heap.cc revision bbd695c71e0bf518f582e84524e1cdeb3de3896c
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 25#include "base/histogram-inl.h" 26#include "base/stl_util.h" 27#include "common_throws.h" 28#include "cutils/sched_policy.h" 29#include "debugger.h" 30#include "gc/accounting/atomic_stack.h" 31#include "gc/accounting/card_table-inl.h" 32#include "gc/accounting/heap_bitmap-inl.h" 33#include "gc/accounting/mod_union_table.h" 34#include "gc/accounting/mod_union_table-inl.h" 35#include "gc/accounting/remembered_set.h" 36#include "gc/accounting/space_bitmap-inl.h" 37#include "gc/collector/concurrent_copying.h" 38#include "gc/collector/mark_sweep-inl.h" 39#include "gc/collector/partial_mark_sweep.h" 40#include "gc/collector/semi_space.h" 41#include "gc/collector/sticky_mark_sweep.h" 42#include "gc/space/bump_pointer_space.h" 43#include "gc/space/dlmalloc_space-inl.h" 44#include "gc/space/image_space.h" 45#include "gc/space/large_object_space.h" 46#include "gc/space/rosalloc_space-inl.h" 47#include "gc/space/space-inl.h" 48#include "gc/space/zygote_space.h" 49#include "entrypoints/quick/quick_alloc_entrypoints.h" 50#include "heap-inl.h" 51#include "image.h" 52#include "mirror/art_field-inl.h" 53#include "mirror/class-inl.h" 54#include "mirror/object.h" 55#include "mirror/object-inl.h" 56#include "mirror/object_array-inl.h" 57#include "mirror/reference-inl.h" 58#include "object_utils.h" 59#include "os.h" 60#include "reflection.h" 61#include "runtime.h" 62#include "ScopedLocalRef.h" 63#include "scoped_thread_state_change.h" 64#include "sirt_ref.h" 65#include "thread_list.h" 66#include "UniquePtr.h" 67#include "well_known_classes.h" 68 69namespace art { 70 71namespace gc { 72 73static constexpr size_t kCollectorTransitionStressIterations = 0; 74static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 75static constexpr bool kGCALotMode = false; 76static constexpr size_t kGcAlotInterval = KB; 77// Minimum amount of remaining bytes before a concurrent GC is triggered. 78static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 79static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 80// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 81// relative to partial/full GC. This is desirable since sticky GCs interfere less with mutator 82// threads (lower pauses, use less memory bandwidth). 83static constexpr double kStickyGcThroughputAdjustment = 1.25; 84// Whether or not we use the free list large object space. 85static constexpr bool kUseFreeListSpaceForLOS = false; 86// Whtehr or not we compact the zygote in PreZygoteFork. 87static constexpr bool kCompactZygote = kMovingCollector; 88static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 89 90Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 91 double target_utilization, double foreground_heap_growth_multiplier, size_t capacity, 92 const std::string& image_file_name, 93 CollectorType foreground_collector_type, CollectorType background_collector_type, 94 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 95 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 96 bool ignore_max_footprint, bool use_tlab, bool verify_pre_gc_heap, 97 bool verify_post_gc_heap, bool verify_pre_gc_rosalloc, 98 bool verify_post_gc_rosalloc) 99 : non_moving_space_(nullptr), 100 rosalloc_space_(nullptr), 101 dlmalloc_space_(nullptr), 102 main_space_(nullptr), 103 collector_type_(kCollectorTypeNone), 104 foreground_collector_type_(foreground_collector_type), 105 background_collector_type_(background_collector_type), 106 desired_collector_type_(foreground_collector_type_), 107 heap_trim_request_lock_(nullptr), 108 last_trim_time_(0), 109 heap_transition_target_time_(0), 110 heap_trim_request_pending_(false), 111 parallel_gc_threads_(parallel_gc_threads), 112 conc_gc_threads_(conc_gc_threads), 113 low_memory_mode_(low_memory_mode), 114 long_pause_log_threshold_(long_pause_log_threshold), 115 long_gc_log_threshold_(long_gc_log_threshold), 116 ignore_max_footprint_(ignore_max_footprint), 117 have_zygote_space_(false), 118 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 119 collector_type_running_(kCollectorTypeNone), 120 last_gc_type_(collector::kGcTypeNone), 121 next_gc_type_(collector::kGcTypePartial), 122 capacity_(capacity), 123 growth_limit_(growth_limit), 124 max_allowed_footprint_(initial_size), 125 native_footprint_gc_watermark_(initial_size), 126 native_footprint_limit_(2 * initial_size), 127 native_need_to_run_finalization_(false), 128 // Initially assume we perceive jank in case the process state is never updated. 129 process_state_(kProcessStateJankPerceptible), 130 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 131 total_bytes_freed_ever_(0), 132 total_objects_freed_ever_(0), 133 num_bytes_allocated_(0), 134 native_bytes_allocated_(0), 135 gc_memory_overhead_(0), 136 verify_missing_card_marks_(false), 137 verify_system_weaks_(false), 138 verify_pre_gc_heap_(verify_pre_gc_heap), 139 verify_post_gc_heap_(verify_post_gc_heap), 140 verify_mod_union_table_(false), 141 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 142 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 143 allocation_rate_(0), 144 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 145 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 146 * verification is enabled, we limit the size of allocation stacks to speed up their 147 * searching. 148 */ 149 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 150 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 151 current_allocator_(kAllocatorTypeDlMalloc), 152 current_non_moving_allocator_(kAllocatorTypeNonMoving), 153 bump_pointer_space_(nullptr), 154 temp_space_(nullptr), 155 min_free_(min_free), 156 max_free_(max_free), 157 target_utilization_(target_utilization), 158 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 159 total_wait_time_(0), 160 total_allocation_time_(0), 161 verify_object_mode_(kVerifyObjectModeDisabled), 162 disable_moving_gc_count_(0), 163 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 164 use_tlab_(use_tlab) { 165 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 166 LOG(INFO) << "Heap() entering"; 167 } 168 const bool is_zygote = Runtime::Current()->IsZygote(); 169 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 170 // entrypoints. 171 if (!is_zygote) { 172 large_object_threshold_ = kDefaultLargeObjectThreshold; 173 // Background compaction is currently not supported for command line runs. 174 if (background_collector_type_ != foreground_collector_type_) { 175 LOG(WARNING) << "Disabling background compaction for non zygote"; 176 background_collector_type_ = foreground_collector_type_; 177 } 178 } 179 ChangeCollector(desired_collector_type_); 180 181 live_bitmap_.reset(new accounting::HeapBitmap(this)); 182 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 183 // Requested begin for the alloc space, to follow the mapped image and oat files 184 byte* requested_alloc_space_begin = nullptr; 185 if (!image_file_name.empty()) { 186 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str()); 187 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 188 AddSpace(image_space); 189 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 190 // isn't going to get in the middle 191 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 192 CHECK_GT(oat_file_end_addr, image_space->End()); 193 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 194 } 195 if (is_zygote) { 196 // Reserve the address range before we create the non moving space to make sure bitmaps don't 197 // take it. 198 std::string error_str; 199 MemMap* mem_map = MemMap::MapAnonymous( 200 "main space", requested_alloc_space_begin + kNonMovingSpaceCapacity, capacity, 201 PROT_READ | PROT_WRITE, true, &error_str); 202 CHECK(mem_map != nullptr) << error_str; 203 // Non moving space is always dlmalloc since we currently don't have support for multiple 204 // rosalloc spaces. 205 non_moving_space_ = space::DlMallocSpace::Create( 206 "zygote / non moving space", initial_size, kNonMovingSpaceCapacity, kNonMovingSpaceCapacity, 207 requested_alloc_space_begin, false); 208 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 209 CreateMainMallocSpace(mem_map, initial_size, growth_limit, capacity); 210 } else { 211 std::string error_str; 212 MemMap* mem_map = MemMap::MapAnonymous("main/non-moving space", requested_alloc_space_begin, 213 capacity, PROT_READ | PROT_WRITE, true, &error_str); 214 CHECK(mem_map != nullptr) << error_str; 215 // Create the main free list space, which doubles as the non moving space. We can do this since 216 // non zygote means that we won't have any background compaction. 217 CreateMainMallocSpace(mem_map, initial_size, growth_limit, capacity); 218 non_moving_space_ = main_space_; 219 } 220 CHECK(non_moving_space_ != nullptr); 221 222 // We need to create the bump pointer if the foreground collector is a compacting GC. We only 223 // create the bump pointer space if we are not a moving foreground collector but have a moving 224 // background collector since the heap transition code will create the temp space by recycling 225 // the bitmap from the main space. 226 if (kMovingCollector) { 227 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 228 // TODO: Not create all the bump pointer spaces if not necessary (currently only GSS needs all 229 // 2 of bump pointer spaces + main space) b/14059466. Divide by 2 for a temporary fix. 230 const size_t bump_pointer_space_capacity = capacity / 2; 231 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space", 232 bump_pointer_space_capacity, nullptr); 233 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 234 AddSpace(bump_pointer_space_); 235 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 236 bump_pointer_space_capacity, nullptr); 237 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 238 AddSpace(temp_space_); 239 } 240 if (non_moving_space_ != main_space_) { 241 AddSpace(non_moving_space_); 242 } 243 if (main_space_ != nullptr) { 244 AddSpace(main_space_); 245 } 246 247 // Allocate the large object space. 248 if (kUseFreeListSpaceForLOS) { 249 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity); 250 } else { 251 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 252 } 253 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 254 AddSpace(large_object_space_); 255 256 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 257 CHECK(!continuous_spaces_.empty()); 258 259 // Relies on the spaces being sorted. 260 byte* heap_begin = continuous_spaces_.front()->Begin(); 261 byte* heap_end = continuous_spaces_.back()->Limit(); 262 size_t heap_capacity = heap_end - heap_begin; 263 264 // Allocate the card table. 265 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 266 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 267 268 // Card cache for now since it makes it easier for us to update the references to the copying 269 // spaces. 270 accounting::ModUnionTable* mod_union_table = 271 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 272 GetImageSpace()); 273 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 274 AddModUnionTable(mod_union_table); 275 276 if (collector::SemiSpace::kUseRememberedSet) { 277 accounting::RememberedSet* non_moving_space_rem_set = 278 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 279 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 280 AddRememberedSet(non_moving_space_rem_set); 281 if (main_space_ != nullptr && main_space_ != non_moving_space_) { 282 accounting::RememberedSet* main_space_rem_set = 283 new accounting::RememberedSet("Main space remembered set", this, main_space_); 284 CHECK(main_space_rem_set != nullptr) << "Failed to create main space remembered set"; 285 AddRememberedSet(main_space_rem_set); 286 } 287 } 288 289 // TODO: Count objects in the image space here. 290 num_bytes_allocated_ = 0; 291 292 // Default mark stack size in bytes. 293 static const size_t default_mark_stack_size = 64 * KB; 294 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", default_mark_stack_size)); 295 allocation_stack_.reset(accounting::ObjectStack::Create("allocation stack", 296 max_allocation_stack_size_)); 297 live_stack_.reset(accounting::ObjectStack::Create("live stack", 298 max_allocation_stack_size_)); 299 300 // It's still too early to take a lock because there are no threads yet, but we can create locks 301 // now. We don't create it earlier to make it clear that you can't use locks during heap 302 // initialization. 303 gc_complete_lock_ = new Mutex("GC complete lock"); 304 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 305 *gc_complete_lock_)); 306 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 307 last_gc_size_ = GetBytesAllocated(); 308 309 if (ignore_max_footprint_) { 310 SetIdealFootprint(std::numeric_limits<size_t>::max()); 311 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 312 } 313 CHECK_NE(max_allowed_footprint_, 0U); 314 315 // Create our garbage collectors. 316 for (size_t i = 0; i < 2; ++i) { 317 const bool concurrent = i != 0; 318 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 319 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 320 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 321 } 322 if (kMovingCollector) { 323 // TODO: Clean this up. 324 bool generational = foreground_collector_type_ == kCollectorTypeGSS; 325 semi_space_collector_ = new collector::SemiSpace(this, generational, 326 generational ? "generational" : ""); 327 garbage_collectors_.push_back(semi_space_collector_); 328 329 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 330 garbage_collectors_.push_back(concurrent_copying_collector_); 331 } 332 333 if (running_on_valgrind_) { 334 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 335 } 336 337 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 338 LOG(INFO) << "Heap() exiting"; 339 } 340} 341 342void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 343 size_t capacity) { 344 // Is background compaction is enabled? 345 bool can_move_objects = IsMovingGc(background_collector_type_) != 346 IsMovingGc(foreground_collector_type_); 347 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 348 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 349 // from the main space to the zygote space. If background compaction is enabled, always pass in 350 // that we can move objets. 351 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 352 // After the zygote we want this to be false if we don't have background compaction enabled so 353 // that getting primitive array elements is faster. 354 can_move_objects = !have_zygote_space_; 355 } 356 if (kUseRosAlloc) { 357 main_space_ = space::RosAllocSpace::CreateFromMemMap(mem_map, "main rosalloc space", 358 kDefaultStartingSize, initial_size, 359 growth_limit, capacity, low_memory_mode_, 360 can_move_objects); 361 CHECK(main_space_ != nullptr) << "Failed to create rosalloc space"; 362 } else { 363 main_space_ = space::DlMallocSpace::CreateFromMemMap(mem_map, "main dlmalloc space", 364 kDefaultStartingSize, initial_size, 365 growth_limit, capacity, 366 can_move_objects); 367 CHECK(main_space_ != nullptr) << "Failed to create dlmalloc space"; 368 } 369 main_space_->SetFootprintLimit(main_space_->Capacity()); 370 VLOG(heap) << "Created main space " << main_space_; 371} 372 373void Heap::ChangeAllocator(AllocatorType allocator) { 374 if (current_allocator_ != allocator) { 375 // These two allocators are only used internally and don't have any entrypoints. 376 CHECK_NE(allocator, kAllocatorTypeLOS); 377 CHECK_NE(allocator, kAllocatorTypeNonMoving); 378 current_allocator_ = allocator; 379 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 380 SetQuickAllocEntryPointsAllocator(current_allocator_); 381 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 382 } 383} 384 385void Heap::DisableCompaction() { 386 if (IsMovingGc(foreground_collector_type_)) { 387 foreground_collector_type_ = kCollectorTypeCMS; 388 } 389 if (IsMovingGc(background_collector_type_)) { 390 background_collector_type_ = foreground_collector_type_; 391 } 392 TransitionCollector(foreground_collector_type_); 393} 394 395std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 396 if (!IsValidContinuousSpaceObjectAddress(klass)) { 397 return StringPrintf("<non heap address klass %p>", klass); 398 } 399 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 400 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 401 std::string result("["); 402 result += SafeGetClassDescriptor(component_type); 403 return result; 404 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 405 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 406 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 407 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 408 } else { 409 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 410 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 411 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 412 } 413 const DexFile* dex_file = dex_cache->GetDexFile(); 414 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 415 if (class_def_idx == DexFile::kDexNoIndex16) { 416 return "<class def not found>"; 417 } 418 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 419 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 420 return dex_file->GetTypeDescriptor(type_id); 421 } 422} 423 424std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 425 if (obj == nullptr) { 426 return "null"; 427 } 428 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 429 if (klass == nullptr) { 430 return "(class=null)"; 431 } 432 std::string result(SafeGetClassDescriptor(klass)); 433 if (obj->IsClass()) { 434 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 435 } 436 return result; 437} 438 439void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 440 if (obj == nullptr) { 441 stream << "(obj=null)"; 442 return; 443 } 444 if (IsAligned<kObjectAlignment>(obj)) { 445 space::Space* space = nullptr; 446 // Don't use find space since it only finds spaces which actually contain objects instead of 447 // spaces which may contain objects (e.g. cleared bump pointer spaces). 448 for (const auto& cur_space : continuous_spaces_) { 449 if (cur_space->HasAddress(obj)) { 450 space = cur_space; 451 break; 452 } 453 } 454 // Unprotect all the spaces. 455 for (const auto& space : continuous_spaces_) { 456 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 457 } 458 stream << "Object " << obj; 459 if (space != nullptr) { 460 stream << " in space " << *space; 461 } 462 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 463 stream << "\nclass=" << klass; 464 if (klass != nullptr) { 465 stream << " type= " << SafePrettyTypeOf(obj); 466 } 467 // Re-protect the address we faulted on. 468 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 469 } 470} 471 472bool Heap::IsCompilingBoot() const { 473 for (const auto& space : continuous_spaces_) { 474 if (space->IsImageSpace() || space->IsZygoteSpace()) { 475 return false; 476 } 477 } 478 return true; 479} 480 481bool Heap::HasImageSpace() const { 482 for (const auto& space : continuous_spaces_) { 483 if (space->IsImageSpace()) { 484 return true; 485 } 486 } 487 return false; 488} 489 490void Heap::IncrementDisableMovingGC(Thread* self) { 491 // Need to do this holding the lock to prevent races where the GC is about to run / running when 492 // we attempt to disable it. 493 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 494 MutexLock mu(self, *gc_complete_lock_); 495 ++disable_moving_gc_count_; 496 if (IsMovingGc(collector_type_running_)) { 497 WaitForGcToCompleteLocked(self); 498 } 499} 500 501void Heap::DecrementDisableMovingGC(Thread* self) { 502 MutexLock mu(self, *gc_complete_lock_); 503 CHECK_GE(disable_moving_gc_count_, 0U); 504 --disable_moving_gc_count_; 505} 506 507void Heap::UpdateProcessState(ProcessState process_state) { 508 if (process_state_ != process_state) { 509 process_state_ = process_state; 510 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 511 // Start at index 1 to avoid "is always false" warning. 512 // Have iteration 1 always transition the collector. 513 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 514 ? foreground_collector_type_ : background_collector_type_); 515 usleep(kCollectorTransitionStressWait); 516 } 517 if (process_state_ == kProcessStateJankPerceptible) { 518 // Transition back to foreground right away to prevent jank. 519 RequestCollectorTransition(foreground_collector_type_, 0); 520 } else { 521 // Don't delay for debug builds since we may want to stress test the GC. 522 RequestCollectorTransition(background_collector_type_, kIsDebugBuild ? 0 : 523 kCollectorTransitionWait); 524 } 525 } 526} 527 528void Heap::CreateThreadPool() { 529 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 530 if (num_threads != 0) { 531 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 532 } 533} 534 535void Heap::VisitObjects(ObjectCallback callback, void* arg) { 536 Thread* self = Thread::Current(); 537 // GCs can move objects, so don't allow this. 538 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 539 if (bump_pointer_space_ != nullptr) { 540 // Visit objects in bump pointer space. 541 bump_pointer_space_->Walk(callback, arg); 542 } 543 // TODO: Switch to standard begin and end to use ranged a based loop. 544 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 545 it < end; ++it) { 546 mirror::Object* obj = *it; 547 if (obj != nullptr && obj->GetClass() != nullptr) { 548 // Avoid the race condition caused by the object not yet being written into the allocation 549 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 550 // there can be nulls on the allocation stack. 551 callback(obj, arg); 552 } 553 } 554 GetLiveBitmap()->Walk(callback, arg); 555 self->EndAssertNoThreadSuspension(old_cause); 556} 557 558void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 559 space::ContinuousSpace* space1 = rosalloc_space_ != nullptr ? rosalloc_space_ : non_moving_space_; 560 space::ContinuousSpace* space2 = dlmalloc_space_ != nullptr ? dlmalloc_space_ : non_moving_space_; 561 // This is just logic to handle a case of either not having a rosalloc or dlmalloc space. 562 // TODO: Generalize this to n bitmaps? 563 if (space1 == nullptr) { 564 DCHECK(space2 != nullptr); 565 space1 = space2; 566 } 567 if (space2 == nullptr) { 568 DCHECK(space1 != nullptr); 569 space2 = space1; 570 } 571 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 572 large_object_space_->GetLiveBitmap(), stack); 573} 574 575void Heap::DeleteThreadPool() { 576 thread_pool_.reset(nullptr); 577} 578 579void Heap::AddSpace(space::Space* space, bool set_as_default) { 580 DCHECK(space != nullptr); 581 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 582 if (space->IsContinuousSpace()) { 583 DCHECK(!space->IsDiscontinuousSpace()); 584 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 585 // Continuous spaces don't necessarily have bitmaps. 586 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 587 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 588 if (live_bitmap != nullptr) { 589 DCHECK(mark_bitmap != nullptr); 590 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 591 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 592 } 593 continuous_spaces_.push_back(continuous_space); 594 if (set_as_default) { 595 if (continuous_space->IsDlMallocSpace()) { 596 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 597 } else if (continuous_space->IsRosAllocSpace()) { 598 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 599 } 600 } 601 // Ensure that spaces remain sorted in increasing order of start address. 602 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 603 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 604 return a->Begin() < b->Begin(); 605 }); 606 } else { 607 DCHECK(space->IsDiscontinuousSpace()); 608 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 609 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 610 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 611 discontinuous_spaces_.push_back(discontinuous_space); 612 } 613 if (space->IsAllocSpace()) { 614 alloc_spaces_.push_back(space->AsAllocSpace()); 615 } 616} 617 618void Heap::RemoveSpace(space::Space* space) { 619 DCHECK(space != nullptr); 620 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 621 if (space->IsContinuousSpace()) { 622 DCHECK(!space->IsDiscontinuousSpace()); 623 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 624 // Continuous spaces don't necessarily have bitmaps. 625 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 626 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 627 if (live_bitmap != nullptr) { 628 DCHECK(mark_bitmap != nullptr); 629 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 630 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 631 } 632 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 633 DCHECK(it != continuous_spaces_.end()); 634 continuous_spaces_.erase(it); 635 if (continuous_space == dlmalloc_space_) { 636 dlmalloc_space_ = nullptr; 637 } else if (continuous_space == rosalloc_space_) { 638 rosalloc_space_ = nullptr; 639 } 640 if (continuous_space == main_space_) { 641 main_space_ = nullptr; 642 } else if (continuous_space == bump_pointer_space_) { 643 bump_pointer_space_ = nullptr; 644 } else if (continuous_space == temp_space_) { 645 temp_space_ = nullptr; 646 } 647 } else { 648 DCHECK(space->IsDiscontinuousSpace()); 649 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 650 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 651 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 652 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 653 discontinuous_space); 654 DCHECK(it != discontinuous_spaces_.end()); 655 discontinuous_spaces_.erase(it); 656 } 657 if (space->IsAllocSpace()) { 658 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 659 DCHECK(it != alloc_spaces_.end()); 660 alloc_spaces_.erase(it); 661 } 662} 663 664void Heap::RegisterGCAllocation(size_t bytes) { 665 if (this != nullptr) { 666 gc_memory_overhead_.FetchAndAdd(bytes); 667 } 668} 669 670void Heap::RegisterGCDeAllocation(size_t bytes) { 671 if (this != nullptr) { 672 gc_memory_overhead_.FetchAndSub(bytes); 673 } 674} 675 676void Heap::DumpGcPerformanceInfo(std::ostream& os) { 677 // Dump cumulative timings. 678 os << "Dumping cumulative Gc timings\n"; 679 uint64_t total_duration = 0; 680 // Dump cumulative loggers for each GC type. 681 uint64_t total_paused_time = 0; 682 for (auto& collector : garbage_collectors_) { 683 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 684 const size_t iterations = logger.GetIterations(); 685 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 686 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 687 os << ConstDumpable<CumulativeLogger>(logger); 688 const uint64_t total_ns = logger.GetTotalNs(); 689 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 690 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 691 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 692 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 693 Histogram<uint64_t>::CumulativeData cumulative_data; 694 pause_histogram.CreateHistogram(&cumulative_data); 695 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 696 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 697 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 698 << collector->GetName() << " freed: " << freed_objects 699 << " objects with total size " << PrettySize(freed_bytes) << "\n" 700 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 701 << PrettySize(freed_bytes / seconds) << "/s\n"; 702 total_duration += total_ns; 703 total_paused_time += total_pause_ns; 704 } 705 collector->ResetMeasurements(); 706 } 707 uint64_t allocation_time = static_cast<uint64_t>(total_allocation_time_) * kTimeAdjust; 708 if (total_duration != 0) { 709 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 710 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 711 os << "Mean GC size throughput: " 712 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 713 os << "Mean GC object throughput: " 714 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 715 } 716 size_t total_objects_allocated = GetObjectsAllocatedEver(); 717 os << "Total number of allocations: " << total_objects_allocated << "\n"; 718 size_t total_bytes_allocated = GetBytesAllocatedEver(); 719 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 720 if (kMeasureAllocationTime) { 721 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 722 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 723 << "\n"; 724 } 725 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 726 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 727 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_; 728} 729 730Heap::~Heap() { 731 VLOG(heap) << "Starting ~Heap()"; 732 STLDeleteElements(&garbage_collectors_); 733 // If we don't reset then the mark stack complains in its destructor. 734 allocation_stack_->Reset(); 735 live_stack_->Reset(); 736 STLDeleteValues(&mod_union_tables_); 737 STLDeleteValues(&remembered_sets_); 738 STLDeleteElements(&continuous_spaces_); 739 STLDeleteElements(&discontinuous_spaces_); 740 delete gc_complete_lock_; 741 delete heap_trim_request_lock_; 742 VLOG(heap) << "Finished ~Heap()"; 743} 744 745space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 746 bool fail_ok) const { 747 for (const auto& space : continuous_spaces_) { 748 if (space->Contains(obj)) { 749 return space; 750 } 751 } 752 if (!fail_ok) { 753 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 754 } 755 return NULL; 756} 757 758space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 759 bool fail_ok) const { 760 for (const auto& space : discontinuous_spaces_) { 761 if (space->Contains(obj)) { 762 return space; 763 } 764 } 765 if (!fail_ok) { 766 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 767 } 768 return NULL; 769} 770 771space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 772 space::Space* result = FindContinuousSpaceFromObject(obj, true); 773 if (result != NULL) { 774 return result; 775 } 776 return FindDiscontinuousSpaceFromObject(obj, true); 777} 778 779struct SoftReferenceArgs { 780 IsMarkedCallback* is_marked_callback_; 781 MarkObjectCallback* mark_callback_; 782 void* arg_; 783}; 784 785mirror::Object* Heap::PreserveSoftReferenceCallback(mirror::Object* obj, void* arg) { 786 SoftReferenceArgs* args = reinterpret_cast<SoftReferenceArgs*>(arg); 787 // TODO: Not preserve all soft references. 788 return args->mark_callback_(obj, args->arg_); 789} 790 791void Heap::ProcessSoftReferences(TimingLogger& timings, bool clear_soft, 792 IsMarkedCallback* is_marked_callback, 793 MarkObjectCallback* mark_object_callback, 794 ProcessMarkStackCallback* process_mark_stack_callback, void* arg) { 795 // Unless required to clear soft references with white references, preserve some white referents. 796 if (!clear_soft) { 797 // Don't clear for sticky GC. 798 SoftReferenceArgs soft_reference_args; 799 soft_reference_args.is_marked_callback_ = is_marked_callback; 800 soft_reference_args.mark_callback_ = mark_object_callback; 801 soft_reference_args.arg_ = arg; 802 // References with a marked referent are removed from the list. 803 soft_reference_queue_.PreserveSomeSoftReferences(&PreserveSoftReferenceCallback, 804 &soft_reference_args); 805 process_mark_stack_callback(arg); 806 } 807} 808 809// Process reference class instances and schedule finalizations. 810void Heap::ProcessReferences(TimingLogger& timings, bool clear_soft, 811 IsMarkedCallback* is_marked_callback, 812 MarkObjectCallback* mark_object_callback, 813 ProcessMarkStackCallback* process_mark_stack_callback, void* arg) { 814 timings.StartSplit("(Paused)ProcessReferences"); 815 ProcessSoftReferences(timings, clear_soft, is_marked_callback, mark_object_callback, 816 process_mark_stack_callback, arg); 817 // Clear all remaining soft and weak references with white referents. 818 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 819 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 820 timings.EndSplit(); 821 // Preserve all white objects with finalize methods and schedule them for finalization. 822 timings.StartSplit("(Paused)EnqueueFinalizerReferences"); 823 finalizer_reference_queue_.EnqueueFinalizerReferences(cleared_references_, is_marked_callback, 824 mark_object_callback, arg); 825 process_mark_stack_callback(arg); 826 timings.EndSplit(); 827 timings.StartSplit("(Paused)ProcessReferences"); 828 // Clear all f-reachable soft and weak references with white referents. 829 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 830 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 831 // Clear all phantom references with white referents. 832 phantom_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 833 // At this point all reference queues other than the cleared references should be empty. 834 DCHECK(soft_reference_queue_.IsEmpty()); 835 DCHECK(weak_reference_queue_.IsEmpty()); 836 DCHECK(finalizer_reference_queue_.IsEmpty()); 837 DCHECK(phantom_reference_queue_.IsEmpty()); 838 timings.EndSplit(); 839} 840 841// Process the "referent" field in a java.lang.ref.Reference. If the referent has not yet been 842// marked, put it on the appropriate list in the heap for later processing. 843void Heap::DelayReferenceReferent(mirror::Class* klass, mirror::Reference* ref, 844 IsMarkedCallback is_marked_callback, void* arg) { 845 // klass can be the class of the old object if the visitor already updated the class of ref. 846 DCHECK(klass->IsReferenceClass()); 847 mirror::Object* referent = ref->GetReferent(); 848 if (referent != nullptr) { 849 mirror::Object* forward_address = is_marked_callback(referent, arg); 850 // Null means that the object is not currently marked. 851 if (forward_address == nullptr) { 852 Thread* self = Thread::Current(); 853 // TODO: Remove these locks, and use atomic stacks for storing references? 854 // We need to check that the references haven't already been enqueued since we can end up 855 // scanning the same reference multiple times due to dirty cards. 856 if (klass->IsSoftReferenceClass()) { 857 soft_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 858 } else if (klass->IsWeakReferenceClass()) { 859 weak_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 860 } else if (klass->IsFinalizerReferenceClass()) { 861 finalizer_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 862 } else if (klass->IsPhantomReferenceClass()) { 863 phantom_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 864 } else { 865 LOG(FATAL) << "Invalid reference type " << PrettyClass(klass) << " " << std::hex 866 << klass->GetAccessFlags(); 867 } 868 } else if (referent != forward_address) { 869 // Referent is already marked and we need to update it. 870 ref->SetReferent<false>(forward_address); 871 } 872 } 873} 874 875space::ImageSpace* Heap::GetImageSpace() const { 876 for (const auto& space : continuous_spaces_) { 877 if (space->IsImageSpace()) { 878 return space->AsImageSpace(); 879 } 880 } 881 return NULL; 882} 883 884static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) { 885 size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start); 886 if (used_bytes < chunk_size) { 887 size_t chunk_free_bytes = chunk_size - used_bytes; 888 size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg); 889 max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes); 890 } 891} 892 893void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, bool large_object_allocation) { 894 std::ostringstream oss; 895 size_t total_bytes_free = GetFreeMemory(); 896 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 897 << " free bytes"; 898 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 899 if (!large_object_allocation && total_bytes_free >= byte_count) { 900 size_t max_contiguous_allocation = 0; 901 for (const auto& space : continuous_spaces_) { 902 if (space->IsMallocSpace()) { 903 // To allow the Walk/InspectAll() to exclusively-lock the mutator 904 // lock, temporarily release the shared access to the mutator 905 // lock here by transitioning to the suspended state. 906 Locks::mutator_lock_->AssertSharedHeld(self); 907 self->TransitionFromRunnableToSuspended(kSuspended); 908 space->AsMallocSpace()->Walk(MSpaceChunkCallback, &max_contiguous_allocation); 909 self->TransitionFromSuspendedToRunnable(); 910 Locks::mutator_lock_->AssertSharedHeld(self); 911 } 912 } 913 oss << "; failed due to fragmentation (largest possible contiguous allocation " 914 << max_contiguous_allocation << " bytes)"; 915 } 916 self->ThrowOutOfMemoryError(oss.str().c_str()); 917} 918 919void Heap::DoPendingTransitionOrTrim() { 920 Thread* self = Thread::Current(); 921 CollectorType desired_collector_type; 922 // Wait until we reach the desired transition time. 923 while (true) { 924 uint64_t wait_time; 925 { 926 MutexLock mu(self, *heap_trim_request_lock_); 927 desired_collector_type = desired_collector_type_; 928 uint64_t current_time = NanoTime(); 929 if (current_time >= heap_transition_target_time_) { 930 break; 931 } 932 wait_time = heap_transition_target_time_ - current_time; 933 } 934 ScopedThreadStateChange tsc(self, kSleeping); 935 usleep(wait_time / 1000); // Usleep takes microseconds. 936 } 937 // Transition the collector if the desired collector type is not the same as the current 938 // collector type. 939 TransitionCollector(desired_collector_type); 940 if (!CareAboutPauseTimes()) { 941 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 942 // about pauses. 943 Runtime* runtime = Runtime::Current(); 944 runtime->GetThreadList()->SuspendAll(); 945 runtime->GetMonitorList()->DeflateMonitors(); 946 runtime->GetThreadList()->ResumeAll(); 947 // Do a heap trim if it is needed. 948 Trim(); 949 } 950} 951 952void Heap::Trim() { 953 Thread* self = Thread::Current(); 954 { 955 MutexLock mu(self, *heap_trim_request_lock_); 956 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 957 return; 958 } 959 last_trim_time_ = NanoTime(); 960 heap_trim_request_pending_ = false; 961 } 962 { 963 // Need to do this before acquiring the locks since we don't want to get suspended while 964 // holding any locks. 965 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 966 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 967 // trimming. 968 MutexLock mu(self, *gc_complete_lock_); 969 // Ensure there is only one GC at a time. 970 WaitForGcToCompleteLocked(self); 971 collector_type_running_ = kCollectorTypeHeapTrim; 972 } 973 uint64_t start_ns = NanoTime(); 974 // Trim the managed spaces. 975 uint64_t total_alloc_space_allocated = 0; 976 uint64_t total_alloc_space_size = 0; 977 uint64_t managed_reclaimed = 0; 978 for (const auto& space : continuous_spaces_) { 979 if (space->IsMallocSpace()) { 980 gc::space::MallocSpace* alloc_space = space->AsMallocSpace(); 981 total_alloc_space_size += alloc_space->Size(); 982 managed_reclaimed += alloc_space->Trim(); 983 } 984 } 985 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 986 if (bump_pointer_space_ != nullptr) { 987 total_alloc_space_allocated -= bump_pointer_space_->Size(); 988 } 989 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 990 static_cast<float>(total_alloc_space_size); 991 uint64_t gc_heap_end_ns = NanoTime(); 992 // We never move things in the native heap, so we can finish the GC at this point. 993 FinishGC(self, collector::kGcTypeNone); 994 // Trim the native heap. 995 dlmalloc_trim(0); 996 size_t native_reclaimed = 0; 997 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 998 uint64_t end_ns = NanoTime(); 999 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1000 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1001 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1002 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1003 << "%."; 1004} 1005 1006bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1007 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1008 // taking the lock. 1009 if (obj == nullptr) { 1010 return true; 1011 } 1012 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1013} 1014 1015bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1016 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1017} 1018 1019bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1020 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1021 return false; 1022 } 1023 for (const auto& space : continuous_spaces_) { 1024 if (space->HasAddress(obj)) { 1025 return true; 1026 } 1027 } 1028 return false; 1029} 1030 1031bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1032 bool search_live_stack, bool sorted) { 1033 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1034 return false; 1035 } 1036 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1037 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1038 if (obj == klass) { 1039 // This case happens for java.lang.Class. 1040 return true; 1041 } 1042 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1043 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1044 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1045 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1046 return temp_space_->Contains(obj); 1047 } 1048 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1049 space::DiscontinuousSpace* d_space = nullptr; 1050 if (c_space != nullptr) { 1051 if (c_space->GetLiveBitmap()->Test(obj)) { 1052 return true; 1053 } 1054 } else { 1055 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1056 if (d_space != nullptr) { 1057 if (d_space->GetLiveBitmap()->Test(obj)) { 1058 return true; 1059 } 1060 } 1061 } 1062 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1063 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1064 if (i > 0) { 1065 NanoSleep(MsToNs(10)); 1066 } 1067 if (search_allocation_stack) { 1068 if (sorted) { 1069 if (allocation_stack_->ContainsSorted(obj)) { 1070 return true; 1071 } 1072 } else if (allocation_stack_->Contains(obj)) { 1073 return true; 1074 } 1075 } 1076 1077 if (search_live_stack) { 1078 if (sorted) { 1079 if (live_stack_->ContainsSorted(obj)) { 1080 return true; 1081 } 1082 } else if (live_stack_->Contains(obj)) { 1083 return true; 1084 } 1085 } 1086 } 1087 // We need to check the bitmaps again since there is a race where we mark something as live and 1088 // then clear the stack containing it. 1089 if (c_space != nullptr) { 1090 if (c_space->GetLiveBitmap()->Test(obj)) { 1091 return true; 1092 } 1093 } else { 1094 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1095 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1096 return true; 1097 } 1098 } 1099 return false; 1100} 1101 1102void Heap::DumpSpaces(std::ostream& stream) { 1103 for (const auto& space : continuous_spaces_) { 1104 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1105 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1106 stream << space << " " << *space << "\n"; 1107 if (live_bitmap != nullptr) { 1108 stream << live_bitmap << " " << *live_bitmap << "\n"; 1109 } 1110 if (mark_bitmap != nullptr) { 1111 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1112 } 1113 } 1114 for (const auto& space : discontinuous_spaces_) { 1115 stream << space << " " << *space << "\n"; 1116 } 1117} 1118 1119void Heap::VerifyObjectBody(mirror::Object* obj) { 1120 if (this == nullptr && verify_object_mode_ == kVerifyObjectModeDisabled) { 1121 return; 1122 } 1123 // Ignore early dawn of the universe verifications. 1124 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.Load()) < 10 * KB)) { 1125 return; 1126 } 1127 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1128 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>( 1129 mirror::Object::ClassOffset(), false); 1130 CHECK(c != nullptr) << "Null class in object " << obj; 1131 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1132 CHECK(VerifyClassClass(c)); 1133 1134 if (verify_object_mode_ > kVerifyObjectModeFast) { 1135 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1136 if (!IsLiveObjectLocked(obj)) { 1137 DumpSpaces(); 1138 LOG(FATAL) << "Object is dead: " << obj; 1139 } 1140 } 1141} 1142 1143void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1144 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1145} 1146 1147void Heap::VerifyHeap() { 1148 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1149 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1150} 1151 1152void Heap::RecordFree(ssize_t freed_objects, ssize_t freed_bytes) { 1153 // Use signed comparison since freed bytes can be negative when background compaction foreground 1154 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1155 // free list backed space typically increasing memory footprint due to padding and binning. 1156 DCHECK_LE(freed_bytes, static_cast<ssize_t>(num_bytes_allocated_.Load())); 1157 DCHECK_GE(freed_objects, 0); 1158 num_bytes_allocated_.FetchAndSub(freed_bytes); 1159 if (Runtime::Current()->HasStatsEnabled()) { 1160 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1161 thread_stats->freed_objects += freed_objects; 1162 thread_stats->freed_bytes += freed_bytes; 1163 // TODO: Do this concurrently. 1164 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1165 global_stats->freed_objects += freed_objects; 1166 global_stats->freed_bytes += freed_bytes; 1167 } 1168} 1169 1170mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1171 size_t alloc_size, size_t* bytes_allocated, 1172 size_t* usable_size, 1173 mirror::Class** klass) { 1174 mirror::Object* ptr = nullptr; 1175 bool was_default_allocator = allocator == GetCurrentAllocator(); 1176 DCHECK(klass != nullptr); 1177 SirtRef<mirror::Class> sirt_klass(self, *klass); 1178 // The allocation failed. If the GC is running, block until it completes, and then retry the 1179 // allocation. 1180 collector::GcType last_gc = WaitForGcToComplete(self); 1181 if (last_gc != collector::kGcTypeNone) { 1182 // If we were the default allocator but the allocator changed while we were suspended, 1183 // abort the allocation. 1184 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1185 *klass = sirt_klass.get(); 1186 return nullptr; 1187 } 1188 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1189 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1190 } 1191 1192 collector::GcType tried_type = next_gc_type_; 1193 if (ptr == nullptr) { 1194 const bool gc_ran = 1195 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1196 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1197 *klass = sirt_klass.get(); 1198 return nullptr; 1199 } 1200 if (gc_ran) { 1201 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1202 } 1203 } 1204 1205 // Loop through our different Gc types and try to Gc until we get enough free memory. 1206 for (collector::GcType gc_type : gc_plan_) { 1207 if (ptr != nullptr) { 1208 break; 1209 } 1210 if (gc_type == tried_type) { 1211 continue; 1212 } 1213 // Attempt to run the collector, if we succeed, re-try the allocation. 1214 const bool gc_ran = 1215 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1216 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1217 *klass = sirt_klass.get(); 1218 return nullptr; 1219 } 1220 if (gc_ran) { 1221 // Did we free sufficient memory for the allocation to succeed? 1222 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1223 } 1224 } 1225 // Allocations have failed after GCs; this is an exceptional state. 1226 if (ptr == nullptr) { 1227 // Try harder, growing the heap if necessary. 1228 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1229 } 1230 if (ptr == nullptr) { 1231 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1232 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1233 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1234 // OOME. 1235 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1236 << " allocation"; 1237 // TODO: Run finalization, but this may cause more allocations to occur. 1238 // We don't need a WaitForGcToComplete here either. 1239 DCHECK(!gc_plan_.empty()); 1240 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1241 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1242 *klass = sirt_klass.get(); 1243 return nullptr; 1244 } 1245 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1246 if (ptr == nullptr) { 1247 ThrowOutOfMemoryError(self, alloc_size, false); 1248 } 1249 } 1250 *klass = sirt_klass.get(); 1251 return ptr; 1252} 1253 1254void Heap::SetTargetHeapUtilization(float target) { 1255 DCHECK_GT(target, 0.0f); // asserted in Java code 1256 DCHECK_LT(target, 1.0f); 1257 target_utilization_ = target; 1258} 1259 1260size_t Heap::GetObjectsAllocated() const { 1261 size_t total = 0; 1262 for (space::AllocSpace* space : alloc_spaces_) { 1263 total += space->GetObjectsAllocated(); 1264 } 1265 return total; 1266} 1267 1268size_t Heap::GetObjectsAllocatedEver() const { 1269 return GetObjectsFreedEver() + GetObjectsAllocated(); 1270} 1271 1272size_t Heap::GetBytesAllocatedEver() const { 1273 return GetBytesFreedEver() + GetBytesAllocated(); 1274} 1275 1276class InstanceCounter { 1277 public: 1278 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1279 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1280 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1281 } 1282 static void Callback(mirror::Object* obj, void* arg) 1283 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1284 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1285 mirror::Class* instance_class = obj->GetClass(); 1286 CHECK(instance_class != nullptr); 1287 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1288 if (instance_counter->use_is_assignable_from_) { 1289 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1290 ++instance_counter->counts_[i]; 1291 } 1292 } else if (instance_class == instance_counter->classes_[i]) { 1293 ++instance_counter->counts_[i]; 1294 } 1295 } 1296 } 1297 1298 private: 1299 const std::vector<mirror::Class*>& classes_; 1300 bool use_is_assignable_from_; 1301 uint64_t* const counts_; 1302 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1303}; 1304 1305void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1306 uint64_t* counts) { 1307 // Can't do any GC in this function since this may move classes. 1308 Thread* self = Thread::Current(); 1309 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1310 InstanceCounter counter(classes, use_is_assignable_from, counts); 1311 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1312 VisitObjects(InstanceCounter::Callback, &counter); 1313 self->EndAssertNoThreadSuspension(old_cause); 1314} 1315 1316class InstanceCollector { 1317 public: 1318 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1319 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1320 : class_(c), max_count_(max_count), instances_(instances) { 1321 } 1322 static void Callback(mirror::Object* obj, void* arg) 1323 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1324 DCHECK(arg != nullptr); 1325 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1326 mirror::Class* instance_class = obj->GetClass(); 1327 if (instance_class == instance_collector->class_) { 1328 if (instance_collector->max_count_ == 0 || 1329 instance_collector->instances_.size() < instance_collector->max_count_) { 1330 instance_collector->instances_.push_back(obj); 1331 } 1332 } 1333 } 1334 1335 private: 1336 mirror::Class* class_; 1337 uint32_t max_count_; 1338 std::vector<mirror::Object*>& instances_; 1339 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1340}; 1341 1342void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1343 std::vector<mirror::Object*>& instances) { 1344 // Can't do any GC in this function since this may move classes. 1345 Thread* self = Thread::Current(); 1346 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1347 InstanceCollector collector(c, max_count, instances); 1348 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1349 VisitObjects(&InstanceCollector::Callback, &collector); 1350 self->EndAssertNoThreadSuspension(old_cause); 1351} 1352 1353class ReferringObjectsFinder { 1354 public: 1355 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1356 std::vector<mirror::Object*>& referring_objects) 1357 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1358 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1359 } 1360 1361 static void Callback(mirror::Object* obj, void* arg) 1362 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1363 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1364 } 1365 1366 // For bitmap Visit. 1367 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1368 // annotalysis on visitors. 1369 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1370 o->VisitReferences<true>(*this); 1371 } 1372 1373 // For Object::VisitReferences. 1374 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1375 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1376 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset, false); 1377 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1378 referring_objects_.push_back(obj); 1379 } 1380 } 1381 1382 private: 1383 mirror::Object* object_; 1384 uint32_t max_count_; 1385 std::vector<mirror::Object*>& referring_objects_; 1386 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1387}; 1388 1389void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1390 std::vector<mirror::Object*>& referring_objects) { 1391 // Can't do any GC in this function since this may move the object o. 1392 Thread* self = Thread::Current(); 1393 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1394 ReferringObjectsFinder finder(o, max_count, referring_objects); 1395 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1396 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1397 self->EndAssertNoThreadSuspension(old_cause); 1398} 1399 1400void Heap::CollectGarbage(bool clear_soft_references) { 1401 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1402 // last GC will not have necessarily been cleared. 1403 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1404} 1405 1406void Heap::TransitionCollector(CollectorType collector_type) { 1407 if (collector_type == collector_type_) { 1408 return; 1409 } 1410 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1411 << " -> " << static_cast<int>(collector_type); 1412 uint64_t start_time = NanoTime(); 1413 uint32_t before_allocated = num_bytes_allocated_.Load(); 1414 ThreadList* tl = Runtime::Current()->GetThreadList(); 1415 Thread* self = Thread::Current(); 1416 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1417 Locks::mutator_lock_->AssertNotHeld(self); 1418 const bool copying_transition = 1419 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1420 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1421 // compacting_gc_disable_count_, this should rarely occurs). 1422 for (;;) { 1423 { 1424 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1425 MutexLock mu(self, *gc_complete_lock_); 1426 // Ensure there is only one GC at a time. 1427 WaitForGcToCompleteLocked(self); 1428 // If someone else beat us to it and changed the collector before we could, exit. 1429 // This is safe to do before the suspend all since we set the collector_type_running_ before 1430 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1431 // then it would get blocked on WaitForGcToCompleteLocked. 1432 if (collector_type == collector_type_) { 1433 return; 1434 } 1435 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1436 if (!copying_transition || disable_moving_gc_count_ == 0) { 1437 // TODO: Not hard code in semi-space collector? 1438 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1439 break; 1440 } 1441 } 1442 usleep(1000); 1443 } 1444 tl->SuspendAll(); 1445 PreGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1446 switch (collector_type) { 1447 case kCollectorTypeSS: 1448 // Fall-through. 1449 case kCollectorTypeGSS: { 1450 if (!IsMovingGc(collector_type_)) { 1451 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1452 // pointer space last transition it will be protected. 1453 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1454 Compact(bump_pointer_space_, main_space_); 1455 } 1456 break; 1457 } 1458 case kCollectorTypeMS: 1459 // Fall through. 1460 case kCollectorTypeCMS: { 1461 if (IsMovingGc(collector_type_)) { 1462 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1463 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1464 Compact(main_space_, bump_pointer_space_); 1465 } 1466 break; 1467 } 1468 default: { 1469 LOG(FATAL) << "Attempted to transition to invalid collector type " 1470 << static_cast<size_t>(collector_type); 1471 break; 1472 } 1473 } 1474 ChangeCollector(collector_type); 1475 PostGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1476 tl->ResumeAll(); 1477 // Can't call into java code with all threads suspended. 1478 EnqueueClearedReferences(); 1479 uint64_t duration = NanoTime() - start_time; 1480 GrowForUtilization(semi_space_collector_); 1481 FinishGC(self, collector::kGcTypeFull); 1482 int32_t after_allocated = num_bytes_allocated_.Load(); 1483 int32_t delta_allocated = before_allocated - after_allocated; 1484 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1485 << PrettyDuration(duration) << " saved at least " << PrettySize(delta_allocated); 1486} 1487 1488void Heap::ChangeCollector(CollectorType collector_type) { 1489 // TODO: Only do this with all mutators suspended to avoid races. 1490 if (collector_type != collector_type_) { 1491 collector_type_ = collector_type; 1492 gc_plan_.clear(); 1493 switch (collector_type_) { 1494 case kCollectorTypeCC: // Fall-through. 1495 case kCollectorTypeSS: // Fall-through. 1496 case kCollectorTypeGSS: { 1497 gc_plan_.push_back(collector::kGcTypeFull); 1498 if (use_tlab_) { 1499 ChangeAllocator(kAllocatorTypeTLAB); 1500 } else { 1501 ChangeAllocator(kAllocatorTypeBumpPointer); 1502 } 1503 break; 1504 } 1505 case kCollectorTypeMS: { 1506 gc_plan_.push_back(collector::kGcTypeSticky); 1507 gc_plan_.push_back(collector::kGcTypePartial); 1508 gc_plan_.push_back(collector::kGcTypeFull); 1509 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1510 break; 1511 } 1512 case kCollectorTypeCMS: { 1513 gc_plan_.push_back(collector::kGcTypeSticky); 1514 gc_plan_.push_back(collector::kGcTypePartial); 1515 gc_plan_.push_back(collector::kGcTypeFull); 1516 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1517 break; 1518 } 1519 default: { 1520 LOG(FATAL) << "Unimplemented"; 1521 } 1522 } 1523 if (IsGcConcurrent()) { 1524 concurrent_start_bytes_ = 1525 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1526 } else { 1527 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1528 } 1529 } 1530} 1531 1532// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1533class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1534 public: 1535 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1536 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1537 } 1538 1539 void BuildBins(space::ContinuousSpace* space) { 1540 bin_live_bitmap_ = space->GetLiveBitmap(); 1541 bin_mark_bitmap_ = space->GetMarkBitmap(); 1542 BinContext context; 1543 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1544 context.collector_ = this; 1545 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1546 // Note: This requires traversing the space in increasing order of object addresses. 1547 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1548 // Add the last bin which spans after the last object to the end of the space. 1549 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1550 } 1551 1552 private: 1553 struct BinContext { 1554 uintptr_t prev_; // The end of the previous object. 1555 ZygoteCompactingCollector* collector_; 1556 }; 1557 // Maps from bin sizes to locations. 1558 std::multimap<size_t, uintptr_t> bins_; 1559 // Live bitmap of the space which contains the bins. 1560 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1561 // Mark bitmap of the space which contains the bins. 1562 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1563 1564 static void Callback(mirror::Object* obj, void* arg) 1565 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1566 DCHECK(arg != nullptr); 1567 BinContext* context = reinterpret_cast<BinContext*>(arg); 1568 ZygoteCompactingCollector* collector = context->collector_; 1569 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1570 size_t bin_size = object_addr - context->prev_; 1571 // Add the bin consisting of the end of the previous object to the start of the current object. 1572 collector->AddBin(bin_size, context->prev_); 1573 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1574 } 1575 1576 void AddBin(size_t size, uintptr_t position) { 1577 if (size != 0) { 1578 bins_.insert(std::make_pair(size, position)); 1579 } 1580 } 1581 1582 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1583 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1584 // allocator. 1585 return false; 1586 } 1587 1588 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1589 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1590 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1591 mirror::Object* forward_address; 1592 // Find the smallest bin which we can move obj in. 1593 auto it = bins_.lower_bound(object_size); 1594 if (it == bins_.end()) { 1595 // No available space in the bins, place it in the target space instead (grows the zygote 1596 // space). 1597 size_t bytes_allocated; 1598 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1599 if (to_space_live_bitmap_ != nullptr) { 1600 to_space_live_bitmap_->Set(forward_address); 1601 } else { 1602 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1603 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1604 } 1605 } else { 1606 size_t size = it->first; 1607 uintptr_t pos = it->second; 1608 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1609 forward_address = reinterpret_cast<mirror::Object*>(pos); 1610 // Set the live and mark bits so that sweeping system weaks works properly. 1611 bin_live_bitmap_->Set(forward_address); 1612 bin_mark_bitmap_->Set(forward_address); 1613 DCHECK_GE(size, object_size); 1614 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1615 } 1616 // Copy the object over to its new location. 1617 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1618 if (kUseBakerOrBrooksReadBarrier) { 1619 obj->AssertReadBarrierPointer(); 1620 if (kUseBrooksReadBarrier) { 1621 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1622 forward_address->SetReadBarrierPointer(forward_address); 1623 } 1624 forward_address->AssertReadBarrierPointer(); 1625 } 1626 return forward_address; 1627 } 1628}; 1629 1630void Heap::UnBindBitmaps() { 1631 for (const auto& space : GetContinuousSpaces()) { 1632 if (space->IsContinuousMemMapAllocSpace()) { 1633 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1634 if (alloc_space->HasBoundBitmaps()) { 1635 alloc_space->UnBindBitmaps(); 1636 } 1637 } 1638 } 1639} 1640 1641void Heap::PreZygoteFork() { 1642 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1643 static Mutex zygote_creation_lock_("zygote creation lock", kZygoteCreationLock); 1644 Thread* self = Thread::Current(); 1645 MutexLock mu(self, zygote_creation_lock_); 1646 // Try to see if we have any Zygote spaces. 1647 if (have_zygote_space_) { 1648 return; 1649 } 1650 VLOG(heap) << "Starting PreZygoteFork"; 1651 // Trim the pages at the end of the non moving space. 1652 non_moving_space_->Trim(); 1653 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1654 // there. 1655 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1656 // Change the collector to the post zygote one. 1657 if (kCompactZygote) { 1658 DCHECK(semi_space_collector_ != nullptr); 1659 // Temporarily disable rosalloc verification because the zygote 1660 // compaction will mess up the rosalloc internal metadata. 1661 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1662 ZygoteCompactingCollector zygote_collector(this); 1663 zygote_collector.BuildBins(non_moving_space_); 1664 // Create a new bump pointer space which we will compact into. 1665 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1666 non_moving_space_->Limit()); 1667 // Compact the bump pointer space to a new zygote bump pointer space. 1668 bool reset_main_space = false; 1669 if (IsMovingGc(collector_type_)) { 1670 zygote_collector.SetFromSpace(bump_pointer_space_); 1671 } else { 1672 CHECK(main_space_ != nullptr); 1673 // Copy from the main space. 1674 zygote_collector.SetFromSpace(main_space_); 1675 reset_main_space = true; 1676 } 1677 zygote_collector.SetToSpace(&target_space); 1678 1679 Runtime::Current()->GetThreadList()->SuspendAll(); 1680 zygote_collector.Run(kGcCauseCollectorTransition, false); 1681 if (IsMovingGc(collector_type_)) { 1682 SwapSemiSpaces(); 1683 } 1684 Runtime::Current()->GetThreadList()->ResumeAll(); 1685 1686 if (reset_main_space) { 1687 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1688 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1689 MemMap* mem_map = main_space_->ReleaseMemMap(); 1690 RemoveSpace(main_space_); 1691 delete main_space_; 1692 main_space_ = nullptr; 1693 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1694 AddSpace(main_space_); 1695 } else { 1696 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1697 } 1698 if (temp_space_ != nullptr) { 1699 CHECK(temp_space_->IsEmpty()); 1700 } 1701 total_objects_freed_ever_ += semi_space_collector_->GetFreedObjects(); 1702 total_bytes_freed_ever_ += semi_space_collector_->GetFreedBytes(); 1703 // Update the end and write out image. 1704 non_moving_space_->SetEnd(target_space.End()); 1705 non_moving_space_->SetLimit(target_space.Limit()); 1706 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1707 } 1708 ChangeCollector(foreground_collector_type_); 1709 // Save the old space so that we can remove it after we complete creating the zygote space. 1710 space::MallocSpace* old_alloc_space = non_moving_space_; 1711 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1712 // the remaining available space. 1713 // Remove the old space before creating the zygote space since creating the zygote space sets 1714 // the old alloc space's bitmaps to nullptr. 1715 RemoveSpace(old_alloc_space); 1716 if (collector::SemiSpace::kUseRememberedSet) { 1717 // Sanity bound check. 1718 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1719 // Remove the remembered set for the now zygote space (the old 1720 // non-moving space). Note now that we have compacted objects into 1721 // the zygote space, the data in the remembered set is no longer 1722 // needed. The zygote space will instead have a mod-union table 1723 // from this point on. 1724 RemoveRememberedSet(old_alloc_space); 1725 } 1726 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1727 low_memory_mode_, 1728 &non_moving_space_); 1729 delete old_alloc_space; 1730 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1731 AddSpace(zygote_space, false); 1732 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1733 AddSpace(non_moving_space_); 1734 have_zygote_space_ = true; 1735 // Enable large object space allocations. 1736 large_object_threshold_ = kDefaultLargeObjectThreshold; 1737 // Create the zygote space mod union table. 1738 accounting::ModUnionTable* mod_union_table = 1739 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1740 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1741 AddModUnionTable(mod_union_table); 1742 if (collector::SemiSpace::kUseRememberedSet) { 1743 // Add a new remembered set for the post-zygote non-moving space. 1744 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1745 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1746 non_moving_space_); 1747 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1748 << "Failed to create post-zygote non-moving space remembered set"; 1749 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1750 } 1751} 1752 1753void Heap::FlushAllocStack() { 1754 MarkAllocStackAsLive(allocation_stack_.get()); 1755 allocation_stack_->Reset(); 1756} 1757 1758void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1759 accounting::ContinuousSpaceBitmap* bitmap2, 1760 accounting::LargeObjectBitmap* large_objects, 1761 accounting::ObjectStack* stack) { 1762 DCHECK(bitmap1 != nullptr); 1763 DCHECK(bitmap2 != nullptr); 1764 mirror::Object** limit = stack->End(); 1765 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1766 const mirror::Object* obj = *it; 1767 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1768 if (bitmap1->HasAddress(obj)) { 1769 bitmap1->Set(obj); 1770 } else if (bitmap2->HasAddress(obj)) { 1771 bitmap2->Set(obj); 1772 } else { 1773 large_objects->Set(obj); 1774 } 1775 } 1776 } 1777} 1778 1779void Heap::SwapSemiSpaces() { 1780 CHECK(bump_pointer_space_ != nullptr); 1781 CHECK(temp_space_ != nullptr); 1782 std::swap(bump_pointer_space_, temp_space_); 1783} 1784 1785void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1786 space::ContinuousMemMapAllocSpace* source_space) { 1787 CHECK(kMovingCollector); 1788 CHECK_NE(target_space, source_space) << "In-place compaction currently unsupported"; 1789 if (target_space != source_space) { 1790 semi_space_collector_->SetFromSpace(source_space); 1791 semi_space_collector_->SetToSpace(target_space); 1792 semi_space_collector_->Run(kGcCauseCollectorTransition, false); 1793 } 1794} 1795 1796collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1797 bool clear_soft_references) { 1798 Thread* self = Thread::Current(); 1799 Runtime* runtime = Runtime::Current(); 1800 // If the heap can't run the GC, silently fail and return that no GC was run. 1801 switch (gc_type) { 1802 case collector::kGcTypePartial: { 1803 if (!have_zygote_space_) { 1804 return collector::kGcTypeNone; 1805 } 1806 break; 1807 } 1808 default: { 1809 // Other GC types don't have any special cases which makes them not runnable. The main case 1810 // here is full GC. 1811 } 1812 } 1813 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1814 Locks::mutator_lock_->AssertNotHeld(self); 1815 if (self->IsHandlingStackOverflow()) { 1816 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 1817 } 1818 bool compacting_gc; 1819 { 1820 gc_complete_lock_->AssertNotHeld(self); 1821 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1822 MutexLock mu(self, *gc_complete_lock_); 1823 // Ensure there is only one GC at a time. 1824 WaitForGcToCompleteLocked(self); 1825 compacting_gc = IsMovingGc(collector_type_); 1826 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 1827 if (compacting_gc && disable_moving_gc_count_ != 0) { 1828 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 1829 return collector::kGcTypeNone; 1830 } 1831 collector_type_running_ = collector_type_; 1832 } 1833 1834 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 1835 ++runtime->GetStats()->gc_for_alloc_count; 1836 ++self->GetStats()->gc_for_alloc_count; 1837 } 1838 uint64_t gc_start_time_ns = NanoTime(); 1839 uint64_t gc_start_size = GetBytesAllocated(); 1840 // Approximate allocation rate in bytes / second. 1841 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 1842 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 1843 if (LIKELY(ms_delta != 0)) { 1844 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 1845 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 1846 } 1847 1848 DCHECK_LT(gc_type, collector::kGcTypeMax); 1849 DCHECK_NE(gc_type, collector::kGcTypeNone); 1850 1851 collector::GarbageCollector* collector = nullptr; 1852 // TODO: Clean this up. 1853 if (compacting_gc) { 1854 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 1855 current_allocator_ == kAllocatorTypeTLAB); 1856 if (collector_type_ == kCollectorTypeSS || collector_type_ == kCollectorTypeGSS) { 1857 gc_type = semi_space_collector_->GetGcType(); 1858 semi_space_collector_->SetFromSpace(bump_pointer_space_); 1859 semi_space_collector_->SetToSpace(temp_space_); 1860 collector = semi_space_collector_; 1861 } else if (collector_type_ == kCollectorTypeCC) { 1862 gc_type = concurrent_copying_collector_->GetGcType(); 1863 collector = concurrent_copying_collector_; 1864 } else { 1865 LOG(FATAL) << "Unreachable - invalid collector type " << static_cast<size_t>(collector_type_); 1866 } 1867 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1868 CHECK(temp_space_->IsEmpty()); 1869 gc_type = collector::kGcTypeFull; 1870 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 1871 current_allocator_ == kAllocatorTypeDlMalloc) { 1872 collector = FindCollectorByGcType(gc_type); 1873 } else { 1874 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 1875 } 1876 CHECK(collector != nullptr) 1877 << "Could not find garbage collector with collector_type=" 1878 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 1879 ATRACE_BEGIN(StringPrintf("%s %s GC", PrettyCause(gc_cause), collector->GetName()).c_str()); 1880 if (compacting_gc) { 1881 runtime->GetThreadList()->SuspendAll(); 1882 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 1883 SwapSemiSpaces(); 1884 runtime->GetThreadList()->ResumeAll(); 1885 } else { 1886 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 1887 } 1888 total_objects_freed_ever_ += collector->GetFreedObjects(); 1889 total_bytes_freed_ever_ += collector->GetFreedBytes(); 1890 RequestHeapTrim(); 1891 // Enqueue cleared references. 1892 EnqueueClearedReferences(); 1893 // Grow the heap so that we know when to perform the next GC. 1894 GrowForUtilization(collector); 1895 if (CareAboutPauseTimes()) { 1896 const size_t duration = collector->GetDurationNs(); 1897 std::vector<uint64_t> pauses = collector->GetPauseTimes(); 1898 // GC for alloc pauses the allocating thread, so consider it as a pause. 1899 bool was_slow = duration > long_gc_log_threshold_ || 1900 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 1901 if (!was_slow) { 1902 for (uint64_t pause : pauses) { 1903 was_slow = was_slow || pause > long_pause_log_threshold_; 1904 } 1905 } 1906 if (was_slow) { 1907 const size_t percent_free = GetPercentFree(); 1908 const size_t current_heap_size = GetBytesAllocated(); 1909 const size_t total_memory = GetTotalMemory(); 1910 std::ostringstream pause_string; 1911 for (size_t i = 0; i < pauses.size(); ++i) { 1912 pause_string << PrettyDuration((pauses[i] / 1000) * 1000) 1913 << ((i != pauses.size() - 1) ? ", " : ""); 1914 } 1915 LOG(INFO) << gc_cause << " " << collector->GetName() 1916 << " GC freed " << collector->GetFreedObjects() << "(" 1917 << PrettySize(collector->GetFreedBytes()) << ") AllocSpace objects, " 1918 << collector->GetFreedLargeObjects() << "(" 1919 << PrettySize(collector->GetFreedLargeObjectBytes()) << ") LOS objects, " 1920 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 1921 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 1922 << " total " << PrettyDuration((duration / 1000) * 1000); 1923 VLOG(heap) << ConstDumpable<TimingLogger>(collector->GetTimings()); 1924 } 1925 } 1926 FinishGC(self, gc_type); 1927 ATRACE_END(); 1928 1929 // Inform DDMS that a GC completed. 1930 Dbg::GcDidFinish(); 1931 return gc_type; 1932} 1933 1934void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 1935 MutexLock mu(self, *gc_complete_lock_); 1936 collector_type_running_ = kCollectorTypeNone; 1937 if (gc_type != collector::kGcTypeNone) { 1938 last_gc_type_ = gc_type; 1939 } 1940 // Wake anyone who may have been waiting for the GC to complete. 1941 gc_complete_cond_->Broadcast(self); 1942} 1943 1944static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 1945 RootType /*root_type*/) { 1946 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 1947 if (*root == obj) { 1948 LOG(INFO) << "Object " << obj << " is a root"; 1949 } 1950} 1951 1952class ScanVisitor { 1953 public: 1954 void operator()(const mirror::Object* obj) const { 1955 LOG(ERROR) << "Would have rescanned object " << obj; 1956 } 1957}; 1958 1959// Verify a reference from an object. 1960class VerifyReferenceVisitor { 1961 public: 1962 explicit VerifyReferenceVisitor(Heap* heap) 1963 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 1964 : heap_(heap), failed_(false) {} 1965 1966 bool Failed() const { 1967 return failed_; 1968 } 1969 1970 void operator()(mirror::Class* klass, mirror::Reference* ref) const 1971 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1972 this->operator()(ref, mirror::Reference::ReferentOffset(), false); 1973 } 1974 1975 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 1976 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1977 this->operator()(obj, obj->GetFieldObject<mirror::Object>(offset, false), offset); 1978 } 1979 1980 // TODO: Fix the no thread safety analysis. 1981 void operator()(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 1982 NO_THREAD_SAFETY_ANALYSIS { 1983 if (ref == nullptr || IsLive(ref)) { 1984 // Verify that the reference is live. 1985 return; 1986 } 1987 if (!failed_) { 1988 // Print message on only on first failure to prevent spam. 1989 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 1990 failed_ = true; 1991 } 1992 if (obj != nullptr) { 1993 accounting::CardTable* card_table = heap_->GetCardTable(); 1994 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 1995 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 1996 byte* card_addr = card_table->CardFromAddr(obj); 1997 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 1998 << offset << "\n card value = " << static_cast<int>(*card_addr); 1999 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2000 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2001 } else { 2002 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2003 } 2004 2005 // Attmept to find the class inside of the recently freed objects. 2006 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2007 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2008 space::MallocSpace* space = ref_space->AsMallocSpace(); 2009 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2010 if (ref_class != nullptr) { 2011 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2012 << PrettyClass(ref_class); 2013 } else { 2014 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2015 } 2016 } 2017 2018 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2019 ref->GetClass()->IsClass()) { 2020 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2021 } else { 2022 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2023 << ") is not a valid heap address"; 2024 } 2025 2026 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2027 void* cover_begin = card_table->AddrFromCard(card_addr); 2028 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2029 accounting::CardTable::kCardSize); 2030 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2031 << "-" << cover_end; 2032 accounting::ContinuousSpaceBitmap* bitmap = 2033 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2034 2035 if (bitmap == nullptr) { 2036 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2037 if (!VerifyClassClass(obj->GetClass())) { 2038 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2039 } 2040 } else { 2041 // Print out how the object is live. 2042 if (bitmap->Test(obj)) { 2043 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2044 } 2045 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2046 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2047 } 2048 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2049 LOG(ERROR) << "Object " << obj << " found in live stack"; 2050 } 2051 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2052 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2053 } 2054 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2055 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2056 } 2057 // Attempt to see if the card table missed the reference. 2058 ScanVisitor scan_visitor; 2059 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2060 card_table->Scan(bitmap, byte_cover_begin, 2061 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2062 } 2063 2064 // Search to see if any of the roots reference our object. 2065 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2066 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2067 2068 // Search to see if any of the roots reference our reference. 2069 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2070 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2071 } else { 2072 LOG(ERROR) << "Root " << ref << " is dead with type " << PrettyTypeOf(ref); 2073 } 2074 } 2075 2076 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2077 return heap_->IsLiveObjectLocked(obj, true, false, true); 2078 } 2079 2080 static void VerifyRoots(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2081 RootType /*root_type*/) { 2082 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2083 (*visitor)(nullptr, *root, MemberOffset(0)); 2084 } 2085 2086 private: 2087 Heap* const heap_; 2088 mutable bool failed_; 2089}; 2090 2091// Verify all references within an object, for use with HeapBitmap::Visit. 2092class VerifyObjectVisitor { 2093 public: 2094 explicit VerifyObjectVisitor(Heap* heap) : heap_(heap), failed_(false) {} 2095 2096 void operator()(mirror::Object* obj) const 2097 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2098 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2099 // be live or else how did we find it in the live bitmap? 2100 VerifyReferenceVisitor visitor(heap_); 2101 // The class doesn't count as a reference but we should verify it anyways. 2102 obj->VisitReferences<true>(visitor, visitor); 2103 failed_ = failed_ || visitor.Failed(); 2104 } 2105 2106 static void VisitCallback(mirror::Object* obj, void* arg) 2107 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2108 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2109 visitor->operator()(obj); 2110 } 2111 2112 bool Failed() const { 2113 return failed_; 2114 } 2115 2116 private: 2117 Heap* const heap_; 2118 mutable bool failed_; 2119}; 2120 2121// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2122bool Heap::VerifyHeapReferences() { 2123 Thread* self = Thread::Current(); 2124 Locks::mutator_lock_->AssertExclusiveHeld(self); 2125 // Lets sort our allocation stacks so that we can efficiently binary search them. 2126 allocation_stack_->Sort(); 2127 live_stack_->Sort(); 2128 // Since we sorted the allocation stack content, need to revoke all 2129 // thread-local allocation stacks. 2130 RevokeAllThreadLocalAllocationStacks(self); 2131 VerifyObjectVisitor visitor(this); 2132 // Verify objects in the allocation stack since these will be objects which were: 2133 // 1. Allocated prior to the GC (pre GC verification). 2134 // 2. Allocated during the GC (pre sweep GC verification). 2135 // We don't want to verify the objects in the live stack since they themselves may be 2136 // pointing to dead objects if they are not reachable. 2137 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2138 // Verify the roots: 2139 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRoots, &visitor); 2140 if (visitor.Failed()) { 2141 // Dump mod-union tables. 2142 for (const auto& table_pair : mod_union_tables_) { 2143 accounting::ModUnionTable* mod_union_table = table_pair.second; 2144 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2145 } 2146 // Dump remembered sets. 2147 for (const auto& table_pair : remembered_sets_) { 2148 accounting::RememberedSet* remembered_set = table_pair.second; 2149 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2150 } 2151 DumpSpaces(); 2152 return false; 2153 } 2154 return true; 2155} 2156 2157class VerifyReferenceCardVisitor { 2158 public: 2159 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2160 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2161 Locks::heap_bitmap_lock_) 2162 : heap_(heap), failed_(failed) { 2163 } 2164 2165 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2166 // annotalysis on visitors. 2167 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2168 NO_THREAD_SAFETY_ANALYSIS { 2169 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset, false); 2170 // Filter out class references since changing an object's class does not mark the card as dirty. 2171 // Also handles large objects, since the only reference they hold is a class reference. 2172 if (ref != nullptr && !ref->IsClass()) { 2173 accounting::CardTable* card_table = heap_->GetCardTable(); 2174 // If the object is not dirty and it is referencing something in the live stack other than 2175 // class, then it must be on a dirty card. 2176 if (!card_table->AddrIsInCardTable(obj)) { 2177 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2178 *failed_ = true; 2179 } else if (!card_table->IsDirty(obj)) { 2180 // TODO: Check mod-union tables. 2181 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2182 // kCardDirty - 1 if it didnt get touched since we aged it. 2183 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2184 if (live_stack->ContainsSorted(ref)) { 2185 if (live_stack->ContainsSorted(obj)) { 2186 LOG(ERROR) << "Object " << obj << " found in live stack"; 2187 } 2188 if (heap_->GetLiveBitmap()->Test(obj)) { 2189 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2190 } 2191 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2192 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2193 2194 // Print which field of the object is dead. 2195 if (!obj->IsObjectArray()) { 2196 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2197 CHECK(klass != NULL); 2198 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2199 : klass->GetIFields(); 2200 CHECK(fields != NULL); 2201 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2202 mirror::ArtField* cur = fields->Get(i); 2203 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2204 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2205 << PrettyField(cur); 2206 break; 2207 } 2208 } 2209 } else { 2210 mirror::ObjectArray<mirror::Object>* object_array = 2211 obj->AsObjectArray<mirror::Object>(); 2212 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2213 if (object_array->Get(i) == ref) { 2214 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2215 } 2216 } 2217 } 2218 2219 *failed_ = true; 2220 } 2221 } 2222 } 2223 } 2224 2225 private: 2226 Heap* const heap_; 2227 bool* const failed_; 2228}; 2229 2230class VerifyLiveStackReferences { 2231 public: 2232 explicit VerifyLiveStackReferences(Heap* heap) 2233 : heap_(heap), 2234 failed_(false) {} 2235 2236 void operator()(mirror::Object* obj) const 2237 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2238 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2239 obj->VisitReferences<true>(visitor); 2240 } 2241 2242 bool Failed() const { 2243 return failed_; 2244 } 2245 2246 private: 2247 Heap* const heap_; 2248 bool failed_; 2249}; 2250 2251bool Heap::VerifyMissingCardMarks() { 2252 Thread* self = Thread::Current(); 2253 Locks::mutator_lock_->AssertExclusiveHeld(self); 2254 2255 // We need to sort the live stack since we binary search it. 2256 live_stack_->Sort(); 2257 // Since we sorted the allocation stack content, need to revoke all 2258 // thread-local allocation stacks. 2259 RevokeAllThreadLocalAllocationStacks(self); 2260 VerifyLiveStackReferences visitor(this); 2261 GetLiveBitmap()->Visit(visitor); 2262 2263 // We can verify objects in the live stack since none of these should reference dead objects. 2264 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2265 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2266 visitor(*it); 2267 } 2268 } 2269 2270 if (visitor.Failed()) { 2271 DumpSpaces(); 2272 return false; 2273 } 2274 return true; 2275} 2276 2277void Heap::SwapStacks(Thread* self) { 2278 if (kUseThreadLocalAllocationStack) { 2279 live_stack_->AssertAllZero(); 2280 } 2281 allocation_stack_.swap(live_stack_); 2282} 2283 2284void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2285 // This must be called only during the pause. 2286 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2287 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2288 MutexLock mu2(self, *Locks::thread_list_lock_); 2289 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2290 for (Thread* t : thread_list) { 2291 t->RevokeThreadLocalAllocationStack(); 2292 } 2293} 2294 2295void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2296 if (kIsDebugBuild) { 2297 if (bump_pointer_space_ != nullptr) { 2298 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2299 } 2300 } 2301} 2302 2303accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2304 auto it = mod_union_tables_.find(space); 2305 if (it == mod_union_tables_.end()) { 2306 return nullptr; 2307 } 2308 return it->second; 2309} 2310 2311accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2312 auto it = remembered_sets_.find(space); 2313 if (it == remembered_sets_.end()) { 2314 return nullptr; 2315 } 2316 return it->second; 2317} 2318 2319void Heap::ProcessCards(TimingLogger& timings, bool use_rem_sets) { 2320 // Clear cards and keep track of cards cleared in the mod-union table. 2321 for (const auto& space : continuous_spaces_) { 2322 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2323 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2324 if (table != nullptr) { 2325 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2326 "ImageModUnionClearCards"; 2327 TimingLogger::ScopedSplit split(name, &timings); 2328 table->ClearCards(); 2329 } else if (use_rem_sets && rem_set != nullptr) { 2330 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2331 << static_cast<int>(collector_type_); 2332 TimingLogger::ScopedSplit split("AllocSpaceRemSetClearCards", &timings); 2333 rem_set->ClearCards(); 2334 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2335 TimingLogger::ScopedSplit split("AllocSpaceClearCards", &timings); 2336 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2337 // were dirty before the GC started. 2338 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2339 // -> clean(cleaning thread). 2340 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2341 // roots and then we scan / update mod union tables after. We will always scan either card. 2342 // If we end up with the non aged card, we scan it it in the pause. 2343 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), VoidFunctor()); 2344 } 2345 } 2346} 2347 2348static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2349} 2350 2351void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2352 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 2353 Thread* self = Thread::Current(); 2354 2355 if (verify_pre_gc_heap_) { 2356 thread_list->SuspendAll(); 2357 { 2358 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2359 if (!VerifyHeapReferences()) { 2360 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed"; 2361 } 2362 } 2363 thread_list->ResumeAll(); 2364 } 2365 2366 // Check that all objects which reference things in the live stack are on dirty cards. 2367 if (verify_missing_card_marks_) { 2368 thread_list->SuspendAll(); 2369 { 2370 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2371 SwapStacks(self); 2372 // Sort the live stack so that we can quickly binary search it later. 2373 if (!VerifyMissingCardMarks()) { 2374 LOG(FATAL) << "Pre " << gc->GetName() << " missing card mark verification failed"; 2375 } 2376 SwapStacks(self); 2377 } 2378 thread_list->ResumeAll(); 2379 } 2380 2381 if (verify_mod_union_table_) { 2382 thread_list->SuspendAll(); 2383 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2384 for (const auto& table_pair : mod_union_tables_) { 2385 accounting::ModUnionTable* mod_union_table = table_pair.second; 2386 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2387 mod_union_table->Verify(); 2388 } 2389 thread_list->ResumeAll(); 2390 } 2391} 2392 2393void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2394 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2395 // reachable objects. 2396 if (verify_post_gc_heap_) { 2397 Thread* self = Thread::Current(); 2398 CHECK_NE(self->GetState(), kRunnable); 2399 { 2400 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2401 // Swapping bound bitmaps does nothing. 2402 gc->SwapBitmaps(); 2403 SwapSemiSpaces(); 2404 if (!VerifyHeapReferences()) { 2405 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed"; 2406 } 2407 SwapSemiSpaces(); 2408 gc->SwapBitmaps(); 2409 } 2410 } 2411} 2412 2413void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2414 if (verify_system_weaks_) { 2415 Thread* self = Thread::Current(); 2416 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2417 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2418 mark_sweep->VerifySystemWeaks(); 2419 } 2420} 2421 2422void Heap::PreGcRosAllocVerification(TimingLogger* timings) { 2423 if (verify_pre_gc_rosalloc_) { 2424 TimingLogger::ScopedSplit split("PreGcRosAllocVerification", timings); 2425 for (const auto& space : continuous_spaces_) { 2426 if (space->IsRosAllocSpace()) { 2427 VLOG(heap) << "PreGcRosAllocVerification : " << space->GetName(); 2428 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2429 rosalloc_space->Verify(); 2430 } 2431 } 2432 } 2433} 2434 2435void Heap::PostGcRosAllocVerification(TimingLogger* timings) { 2436 if (verify_post_gc_rosalloc_) { 2437 TimingLogger::ScopedSplit split("PostGcRosAllocVerification", timings); 2438 for (const auto& space : continuous_spaces_) { 2439 if (space->IsRosAllocSpace()) { 2440 VLOG(heap) << "PostGcRosAllocVerification : " << space->GetName(); 2441 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2442 rosalloc_space->Verify(); 2443 } 2444 } 2445 } 2446} 2447 2448collector::GcType Heap::WaitForGcToComplete(Thread* self) { 2449 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2450 MutexLock mu(self, *gc_complete_lock_); 2451 return WaitForGcToCompleteLocked(self); 2452} 2453 2454collector::GcType Heap::WaitForGcToCompleteLocked(Thread* self) { 2455 collector::GcType last_gc_type = collector::kGcTypeNone; 2456 uint64_t wait_start = NanoTime(); 2457 while (collector_type_running_ != kCollectorTypeNone) { 2458 ATRACE_BEGIN("GC: Wait For Completion"); 2459 // We must wait, change thread state then sleep on gc_complete_cond_; 2460 gc_complete_cond_->Wait(self); 2461 last_gc_type = last_gc_type_; 2462 ATRACE_END(); 2463 } 2464 uint64_t wait_time = NanoTime() - wait_start; 2465 total_wait_time_ += wait_time; 2466 if (wait_time > long_pause_log_threshold_) { 2467 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time); 2468 } 2469 return last_gc_type; 2470} 2471 2472void Heap::DumpForSigQuit(std::ostream& os) { 2473 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2474 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2475 DumpGcPerformanceInfo(os); 2476} 2477 2478size_t Heap::GetPercentFree() { 2479 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / GetTotalMemory()); 2480} 2481 2482void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2483 if (max_allowed_footprint > GetMaxMemory()) { 2484 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2485 << PrettySize(GetMaxMemory()); 2486 max_allowed_footprint = GetMaxMemory(); 2487 } 2488 max_allowed_footprint_ = max_allowed_footprint; 2489} 2490 2491bool Heap::IsMovableObject(const mirror::Object* obj) const { 2492 if (kMovingCollector) { 2493 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2494 if (space != nullptr) { 2495 // TODO: Check large object? 2496 return space->CanMoveObjects(); 2497 } 2498 } 2499 return false; 2500} 2501 2502void Heap::UpdateMaxNativeFootprint() { 2503 size_t native_size = native_bytes_allocated_; 2504 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2505 size_t target_size = native_size / GetTargetHeapUtilization(); 2506 if (target_size > native_size + max_free_) { 2507 target_size = native_size + max_free_; 2508 } else if (target_size < native_size + min_free_) { 2509 target_size = native_size + min_free_; 2510 } 2511 native_footprint_gc_watermark_ = target_size; 2512 native_footprint_limit_ = 2 * target_size - native_size; 2513} 2514 2515collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2516 for (const auto& collector : garbage_collectors_) { 2517 if (collector->GetCollectorType() == collector_type_ && 2518 collector->GetGcType() == gc_type) { 2519 return collector; 2520 } 2521 } 2522 return nullptr; 2523} 2524 2525double Heap::HeapGrowthMultiplier() const { 2526 // If we don't care about pause times we are background, so return 1.0. 2527 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2528 return 1.0; 2529 } 2530 return foreground_heap_growth_multiplier_; 2531} 2532 2533void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2534 // We know what our utilization is at this moment. 2535 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2536 const uint64_t bytes_allocated = GetBytesAllocated(); 2537 last_gc_size_ = bytes_allocated; 2538 last_gc_time_ns_ = NanoTime(); 2539 uint64_t target_size; 2540 collector::GcType gc_type = collector_ran->GetGcType(); 2541 if (gc_type != collector::kGcTypeSticky) { 2542 // Grow the heap for non sticky GC. 2543 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2544 // foreground. 2545 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2546 CHECK_GE(delta, 0); 2547 target_size = bytes_allocated + delta * multiplier; 2548 target_size = std::min(target_size, 2549 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2550 target_size = std::max(target_size, 2551 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2552 native_need_to_run_finalization_ = true; 2553 next_gc_type_ = collector::kGcTypeSticky; 2554 } else { 2555 collector::GcType non_sticky_gc_type = 2556 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2557 // Find what the next non sticky collector will be. 2558 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2559 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2560 // do another sticky collection next. 2561 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2562 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2563 // if the sticky GC throughput always remained >= the full/partial throughput. 2564 if (collector_ran->GetEstimatedLastIterationThroughput() * kStickyGcThroughputAdjustment >= 2565 non_sticky_collector->GetEstimatedMeanThroughput() && 2566 non_sticky_collector->GetIterations() > 0 && 2567 bytes_allocated <= max_allowed_footprint_) { 2568 next_gc_type_ = collector::kGcTypeSticky; 2569 } else { 2570 next_gc_type_ = non_sticky_gc_type; 2571 } 2572 // If we have freed enough memory, shrink the heap back down. 2573 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2574 target_size = bytes_allocated + max_free_; 2575 } else { 2576 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2577 } 2578 } 2579 if (!ignore_max_footprint_) { 2580 SetIdealFootprint(target_size); 2581 if (IsGcConcurrent()) { 2582 // Calculate when to perform the next ConcurrentGC. 2583 // Calculate the estimated GC duration. 2584 const double gc_duration_seconds = NsToMs(collector_ran->GetDurationNs()) / 1000.0; 2585 // Estimate how many remaining bytes we will have when we need to start the next GC. 2586 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2587 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2588 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2589 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2590 // A never going to happen situation that from the estimated allocation rate we will exceed 2591 // the applications entire footprint with the given estimated allocation rate. Schedule 2592 // another GC nearly straight away. 2593 remaining_bytes = kMinConcurrentRemainingBytes; 2594 } 2595 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2596 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2597 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2598 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2599 // right away. 2600 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2601 static_cast<size_t>(bytes_allocated)); 2602 } 2603 } 2604} 2605 2606void Heap::ClearGrowthLimit() { 2607 growth_limit_ = capacity_; 2608 non_moving_space_->ClearGrowthLimit(); 2609} 2610 2611void Heap::AddFinalizerReference(Thread* self, mirror::Object* object) { 2612 ScopedObjectAccess soa(self); 2613 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(object)); 2614 jvalue args[1]; 2615 args[0].l = arg.get(); 2616 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2617} 2618 2619void Heap::EnqueueClearedReferences() { 2620 Thread* self = Thread::Current(); 2621 Locks::mutator_lock_->AssertNotHeld(self); 2622 if (!cleared_references_.IsEmpty()) { 2623 // When a runtime isn't started there are no reference queues to care about so ignore. 2624 if (LIKELY(Runtime::Current()->IsStarted())) { 2625 ScopedObjectAccess soa(self); 2626 ScopedLocalRef<jobject> arg(self->GetJniEnv(), 2627 soa.AddLocalReference<jobject>(cleared_references_.GetList())); 2628 jvalue args[1]; 2629 args[0].l = arg.get(); 2630 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_ReferenceQueue_add, args); 2631 } 2632 cleared_references_.Clear(); 2633 } 2634} 2635 2636void Heap::RequestConcurrentGC(Thread* self) { 2637 // Make sure that we can do a concurrent GC. 2638 Runtime* runtime = Runtime::Current(); 2639 if (runtime == NULL || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2640 self->IsHandlingStackOverflow()) { 2641 return; 2642 } 2643 // We already have a request pending, no reason to start more until we update 2644 // concurrent_start_bytes_. 2645 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2646 JNIEnv* env = self->GetJniEnv(); 2647 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2648 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2649 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2650 WellKnownClasses::java_lang_Daemons_requestGC); 2651 CHECK(!env->ExceptionCheck()); 2652} 2653 2654void Heap::ConcurrentGC(Thread* self) { 2655 if (Runtime::Current()->IsShuttingDown(self)) { 2656 return; 2657 } 2658 // Wait for any GCs currently running to finish. 2659 if (WaitForGcToComplete(self) == collector::kGcTypeNone) { 2660 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2661 // instead. E.g. can't do partial, so do full instead. 2662 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2663 collector::kGcTypeNone) { 2664 for (collector::GcType gc_type : gc_plan_) { 2665 // Attempt to run the collector, if we succeed, we are done. 2666 if (gc_type > next_gc_type_ && 2667 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2668 break; 2669 } 2670 } 2671 } 2672 } 2673} 2674 2675void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2676 Thread* self = Thread::Current(); 2677 { 2678 MutexLock mu(self, *heap_trim_request_lock_); 2679 if (desired_collector_type_ == desired_collector_type) { 2680 return; 2681 } 2682 heap_transition_target_time_ = std::max(heap_transition_target_time_, NanoTime() + delta_time); 2683 desired_collector_type_ = desired_collector_type; 2684 } 2685 SignalHeapTrimDaemon(self); 2686} 2687 2688void Heap::RequestHeapTrim() { 2689 // Request a heap trim only if we do not currently care about pause times. 2690 if (CareAboutPauseTimes()) { 2691 return; 2692 } 2693 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2694 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2695 // a space it will hold its lock and can become a cause of jank. 2696 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2697 // forking. 2698 2699 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2700 // because that only marks object heads, so a large array looks like lots of empty space. We 2701 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2702 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2703 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2704 // not how much use we're making of those pages. 2705 2706 Thread* self = Thread::Current(); 2707 Runtime* runtime = Runtime::Current(); 2708 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2709 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2710 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2711 // as we don't hold the lock while requesting the trim). 2712 return; 2713 } 2714 { 2715 MutexLock mu(self, *heap_trim_request_lock_); 2716 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2717 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2718 // just yet. 2719 return; 2720 } 2721 heap_trim_request_pending_ = true; 2722 } 2723 // Notify the daemon thread which will actually do the heap trim. 2724 SignalHeapTrimDaemon(self); 2725} 2726 2727void Heap::SignalHeapTrimDaemon(Thread* self) { 2728 JNIEnv* env = self->GetJniEnv(); 2729 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2730 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2731 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2732 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2733 CHECK(!env->ExceptionCheck()); 2734} 2735 2736void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2737 if (rosalloc_space_ != nullptr) { 2738 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2739 } 2740 if (bump_pointer_space_ != nullptr) { 2741 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2742 } 2743} 2744 2745void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2746 if (rosalloc_space_ != nullptr) { 2747 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2748 } 2749} 2750 2751void Heap::RevokeAllThreadLocalBuffers() { 2752 if (rosalloc_space_ != nullptr) { 2753 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2754 } 2755 if (bump_pointer_space_ != nullptr) { 2756 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 2757 } 2758} 2759 2760bool Heap::IsGCRequestPending() const { 2761 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 2762} 2763 2764void Heap::RunFinalization(JNIEnv* env) { 2765 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 2766 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 2767 CHECK(WellKnownClasses::java_lang_System != nullptr); 2768 WellKnownClasses::java_lang_System_runFinalization = 2769 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 2770 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 2771 } 2772 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 2773 WellKnownClasses::java_lang_System_runFinalization); 2774} 2775 2776void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 2777 Thread* self = ThreadForEnv(env); 2778 if (native_need_to_run_finalization_) { 2779 RunFinalization(env); 2780 UpdateMaxNativeFootprint(); 2781 native_need_to_run_finalization_ = false; 2782 } 2783 // Total number of native bytes allocated. 2784 native_bytes_allocated_.FetchAndAdd(bytes); 2785 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_gc_watermark_) { 2786 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 2787 collector::kGcTypeFull; 2788 2789 // The second watermark is higher than the gc watermark. If you hit this it means you are 2790 // allocating native objects faster than the GC can keep up with. 2791 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2792 if (WaitForGcToComplete(self) != collector::kGcTypeNone) { 2793 // Just finished a GC, attempt to run finalizers. 2794 RunFinalization(env); 2795 CHECK(!env->ExceptionCheck()); 2796 } 2797 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 2798 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2799 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 2800 RunFinalization(env); 2801 native_need_to_run_finalization_ = false; 2802 CHECK(!env->ExceptionCheck()); 2803 } 2804 // We have just run finalizers, update the native watermark since it is very likely that 2805 // finalizers released native managed allocations. 2806 UpdateMaxNativeFootprint(); 2807 } else if (!IsGCRequestPending()) { 2808 if (IsGcConcurrent()) { 2809 RequestConcurrentGC(self); 2810 } else { 2811 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 2812 } 2813 } 2814 } 2815} 2816 2817void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 2818 int expected_size, new_size; 2819 do { 2820 expected_size = native_bytes_allocated_.Load(); 2821 new_size = expected_size - bytes; 2822 if (UNLIKELY(new_size < 0)) { 2823 ScopedObjectAccess soa(env); 2824 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 2825 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 2826 "registered as allocated", bytes, expected_size).c_str()); 2827 break; 2828 } 2829 } while (!native_bytes_allocated_.CompareAndSwap(expected_size, new_size)); 2830} 2831 2832size_t Heap::GetTotalMemory() const { 2833 size_t ret = 0; 2834 for (const auto& space : continuous_spaces_) { 2835 // Currently don't include the image space. 2836 if (!space->IsImageSpace()) { 2837 ret += space->Size(); 2838 } 2839 } 2840 for (const auto& space : discontinuous_spaces_) { 2841 if (space->IsLargeObjectSpace()) { 2842 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 2843 } 2844 } 2845 return ret; 2846} 2847 2848void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 2849 DCHECK(mod_union_table != nullptr); 2850 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 2851} 2852 2853void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 2854 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 2855 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 2856 strlen(ClassHelper(c).GetDescriptor()) == 0); 2857 CHECK_GE(byte_count, sizeof(mirror::Object)); 2858} 2859 2860void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 2861 CHECK(remembered_set != nullptr); 2862 space::Space* space = remembered_set->GetSpace(); 2863 CHECK(space != nullptr); 2864 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2865 remembered_sets_.Put(space, remembered_set); 2866 CHECK(remembered_sets_.find(space) != remembered_sets_.end()); 2867} 2868 2869void Heap::RemoveRememberedSet(space::Space* space) { 2870 CHECK(space != nullptr); 2871 auto it = remembered_sets_.find(space); 2872 CHECK(it != remembered_sets_.end()); 2873 remembered_sets_.erase(it); 2874 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2875} 2876 2877void Heap::ClearMarkedObjects() { 2878 // Clear all of the spaces' mark bitmaps. 2879 for (const auto& space : GetContinuousSpaces()) { 2880 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 2881 if (space->GetLiveBitmap() != mark_bitmap) { 2882 mark_bitmap->Clear(); 2883 } 2884 } 2885 // Clear the marked objects in the discontinous space object sets. 2886 for (const auto& space : GetDiscontinuousSpaces()) { 2887 space->GetMarkBitmap()->Clear(); 2888 } 2889} 2890 2891} // namespace gc 2892} // namespace art 2893