc_memory_overhead_.FetchAndAdd(bytes); 504 } 505} 506 507void Heap::RegisterGCDeAllocation(size_t bytes) { 508 if (this != nullptr) { 509 gc_memory_overhead_.FetchAndSub(bytes); 510 } 511} 512 513void Heap::DumpGcPerformanceInfo(std::ostream& os) { 514 // Dump cumulative timings. 515 os << "Dumping cumulative Gc timings\n"; 516 uint64_t total_duration = 0; 517 518 // Dump cumulative loggers for each GC type. 519 uint64_t total_paused_time = 0; 520 for (const auto& collector : garbage_collectors_) { 521 CumulativeLogger& logger = collector->GetCumulativeTimings(); 522 if (logger.GetTotalNs() != 0) { 523 os << Dumpable<CumulativeLogger>(logger); 524 const uint64_t total_ns = logger.GetTotalNs(); 525 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 526 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 527 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 528 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 529 Histogram<uint64_t>::CumulativeData cumulative_data; 530 collector->GetPauseHistogram().CreateHistogram(&cumulative_data); 531 collector->GetPauseHistogram().PrintConfidenceIntervals(os, 0.99, cumulative_data); 532 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) << "\n" 533 << collector->GetName() << " freed: " << freed_objects 534 << " objects with total size " << PrettySize(freed_bytes) << "\n" 535 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 536 << PrettySize(freed_bytes / seconds) << "/s\n"; 537 total_duration += total_ns; 538 total_paused_time += total_pause_ns; 539 } 540 } 541 uint64_t allocation_time = static_cast<uint64_t>(total_allocation_time_) * kTimeAdjust; 542 if (total_duration != 0) { 543 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 544 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 545 os << "Mean GC size throughput: " 546 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 547 os << "Mean GC object throughput: " 548 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 549 } 550 size_t total_objects_allocated = GetObjectsAllocatedEver(); 551 os << "Total number of allocations: " << total_objects_allocated << "\n"; 552 size_t total_bytes_allocated = GetBytesAllocatedEver(); 553 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 554 if (kMeasureAllocationTime) { 555 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 556 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 557 << "\n"; 558 } 559 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 560 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 561 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_; 562} 563 564Heap::~Heap() { 565 VLOG(heap) << "Starting ~Heap()"; 566 STLDeleteElements(&garbage_collectors_); 567 // If we don't reset then the mark stack complains in its destructor. 568 allocation_stack_->Reset(); 569 live_stack_->Reset(); 570 STLDeleteValues(&mod_union_tables_); 571 STLDeleteElements(&continuous_spaces_); 572 STLDeleteElements(&discontinuous_spaces_); 573 delete gc_complete_lock_; 574 VLOG(heap) << "Finished ~Heap()"; 575} 576 577space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 578 bool fail_ok) const { 579 for (const auto& space : continuous_spaces_) { 580 if (space->Contains(obj)) { 581 return space; 582 } 583 } 584 if (!fail_ok) { 585 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 586 } 587 return NULL; 588} 589 590space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 591 bool fail_ok) const { 592 for (const auto& space : discontinuous_spaces_) { 593 if (space->Contains(obj)) { 594 return space; 595 } 596 } 597 if (!fail_ok) { 598 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 599 } 600 return NULL; 601} 602 603space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 604 space::Space* result = FindContinuousSpaceFromObject(obj, true); 605 if (result != NULL) { 606 return result; 607 } 608 return FindDiscontinuousSpaceFromObject(obj, true); 609} 610 611struct SoftReferenceArgs { 612 IsMarkedCallback* is_marked_callback_; 613 MarkObjectCallback* recursive_mark_callback_; 614 void* arg_; 615}; 616 617mirror::Object* Heap::PreserveSoftReferenceCallback(mirror::Object* obj, void* arg) { 618 SoftReferenceArgs* args = reinterpret_cast<SoftReferenceArgs*>(arg); 619 // TODO: Not preserve all soft references. 620 return args->recursive_mark_callback_(obj, args->arg_); 621} 622 623// Process reference class instances and schedule finalizations. 624void Heap::ProcessReferences(TimingLogger& timings, bool clear_soft, 625 IsMarkedCallback* is_marked_callback, 626 MarkObjectCallback* recursive_mark_object_callback, void* arg) { 627 // Unless we are in the zygote or required to clear soft references with white references, 628 // preserve some white referents. 629 if (!clear_soft && !Runtime::Current()->IsZygote()) { 630 SoftReferenceArgs soft_reference_args; 631 soft_reference_args.is_marked_callback_ = is_marked_callback; 632 soft_reference_args.recursive_mark_callback_ = recursive_mark_object_callback; 633 soft_reference_args.arg_ = arg; 634 soft_reference_queue_.PreserveSomeSoftReferences(&PreserveSoftReferenceCallback, 635 &soft_reference_args); 636 } 637 timings.StartSplit("ProcessReferences"); 638 // Clear all remaining soft and weak references with white referents. 639 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 640 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 641 timings.EndSplit(); 642 // Preserve all white objects with finalize methods and schedule them for finalization. 643 timings.StartSplit("EnqueueFinalizerReferences"); 644 finalizer_reference_queue_.EnqueueFinalizerReferences(cleared_references_, is_marked_callback, 645 recursive_mark_object_callback, arg); 646 timings.EndSplit(); 647 timings.StartSplit("ProcessReferences"); 648 // Clear all f-reachable soft and weak references with white referents. 649 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 650 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 651 // Clear all phantom references with white referents. 652 phantom_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 653 // At this point all reference queues other than the cleared references should be empty. 654 DCHECK(soft_reference_queue_.IsEmpty()); 655 DCHECK(weak_reference_queue_.IsEmpty()); 656 DCHECK(finalizer_reference_queue_.IsEmpty()); 657 DCHECK(phantom_reference_queue_.IsEmpty()); 658 timings.EndSplit(); 659} 660 661bool Heap::IsEnqueued(mirror::Object* ref) const { 662 // Since the references are stored as cyclic lists it means that once enqueued, the pending next 663 // will always be non-null. 664 return ref->GetFieldObject<mirror::Object>(GetReferencePendingNextOffset(), false) != nullptr; 665} 666 667bool Heap::IsEnqueuable(mirror::Object* ref) const { 668 DCHECK(ref != nullptr); 669 const mirror::Object* queue = 670 ref->GetFieldObject<mirror::Object>(GetReferenceQueueOffset(), false); 671 const mirror::Object* queue_next = 672 ref->GetFieldObject<mirror::Object>(GetReferenceQueueNextOffset(), false); 673 return queue != nullptr && queue_next == nullptr; 674} 675 676// Process the "referent" field in a java.lang.ref.Reference. If the referent has not yet been 677// marked, put it on the appropriate list in the heap for later processing. 678void Heap::DelayReferenceReferent(mirror::Class* klass, mirror::Object* obj, 679 IsMarkedCallback is_marked_callback, void* arg) { 680 DCHECK(klass != nullptr); 681 DCHECK(klass->IsReferenceClass()); 682 DCHECK(obj != nullptr); 683 mirror::Object* referent = GetReferenceReferent(obj); 684 if (referent != nullptr) { 685 mirror::Object* forward_address = is_marked_callback(referent, arg); 686 // Null means that the object is not currently marked. 687 if (forward_address == nullptr) { 688 Thread* self = Thread::Current(); 689 // TODO: Remove these locks, and use atomic stacks for storing references? 690 // We need to check that the references haven't already been enqueued since we can end up 691 // scanning the same reference multiple times due to dirty cards. 692 if (klass->IsSoftReferenceClass()) { 693 soft_reference_queue_.AtomicEnqueueIfNotEnqueued(self, obj); 694 } else if (klass->IsWeakReferenceClass()) { 695 weak_reference_queue_.AtomicEnqueueIfNotEnqueued(self, obj); 696 } else if (klass->IsFinalizerReferenceClass()) { 697 finalizer_reference_queue_.AtomicEnqueueIfNotEnqueued(self, obj); 698 } else if (klass->IsPhantomReferenceClass()) { 699 phantom_reference_queue_.AtomicEnqueueIfNotEnqueued(self, obj); 700 } else { 701 LOG(FATAL) << "Invalid reference type " << PrettyClass(klass) << " " << std::hex 702 << klass->GetAccessFlags(); 703 } 704 } else if (referent != forward_address) { 705 // Referent is already marked and we need to update it. 706 SetReferenceReferent(obj, forward_address); 707 } 708 } 709} 710 711space::ImageSpace* Heap::GetImageSpace() const { 712 for (const auto& space : continuous_spaces_) { 713 if (space->IsImageSpace()) { 714 return space->AsImageSpace(); 715 } 716 } 717 return NULL; 718} 719 720static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) { 721 size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start); 722 if (used_bytes < chunk_size) { 723 size_t chunk_free_bytes = chunk_size - used_bytes; 724 size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg); 725 max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes); 726 } 727} 728 729void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, bool large_object_allocation) { 730 std::ostringstream oss; 731 size_t total_bytes_free = GetFreeMemory(); 732 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 733 << " free bytes"; 734 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 735 if (!large_object_allocation && total_bytes_free >= byte_count) { 736 size_t max_contiguous_allocation = 0; 737 for (const auto& space : continuous_spaces_) { 738 if (space->IsMallocSpace()) { 739 // To allow the Walk/InspectAll() to exclusively-lock the mutator 740 // lock, temporarily release the shared access to the mutator 741 // lock here by transitioning to the suspended state. 742 Locks::mutator_lock_->AssertSharedHeld(self); 743 self->TransitionFromRunnableToSuspended(kSuspended); 744 space->AsMallocSpace()->Walk(MSpaceChunkCallback, &max_contiguous_allocation); 745 self->TransitionFromSuspendedToRunnable(); 746 Locks::mutator_lock_->AssertSharedHeld(self); 747 } 748 } 749 oss << "; failed due to fragmentation (largest possible contiguous allocation " 750 << max_contiguous_allocation << " bytes)"; 751 } 752 self->ThrowOutOfMemoryError(oss.str().c_str()); 753} 754 755void Heap::Trim() { 756 Thread* self = Thread::Current(); 757 { 758 // Need to do this before acquiring the locks since we don't want to get suspended while 759 // holding any locks. 760 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 761 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 762 // trimming. 763 MutexLock mu(self, *gc_complete_lock_); 764 // Ensure there is only one GC at a time. 765 WaitForGcToCompleteLocked(self); 766 collector_type_running_ = kCollectorTypeHeapTrim; 767 } 768 uint64_t start_ns = NanoTime(); 769 // Trim the managed spaces. 770 uint64_t total_alloc_space_allocated = 0; 771 uint64_t total_alloc_space_size = 0; 772 uint64_t managed_reclaimed = 0; 773 for (const auto& space : continuous_spaces_) { 774 if (space->IsMallocSpace()) { 775 gc::space::MallocSpace* alloc_space = space->AsMallocSpace(); 776 total_alloc_space_size += alloc_space->Size(); 777 managed_reclaimed += alloc_space->Trim(); 778 } 779 } 780 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated() - 781 bump_pointer_space_->Size(); 782 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 783 static_cast<float>(total_alloc_space_size); 784 uint64_t gc_heap_end_ns = NanoTime(); 785 // We never move things in the native heap, so we can finish the GC at this point. 786 FinishGC(self, collector::kGcTypeNone); 787 // Trim the native heap. 788 dlmalloc_trim(0); 789 size_t native_reclaimed = 0; 790 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 791 uint64_t end_ns = NanoTime(); 792 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 793 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 794 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 795 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 796 << "%."; 797} 798 799bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 800 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 801 // taking the lock. 802 if (obj == nullptr) { 803 return true; 804 } 805 return IsAligned<kObjectAlignment>(obj) && IsHeapAddress(obj); 806} 807 808bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 809 return FindContinuousSpaceFromObject(obj, true) != nullptr; 810} 811 812bool Heap::IsHeapAddress(const mirror::Object* obj) const { 813 // TODO: This might not work for large objects. 814 return FindSpaceFromObject(obj, true) != nullptr; 815} 816 817bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 818 bool search_live_stack, bool sorted) { 819 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 820 return false; 821 } 822 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 823 mirror::Class* klass = obj->GetClass(); 824 if (obj == klass) { 825 // This case happens for java.lang.Class. 826 return true; 827 } 828 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 829 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 830 return false; 831 } 832 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 833 space::DiscontinuousSpace* d_space = NULL; 834 if (c_space != nullptr) { 835 if (c_space->GetLiveBitmap()->Test(obj)) { 836 return true; 837 } 838 } else { 839 d_space = FindDiscontinuousSpaceFromObject(obj, true); 840 if (d_space != nullptr) { 841 if (d_space->GetLiveObjects()->Test(obj)) { 842 return true; 843 } 844 } 845 } 846 // This is covering the allocation/live stack swapping that is done without mutators suspended. 847 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 848 if (i > 0) { 849 NanoSleep(MsToNs(10)); 850 } 851 if (search_allocation_stack) { 852 if (sorted) { 853 if (allocation_stack_->ContainsSorted(const_cast<mirror::Object*>(obj))) { 854 return true; 855 } 856 } else if (allocation_stack_->Contains(const_cast<mirror::Object*>(obj))) { 857 return true; 858 } 859 } 860 861 if (search_live_stack) { 862 if (sorted) { 863 if (live_stack_->ContainsSorted(const_cast<mirror::Object*>(obj))) { 864 return true; 865 } 866 } else if (live_stack_->Contains(const_cast<mirror::Object*>(obj))) { 867 return true; 868 } 869 } 870 } 871 // We need to check the bitmaps again since there is a race where we mark something as live and 872 // then clear the stack containing it. 873 if (c_space != nullptr) { 874 if (c_space->GetLiveBitmap()->Test(obj)) { 875 return true; 876 } 877 } else { 878 d_space = FindDiscontinuousSpaceFromObject(obj, true); 879 if (d_space != nullptr && d_space->GetLiveObjects()->Test(obj)) { 880 return true; 881 } 882 } 883 return false; 884} 885 886void Heap::VerifyObjectImpl(mirror::Object* obj) { 887 if (Thread::Current() == NULL || 888 Runtime::Current()->GetThreadList()->GetLockOwner() == Thread::Current()->GetTid()) { 889 return; 890 } 891 VerifyObjectBody(obj); 892} 893 894bool Heap::VerifyClassClass(const mirror::Class* c) const { 895 // Note: we don't use the accessors here as they have internal sanity checks that we don't want 896 // to run 897 const byte* raw_addr = 898 reinterpret_cast<const byte*>(c) + mirror::Object::ClassOffset().Int32Value(); 899 mirror::Class* c_c = reinterpret_cast<mirror::HeapReference<mirror::Class> const *>(raw_addr)->AsMirrorPtr(); 900 raw_addr = reinterpret_cast<const byte*>(c_c) + mirror::Object::ClassOffset().Int32Value(); 901 mirror::Class* c_c_c = reinterpret_cast<mirror::HeapReference<mirror::Class> const *>(raw_addr)->AsMirrorPtr(); 902 return c_c == c_c_c; 903} 904 905void Heap::DumpSpaces(std::ostream& stream) { 906 for (const auto& space : continuous_spaces_) { 907 accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); 908 accounting::SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 909 stream << space << " " << *space << "\n"; 910 if (live_bitmap != nullptr) { 911 stream << live_bitmap << " " << *live_bitmap << "\n"; 912 } 913 if (mark_bitmap != nullptr) { 914 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 915 } 916 } 917 for (const auto& space : discontinuous_spaces_) { 918 stream << space << " " << *space << "\n"; 919 } 920} 921 922void Heap::VerifyObjectBody(mirror::Object* obj) { 923 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 924 // Ignore early dawn of the universe verifications. 925 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.Load()) < 10 * KB)) { 926 return; 927 } 928 const byte* raw_addr = reinterpret_cast<const byte*>(obj) + 929 mirror::Object::ClassOffset().Int32Value(); 930 mirror::Class* c = reinterpret_cast<mirror::HeapReference<mirror::Class> const *>(raw_addr)->AsMirrorPtr(); 931 if (UNLIKELY(c == NULL)) { 932 LOG(FATAL) << "Null class in object: " << obj; 933 } else if (UNLIKELY(!IsAligned<kObjectAlignment>(c))) { 934 LOG(FATAL) << "Class isn't aligned: " << c << " in object: " << obj; 935 } 936 CHECK(VerifyClassClass(c)); 937 938 if (verify_object_mode_ > kVerifyAllFast) { 939 // TODO: the bitmap tests below are racy if VerifyObjectBody is called without the 940 // heap_bitmap_lock_. 941 if (!IsLiveObjectLocked(obj)) { 942 DumpSpaces(); 943 LOG(FATAL) << "Object is dead: " << obj; 944 } 945 if (!IsLiveObjectLocked(c)) { 946 LOG(FATAL) << "Class of object is dead: " << c << " in object: " << obj; 947 } 948 } 949} 950 951void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 952 DCHECK(obj != NULL); 953 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 954} 955 956void Heap::VerifyHeap() { 957 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 958 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 959} 960 961void Heap::RecordFree(size_t freed_objects, size_t freed_bytes) { 962 DCHECK_LE(freed_bytes, num_bytes_allocated_.Load()); 963 num_bytes_allocated_.FetchAndSub(freed_bytes); 964 if (Runtime::Current()->HasStatsEnabled()) { 965 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 966 thread_stats->freed_objects += freed_objects; 967 thread_stats->freed_bytes += freed_bytes; 968 // TODO: Do this concurrently. 969 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 970 global_stats->freed_objects += freed_objects; 971 global_stats->freed_bytes += freed_bytes; 972 } 973} 974 975mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 976 size_t alloc_size, size_t* bytes_allocated, 977 mirror::Class** klass) { 978 mirror::Object* ptr = nullptr; 979 bool was_default_allocator = allocator == GetCurrentAllocator(); 980 DCHECK(klass != nullptr); 981 SirtRef<mirror::Class> sirt_klass(self, *klass); 982 // The allocation failed. If the GC is running, block until it completes, and then retry the 983 // allocation. 984 collector::GcType last_gc = WaitForGcToComplete(self); 985 if (last_gc != collector::kGcTypeNone) { 986 // If we were the default allocator but the allocator changed while we were suspended, 987 // abort the allocation. 988 if (was_default_allocator && allocator != GetCurrentAllocator()) { 989 *klass = sirt_klass.get(); 990 return nullptr; 991 } 992 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 993 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated); 994 } 995 996 // Loop through our different Gc types and try to Gc until we get enough free memory. 997 for (collector::GcType gc_type : gc_plan_) { 998 if (ptr != nullptr) { 999 break; 1000 } 1001 // Attempt to run the collector, if we succeed, re-try the allocation. 1002 bool gc_ran = 1003 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1004 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1005 *klass = sirt_klass.get(); 1006 return nullptr; 1007 } 1008 if (gc_ran) { 1009 // Did we free sufficient memory for the allocation to succeed? 1010 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated); 1011 } 1012 } 1013 // Allocations have failed after GCs; this is an exceptional state. 1014 if (ptr == nullptr) { 1015 // Try harder, growing the heap if necessary. 1016 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated); 1017 } 1018 if (ptr == nullptr) { 1019 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1020 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1021 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1022 // OOME. 1023 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1024 << " allocation"; 1025 // TODO: Run finalization, but this may cause more allocations to occur. 1026 // We don't need a WaitForGcToComplete here either. 1027 DCHECK(!gc_plan_.empty()); 1028 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1029 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1030 *klass = sirt_klass.get(); 1031 return nullptr; 1032 } 1033 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated); 1034 if (ptr == nullptr) { 1035 ThrowOutOfMemoryError(self, alloc_size, false); 1036 } 1037 } 1038 *klass = sirt_klass.get(); 1039 return ptr; 1040} 1041 1042void Heap::SetTargetHeapUtilization(float target) { 1043 DCHECK_GT(target, 0.0f); // asserted in Java code 1044 DCHECK_LT(target, 1.0f); 1045 target_utilization_ = target; 1046} 1047 1048size_t Heap::GetObjectsAllocated() const { 1049 size_t total = 0; 1050 for (space::AllocSpace* space : alloc_spaces_) { 1051 total += space->GetObjectsAllocated(); 1052 } 1053 return total; 1054} 1055 1056size_t Heap::GetObjectsAllocatedEver() const { 1057 return GetObjectsFreedEver() + GetObjectsAllocated(); 1058} 1059 1060size_t Heap::GetBytesAllocatedEver() const { 1061 return GetBytesFreedEver() + GetBytesAllocated(); 1062} 1063 1064class InstanceCounter { 1065 public: 1066 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1067 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1068 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1069 } 1070 static void Callback(mirror::Object* obj, void* arg) 1071 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1072 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1073 mirror::Class* instance_class = obj->GetClass(); 1074 CHECK(instance_class != nullptr); 1075 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1076 if (instance_counter->use_is_assignable_from_) { 1077 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1078 ++instance_counter->counts_[i]; 1079 } 1080 } else if (instance_class == instance_counter->classes_[i]) { 1081 ++instance_counter->counts_[i]; 1082 } 1083 } 1084 } 1085 1086 private: 1087 const std::vector<mirror::Class*>& classes_; 1088 bool use_is_assignable_from_; 1089 uint64_t* const counts_; 1090 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1091}; 1092 1093void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1094 uint64_t* counts) { 1095 // Can't do any GC in this function since this may move classes. 1096 Thread* self = Thread::Current(); 1097 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1098 InstanceCounter counter(classes, use_is_assignable_from, counts); 1099 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1100 VisitObjects(InstanceCounter::Callback, &counter); 1101 self->EndAssertNoThreadSuspension(old_cause); 1102} 1103 1104class InstanceCollector { 1105 public: 1106 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1107 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1108 : class_(c), max_count_(max_count), instances_(instances) { 1109 } 1110 static void Callback(mirror::Object* obj, void* arg) 1111 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1112 DCHECK(arg != nullptr); 1113 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1114 mirror::Class* instance_class = obj->GetClass(); 1115 if (instance_class == instance_collector->class_) { 1116 if (instance_collector->max_count_ == 0 || 1117 instance_collector->instances_.size() < instance_collector->max_count_) { 1118 instance_collector->instances_.push_back(obj); 1119 } 1120 } 1121 } 1122 1123 private: 1124 mirror::Class* class_; 1125 uint32_t max_count_; 1126 std::vector<mirror::Object*>& instances_; 1127 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1128}; 1129 1130void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1131 std::vector<mirror::Object*>& instances) { 1132 // Can't do any GC in this function since this may move classes. 1133 Thread* self = Thread::Current(); 1134 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1135 InstanceCollector collector(c, max_count, instances); 1136 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1137 VisitObjects(&InstanceCollector::Callback, &collector); 1138 self->EndAssertNoThreadSuspension(old_cause); 1139} 1140 1141class ReferringObjectsFinder { 1142 public: 1143 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1144 std::vector<mirror::Object*>& referring_objects) 1145 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1146 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1147 } 1148 1149 static void Callback(mirror::Object* obj, void* arg) 1150 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1151 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1152 } 1153 1154 // For bitmap Visit. 1155 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1156 // annotalysis on visitors. 1157 void operator()(const mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1158 collector::MarkSweep::VisitObjectReferences(const_cast<mirror::Object*>(o), *this, true); 1159 } 1160 1161 // For MarkSweep::VisitObjectReferences. 1162 void operator()(mirror::Object* referrer, mirror::Object* object, 1163 const MemberOffset&, bool) const { 1164 if (object == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1165 referring_objects_.push_back(referrer); 1166 } 1167 } 1168 1169 private: 1170 mirror::Object* object_; 1171 uint32_t max_count_; 1172 std::vector<mirror::Object*>& referring_objects_; 1173 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1174}; 1175 1176void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1177 std::vector<mirror::Object*>& referring_objects) { 1178 // Can't do any GC in this function since this may move the object o. 1179 Thread* self = Thread::Current(); 1180 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1181 ReferringObjectsFinder finder(o, max_count, referring_objects); 1182 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1183 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1184 self->EndAssertNoThreadSuspension(old_cause); 1185} 1186 1187void Heap::CollectGarbage(bool clear_soft_references) { 1188 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1189 // last GC will not have necessarily been cleared. 1190 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1191} 1192 1193void Heap::TransitionCollector(CollectorType collector_type) { 1194 if (collector_type == collector_type_) { 1195 return; 1196 } 1197 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1198 << " -> " << static_cast<int>(collector_type); 1199 uint64_t start_time = NanoTime(); 1200 uint32_t before_size = GetTotalMemory(); 1201 uint32_t before_allocated = num_bytes_allocated_.Load(); 1202 ThreadList* tl = Runtime::Current()->GetThreadList(); 1203 Thread* self = Thread::Current(); 1204 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1205 Locks::mutator_lock_->AssertNotHeld(self); 1206 const bool copying_transition = 1207 IsCompactingGC(background_collector_type_) || IsCompactingGC(post_zygote_collector_type_); 1208 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1209 // compacting_gc_disable_count_, this should rarely occurs). 1210 for (;;) { 1211 { 1212 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1213 MutexLock mu(self, *gc_complete_lock_); 1214 // Ensure there is only one GC at a time. 1215 WaitForGcToCompleteLocked(self); 1216 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1217 if (!copying_transition || disable_moving_gc_count_ == 0) { 1218 // TODO: Not hard code in semi-space collector? 1219 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1220 break; 1221 } 1222 } 1223 usleep(1000); 1224 } 1225 tl->SuspendAll(); 1226 PreGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1227 switch (collector_type) { 1228 case kCollectorTypeSS: 1229 // Fall-through. 1230 case kCollectorTypeGSS: { 1231 mprotect(temp_space_->Begin(), temp_space_->Capacity(), PROT_READ | PROT_WRITE); 1232 CHECK(main_space_ != nullptr); 1233 Compact(temp_space_, main_space_); 1234 DCHECK(allocator_mem_map_.get() == nullptr); 1235 allocator_mem_map_.reset(main_space_->ReleaseMemMap()); 1236 madvise(main_space_->Begin(), main_space_->Size(), MADV_DONTNEED); 1237 // RemoveSpace does not delete the removed space. 1238 space::Space* old_space = main_space_; 1239 RemoveSpace(old_space); 1240 delete old_space; 1241 break; 1242 } 1243 case kCollectorTypeMS: 1244 // Fall through. 1245 case kCollectorTypeCMS: { 1246 if (IsCompactingGC(collector_type_)) { 1247 // TODO: Use mem-map from temp space? 1248 MemMap* mem_map = allocator_mem_map_.release(); 1249 CHECK(mem_map != nullptr); 1250 size_t initial_size = kDefaultInitialSize; 1251 mprotect(mem_map->Begin(), initial_size, PROT_READ | PROT_WRITE); 1252 CHECK(main_space_ == nullptr); 1253 if (kUseRosAlloc) { 1254 main_space_ = 1255 space::RosAllocSpace::CreateFromMemMap(mem_map, "alloc space", kPageSize, 1256 initial_size, mem_map->Size(), 1257 mem_map->Size(), low_memory_mode_); 1258 } else { 1259 main_space_ = 1260 space::DlMallocSpace::CreateFromMemMap(mem_map, "alloc space", kPageSize, 1261 initial_size, mem_map->Size(), 1262 mem_map->Size()); 1263 } 1264 main_space_->SetFootprintLimit(main_space_->Capacity()); 1265 AddSpace(main_space_); 1266 Compact(main_space_, bump_pointer_space_); 1267 } 1268 break; 1269 } 1270 default: { 1271 LOG(FATAL) << "Attempted to transition to invalid collector type"; 1272 break; 1273 } 1274 } 1275 ChangeCollector(collector_type); 1276 PostGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1277 tl->ResumeAll(); 1278 // Can't call into java code with all threads suspended. 1279 EnqueueClearedReferences(); 1280 uint64_t duration = NanoTime() - start_time; 1281 GrowForUtilization(collector::kGcTypeFull, duration); 1282 FinishGC(self, collector::kGcTypeFull); 1283 int32_t after_size = GetTotalMemory(); 1284 int32_t delta_size = before_size - after_size; 1285 int32_t after_allocated = num_bytes_allocated_.Load(); 1286 int32_t delta_allocated = before_allocated - after_allocated; 1287 const std::string saved_bytes_str = 1288 delta_size < 0 ? "-" + PrettySize(-delta_size) : PrettySize(delta_size); 1289 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1290 << PrettyDuration(duration) << " " << PrettySize(before_size) << "->" 1291 << PrettySize(after_size) << " from " << PrettySize(delta_allocated) << " to " 1292 << PrettySize(delta_size) << " saved"; 1293} 1294 1295void Heap::ChangeCollector(CollectorType collector_type) { 1296 // TODO: Only do this with all mutators suspended to avoid races. 1297 if (collector_type != collector_type_) { 1298 collector_type_ = collector_type; 1299 gc_plan_.clear(); 1300 switch (collector_type_) { 1301 case kCollectorTypeSS: 1302 // Fall-through. 1303 case kCollectorTypeGSS: { 1304 concurrent_gc_ = false; 1305 gc_plan_.push_back(collector::kGcTypeFull); 1306 if (use_tlab_) { 1307 ChangeAllocator(kAllocatorTypeTLAB); 1308 } else { 1309 ChangeAllocator(kAllocatorTypeBumpPointer); 1310 } 1311 break; 1312 } 1313 case kCollectorTypeMS: { 1314 concurrent_gc_ = false; 1315 gc_plan_.push_back(collector::kGcTypeSticky); 1316 gc_plan_.push_back(collector::kGcTypePartial); 1317 gc_plan_.push_back(collector::kGcTypeFull); 1318 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1319 break; 1320 } 1321 case kCollectorTypeCMS: { 1322 concurrent_gc_ = true; 1323 gc_plan_.push_back(collector::kGcTypeSticky); 1324 gc_plan_.push_back(collector::kGcTypePartial); 1325 gc_plan_.push_back(collector::kGcTypeFull); 1326 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1327 break; 1328 } 1329 default: { 1330 LOG(FATAL) << "Unimplemented"; 1331 } 1332 } 1333 if (concurrent_gc_) { 1334 concurrent_start_bytes_ = 1335 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1336 } else { 1337 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1338 } 1339 } 1340} 1341 1342// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1343class ZygoteCompactingCollector : public collector::SemiSpace { 1344 public: 1345 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, "zygote collector") { 1346 } 1347 1348 void BuildBins(space::ContinuousSpace* space) { 1349 bin_live_bitmap_ = space->GetLiveBitmap(); 1350 bin_mark_bitmap_ = space->GetMarkBitmap(); 1351 BinContext context; 1352 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1353 context.collector_ = this; 1354 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1355 // Note: This requires traversing the space in increasing order of object addresses. 1356 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1357 // Add the last bin which spans after the last object to the end of the space. 1358 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1359 } 1360 1361 private: 1362 struct BinContext { 1363 uintptr_t prev_; // The end of the previous object. 1364 ZygoteCompactingCollector* collector_; 1365 }; 1366 // Maps from bin sizes to locations. 1367 std::multimap<size_t, uintptr_t> bins_; 1368 // Live bitmap of the space which contains the bins. 1369 accounting::SpaceBitmap* bin_live_bitmap_; 1370 // Mark bitmap of the space which contains the bins. 1371 accounting::SpaceBitmap* bin_mark_bitmap_; 1372 1373 static void Callback(mirror::Object* obj, void* arg) 1374 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1375 DCHECK(arg != nullptr); 1376 BinContext* context = reinterpret_cast<BinContext*>(arg); 1377 ZygoteCompactingCollector* collector = context->collector_; 1378 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1379 size_t bin_size = object_addr - context->prev_; 1380 // Add the bin consisting of the end of the previous object to the start of the current object. 1381 collector->AddBin(bin_size, context->prev_); 1382 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1383 } 1384 1385 void AddBin(size_t size, uintptr_t position) { 1386 if (size != 0) { 1387 bins_.insert(std::make_pair(size, position)); 1388 } 1389 } 1390 1391 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1392 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1393 // allocator. 1394 return false; 1395 } 1396 1397 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1398 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1399 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1400 mirror::Object* forward_address; 1401 // Find the smallest bin which we can move obj in. 1402 auto it = bins_.lower_bound(object_size); 1403 if (it == bins_.end()) { 1404 // No available space in the bins, place it in the target space instead (grows the zygote 1405 // space). 1406 size_t bytes_allocated; 1407 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated); 1408 if (to_space_live_bitmap_ != nullptr) { 1409 to_space_live_bitmap_->Set(forward_address); 1410 } else { 1411 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1412 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1413 } 1414 } else { 1415 size_t size = it->first; 1416 uintptr_t pos = it->second; 1417 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1418 forward_address = reinterpret_cast<mirror::Object*>(pos); 1419 // Set the live and mark bits so that sweeping system weaks works properly. 1420 bin_live_bitmap_->Set(forward_address); 1421 bin_mark_bitmap_->Set(forward_address); 1422 DCHECK_GE(size, object_size); 1423 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1424 } 1425 // Copy the object over to its new location. 1426 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1427 return forward_address; 1428 } 1429}; 1430 1431void Heap::UnBindBitmaps() { 1432 for (const auto& space : GetContinuousSpaces()) { 1433 if (space->IsContinuousMemMapAllocSpace()) { 1434 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1435 if (alloc_space->HasBoundBitmaps()) { 1436 alloc_space->UnBindBitmaps(); 1437 } 1438 } 1439 } 1440} 1441 1442void Heap::PreZygoteFork() { 1443 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1444 static Mutex zygote_creation_lock_("zygote creation lock", kZygoteCreationLock); 1445 Thread* self = Thread::Current(); 1446 MutexLock mu(self, zygote_creation_lock_); 1447 // Try to see if we have any Zygote spaces. 1448 if (have_zygote_space_) { 1449 return; 1450 } 1451 VLOG(heap) << "Starting PreZygoteFork"; 1452 // Trim the pages at the end of the non moving space. 1453 non_moving_space_->Trim(); 1454 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1455 // Change the collector to the post zygote one. 1456 ChangeCollector(post_zygote_collector_type_); 1457 // TODO: Delete bump_pointer_space_ and temp_pointer_space_? 1458 if (semi_space_collector_ != nullptr) { 1459 // Temporarily disable rosalloc verification because the zygote 1460 // compaction will mess up the rosalloc internal metadata. 1461 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1462 ZygoteCompactingCollector zygote_collector(this); 1463 zygote_collector.BuildBins(non_moving_space_); 1464 // Create a new bump pointer space which we will compact into. 1465 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1466 non_moving_space_->Limit()); 1467 // Compact the bump pointer space to a new zygote bump pointer space. 1468 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1469 zygote_collector.SetFromSpace(bump_pointer_space_); 1470 zygote_collector.SetToSpace(&target_space); 1471 zygote_collector.Run(kGcCauseCollectorTransition, false); 1472 CHECK(temp_space_->IsEmpty()); 1473 total_objects_freed_ever_ += semi_space_collector_->GetFreedObjects(); 1474 total_bytes_freed_ever_ += semi_space_collector_->GetFreedBytes(); 1475 // Update the end and write out image. 1476 non_moving_space_->SetEnd(target_space.End()); 1477 non_moving_space_->SetLimit(target_space.Limit()); 1478 VLOG(heap) << "Zygote size " << non_moving_space_->Size() << " bytes"; 1479 } 1480 // Save the old space so that we can remove it after we complete creating the zygote space. 1481 space::MallocSpace* old_alloc_space = non_moving_space_; 1482 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1483 // the remaining available space. 1484 // Remove the old space before creating the zygote space since creating the zygote space sets 1485 // the old alloc space's bitmaps to nullptr. 1486 RemoveSpace(old_alloc_space); 1487 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1488 low_memory_mode_, 1489 &main_space_); 1490 delete old_alloc_space; 1491 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1492 AddSpace(zygote_space, false); 1493 CHECK(main_space_ != nullptr); 1494 if (main_space_->IsRosAllocSpace()) { 1495 rosalloc_space_ = main_space_->AsRosAllocSpace(); 1496 } else if (main_space_->IsDlMallocSpace()) { 1497 dlmalloc_space_ = main_space_->AsDlMallocSpace(); 1498 } 1499 main_space_->SetFootprintLimit(main_space_->Capacity()); 1500 AddSpace(main_space_); 1501 have_zygote_space_ = true; 1502 // Create the zygote space mod union table. 1503 accounting::ModUnionTable* mod_union_table = 1504 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1505 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1506 AddModUnionTable(mod_union_table); 1507 // Reset the cumulative loggers since we now have a few additional timing phases. 1508 for (const auto& collector : garbage_collectors_) { 1509 collector->ResetCumulativeStatistics(); 1510 } 1511 // Can't use RosAlloc for non moving space due to thread local buffers. 1512 // TODO: Non limited space for non-movable objects? 1513 MemMap* mem_map = post_zygote_non_moving_space_mem_map_.release(); 1514 space::MallocSpace* new_non_moving_space = 1515 space::DlMallocSpace::CreateFromMemMap(mem_map, "Non moving dlmalloc space", kPageSize, 1516 2 * MB, mem_map->Size(), mem_map->Size()); 1517 AddSpace(new_non_moving_space, false); 1518 CHECK(new_non_moving_space != nullptr) << "Failed to create new non-moving space"; 1519 new_non_moving_space->SetFootprintLimit(new_non_moving_space->Capacity()); 1520 non_moving_space_ = new_non_moving_space; 1521} 1522 1523void Heap::FlushAllocStack() { 1524 MarkAllocStackAsLive(allocation_stack_.get()); 1525 allocation_stack_->Reset(); 1526} 1527 1528void Heap::MarkAllocStack(accounting::SpaceBitmap* bitmap1, 1529 accounting::SpaceBitmap* bitmap2, 1530 accounting::ObjectSet* large_objects, 1531 accounting::ObjectStack* stack) { 1532 DCHECK(bitmap1 != nullptr); 1533 DCHECK(bitmap2 != nullptr); 1534 mirror::Object** limit = stack->End(); 1535 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1536 const mirror::Object* obj = *it; 1537 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1538 if (bitmap1->HasAddress(obj)) { 1539 bitmap1->Set(obj); 1540 } else if (bitmap2->HasAddress(obj)) { 1541 bitmap2->Set(obj); 1542 } else { 1543 large_objects->Set(obj); 1544 } 1545 } 1546 } 1547} 1548 1549void Heap::SwapSemiSpaces() { 1550 // Swap the spaces so we allocate into the space which we just evacuated. 1551 std::swap(bump_pointer_space_, temp_space_); 1552} 1553 1554void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1555 space::ContinuousMemMapAllocSpace* source_space) { 1556 CHECK(kMovingCollector); 1557 CHECK_NE(target_space, source_space) << "In-place compaction currently unsupported"; 1558 if (target_space != source_space) { 1559 semi_space_collector_->SetFromSpace(source_space); 1560 semi_space_collector_->SetToSpace(target_space); 1561 semi_space_collector_->Run(kGcCauseCollectorTransition, false); 1562 } 1563} 1564 1565collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1566 bool clear_soft_references) { 1567 Thread* self = Thread::Current(); 1568 Runtime* runtime = Runtime::Current(); 1569 // If the heap can't run the GC, silently fail and return that no GC was run. 1570 switch (gc_type) { 1571 case collector::kGcTypePartial: { 1572 if (!have_zygote_space_) { 1573 return collector::kGcTypeNone; 1574 } 1575 break; 1576 } 1577 default: { 1578 // Other GC types don't have any special cases which makes them not runnable. The main case 1579 // here is full GC. 1580 } 1581 } 1582 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1583 Locks::mutator_lock_->AssertNotHeld(self); 1584 if (self->IsHandlingStackOverflow()) { 1585 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 1586 } 1587 bool compacting_gc; 1588 { 1589 gc_complete_lock_->AssertNotHeld(self); 1590 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1591 MutexLock mu(self, *gc_complete_lock_); 1592 // Ensure there is only one GC at a time. 1593 WaitForGcToCompleteLocked(self); 1594 compacting_gc = IsCompactingGC(collector_type_); 1595 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 1596 if (compacting_gc && disable_moving_gc_count_ != 0) { 1597 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 1598 return collector::kGcTypeNone; 1599 } 1600 collector_type_running_ = collector_type_; 1601 } 1602 1603 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 1604 ++runtime->GetStats()->gc_for_alloc_count; 1605 ++self->GetStats()->gc_for_alloc_count; 1606 } 1607 uint64_t gc_start_time_ns = NanoTime(); 1608 uint64_t gc_start_size = GetBytesAllocated(); 1609 // Approximate allocation rate in bytes / second. 1610 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 1611 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 1612 if (LIKELY(ms_delta != 0)) { 1613 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 1614 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 1615 } 1616 1617 DCHECK_LT(gc_type, collector::kGcTypeMax); 1618 DCHECK_NE(gc_type, collector::kGcTypeNone); 1619 1620 collector::GarbageCollector* collector = nullptr; 1621 // TODO: Clean this up. 1622 if (compacting_gc) { 1623 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 1624 current_allocator_ == kAllocatorTypeTLAB); 1625 gc_type = semi_space_collector_->GetGcType(); 1626 CHECK(temp_space_->IsEmpty()); 1627 semi_space_collector_->SetFromSpace(bump_pointer_space_); 1628 semi_space_collector_->SetToSpace(temp_space_); 1629 mprotect(temp_space_->Begin(), temp_space_->Capacity(), PROT_READ | PROT_WRITE); 1630 collector = semi_space_collector_; 1631 gc_type = collector::kGcTypeFull; 1632 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 1633 current_allocator_ == kAllocatorTypeDlMalloc) { 1634 for (const auto& cur_collector : garbage_collectors_) { 1635 if (cur_collector->IsConcurrent() == concurrent_gc_ && 1636 cur_collector->GetGcType() == gc_type) { 1637 collector = cur_collector; 1638 break; 1639 } 1640 } 1641 } else { 1642 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 1643 } 1644 CHECK(collector != nullptr) 1645 << "Could not find garbage collector with concurrent=" << concurrent_gc_ 1646 << " and type=" << gc_type; 1647 ATRACE_BEGIN(StringPrintf("%s %s GC", PrettyCause(gc_cause), collector->GetName()).c_str()); 1648 collector->Run(gc_cause, clear_soft_references); 1649 total_objects_freed_ever_ += collector->GetFreedObjects(); 1650 total_bytes_freed_ever_ += collector->GetFreedBytes(); 1651 // Enqueue cleared references. 1652 EnqueueClearedReferences(); 1653 // Grow the heap so that we know when to perform the next GC. 1654 GrowForUtilization(gc_type, collector->GetDurationNs()); 1655 if (CareAboutPauseTimes()) { 1656 const size_t duration = collector->GetDurationNs(); 1657 std::vector<uint64_t> pauses = collector->GetPauseTimes(); 1658 // GC for alloc pauses the allocating thread, so consider it as a pause. 1659 bool was_slow = duration > long_gc_log_threshold_ || 1660 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 1661 if (!was_slow) { 1662 for (uint64_t pause : pauses) { 1663 was_slow = was_slow || pause > long_pause_log_threshold_; 1664 } 1665 } 1666 if (was_slow) { 1667 const size_t percent_free = GetPercentFree(); 1668 const size_t current_heap_size = GetBytesAllocated(); 1669 const size_t total_memory = GetTotalMemory(); 1670 std::ostringstream pause_string; 1671 for (size_t i = 0; i < pauses.size(); ++i) { 1672 pause_string << PrettyDuration((pauses[i] / 1000) * 1000) 1673 << ((i != pauses.size() - 1) ? ", " : ""); 1674 } 1675 LOG(INFO) << gc_cause << " " << collector->GetName() 1676 << " GC freed " << collector->GetFreedObjects() << "(" 1677 << PrettySize(collector->GetFreedBytes()) << ") AllocSpace objects, " 1678 << collector->GetFreedLargeObjects() << "(" 1679 << PrettySize(collector->GetFreedLargeObjectBytes()) << ") LOS objects, " 1680 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 1681 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 1682 << " total " << PrettyDuration((duration / 1000) * 1000); 1683 if (VLOG_IS_ON(heap)) { 1684 LOG(INFO) << Dumpable<TimingLogger>(collector->GetTimings()); 1685 } 1686 } 1687 } 1688 FinishGC(self, gc_type); 1689 ATRACE_END(); 1690 1691 // Inform DDMS that a GC completed. 1692 Dbg::GcDidFinish(); 1693 return gc_type; 1694} 1695 1696void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 1697 MutexLock mu(self, *gc_complete_lock_); 1698 collector_type_running_ = kCollectorTypeNone; 1699 if (gc_type != collector::kGcTypeNone) { 1700 last_gc_type_ = gc_type; 1701 } 1702 // Wake anyone who may have been waiting for the GC to complete. 1703 gc_complete_cond_->Broadcast(self); 1704} 1705 1706static mirror::Object* RootMatchesObjectVisitor(mirror::Object* root, void* arg, 1707 uint32_t /*thread_id*/, RootType /*root_type*/) { 1708 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 1709 if (root == obj) { 1710 LOG(INFO) << "Object " << obj << " is a root"; 1711 } 1712 return root; 1713} 1714 1715class ScanVisitor { 1716 public: 1717 void operator()(const mirror::Object* obj) const { 1718 LOG(ERROR) << "Would have rescanned object " << obj; 1719 } 1720}; 1721 1722// Verify a reference from an object. 1723class VerifyReferenceVisitor { 1724 public: 1725 explicit VerifyReferenceVisitor(Heap* heap) 1726 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 1727 : heap_(heap), failed_(false) {} 1728 1729 bool Failed() const { 1730 return failed_; 1731 } 1732 1733 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for smarter 1734 // analysis on visitors. 1735 void operator()(mirror::Object* obj, mirror::Object* ref, 1736 const MemberOffset& offset, bool /* is_static */) const 1737 NO_THREAD_SAFETY_ANALYSIS { 1738 if (ref == nullptr || IsLive(ref)) { 1739 // Verify that the reference is live. 1740 return; 1741 } 1742 if (!failed_) { 1743 // Print message on only on first failure to prevent spam. 1744 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 1745 failed_ = true; 1746 } 1747 if (obj != nullptr) { 1748 accounting::CardTable* card_table = heap_->GetCardTable(); 1749 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 1750 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 1751 byte* card_addr = card_table->CardFromAddr(obj); 1752 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 1753 << offset << "\n card value = " << static_cast<int>(*card_addr); 1754 if (heap_->IsValidObjectAddress(obj->GetClass())) { 1755 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 1756 } else { 1757 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 1758 } 1759 1760 // Attmept to find the class inside of the recently freed objects. 1761 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 1762 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 1763 space::MallocSpace* space = ref_space->AsMallocSpace(); 1764 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 1765 if (ref_class != nullptr) { 1766 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 1767 << PrettyClass(ref_class); 1768 } else { 1769 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 1770 } 1771 } 1772 1773 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 1774 ref->GetClass()->IsClass()) { 1775 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 1776 } else { 1777 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 1778 << ") is not a valid heap address"; 1779 } 1780 1781 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 1782 void* cover_begin = card_table->AddrFromCard(card_addr); 1783 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 1784 accounting::CardTable::kCardSize); 1785 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 1786 << "-" << cover_end; 1787 accounting::SpaceBitmap* bitmap = heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 1788 1789 if (bitmap == nullptr) { 1790 LOG(ERROR) << "Object " << obj << " has no bitmap"; 1791 if (!heap_->VerifyClassClass(obj->GetClass())) { 1792 LOG(ERROR) << "Object " << obj << " failed class verification!"; 1793 } 1794 } else { 1795 // Print out how the object is live. 1796 if (bitmap->Test(obj)) { 1797 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 1798 } 1799 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 1800 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 1801 } 1802 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 1803 LOG(ERROR) << "Object " << obj << " found in live stack"; 1804 } 1805 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 1806 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 1807 } 1808 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 1809 LOG(ERROR) << "Ref " << ref << " found in live stack"; 1810 } 1811 // Attempt to see if the card table missed the reference. 1812 ScanVisitor scan_visitor; 1813 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 1814 card_table->Scan(bitmap, byte_cover_begin, 1815 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 1816 } 1817 1818 // Search to see if any of the roots reference our object. 1819 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 1820 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg, false, false); 1821 1822 // Search to see if any of the roots reference our reference. 1823 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 1824 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg, false, false); 1825 } else { 1826 LOG(ERROR) << "Root " << ref << " is dead with type " << PrettyTypeOf(ref); 1827 } 1828 } 1829 1830 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 1831 return heap_->IsLiveObjectLocked(obj, true, false, true); 1832 } 1833 1834 static mirror::Object* VerifyRoots(mirror::Object* root, void* arg, uint32_t /*thread_id*/, 1835 RootType /*root_type*/) { 1836 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 1837 (*visitor)(nullptr, root, MemberOffset(0), true); 1838 return root; 1839 } 1840 1841 private: 1842 Heap* const heap_; 1843 mutable bool failed_; 1844}; 1845 1846// Verify all references within an object, for use with HeapBitmap::Visit. 1847class VerifyObjectVisitor { 1848 public: 1849 explicit VerifyObjectVisitor(Heap* heap) : heap_(heap), failed_(false) {} 1850 1851 void operator()(mirror::Object* obj) const 1852 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1853 // Note: we are verifying the references in obj but not obj itself, this is because obj must 1854 // be live or else how did we find it in the live bitmap? 1855 VerifyReferenceVisitor visitor(heap_); 1856 // The class doesn't count as a reference but we should verify it anyways. 1857 collector::MarkSweep::VisitObjectReferences(obj, visitor, true); 1858 if (obj->GetClass()->IsReferenceClass()) { 1859 visitor(obj, heap_->GetReferenceReferent(obj), MemberOffset(0), false); 1860 } 1861 failed_ = failed_ || visitor.Failed(); 1862 } 1863 1864 static void VisitCallback(mirror::Object* obj, void* arg) 1865 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1866 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 1867 visitor->operator()(obj); 1868 } 1869 1870 bool Failed() const { 1871 return failed_; 1872 } 1873 1874 private: 1875 Heap* const heap_; 1876 mutable bool failed_; 1877}; 1878 1879// Must do this with mutators suspended since we are directly accessing the allocation stacks. 1880bool Heap::VerifyHeapReferences() { 1881 Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current()); 1882 // Lets sort our allocation stacks so that we can efficiently binary search them. 1883 allocation_stack_->Sort(); 1884 live_stack_->Sort(); 1885 VerifyObjectVisitor visitor(this); 1886 // Verify objects in the allocation stack since these will be objects which were: 1887 // 1. Allocated prior to the GC (pre GC verification). 1888 // 2. Allocated during the GC (pre sweep GC verification). 1889 // We don't want to verify the objects in the live stack since they themselves may be 1890 // pointing to dead objects if they are not reachable. 1891 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 1892 // Verify the roots: 1893 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRoots, &visitor, false, false); 1894 if (visitor.Failed()) { 1895 // Dump mod-union tables. 1896 for (const auto& table_pair : mod_union_tables_) { 1897 accounting::ModUnionTable* mod_union_table = table_pair.second; 1898 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 1899 } 1900 DumpSpaces(); 1901 return false; 1902 } 1903 return true; 1904} 1905 1906class VerifyReferenceCardVisitor { 1907 public: 1908 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 1909 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 1910 Locks::heap_bitmap_lock_) 1911 : heap_(heap), failed_(failed) { 1912 } 1913 1914 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1915 // annotalysis on visitors. 1916 void operator()(mirror::Object* obj, mirror::Object* ref, const MemberOffset& offset, 1917 bool is_static) const NO_THREAD_SAFETY_ANALYSIS { 1918 // Filter out class references since changing an object's class does not mark the card as dirty. 1919 // Also handles large objects, since the only reference they hold is a class reference. 1920 if (ref != NULL && !ref->IsClass()) { 1921 accounting::CardTable* card_table = heap_->GetCardTable(); 1922 // If the object is not dirty and it is referencing something in the live stack other than 1923 // class, then it must be on a dirty card. 1924 if (!card_table->AddrIsInCardTable(obj)) { 1925 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 1926 *failed_ = true; 1927 } else if (!card_table->IsDirty(obj)) { 1928 // TODO: Check mod-union tables. 1929 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 1930 // kCardDirty - 1 if it didnt get touched since we aged it. 1931 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 1932 if (live_stack->ContainsSorted(const_cast<mirror::Object*>(ref))) { 1933 if (live_stack->ContainsSorted(const_cast<mirror::Object*>(obj))) { 1934 LOG(ERROR) << "Object " << obj << " found in live stack"; 1935 } 1936 if (heap_->GetLiveBitmap()->Test(obj)) { 1937 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 1938 } 1939 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 1940 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 1941 1942 // Print which field of the object is dead. 1943 if (!obj->IsObjectArray()) { 1944 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 1945 CHECK(klass != NULL); 1946 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 1947 : klass->GetIFields(); 1948 CHECK(fields != NULL); 1949 for (int32_t i = 0; i < fields->GetLength(); ++i) { 1950 mirror::ArtField* cur = fields->Get(i); 1951 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 1952 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 1953 << PrettyField(cur); 1954 break; 1955 } 1956 } 1957 } else { 1958 mirror::ObjectArray<mirror::Object>* object_array = 1959 obj->AsObjectArray<mirror::Object>(); 1960 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 1961 if (object_array->Get(i) == ref) { 1962 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 1963 } 1964 } 1965 } 1966 1967 *failed_ = true; 1968 } 1969 } 1970 } 1971 } 1972 1973 private: 1974 Heap* const heap_; 1975 bool* const failed_; 1976}; 1977 1978class VerifyLiveStackReferences { 1979 public: 1980 explicit VerifyLiveStackReferences(Heap* heap) 1981 : heap_(heap), 1982 failed_(false) {} 1983 1984 void operator()(mirror::Object* obj) const 1985 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1986 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 1987 collector::MarkSweep::VisitObjectReferences(const_cast<mirror::Object*>(obj), visitor, true); 1988 } 1989 1990 bool Failed() const { 1991 return failed_; 1992 } 1993 1994 private: 1995 Heap* const heap_; 1996 bool failed_; 1997}; 1998 1999bool Heap::VerifyMissingCardMarks() { 2000 Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current()); 2001 2002 // We need to sort the live stack since we binary search it. 2003 live_stack_->Sort(); 2004 VerifyLiveStackReferences visitor(this); 2005 GetLiveBitmap()->Visit(visitor); 2006 2007 // We can verify objects in the live stack since none of these should reference dead objects. 2008 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2009 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2010 visitor(*it); 2011 } 2012 } 2013 2014 if (visitor.Failed()) { 2015 DumpSpaces(); 2016 return false; 2017 } 2018 return true; 2019} 2020 2021void Heap::SwapStacks(Thread* self) { 2022 if (kUseThreadLocalAllocationStack) { 2023 live_stack_->AssertAllZero(); 2024 } 2025 allocation_stack_.swap(live_stack_); 2026} 2027 2028void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2029 if (!Runtime::Current()->IsStarted()) { 2030 // There's no thread list if the runtime hasn't started (eg 2031 // dex2oat or a test). Just revoke for self. 2032 self->RevokeThreadLocalAllocationStack(); 2033 return; 2034 } 2035 // This must be called only during the pause. 2036 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2037 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2038 MutexLock mu2(self, *Locks::thread_list_lock_); 2039 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2040 for (Thread* t : thread_list) { 2041 t->RevokeThreadLocalAllocationStack(); 2042 } 2043} 2044 2045accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2046 auto it = mod_union_tables_.find(space); 2047 if (it == mod_union_tables_.end()) { 2048 return nullptr; 2049 } 2050 return it->second; 2051} 2052 2053void Heap::ProcessCards(TimingLogger& timings) { 2054 // Clear cards and keep track of cards cleared in the mod-union table. 2055 for (const auto& space : continuous_spaces_) { 2056 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2057 if (table != nullptr) { 2058 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2059 "ImageModUnionClearCards"; 2060 TimingLogger::ScopedSplit split(name, &timings); 2061 table->ClearCards(); 2062 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2063 TimingLogger::ScopedSplit split("AllocSpaceClearCards", &timings); 2064 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2065 // were dirty before the GC started. 2066 // TODO: Don't need to use atomic. 2067 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2068 // roots and then we scan / update mod union tables after. We will always scan either card. 2069 // If we end up with the non aged card, we scan it it in the pause. 2070 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), VoidFunctor()); 2071 } 2072 } 2073} 2074 2075static mirror::Object* IdentityRootCallback(mirror::Object* obj, void*, uint32_t, RootType) { 2076 return obj; 2077} 2078 2079void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2080 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 2081 Thread* self = Thread::Current(); 2082 2083 if (verify_pre_gc_heap_) { 2084 thread_list->SuspendAll(); 2085 { 2086 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2087 if (!VerifyHeapReferences()) { 2088 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed"; 2089 } 2090 } 2091 thread_list->ResumeAll(); 2092 } 2093 2094 // Check that all objects which reference things in the live stack are on dirty cards. 2095 if (verify_missing_card_marks_) { 2096 thread_list->SuspendAll(); 2097 { 2098 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2099 SwapStacks(self); 2100 // Sort the live stack so that we can quickly binary search it later. 2101 if (!VerifyMissingCardMarks()) { 2102 LOG(FATAL) << "Pre " << gc->GetName() << " missing card mark verification failed"; 2103 } 2104 SwapStacks(self); 2105 } 2106 thread_list->ResumeAll(); 2107 } 2108 2109 if (verify_mod_union_table_) { 2110 thread_list->SuspendAll(); 2111 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2112 for (const auto& table_pair : mod_union_tables_) { 2113 accounting::ModUnionTable* mod_union_table = table_pair.second; 2114 mod_union_table->UpdateAndMarkReferences(IdentityRootCallback, nullptr); 2115 mod_union_table->Verify(); 2116 } 2117 thread_list->ResumeAll(); 2118 } 2119} 2120 2121void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2122 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2123 // reachable objects. 2124 if (verify_post_gc_heap_) { 2125 Thread* self = Thread::Current(); 2126 CHECK_NE(self->GetState(), kRunnable); 2127 { 2128 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2129 // Swapping bound bitmaps does nothing. 2130 gc->SwapBitmaps(); 2131 if (!VerifyHeapReferences()) { 2132 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed"; 2133 } 2134 gc->SwapBitmaps(); 2135 } 2136 } 2137} 2138 2139void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2140 if (verify_system_weaks_) { 2141 Thread* self = Thread::Current(); 2142 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2143 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2144 mark_sweep->VerifySystemWeaks(); 2145 } 2146} 2147 2148void Heap::PreGcRosAllocVerification(TimingLogger* timings) { 2149 if (verify_pre_gc_rosalloc_) { 2150 TimingLogger::ScopedSplit split("PreGcRosAllocVerification", timings); 2151 for (const auto& space : continuous_spaces_) { 2152 if (space->IsRosAllocSpace()) { 2153 VLOG(heap) << "PreGcRosAllocVerification : " << space->GetName(); 2154 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2155 rosalloc_space->Verify(); 2156 } 2157 } 2158 } 2159} 2160 2161void Heap::PostGcRosAllocVerification(TimingLogger* timings) { 2162 if (verify_post_gc_rosalloc_) { 2163 TimingLogger::ScopedSplit split("PostGcRosAllocVerification", timings); 2164 for (const auto& space : continuous_spaces_) { 2165 if (space->IsRosAllocSpace()) { 2166 VLOG(heap) << "PostGcRosAllocVerification : " << space->GetName(); 2167 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2168 rosalloc_space->Verify(); 2169 } 2170 } 2171 } 2172} 2173 2174collector::GcType Heap::WaitForGcToComplete(Thread* self) { 2175 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2176 MutexLock mu(self, *gc_complete_lock_); 2177 return WaitForGcToCompleteLocked(self); 2178} 2179 2180collector::GcType Heap::WaitForGcToCompleteLocked(Thread* self) { 2181 collector::GcType last_gc_type = collector::kGcTypeNone; 2182 uint64_t wait_start = NanoTime(); 2183 while (collector_type_running_ != kCollectorTypeNone) { 2184 ATRACE_BEGIN("GC: Wait For Completion"); 2185 // We must wait, change thread state then sleep on gc_complete_cond_; 2186 gc_complete_cond_->Wait(self); 2187 last_gc_type = last_gc_type_; 2188 ATRACE_END(); 2189 } 2190 uint64_t wait_time = NanoTime() - wait_start; 2191 total_wait_time_ += wait_time; 2192 if (wait_time > long_pause_log_threshold_) { 2193 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time); 2194 } 2195 return last_gc_type; 2196} 2197 2198void Heap::DumpForSigQuit(std::ostream& os) { 2199 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2200 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2201 DumpGcPerformanceInfo(os); 2202} 2203 2204size_t Heap::GetPercentFree() { 2205 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / GetTotalMemory()); 2206} 2207 2208void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2209 if (max_allowed_footprint > GetMaxMemory()) { 2210 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2211 << PrettySize(GetMaxMemory()); 2212 max_allowed_footprint = GetMaxMemory(); 2213 } 2214 max_allowed_footprint_ = max_allowed_footprint; 2215} 2216 2217bool Heap::IsMovableObject(const mirror::Object* obj) const { 2218 if (kMovingCollector) { 2219 DCHECK(!IsInTempSpace(obj)); 2220 if (bump_pointer_space_->HasAddress(obj)) { 2221 return true; 2222 } 2223 // TODO: Refactor this logic into the space itself? 2224 // Objects in the main space are only copied during background -> foreground transitions or 2225 // visa versa. 2226 if (main_space_ != nullptr && main_space_->HasAddress(obj) && 2227 (IsCompactingGC(background_collector_type_) || 2228 IsCompactingGC(post_zygote_collector_type_))) { 2229 return true; 2230 } 2231 } 2232 return false; 2233} 2234 2235bool Heap::IsInTempSpace(const mirror::Object* obj) const { 2236 if (temp_space_->HasAddress(obj) && !temp_space_->Contains(obj)) { 2237 return true; 2238 } 2239 return false; 2240} 2241 2242void Heap::UpdateMaxNativeFootprint() { 2243 size_t native_size = native_bytes_allocated_; 2244 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2245 size_t target_size = native_size / GetTargetHeapUtilization(); 2246 if (target_size > native_size + max_free_) { 2247 target_size = native_size + max_free_; 2248 } else if (target_size < native_size + min_free_) { 2249 target_size = native_size + min_free_; 2250 } 2251 native_footprint_gc_watermark_ = target_size; 2252 native_footprint_limit_ = 2 * target_size - native_size; 2253} 2254 2255void Heap::GrowForUtilization(collector::GcType gc_type, uint64_t gc_duration) { 2256 // We know what our utilization is at this moment. 2257 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2258 const size_t bytes_allocated = GetBytesAllocated(); 2259 last_gc_size_ = bytes_allocated; 2260 last_gc_time_ns_ = NanoTime(); 2261 size_t target_size; 2262 if (gc_type != collector::kGcTypeSticky) { 2263 // Grow the heap for non sticky GC. 2264 target_size = bytes_allocated / GetTargetHeapUtilization(); 2265 if (target_size > bytes_allocated + max_free_) { 2266 target_size = bytes_allocated + max_free_; 2267 } else if (target_size < bytes_allocated + min_free_) { 2268 target_size = bytes_allocated + min_free_; 2269 } 2270 native_need_to_run_finalization_ = true; 2271 next_gc_type_ = collector::kGcTypeSticky; 2272 } else { 2273 // Based on how close the current heap size is to the target size, decide 2274 // whether or not to do a partial or sticky GC next. 2275 if (bytes_allocated + min_free_ <= max_allowed_footprint_) { 2276 next_gc_type_ = collector::kGcTypeSticky; 2277 } else { 2278 next_gc_type_ = have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2279 } 2280 // If we have freed enough memory, shrink the heap back down. 2281 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2282 target_size = bytes_allocated + max_free_; 2283 } else { 2284 target_size = std::max(bytes_allocated, max_allowed_footprint_); 2285 } 2286 } 2287 if (!ignore_max_footprint_) { 2288 SetIdealFootprint(target_size); 2289 if (concurrent_gc_) { 2290 // Calculate when to perform the next ConcurrentGC. 2291 // Calculate the estimated GC duration. 2292 const double gc_duration_seconds = NsToMs(gc_duration) / 1000.0; 2293 // Estimate how many remaining bytes we will have when we need to start the next GC. 2294 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2295 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2296 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2297 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2298 // A never going to happen situation that from the estimated allocation rate we will exceed 2299 // the applications entire footprint with the given estimated allocation rate. Schedule 2300 // another GC nearly straight away. 2301 remaining_bytes = kMinConcurrentRemainingBytes; 2302 } 2303 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2304 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2305 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2306 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2307 // right away. 2308 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, bytes_allocated); 2309 } 2310 } 2311} 2312 2313void Heap::ClearGrowthLimit() { 2314 growth_limit_ = capacity_; 2315 non_moving_space_->ClearGrowthLimit(); 2316} 2317 2318void Heap::SetReferenceOffsets(MemberOffset reference_referent_offset, 2319 MemberOffset reference_queue_offset, 2320 MemberOffset reference_queueNext_offset, 2321 MemberOffset reference_pendingNext_offset, 2322 MemberOffset finalizer_reference_zombie_offset) { 2323 reference_referent_offset_ = reference_referent_offset; 2324 reference_queue_offset_ = reference_queue_offset; 2325 reference_queueNext_offset_ = reference_queueNext_offset; 2326 reference_pendingNext_offset_ = reference_pendingNext_offset; 2327 finalizer_reference_zombie_offset_ = finalizer_reference_zombie_offset; 2328 CHECK_NE(reference_referent_offset_.Uint32Value(), 0U); 2329 CHECK_NE(reference_queue_offset_.Uint32Value(), 0U); 2330 CHECK_NE(reference_queueNext_offset_.Uint32Value(), 0U); 2331 CHECK_NE(reference_pendingNext_offset_.Uint32Value(), 0U); 2332 CHECK_NE(finalizer_reference_zombie_offset_.Uint32Value(), 0U); 2333} 2334 2335void Heap::SetReferenceReferent(mirror::Object* reference, mirror::Object* referent) { 2336 DCHECK(reference != NULL); 2337 DCHECK_NE(reference_referent_offset_.Uint32Value(), 0U); 2338 reference->SetFieldObject(reference_referent_offset_, referent, true); 2339} 2340 2341mirror::Object* Heap::GetReferenceReferent(mirror::Object* reference) { 2342 DCHECK(reference != NULL); 2343 DCHECK_NE(reference_referent_offset_.Uint32Value(), 0U); 2344 return reference->GetFieldObject<mirror::Object>(reference_referent_offset_, true); 2345} 2346 2347void Heap::AddFinalizerReference(Thread* self, mirror::Object* object) { 2348 ScopedObjectAccess soa(self); 2349 JValue result; 2350 ArgArray arg_array("VL", 2); 2351 arg_array.Append(object); 2352 soa.DecodeMethod(WellKnownClasses::java_lang_ref_FinalizerReference_add)->Invoke(self, 2353 arg_array.GetArray(), arg_array.GetNumBytes(), &result, "VL"); 2354} 2355 2356void Heap::EnqueueClearedReferences() { 2357 Thread* self = Thread::Current(); 2358 Locks::mutator_lock_->AssertNotHeld(self); 2359 if (!cleared_references_.IsEmpty()) { 2360 // When a runtime isn't started there are no reference queues to care about so ignore. 2361 if (LIKELY(Runtime::Current()->IsStarted())) { 2362 ScopedObjectAccess soa(self); 2363 JValue result; 2364 ArgArray arg_array("VL", 2); 2365 arg_array.Append(cleared_references_.GetList()); 2366 soa.DecodeMethod(WellKnownClasses::java_lang_ref_ReferenceQueue_add)->Invoke(soa.Self(), 2367 arg_array.GetArray(), arg_array.GetNumBytes(), &result, "VL"); 2368 } 2369 cleared_references_.Clear(); 2370 } 2371} 2372 2373void Heap::RequestConcurrentGC(Thread* self) { 2374 // Make sure that we can do a concurrent GC. 2375 Runtime* runtime = Runtime::Current(); 2376 if (runtime == NULL || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2377 self->IsHandlingStackOverflow()) { 2378 return; 2379 } 2380 // We already have a request pending, no reason to start more until we update 2381 // concurrent_start_bytes_. 2382 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2383 JNIEnv* env = self->GetJniEnv(); 2384 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2385 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2386 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2387 WellKnownClasses::java_lang_Daemons_requestGC); 2388 CHECK(!env->ExceptionCheck()); 2389} 2390 2391void Heap::ConcurrentGC(Thread* self) { 2392 if (Runtime::Current()->IsShuttingDown(self)) { 2393 return; 2394 } 2395 // Wait for any GCs currently running to finish. 2396 if (WaitForGcToComplete(self) == collector::kGcTypeNone) { 2397 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2398 // instead. E.g. can't do partial, so do full instead. 2399 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2400 collector::kGcTypeNone) { 2401 for (collector::GcType gc_type : gc_plan_) { 2402 // Attempt to run the collector, if we succeed, we are done. 2403 if (gc_type > next_gc_type_ && 2404 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2405 break; 2406 } 2407 } 2408 } 2409 } 2410} 2411 2412void Heap::RequestHeapTrim() { 2413 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2414 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2415 // a space it will hold its lock and can become a cause of jank. 2416 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2417 // forking. 2418 2419 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2420 // because that only marks object heads, so a large array looks like lots of empty space. We 2421 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2422 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2423 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2424 // not how much use we're making of those pages. 2425 uint64_t ms_time = MilliTime(); 2426 // Don't bother trimming the alloc space if a heap trim occurred in the last two seconds. 2427 if (ms_time - last_trim_time_ms_ < 2 * 1000) { 2428 return; 2429 } 2430 2431 Thread* self = Thread::Current(); 2432 Runtime* runtime = Runtime::Current(); 2433 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2434 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2435 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2436 // as we don't hold the lock while requesting the trim). 2437 return; 2438 } 2439 2440 last_trim_time_ms_ = ms_time; 2441 2442 // Trim only if we do not currently care about pause times. 2443 if (!CareAboutPauseTimes()) { 2444 JNIEnv* env = self->GetJniEnv(); 2445 DCHECK(WellKnownClasses::java_lang_Daemons != NULL); 2446 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != NULL); 2447 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2448 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2449 CHECK(!env->ExceptionCheck()); 2450 } 2451} 2452 2453void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2454 if (rosalloc_space_ != nullptr) { 2455 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2456 } 2457 if (bump_pointer_space_ != nullptr) { 2458 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2459 } 2460} 2461 2462void Heap::RevokeAllThreadLocalBuffers() { 2463 if (rosalloc_space_ != nullptr) { 2464 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2465 } 2466 if (bump_pointer_space_ != nullptr) { 2467 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 2468 } 2469} 2470 2471bool Heap::IsGCRequestPending() const { 2472 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 2473} 2474 2475void Heap::RunFinalization(JNIEnv* env) { 2476 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 2477 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 2478 CHECK(WellKnownClasses::java_lang_System != nullptr); 2479 WellKnownClasses::java_lang_System_runFinalization = 2480 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 2481 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 2482 } 2483 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 2484 WellKnownClasses::java_lang_System_runFinalization); 2485} 2486 2487void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 2488 Thread* self = ThreadForEnv(env); 2489 if (native_need_to_run_finalization_) { 2490 RunFinalization(env); 2491 UpdateMaxNativeFootprint(); 2492 native_need_to_run_finalization_ = false; 2493 } 2494 // Total number of native bytes allocated. 2495 native_bytes_allocated_.FetchAndAdd(bytes); 2496 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_gc_watermark_) { 2497 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 2498 collector::kGcTypeFull; 2499 2500 // The second watermark is higher than the gc watermark. If you hit this it means you are 2501 // allocating native objects faster than the GC can keep up with. 2502 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2503 if (WaitForGcToComplete(self) != collector::kGcTypeNone) { 2504 // Just finished a GC, attempt to run finalizers. 2505 RunFinalization(env); 2506 CHECK(!env->ExceptionCheck()); 2507 } 2508 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 2509 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2510 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 2511 RunFinalization(env); 2512 native_need_to_run_finalization_ = false; 2513 CHECK(!env->ExceptionCheck()); 2514 } 2515 // We have just run finalizers, update the native watermark since it is very likely that 2516 // finalizers released native managed allocations. 2517 UpdateMaxNativeFootprint(); 2518 } else if (!IsGCRequestPending()) { 2519 if (concurrent_gc_) { 2520 RequestConcurrentGC(self); 2521 } else { 2522 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false); 2523 } 2524 } 2525 } 2526} 2527 2528void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 2529 int expected_size, new_size; 2530 do { 2531 expected_size = native_bytes_allocated_.Load(); 2532 new_size = expected_size - bytes; 2533 if (UNLIKELY(new_size < 0)) { 2534 ScopedObjectAccess soa(env); 2535 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 2536 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 2537 "registered as allocated", bytes, expected_size).c_str()); 2538 break; 2539 } 2540 } while (!native_bytes_allocated_.CompareAndSwap(expected_size, new_size)); 2541} 2542 2543size_t Heap::GetTotalMemory() const { 2544 size_t ret = 0; 2545 for (const auto& space : continuous_spaces_) { 2546 // Currently don't include the image space. 2547 if (!space->IsImageSpace()) { 2548 ret += space->Size(); 2549 } 2550 } 2551 for (const auto& space : discontinuous_spaces_) { 2552 if (space->IsLargeObjectSpace()) { 2553 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 2554 } 2555 } 2556 return ret; 2557} 2558 2559void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 2560 DCHECK(mod_union_table != nullptr); 2561 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 2562} 2563 2564} // namespace gc 2565} // namespace art 2566