heap.cc revision be0562fb14e6754ee932b8d9c97e2a6df3a91119
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 <memory> 24#include <vector> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/concurrent_copying.h" 39#include "gc/collector/mark_compact.h" 40#include "gc/collector/mark_sweep-inl.h" 41#include "gc/collector/partial_mark_sweep.h" 42#include "gc/collector/semi_space.h" 43#include "gc/collector/sticky_mark_sweep.h" 44#include "gc/reference_processor.h" 45#include "gc/space/bump_pointer_space.h" 46#include "gc/space/dlmalloc_space-inl.h" 47#include "gc/space/image_space.h" 48#include "gc/space/large_object_space.h" 49#include "gc/space/rosalloc_space-inl.h" 50#include "gc/space/space-inl.h" 51#include "gc/space/zygote_space.h" 52#include "entrypoints/quick/quick_alloc_entrypoints.h" 53#include "heap-inl.h" 54#include "image.h" 55#include "mirror/art_field-inl.h" 56#include "mirror/class-inl.h" 57#include "mirror/object.h" 58#include "mirror/object-inl.h" 59#include "mirror/object_array-inl.h" 60#include "mirror/reference-inl.h" 61#include "object_utils.h" 62#include "os.h" 63#include "reflection.h" 64#include "runtime.h" 65#include "ScopedLocalRef.h" 66#include "scoped_thread_state_change.h" 67#include "handle_scope-inl.h" 68#include "thread_list.h" 69#include "well_known_classes.h" 70 71namespace art { 72 73namespace gc { 74 75static constexpr size_t kCollectorTransitionStressIterations = 0; 76static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 77static constexpr bool kGCALotMode = false; 78static constexpr size_t kGcAlotInterval = KB; 79// Minimum amount of remaining bytes before a concurrent GC is triggered. 80static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 81static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 82// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 83// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 84// threads (lower pauses, use less memory bandwidth). 85static constexpr double kStickyGcThroughputAdjustment = 1.0; 86// Whether or not we use the free list large object space. 87static constexpr bool kUseFreeListSpaceForLOS = false; 88// Whether or not we compact the zygote in PreZygoteFork. 89static constexpr bool kCompactZygote = kMovingCollector; 90static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 91// How many reserve entries are at the end of the allocation stack, these are only needed if the 92// allocation stack overflows. 93static constexpr size_t kAllocationStackReserveSize = 1024; 94// Default mark stack size in bytes. 95static const size_t kDefaultMarkStackSize = 64 * KB; 96// Define space name. 97static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 98static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 99static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 100 101Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 102 double target_utilization, double foreground_heap_growth_multiplier, size_t capacity, 103 const std::string& image_file_name, const InstructionSet image_instruction_set, 104 CollectorType foreground_collector_type, CollectorType background_collector_type, 105 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 106 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 107 bool ignore_max_footprint, bool use_tlab, 108 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 109 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 110 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 111 uint64_t min_interval_homogeneous_space_compaction_by_oom) 112 : non_moving_space_(nullptr), 113 rosalloc_space_(nullptr), 114 dlmalloc_space_(nullptr), 115 main_space_(nullptr), 116 collector_type_(kCollectorTypeNone), 117 foreground_collector_type_(foreground_collector_type), 118 background_collector_type_(background_collector_type), 119 desired_collector_type_(foreground_collector_type_), 120 heap_trim_request_lock_(nullptr), 121 last_trim_time_(0), 122 heap_transition_or_trim_target_time_(0), 123 heap_trim_request_pending_(false), 124 parallel_gc_threads_(parallel_gc_threads), 125 conc_gc_threads_(conc_gc_threads), 126 low_memory_mode_(low_memory_mode), 127 long_pause_log_threshold_(long_pause_log_threshold), 128 long_gc_log_threshold_(long_gc_log_threshold), 129 ignore_max_footprint_(ignore_max_footprint), 130 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 131 have_zygote_space_(false), 132 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 133 collector_type_running_(kCollectorTypeNone), 134 last_gc_type_(collector::kGcTypeNone), 135 next_gc_type_(collector::kGcTypePartial), 136 capacity_(capacity), 137 growth_limit_(growth_limit), 138 max_allowed_footprint_(initial_size), 139 native_footprint_gc_watermark_(initial_size), 140 native_footprint_limit_(2 * initial_size), 141 native_need_to_run_finalization_(false), 142 // Initially assume we perceive jank in case the process state is never updated. 143 process_state_(kProcessStateJankPerceptible), 144 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 145 total_bytes_freed_ever_(0), 146 total_objects_freed_ever_(0), 147 num_bytes_allocated_(0), 148 native_bytes_allocated_(0), 149 gc_memory_overhead_(0), 150 verify_missing_card_marks_(false), 151 verify_system_weaks_(false), 152 verify_pre_gc_heap_(verify_pre_gc_heap), 153 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 154 verify_post_gc_heap_(verify_post_gc_heap), 155 verify_mod_union_table_(false), 156 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 157 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 158 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 159 last_gc_time_ns_(NanoTime()), 160 allocation_rate_(0), 161 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 162 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 163 * verification is enabled, we limit the size of allocation stacks to speed up their 164 * searching. 165 */ 166 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 167 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 168 current_allocator_(kAllocatorTypeDlMalloc), 169 current_non_moving_allocator_(kAllocatorTypeNonMoving), 170 bump_pointer_space_(nullptr), 171 temp_space_(nullptr), 172 min_free_(min_free), 173 max_free_(max_free), 174 target_utilization_(target_utilization), 175 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 176 total_wait_time_(0), 177 total_allocation_time_(0), 178 verify_object_mode_(kVerifyObjectModeDisabled), 179 disable_moving_gc_count_(0), 180 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 181 use_tlab_(use_tlab), 182 main_space_backup_(nullptr), 183 min_interval_homogeneous_space_compaction_by_oom_(min_interval_homogeneous_space_compaction_by_oom), 184 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 185 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 186 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 187 LOG(INFO) << "Heap() entering"; 188 } 189 const bool is_zygote = Runtime::Current()->IsZygote(); 190 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 191 // entrypoints. 192 if (!is_zygote) { 193 large_object_threshold_ = kDefaultLargeObjectThreshold; 194 // Background compaction is currently not supported for command line runs. 195 if (background_collector_type_ != foreground_collector_type_) { 196 VLOG(heap) << "Disabling background compaction for non zygote"; 197 background_collector_type_ = foreground_collector_type_; 198 } 199 } 200 ChangeCollector(desired_collector_type_); 201 202 live_bitmap_.reset(new accounting::HeapBitmap(this)); 203 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 204 // Requested begin for the alloc space, to follow the mapped image and oat files 205 byte* requested_alloc_space_begin = nullptr; 206 if (!image_file_name.empty()) { 207 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 208 image_instruction_set); 209 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 210 AddSpace(image_space); 211 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 212 // isn't going to get in the middle 213 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 214 CHECK_GT(oat_file_end_addr, image_space->End()); 215 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 216 } 217 218 /* 219 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 220 +- nonmoving space (kNonMovingSpaceCapacity) +- 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 222 +- main alloc space (capacity_) +- 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 224 +- main alloc space 1 (capacity_) +- 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 226 */ 227 bool create_backup_main_space = 228 background_collector_type == gc::kCollectorTypeHomogeneousSpaceCompact || 229 use_homogeneous_space_compaction_for_oom; 230 if (is_zygote) { 231 // Reserve the address range before we create the non moving space to make sure bitmaps don't 232 // take it. 233 std::string error_str; 234 MemMap* main_space_map = MemMap::MapAnonymous( 235 kMemMapSpaceName[0], requested_alloc_space_begin + kNonMovingSpaceCapacity, capacity_, 236 PROT_READ | PROT_WRITE, true, &error_str); 237 CHECK(main_space_map != nullptr) << error_str; 238 MemMap* main_space_1_map = nullptr; 239 // Attempt to reserve an extra mem_map for homogeneous space compaction right after the main space map. 240 if (create_backup_main_space) { 241 main_space_1_map = MemMap::MapAnonymous(kMemMapSpaceName[1], main_space_map->End(), capacity_, 242 PROT_READ | PROT_WRITE, true, &error_str); 243 if (main_space_1_map == nullptr) { 244 LOG(WARNING) << "Failed to create map " << kMemMapSpaceName[1] << " with error " 245 << error_str; 246 } 247 } 248 // Non moving space is always dlmalloc since we currently don't have support for multiple 249 // active rosalloc spaces. 250 non_moving_space_ = space::DlMallocSpace::Create( 251 "zygote / non moving space", initial_size, kNonMovingSpaceCapacity, 252 kNonMovingSpaceCapacity, requested_alloc_space_begin, false); 253 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 254 CreateMainMallocSpace(main_space_map, initial_size, growth_limit_, capacity_); 255 if (main_space_1_map != nullptr) { 256 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 257 main_space_backup_ = CreateMallocSpaceFromMemMap(main_space_1_map, initial_size, 258 growth_limit_, capacity_, name, true); 259 } 260 } else { 261 std::string error_str; 262 byte* request_begin = requested_alloc_space_begin; 263 if (request_begin == nullptr) { 264 // Disable homogeneous space compaction since we don't have an image. 265 create_backup_main_space = false; 266 } 267 MemMap* main_space_1_map = nullptr; 268 if (create_backup_main_space) { 269 request_begin += kNonMovingSpaceCapacity; 270 // Attempt to reserve an extra mem_map for homogeneous space compaction right after the main space map. 271 main_space_1_map = MemMap::MapAnonymous(kMemMapSpaceName[1], request_begin + capacity_, 272 capacity_, PROT_READ | PROT_WRITE, true, &error_str); 273 if (main_space_1_map == nullptr) { 274 LOG(WARNING) << "Failed to create map " << kMemMapSpaceName[1] << " with error " 275 << error_str; 276 request_begin = requested_alloc_space_begin; 277 } 278 } 279 MemMap* main_space_map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity_, 280 PROT_READ | PROT_WRITE, true, &error_str); 281 CHECK(main_space_map != nullptr) << error_str; 282 // Introduce a seperate non moving space. 283 if (main_space_1_map != nullptr) { 284 // Do this before creating the main malloc space to prevent bitmaps from being placed here. 285 non_moving_space_ = space::DlMallocSpace::Create( 286 "non moving space", kDefaultInitialSize, kNonMovingSpaceCapacity, kNonMovingSpaceCapacity, 287 requested_alloc_space_begin, false); 288 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 289 } 290 // Create the main free list space, which doubles as the non moving space. We can do this since 291 // non zygote means that we won't have any background compaction. 292 CreateMainMallocSpace(main_space_map, initial_size, growth_limit_, capacity_); 293 if (main_space_1_map != nullptr) { 294 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 295 main_space_backup_ = CreateMallocSpaceFromMemMap(main_space_1_map, initial_size, 296 growth_limit_, capacity_, name, true); 297 CHECK(main_space_backup_ != nullptr); 298 } else { 299 non_moving_space_ = main_space_; 300 } 301 } 302 CHECK(non_moving_space_ != nullptr); 303 304 // We need to create the bump pointer if the foreground collector is a compacting GC. We only 305 // create the bump pointer space if we are not a moving foreground collector but have a moving 306 // background collector since the heap transition code will create the temp space by recycling 307 // the bitmap from the main space. 308 if (kMovingCollector && 309 (IsMovingGc(foreground_collector_type_) || IsMovingGc(background_collector_type_))) { 310 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 311 // Divide by 2 for a temporary fix for reducing virtual memory usage. 312 const size_t bump_pointer_space_capacity = capacity_ / 2; 313 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space", 314 bump_pointer_space_capacity, nullptr); 315 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 316 AddSpace(bump_pointer_space_); 317 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 318 bump_pointer_space_capacity, nullptr); 319 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 320 AddSpace(temp_space_); 321 } 322 if (non_moving_space_ != main_space_) { 323 AddSpace(non_moving_space_); 324 } 325 if (main_space_backup_ != nullptr) { 326 AddSpace(main_space_backup_); 327 } else { 328 const char* disable_msg = "Disabling homogenous space compact due to no backup main space"; 329 if (background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact) { 330 background_collector_type_ = collector_type_; 331 LOG(WARNING) << disable_msg; 332 } else if (use_homogeneous_space_compaction_for_oom_) { 333 LOG(WARNING) << disable_msg; 334 } 335 use_homogeneous_space_compaction_for_oom_ = false; 336 } 337 if (main_space_ != nullptr) { 338 AddSpace(main_space_); 339 } 340 341 // Allocate the large object space. 342 if (kUseFreeListSpaceForLOS) { 343 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 344 } else { 345 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 346 } 347 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 348 AddSpace(large_object_space_); 349 350 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 351 CHECK(!continuous_spaces_.empty()); 352 353 // Relies on the spaces being sorted. 354 byte* heap_begin = continuous_spaces_.front()->Begin(); 355 byte* heap_end = continuous_spaces_.back()->Limit(); 356 size_t heap_capacity = heap_end - heap_begin; 357 358 // Allocate the card table. 359 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 360 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 361 362 // Card cache for now since it makes it easier for us to update the references to the copying 363 // spaces. 364 accounting::ModUnionTable* mod_union_table = 365 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 366 GetImageSpace()); 367 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 368 AddModUnionTable(mod_union_table); 369 370 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 371 accounting::RememberedSet* non_moving_space_rem_set = 372 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 373 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 374 AddRememberedSet(non_moving_space_rem_set); 375 } 376 377 // TODO: Count objects in the image space here. 378 num_bytes_allocated_.StoreRelaxed(0); 379 380 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 381 kDefaultMarkStackSize)); 382 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 383 allocation_stack_.reset(accounting::ObjectStack::Create( 384 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 385 live_stack_.reset(accounting::ObjectStack::Create( 386 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 387 388 // It's still too early to take a lock because there are no threads yet, but we can create locks 389 // now. We don't create it earlier to make it clear that you can't use locks during heap 390 // initialization. 391 gc_complete_lock_ = new Mutex("GC complete lock"); 392 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 393 *gc_complete_lock_)); 394 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 395 last_gc_size_ = GetBytesAllocated(); 396 397 if (ignore_max_footprint_) { 398 SetIdealFootprint(std::numeric_limits<size_t>::max()); 399 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 400 } 401 CHECK_NE(max_allowed_footprint_, 0U); 402 403 // Create our garbage collectors. 404 for (size_t i = 0; i < 2; ++i) { 405 const bool concurrent = i != 0; 406 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 407 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 408 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 409 } 410 if (kMovingCollector) { 411 // TODO: Clean this up. 412 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 413 semi_space_collector_ = new collector::SemiSpace(this, generational, 414 generational ? "generational" : ""); 415 garbage_collectors_.push_back(semi_space_collector_); 416 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 417 garbage_collectors_.push_back(concurrent_copying_collector_); 418 mark_compact_collector_ = new collector::MarkCompact(this); 419 garbage_collectors_.push_back(mark_compact_collector_); 420 } 421 422 if (GetImageSpace() != nullptr && main_space_ != nullptr) { 423 // Check that there's no gap between the image space and the main space so that the immune 424 // region won't break (eg. due to a large object allocated in the gap). 425 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), main_space_->GetMemMap()); 426 if (!no_gap) { 427 MemMap::DumpMaps(LOG(ERROR)); 428 LOG(FATAL) << "There's a gap between the image space and the main space"; 429 } 430 } 431 432 if (running_on_valgrind_) { 433 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 434 } 435 436 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 437 LOG(INFO) << "Heap() exiting"; 438 } 439} 440 441space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 442 size_t growth_limit, size_t capacity, 443 const char* name, bool can_move_objects) { 444 space::MallocSpace* malloc_space = nullptr; 445 if (kUseRosAlloc) { 446 // Create rosalloc space. 447 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 448 initial_size, growth_limit, capacity, 449 low_memory_mode_, can_move_objects); 450 } else { 451 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 452 initial_size, growth_limit, capacity, 453 can_move_objects); 454 } 455 if (collector::SemiSpace::kUseRememberedSet) { 456 accounting::RememberedSet* rem_set = 457 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 458 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 459 AddRememberedSet(rem_set); 460 } 461 CHECK(malloc_space != nullptr) << "Failed to create " << name; 462 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 463 return malloc_space; 464} 465 466void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 467 size_t capacity) { 468 // Is background compaction is enabled? 469 bool can_move_objects = IsMovingGc(background_collector_type_) != 470 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 471 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 472 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 473 // from the main space to the zygote space. If background compaction is enabled, always pass in 474 // that we can move objets. 475 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 476 // After the zygote we want this to be false if we don't have background compaction enabled so 477 // that getting primitive array elements is faster. 478 can_move_objects = !have_zygote_space_; 479 } 480 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 481 RemoveRememberedSet(main_space_); 482 } 483 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 484 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 485 can_move_objects); 486 SetSpaceAsDefault(main_space_); 487 VLOG(heap) << "Created main space " << main_space_; 488} 489 490void Heap::ChangeAllocator(AllocatorType allocator) { 491 if (current_allocator_ != allocator) { 492 // These two allocators are only used internally and don't have any entrypoints. 493 CHECK_NE(allocator, kAllocatorTypeLOS); 494 CHECK_NE(allocator, kAllocatorTypeNonMoving); 495 current_allocator_ = allocator; 496 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 497 SetQuickAllocEntryPointsAllocator(current_allocator_); 498 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 499 } 500} 501 502void Heap::DisableCompaction() { 503 if (IsMovingGc(foreground_collector_type_)) { 504 foreground_collector_type_ = kCollectorTypeCMS; 505 } 506 if (IsMovingGc(background_collector_type_)) { 507 background_collector_type_ = foreground_collector_type_; 508 } 509 TransitionCollector(foreground_collector_type_); 510} 511 512std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 513 if (!IsValidContinuousSpaceObjectAddress(klass)) { 514 return StringPrintf("<non heap address klass %p>", klass); 515 } 516 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 517 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 518 std::string result("["); 519 result += SafeGetClassDescriptor(component_type); 520 return result; 521 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 522 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 523 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 524 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 525 } else { 526 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 527 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 528 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 529 } 530 const DexFile* dex_file = dex_cache->GetDexFile(); 531 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 532 if (class_def_idx == DexFile::kDexNoIndex16) { 533 return "<class def not found>"; 534 } 535 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 536 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 537 return dex_file->GetTypeDescriptor(type_id); 538 } 539} 540 541std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 542 if (obj == nullptr) { 543 return "null"; 544 } 545 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 546 if (klass == nullptr) { 547 return "(class=null)"; 548 } 549 std::string result(SafeGetClassDescriptor(klass)); 550 if (obj->IsClass()) { 551 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 552 } 553 return result; 554} 555 556void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 557 if (obj == nullptr) { 558 stream << "(obj=null)"; 559 return; 560 } 561 if (IsAligned<kObjectAlignment>(obj)) { 562 space::Space* space = nullptr; 563 // Don't use find space since it only finds spaces which actually contain objects instead of 564 // spaces which may contain objects (e.g. cleared bump pointer spaces). 565 for (const auto& cur_space : continuous_spaces_) { 566 if (cur_space->HasAddress(obj)) { 567 space = cur_space; 568 break; 569 } 570 } 571 // Unprotect all the spaces. 572 for (const auto& space : continuous_spaces_) { 573 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 574 } 575 stream << "Object " << obj; 576 if (space != nullptr) { 577 stream << " in space " << *space; 578 } 579 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 580 stream << "\nclass=" << klass; 581 if (klass != nullptr) { 582 stream << " type= " << SafePrettyTypeOf(obj); 583 } 584 // Re-protect the address we faulted on. 585 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 586 } 587} 588 589bool Heap::IsCompilingBoot() const { 590 for (const auto& space : continuous_spaces_) { 591 if (space->IsImageSpace() || space->IsZygoteSpace()) { 592 return false; 593 } 594 } 595 return true; 596} 597 598bool Heap::HasImageSpace() const { 599 for (const auto& space : continuous_spaces_) { 600 if (space->IsImageSpace()) { 601 return true; 602 } 603 } 604 return false; 605} 606 607void Heap::IncrementDisableMovingGC(Thread* self) { 608 // Need to do this holding the lock to prevent races where the GC is about to run / running when 609 // we attempt to disable it. 610 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 611 MutexLock mu(self, *gc_complete_lock_); 612 ++disable_moving_gc_count_; 613 if (IsMovingGc(collector_type_running_)) { 614 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 615 } 616} 617 618void Heap::DecrementDisableMovingGC(Thread* self) { 619 MutexLock mu(self, *gc_complete_lock_); 620 CHECK_GE(disable_moving_gc_count_, 0U); 621 --disable_moving_gc_count_; 622} 623 624void Heap::UpdateProcessState(ProcessState process_state) { 625 if (process_state_ != process_state) { 626 process_state_ = process_state; 627 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 628 // Start at index 1 to avoid "is always false" warning. 629 // Have iteration 1 always transition the collector. 630 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 631 ? foreground_collector_type_ : background_collector_type_); 632 usleep(kCollectorTransitionStressWait); 633 } 634 if (process_state_ == kProcessStateJankPerceptible) { 635 // Transition back to foreground right away to prevent jank. 636 RequestCollectorTransition(foreground_collector_type_, 0); 637 } else { 638 // Don't delay for debug builds since we may want to stress test the GC. 639 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 640 // special handling which does a homogenous space compaction once but then doesn't transition 641 // the collector. 642 RequestCollectorTransition(background_collector_type_, 643 kIsDebugBuild ? 0 : kCollectorTransitionWait); 644 } 645 } 646} 647 648void Heap::CreateThreadPool() { 649 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 650 if (num_threads != 0) { 651 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 652 } 653} 654 655void Heap::VisitObjects(ObjectCallback callback, void* arg) { 656 Thread* self = Thread::Current(); 657 // GCs can move objects, so don't allow this. 658 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 659 if (bump_pointer_space_ != nullptr) { 660 // Visit objects in bump pointer space. 661 bump_pointer_space_->Walk(callback, arg); 662 } 663 // TODO: Switch to standard begin and end to use ranged a based loop. 664 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 665 it < end; ++it) { 666 mirror::Object* obj = *it; 667 if (obj != nullptr && obj->GetClass() != nullptr) { 668 // Avoid the race condition caused by the object not yet being written into the allocation 669 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 670 // there can be nulls on the allocation stack. 671 callback(obj, arg); 672 } 673 } 674 GetLiveBitmap()->Walk(callback, arg); 675 self->EndAssertNoThreadSuspension(old_cause); 676} 677 678void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 679 space::ContinuousSpace* space1 = rosalloc_space_ != nullptr ? rosalloc_space_ : non_moving_space_; 680 space::ContinuousSpace* space2 = dlmalloc_space_ != nullptr ? dlmalloc_space_ : non_moving_space_; 681 // This is just logic to handle a case of either not having a rosalloc or dlmalloc space. 682 // TODO: Generalize this to n bitmaps? 683 if (space1 == nullptr) { 684 DCHECK(space2 != nullptr); 685 space1 = space2; 686 } 687 if (space2 == nullptr) { 688 DCHECK(space1 != nullptr); 689 space2 = space1; 690 } 691 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 692 large_object_space_->GetLiveBitmap(), stack); 693} 694 695void Heap::DeleteThreadPool() { 696 thread_pool_.reset(nullptr); 697} 698 699void Heap::AddSpace(space::Space* space) { 700 CHECK(space != nullptr); 701 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 702 if (space->IsContinuousSpace()) { 703 DCHECK(!space->IsDiscontinuousSpace()); 704 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 705 // Continuous spaces don't necessarily have bitmaps. 706 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 707 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 708 if (live_bitmap != nullptr) { 709 DCHECK(mark_bitmap != nullptr); 710 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 711 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 712 } 713 continuous_spaces_.push_back(continuous_space); 714 // Ensure that spaces remain sorted in increasing order of start address. 715 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 716 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 717 return a->Begin() < b->Begin(); 718 }); 719 } else { 720 DCHECK(space->IsDiscontinuousSpace()); 721 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 722 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 723 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 724 discontinuous_spaces_.push_back(discontinuous_space); 725 } 726 if (space->IsAllocSpace()) { 727 alloc_spaces_.push_back(space->AsAllocSpace()); 728 } 729} 730 731void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 732 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 733 if (continuous_space->IsDlMallocSpace()) { 734 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 735 } else if (continuous_space->IsRosAllocSpace()) { 736 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 737 } 738} 739 740void Heap::RemoveSpace(space::Space* space) { 741 DCHECK(space != nullptr); 742 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 743 if (space->IsContinuousSpace()) { 744 DCHECK(!space->IsDiscontinuousSpace()); 745 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 746 // Continuous spaces don't necessarily have bitmaps. 747 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 748 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 749 if (live_bitmap != nullptr) { 750 DCHECK(mark_bitmap != nullptr); 751 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 752 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 753 } 754 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 755 DCHECK(it != continuous_spaces_.end()); 756 continuous_spaces_.erase(it); 757 } else { 758 DCHECK(space->IsDiscontinuousSpace()); 759 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 760 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 761 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 762 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 763 discontinuous_space); 764 DCHECK(it != discontinuous_spaces_.end()); 765 discontinuous_spaces_.erase(it); 766 } 767 if (space->IsAllocSpace()) { 768 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 769 DCHECK(it != alloc_spaces_.end()); 770 alloc_spaces_.erase(it); 771 } 772} 773 774void Heap::RegisterGCAllocation(size_t bytes) { 775 if (this != nullptr) { 776 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 777 } 778} 779 780void Heap::RegisterGCDeAllocation(size_t bytes) { 781 if (this != nullptr) { 782 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 783 } 784} 785 786void Heap::DumpGcPerformanceInfo(std::ostream& os) { 787 // Dump cumulative timings. 788 os << "Dumping cumulative Gc timings\n"; 789 uint64_t total_duration = 0; 790 // Dump cumulative loggers for each GC type. 791 uint64_t total_paused_time = 0; 792 for (auto& collector : garbage_collectors_) { 793 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 794 const size_t iterations = logger.GetIterations(); 795 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 796 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 797 os << ConstDumpable<CumulativeLogger>(logger); 798 const uint64_t total_ns = logger.GetTotalNs(); 799 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 800 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 801 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 802 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 803 Histogram<uint64_t>::CumulativeData cumulative_data; 804 pause_histogram.CreateHistogram(&cumulative_data); 805 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 806 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 807 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 808 << collector->GetName() << " freed: " << freed_objects 809 << " objects with total size " << PrettySize(freed_bytes) << "\n" 810 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 811 << PrettySize(freed_bytes / seconds) << "/s\n"; 812 total_duration += total_ns; 813 total_paused_time += total_pause_ns; 814 } 815 collector->ResetMeasurements(); 816 } 817 uint64_t allocation_time = 818 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 819 if (total_duration != 0) { 820 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 821 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 822 os << "Mean GC size throughput: " 823 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 824 os << "Mean GC object throughput: " 825 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 826 } 827 size_t total_objects_allocated = GetObjectsAllocatedEver(); 828 os << "Total number of allocations: " << total_objects_allocated << "\n"; 829 size_t total_bytes_allocated = GetBytesAllocatedEver(); 830 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 831 if (kMeasureAllocationTime) { 832 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 833 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 834 << "\n"; 835 } 836 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 837 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 838 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 839 BaseMutex::DumpAll(os); 840} 841 842Heap::~Heap() { 843 VLOG(heap) << "Starting ~Heap()"; 844 STLDeleteElements(&garbage_collectors_); 845 // If we don't reset then the mark stack complains in its destructor. 846 allocation_stack_->Reset(); 847 live_stack_->Reset(); 848 STLDeleteValues(&mod_union_tables_); 849 STLDeleteValues(&remembered_sets_); 850 STLDeleteElements(&continuous_spaces_); 851 STLDeleteElements(&discontinuous_spaces_); 852 delete gc_complete_lock_; 853 delete heap_trim_request_lock_; 854 VLOG(heap) << "Finished ~Heap()"; 855} 856 857space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 858 bool fail_ok) const { 859 for (const auto& space : continuous_spaces_) { 860 if (space->Contains(obj)) { 861 return space; 862 } 863 } 864 if (!fail_ok) { 865 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 866 } 867 return NULL; 868} 869 870space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 871 bool fail_ok) const { 872 for (const auto& space : discontinuous_spaces_) { 873 if (space->Contains(obj)) { 874 return space; 875 } 876 } 877 if (!fail_ok) { 878 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 879 } 880 return NULL; 881} 882 883space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 884 space::Space* result = FindContinuousSpaceFromObject(obj, true); 885 if (result != NULL) { 886 return result; 887 } 888 return FindDiscontinuousSpaceFromObject(obj, true); 889} 890 891space::ImageSpace* Heap::GetImageSpace() const { 892 for (const auto& space : continuous_spaces_) { 893 if (space->IsImageSpace()) { 894 return space->AsImageSpace(); 895 } 896 } 897 return NULL; 898} 899 900void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 901 std::ostringstream oss; 902 size_t total_bytes_free = GetFreeMemory(); 903 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 904 << " free bytes"; 905 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 906 if (total_bytes_free >= byte_count) { 907 space::MallocSpace* space = nullptr; 908 if (allocator_type == kAllocatorTypeNonMoving) { 909 space = non_moving_space_; 910 } else if (allocator_type == kAllocatorTypeRosAlloc || 911 allocator_type == kAllocatorTypeDlMalloc) { 912 space = main_space_; 913 } 914 if (space != nullptr) { 915 space->LogFragmentationAllocFailure(oss, byte_count); 916 } 917 } 918 self->ThrowOutOfMemoryError(oss.str().c_str()); 919} 920 921void Heap::DoPendingTransitionOrTrim() { 922 Thread* self = Thread::Current(); 923 CollectorType desired_collector_type; 924 // Wait until we reach the desired transition time. 925 while (true) { 926 uint64_t wait_time; 927 { 928 MutexLock mu(self, *heap_trim_request_lock_); 929 desired_collector_type = desired_collector_type_; 930 uint64_t current_time = NanoTime(); 931 if (current_time >= heap_transition_or_trim_target_time_) { 932 break; 933 } 934 wait_time = heap_transition_or_trim_target_time_ - current_time; 935 } 936 ScopedThreadStateChange tsc(self, kSleeping); 937 usleep(wait_time / 1000); // Usleep takes microseconds. 938 } 939 // Launch homogeneous space compaction if it is desired. 940 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 941 if (!CareAboutPauseTimes()) { 942 PerformHomogeneousSpaceCompact(); 943 } 944 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 945 desired_collector_type = collector_type_; 946 return; 947 } 948 // Transition the collector if the desired collector type is not the same as the current 949 // collector type. 950 TransitionCollector(desired_collector_type); 951 if (!CareAboutPauseTimes()) { 952 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 953 // about pauses. 954 Runtime* runtime = Runtime::Current(); 955 runtime->GetThreadList()->SuspendAll(); 956 uint64_t start_time = NanoTime(); 957 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 958 VLOG(heap) << "Deflating " << count << " monitors took " 959 << PrettyDuration(NanoTime() - start_time); 960 runtime->GetThreadList()->ResumeAll(); 961 } 962 // Do a heap trim if it is needed. 963 Trim(); 964} 965 966void Heap::Trim() { 967 Thread* self = Thread::Current(); 968 { 969 MutexLock mu(self, *heap_trim_request_lock_); 970 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 971 return; 972 } 973 last_trim_time_ = NanoTime(); 974 heap_trim_request_pending_ = false; 975 } 976 { 977 // Need to do this before acquiring the locks since we don't want to get suspended while 978 // holding any locks. 979 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 980 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 981 // trimming. 982 MutexLock mu(self, *gc_complete_lock_); 983 // Ensure there is only one GC at a time. 984 WaitForGcToCompleteLocked(kGcCauseTrim, self); 985 collector_type_running_ = kCollectorTypeHeapTrim; 986 } 987 uint64_t start_ns = NanoTime(); 988 // Trim the managed spaces. 989 uint64_t total_alloc_space_allocated = 0; 990 uint64_t total_alloc_space_size = 0; 991 uint64_t managed_reclaimed = 0; 992 for (const auto& space : continuous_spaces_) { 993 if (space->IsMallocSpace()) { 994 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 995 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 996 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 997 // for a long period of time. 998 managed_reclaimed += malloc_space->Trim(); 999 } 1000 total_alloc_space_size += malloc_space->Size(); 1001 } 1002 } 1003 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 1004 if (bump_pointer_space_ != nullptr) { 1005 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1006 } 1007 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1008 static_cast<float>(total_alloc_space_size); 1009 uint64_t gc_heap_end_ns = NanoTime(); 1010 // We never move things in the native heap, so we can finish the GC at this point. 1011 FinishGC(self, collector::kGcTypeNone); 1012 size_t native_reclaimed = 0; 1013 // Only trim the native heap if we don't care about pauses. 1014 if (!CareAboutPauseTimes()) { 1015#if defined(USE_DLMALLOC) 1016 // Trim the native heap. 1017 dlmalloc_trim(0); 1018 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1019#elif defined(USE_JEMALLOC) 1020 // Jemalloc does it's own internal trimming. 1021#else 1022 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1023#endif 1024 } 1025 uint64_t end_ns = NanoTime(); 1026 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1027 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1028 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1029 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1030 << "%."; 1031} 1032 1033bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1034 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1035 // taking the lock. 1036 if (obj == nullptr) { 1037 return true; 1038 } 1039 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1040} 1041 1042bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1043 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1044} 1045 1046bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1047 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1048 return false; 1049 } 1050 for (const auto& space : continuous_spaces_) { 1051 if (space->HasAddress(obj)) { 1052 return true; 1053 } 1054 } 1055 return false; 1056} 1057 1058bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1059 bool search_live_stack, bool sorted) { 1060 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1061 return false; 1062 } 1063 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1064 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1065 if (obj == klass) { 1066 // This case happens for java.lang.Class. 1067 return true; 1068 } 1069 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1070 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1071 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1072 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1073 return temp_space_->Contains(obj); 1074 } 1075 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1076 space::DiscontinuousSpace* d_space = nullptr; 1077 if (c_space != nullptr) { 1078 if (c_space->GetLiveBitmap()->Test(obj)) { 1079 return true; 1080 } 1081 } else { 1082 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1083 if (d_space != nullptr) { 1084 if (d_space->GetLiveBitmap()->Test(obj)) { 1085 return true; 1086 } 1087 } 1088 } 1089 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1090 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1091 if (i > 0) { 1092 NanoSleep(MsToNs(10)); 1093 } 1094 if (search_allocation_stack) { 1095 if (sorted) { 1096 if (allocation_stack_->ContainsSorted(obj)) { 1097 return true; 1098 } 1099 } else if (allocation_stack_->Contains(obj)) { 1100 return true; 1101 } 1102 } 1103 1104 if (search_live_stack) { 1105 if (sorted) { 1106 if (live_stack_->ContainsSorted(obj)) { 1107 return true; 1108 } 1109 } else if (live_stack_->Contains(obj)) { 1110 return true; 1111 } 1112 } 1113 } 1114 // We need to check the bitmaps again since there is a race where we mark something as live and 1115 // then clear the stack containing it. 1116 if (c_space != nullptr) { 1117 if (c_space->GetLiveBitmap()->Test(obj)) { 1118 return true; 1119 } 1120 } else { 1121 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1122 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1123 return true; 1124 } 1125 } 1126 return false; 1127} 1128 1129std::string Heap::DumpSpaces() const { 1130 std::ostringstream oss; 1131 DumpSpaces(oss); 1132 return oss.str(); 1133} 1134 1135void Heap::DumpSpaces(std::ostream& stream) const { 1136 for (const auto& space : continuous_spaces_) { 1137 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1138 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1139 stream << space << " " << *space << "\n"; 1140 if (live_bitmap != nullptr) { 1141 stream << live_bitmap << " " << *live_bitmap << "\n"; 1142 } 1143 if (mark_bitmap != nullptr) { 1144 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1145 } 1146 } 1147 for (const auto& space : discontinuous_spaces_) { 1148 stream << space << " " << *space << "\n"; 1149 } 1150} 1151 1152void Heap::VerifyObjectBody(mirror::Object* obj) { 1153 if (this == nullptr && verify_object_mode_ == kVerifyObjectModeDisabled) { 1154 return; 1155 } 1156 // Ignore early dawn of the universe verifications. 1157 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1158 return; 1159 } 1160 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1161 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1162 CHECK(c != nullptr) << "Null class in object " << obj; 1163 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1164 CHECK(VerifyClassClass(c)); 1165 1166 if (verify_object_mode_ > kVerifyObjectModeFast) { 1167 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1168 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1169 } 1170} 1171 1172void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1173 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1174} 1175 1176void Heap::VerifyHeap() { 1177 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1178 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1179} 1180 1181void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1182 // Use signed comparison since freed bytes can be negative when background compaction foreground 1183 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1184 // free list backed space typically increasing memory footprint due to padding and binning. 1185 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1186 // Note: This relies on 2s complement for handling negative freed_bytes. 1187 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1188 if (Runtime::Current()->HasStatsEnabled()) { 1189 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1190 thread_stats->freed_objects += freed_objects; 1191 thread_stats->freed_bytes += freed_bytes; 1192 // TODO: Do this concurrently. 1193 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1194 global_stats->freed_objects += freed_objects; 1195 global_stats->freed_bytes += freed_bytes; 1196 } 1197} 1198 1199space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1200 for (const auto& space : continuous_spaces_) { 1201 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1202 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1203 return space->AsContinuousSpace()->AsRosAllocSpace(); 1204 } 1205 } 1206 } 1207 return nullptr; 1208} 1209 1210mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1211 size_t alloc_size, size_t* bytes_allocated, 1212 size_t* usable_size, 1213 mirror::Class** klass) { 1214 bool was_default_allocator = allocator == GetCurrentAllocator(); 1215 DCHECK(klass != nullptr); 1216 StackHandleScope<1> hs(self); 1217 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1218 klass = nullptr; // Invalidate for safety. 1219 // The allocation failed. If the GC is running, block until it completes, and then retry the 1220 // allocation. 1221 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1222 if (last_gc != collector::kGcTypeNone) { 1223 // If we were the default allocator but the allocator changed while we were suspended, 1224 // abort the allocation. 1225 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1226 return nullptr; 1227 } 1228 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1229 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1230 usable_size); 1231 if (ptr != nullptr) { 1232 return ptr; 1233 } 1234 } 1235 1236 collector::GcType tried_type = next_gc_type_; 1237 const bool gc_ran = 1238 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1239 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1240 return nullptr; 1241 } 1242 if (gc_ran) { 1243 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1244 usable_size); 1245 if (ptr != nullptr) { 1246 return ptr; 1247 } 1248 } 1249 1250 // Loop through our different Gc types and try to Gc until we get enough free memory. 1251 for (collector::GcType gc_type : gc_plan_) { 1252 if (gc_type == tried_type) { 1253 continue; 1254 } 1255 // Attempt to run the collector, if we succeed, re-try the allocation. 1256 const bool gc_ran = 1257 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1258 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1259 return nullptr; 1260 } 1261 if (gc_ran) { 1262 // Did we free sufficient memory for the allocation to succeed? 1263 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1264 usable_size); 1265 if (ptr != nullptr) { 1266 return ptr; 1267 } 1268 } 1269 } 1270 // Allocations have failed after GCs; this is an exceptional state. 1271 // Try harder, growing the heap if necessary. 1272 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1273 usable_size); 1274 if (ptr != nullptr) { 1275 return ptr; 1276 } 1277 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1278 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1279 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1280 // OOME. 1281 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1282 << " allocation"; 1283 // TODO: Run finalization, but this may cause more allocations to occur. 1284 // We don't need a WaitForGcToComplete here either. 1285 DCHECK(!gc_plan_.empty()); 1286 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1287 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1288 return nullptr; 1289 } 1290 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1291 if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) { 1292 const uint64_t current_time = NanoTime(); 1293 if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) && 1294 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1295 min_interval_homogeneous_space_compaction_by_oom_) { 1296 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1297 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1298 switch (result) { 1299 case HomogeneousSpaceCompactResult::kSuccess: 1300 // If the allocation succeeded, we delayed an oom. 1301 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1302 if (ptr != nullptr) { 1303 count_delayed_oom_++; 1304 } 1305 break; 1306 case HomogeneousSpaceCompactResult::kErrorReject: 1307 // Reject due to disabled moving GC. 1308 break; 1309 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1310 // Throw OOM by default. 1311 break; 1312 default: { 1313 LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result); 1314 } 1315 } 1316 // Always print that we ran homogeneous space compation since this can cause jank. 1317 VLOG(heap) << "Ran heap homogeneous space compaction, " 1318 << " requested defragmentation " 1319 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1320 << " performed defragmentation " 1321 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1322 << " ignored homogeneous space compaction " 1323 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1324 << " delayed count = " 1325 << count_delayed_oom_.LoadSequentiallyConsistent(); 1326 } 1327 } 1328 // If the allocation hasn't succeeded by this point, throw an OOM error. 1329 if (ptr == nullptr) { 1330 ThrowOutOfMemoryError(self, alloc_size, allocator); 1331 } 1332 return ptr; 1333} 1334 1335void Heap::SetTargetHeapUtilization(float target) { 1336 DCHECK_GT(target, 0.0f); // asserted in Java code 1337 DCHECK_LT(target, 1.0f); 1338 target_utilization_ = target; 1339} 1340 1341size_t Heap::GetObjectsAllocated() const { 1342 size_t total = 0; 1343 for (space::AllocSpace* space : alloc_spaces_) { 1344 total += space->GetObjectsAllocated(); 1345 } 1346 return total; 1347} 1348 1349size_t Heap::GetObjectsAllocatedEver() const { 1350 return GetObjectsFreedEver() + GetObjectsAllocated(); 1351} 1352 1353size_t Heap::GetBytesAllocatedEver() const { 1354 return GetBytesFreedEver() + GetBytesAllocated(); 1355} 1356 1357class InstanceCounter { 1358 public: 1359 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1360 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1361 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1362 } 1363 static void Callback(mirror::Object* obj, void* arg) 1364 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1365 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1366 mirror::Class* instance_class = obj->GetClass(); 1367 CHECK(instance_class != nullptr); 1368 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1369 if (instance_counter->use_is_assignable_from_) { 1370 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1371 ++instance_counter->counts_[i]; 1372 } 1373 } else if (instance_class == instance_counter->classes_[i]) { 1374 ++instance_counter->counts_[i]; 1375 } 1376 } 1377 } 1378 1379 private: 1380 const std::vector<mirror::Class*>& classes_; 1381 bool use_is_assignable_from_; 1382 uint64_t* const counts_; 1383 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1384}; 1385 1386void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1387 uint64_t* counts) { 1388 // Can't do any GC in this function since this may move classes. 1389 Thread* self = Thread::Current(); 1390 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1391 InstanceCounter counter(classes, use_is_assignable_from, counts); 1392 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1393 VisitObjects(InstanceCounter::Callback, &counter); 1394 self->EndAssertNoThreadSuspension(old_cause); 1395} 1396 1397class InstanceCollector { 1398 public: 1399 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1400 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1401 : class_(c), max_count_(max_count), instances_(instances) { 1402 } 1403 static void Callback(mirror::Object* obj, void* arg) 1404 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1405 DCHECK(arg != nullptr); 1406 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1407 mirror::Class* instance_class = obj->GetClass(); 1408 if (instance_class == instance_collector->class_) { 1409 if (instance_collector->max_count_ == 0 || 1410 instance_collector->instances_.size() < instance_collector->max_count_) { 1411 instance_collector->instances_.push_back(obj); 1412 } 1413 } 1414 } 1415 1416 private: 1417 mirror::Class* class_; 1418 uint32_t max_count_; 1419 std::vector<mirror::Object*>& instances_; 1420 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1421}; 1422 1423void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1424 std::vector<mirror::Object*>& instances) { 1425 // Can't do any GC in this function since this may move classes. 1426 Thread* self = Thread::Current(); 1427 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1428 InstanceCollector collector(c, max_count, instances); 1429 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1430 VisitObjects(&InstanceCollector::Callback, &collector); 1431 self->EndAssertNoThreadSuspension(old_cause); 1432} 1433 1434class ReferringObjectsFinder { 1435 public: 1436 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1437 std::vector<mirror::Object*>& referring_objects) 1438 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1439 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1440 } 1441 1442 static void Callback(mirror::Object* obj, void* arg) 1443 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1444 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1445 } 1446 1447 // For bitmap Visit. 1448 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1449 // annotalysis on visitors. 1450 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1451 o->VisitReferences<true>(*this, VoidFunctor()); 1452 } 1453 1454 // For Object::VisitReferences. 1455 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1456 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1457 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1458 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1459 referring_objects_.push_back(obj); 1460 } 1461 } 1462 1463 private: 1464 mirror::Object* object_; 1465 uint32_t max_count_; 1466 std::vector<mirror::Object*>& referring_objects_; 1467 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1468}; 1469 1470void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1471 std::vector<mirror::Object*>& referring_objects) { 1472 // Can't do any GC in this function since this may move the object o. 1473 Thread* self = Thread::Current(); 1474 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1475 ReferringObjectsFinder finder(o, max_count, referring_objects); 1476 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1477 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1478 self->EndAssertNoThreadSuspension(old_cause); 1479} 1480 1481void Heap::CollectGarbage(bool clear_soft_references) { 1482 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1483 // last GC will not have necessarily been cleared. 1484 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1485} 1486 1487HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1488 Thread* self = Thread::Current(); 1489 // Inc requested homogeneous space compaction. 1490 count_requested_homogeneous_space_compaction_++; 1491 // Store performed homogeneous space compaction at a new request arrival. 1492 ThreadList* tl = Runtime::Current()->GetThreadList(); 1493 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1494 Locks::mutator_lock_->AssertNotHeld(self); 1495 { 1496 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1497 MutexLock mu(self, *gc_complete_lock_); 1498 // Ensure there is only one GC at a time. 1499 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1500 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1501 // is non zero. 1502 // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction, 1503 // exit. 1504 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) { 1505 return HomogeneousSpaceCompactResult::kErrorReject; 1506 } 1507 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1508 } 1509 if (Runtime::Current()->IsShuttingDown(self)) { 1510 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1511 // cause objects to get finalized. 1512 FinishGC(self, collector::kGcTypeNone); 1513 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1514 } 1515 // Suspend all threads. 1516 tl->SuspendAll(); 1517 uint64_t start_time = NanoTime(); 1518 // Launch compaction. 1519 space::MallocSpace* to_space = main_space_backup_; 1520 space::MallocSpace* from_space = main_space_; 1521 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1522 const uint64_t space_size_before_compaction = from_space->Size(); 1523 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1524 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1525 from_space->GetMemMap()->Protect(PROT_READ); 1526 const uint64_t space_size_after_compaction = to_space->Size(); 1527 std::swap(main_space_, main_space_backup_); 1528 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1529 // Update performed homogeneous space compaction count. 1530 count_performed_homogeneous_space_compaction_++; 1531 // Print statics log and resume all threads. 1532 uint64_t duration = NanoTime() - start_time; 1533 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1534 << PrettySize(space_size_before_compaction) << " -> " 1535 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1536 << std::fixed << static_cast<double>(space_size_after_compaction) / 1537 static_cast<double>(space_size_before_compaction); 1538 tl->ResumeAll(); 1539 // Finish GC. 1540 reference_processor_.EnqueueClearedReferences(self); 1541 GrowForUtilization(semi_space_collector_); 1542 FinishGC(self, collector::kGcTypeFull); 1543 return HomogeneousSpaceCompactResult::kSuccess; 1544} 1545 1546 1547void Heap::TransitionCollector(CollectorType collector_type) { 1548 if (collector_type == collector_type_) { 1549 return; 1550 } 1551 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1552 << " -> " << static_cast<int>(collector_type); 1553 uint64_t start_time = NanoTime(); 1554 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1555 Runtime* const runtime = Runtime::Current(); 1556 ThreadList* const tl = runtime->GetThreadList(); 1557 Thread* const self = Thread::Current(); 1558 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1559 Locks::mutator_lock_->AssertNotHeld(self); 1560 const bool copying_transition = 1561 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1562 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1563 // compacting_gc_disable_count_, this should rarely occurs). 1564 for (;;) { 1565 { 1566 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1567 MutexLock mu(self, *gc_complete_lock_); 1568 // Ensure there is only one GC at a time. 1569 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1570 // If someone else beat us to it and changed the collector before we could, exit. 1571 // This is safe to do before the suspend all since we set the collector_type_running_ before 1572 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1573 // then it would get blocked on WaitForGcToCompleteLocked. 1574 if (collector_type == collector_type_) { 1575 return; 1576 } 1577 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1578 if (!copying_transition || disable_moving_gc_count_ == 0) { 1579 // TODO: Not hard code in semi-space collector? 1580 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1581 break; 1582 } 1583 } 1584 usleep(1000); 1585 } 1586 if (runtime->IsShuttingDown(self)) { 1587 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1588 // cause objects to get finalized. 1589 FinishGC(self, collector::kGcTypeNone); 1590 return; 1591 } 1592 tl->SuspendAll(); 1593 switch (collector_type) { 1594 case kCollectorTypeSS: 1595 // Fall-through. 1596 case kCollectorTypeGSS: { 1597 if (!IsMovingGc(collector_type_)) { 1598 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1599 // pointer space last transition it will be protected. 1600 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1601 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1602 // Remove the main space so that we don't try to trim it, this doens't work for debug 1603 // builds since RosAlloc attempts to read the magic number from a protected page. 1604 RemoveSpace(main_space_); 1605 } 1606 break; 1607 } 1608 case kCollectorTypeMS: 1609 // Fall through. 1610 case kCollectorTypeCMS: { 1611 if (IsMovingGc(collector_type_)) { 1612 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1613 AddSpace(main_space_); 1614 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1615 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1616 } 1617 break; 1618 } 1619 default: { 1620 LOG(FATAL) << "Attempted to transition to invalid collector type " 1621 << static_cast<size_t>(collector_type); 1622 break; 1623 } 1624 } 1625 ChangeCollector(collector_type); 1626 tl->ResumeAll(); 1627 // Can't call into java code with all threads suspended. 1628 reference_processor_.EnqueueClearedReferences(self); 1629 uint64_t duration = NanoTime() - start_time; 1630 GrowForUtilization(semi_space_collector_); 1631 FinishGC(self, collector::kGcTypeFull); 1632 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1633 int32_t delta_allocated = before_allocated - after_allocated; 1634 std::string saved_str; 1635 if (delta_allocated >= 0) { 1636 saved_str = " saved at least " + PrettySize(delta_allocated); 1637 } else { 1638 saved_str = " expanded " + PrettySize(-delta_allocated); 1639 } 1640 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1641 << PrettyDuration(duration) << saved_str; 1642} 1643 1644void Heap::ChangeCollector(CollectorType collector_type) { 1645 // TODO: Only do this with all mutators suspended to avoid races. 1646 if (collector_type != collector_type_) { 1647 if (collector_type == kCollectorTypeMC) { 1648 // Don't allow mark compact unless support is compiled in. 1649 CHECK(kMarkCompactSupport); 1650 } 1651 collector_type_ = collector_type; 1652 gc_plan_.clear(); 1653 switch (collector_type_) { 1654 case kCollectorTypeCC: // Fall-through. 1655 case kCollectorTypeMC: // Fall-through. 1656 case kCollectorTypeSS: // Fall-through. 1657 case kCollectorTypeGSS: { 1658 gc_plan_.push_back(collector::kGcTypeFull); 1659 if (use_tlab_) { 1660 ChangeAllocator(kAllocatorTypeTLAB); 1661 } else { 1662 ChangeAllocator(kAllocatorTypeBumpPointer); 1663 } 1664 break; 1665 } 1666 case kCollectorTypeMS: { 1667 gc_plan_.push_back(collector::kGcTypeSticky); 1668 gc_plan_.push_back(collector::kGcTypePartial); 1669 gc_plan_.push_back(collector::kGcTypeFull); 1670 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1671 break; 1672 } 1673 case kCollectorTypeCMS: { 1674 gc_plan_.push_back(collector::kGcTypeSticky); 1675 gc_plan_.push_back(collector::kGcTypePartial); 1676 gc_plan_.push_back(collector::kGcTypeFull); 1677 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1678 break; 1679 } 1680 default: { 1681 LOG(FATAL) << "Unimplemented"; 1682 } 1683 } 1684 if (IsGcConcurrent()) { 1685 concurrent_start_bytes_ = 1686 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1687 } else { 1688 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1689 } 1690 } 1691} 1692 1693// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1694class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1695 public: 1696 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1697 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1698 } 1699 1700 void BuildBins(space::ContinuousSpace* space) { 1701 bin_live_bitmap_ = space->GetLiveBitmap(); 1702 bin_mark_bitmap_ = space->GetMarkBitmap(); 1703 BinContext context; 1704 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1705 context.collector_ = this; 1706 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1707 // Note: This requires traversing the space in increasing order of object addresses. 1708 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1709 // Add the last bin which spans after the last object to the end of the space. 1710 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1711 } 1712 1713 private: 1714 struct BinContext { 1715 uintptr_t prev_; // The end of the previous object. 1716 ZygoteCompactingCollector* collector_; 1717 }; 1718 // Maps from bin sizes to locations. 1719 std::multimap<size_t, uintptr_t> bins_; 1720 // Live bitmap of the space which contains the bins. 1721 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1722 // Mark bitmap of the space which contains the bins. 1723 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1724 1725 static void Callback(mirror::Object* obj, void* arg) 1726 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1727 DCHECK(arg != nullptr); 1728 BinContext* context = reinterpret_cast<BinContext*>(arg); 1729 ZygoteCompactingCollector* collector = context->collector_; 1730 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1731 size_t bin_size = object_addr - context->prev_; 1732 // Add the bin consisting of the end of the previous object to the start of the current object. 1733 collector->AddBin(bin_size, context->prev_); 1734 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1735 } 1736 1737 void AddBin(size_t size, uintptr_t position) { 1738 if (size != 0) { 1739 bins_.insert(std::make_pair(size, position)); 1740 } 1741 } 1742 1743 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1744 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1745 // allocator. 1746 return false; 1747 } 1748 1749 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1750 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1751 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1752 mirror::Object* forward_address; 1753 // Find the smallest bin which we can move obj in. 1754 auto it = bins_.lower_bound(object_size); 1755 if (it == bins_.end()) { 1756 // No available space in the bins, place it in the target space instead (grows the zygote 1757 // space). 1758 size_t bytes_allocated; 1759 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1760 if (to_space_live_bitmap_ != nullptr) { 1761 to_space_live_bitmap_->Set(forward_address); 1762 } else { 1763 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1764 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1765 } 1766 } else { 1767 size_t size = it->first; 1768 uintptr_t pos = it->second; 1769 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1770 forward_address = reinterpret_cast<mirror::Object*>(pos); 1771 // Set the live and mark bits so that sweeping system weaks works properly. 1772 bin_live_bitmap_->Set(forward_address); 1773 bin_mark_bitmap_->Set(forward_address); 1774 DCHECK_GE(size, object_size); 1775 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1776 } 1777 // Copy the object over to its new location. 1778 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1779 if (kUseBakerOrBrooksReadBarrier) { 1780 obj->AssertReadBarrierPointer(); 1781 if (kUseBrooksReadBarrier) { 1782 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1783 forward_address->SetReadBarrierPointer(forward_address); 1784 } 1785 forward_address->AssertReadBarrierPointer(); 1786 } 1787 return forward_address; 1788 } 1789}; 1790 1791void Heap::UnBindBitmaps() { 1792 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1793 for (const auto& space : GetContinuousSpaces()) { 1794 if (space->IsContinuousMemMapAllocSpace()) { 1795 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1796 if (alloc_space->HasBoundBitmaps()) { 1797 alloc_space->UnBindBitmaps(); 1798 } 1799 } 1800 } 1801} 1802 1803void Heap::PreZygoteFork() { 1804 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1805 Thread* self = Thread::Current(); 1806 MutexLock mu(self, zygote_creation_lock_); 1807 // Try to see if we have any Zygote spaces. 1808 if (have_zygote_space_) { 1809 return; 1810 } 1811 VLOG(heap) << "Starting PreZygoteFork"; 1812 // Trim the pages at the end of the non moving space. 1813 non_moving_space_->Trim(); 1814 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1815 // there. 1816 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1817 // Change the collector to the post zygote one. 1818 if (kCompactZygote) { 1819 DCHECK(semi_space_collector_ != nullptr); 1820 // Temporarily disable rosalloc verification because the zygote 1821 // compaction will mess up the rosalloc internal metadata. 1822 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1823 ZygoteCompactingCollector zygote_collector(this); 1824 zygote_collector.BuildBins(non_moving_space_); 1825 // Create a new bump pointer space which we will compact into. 1826 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1827 non_moving_space_->Limit()); 1828 // Compact the bump pointer space to a new zygote bump pointer space. 1829 bool reset_main_space = false; 1830 if (IsMovingGc(collector_type_)) { 1831 zygote_collector.SetFromSpace(bump_pointer_space_); 1832 } else { 1833 CHECK(main_space_ != nullptr); 1834 // Copy from the main space. 1835 zygote_collector.SetFromSpace(main_space_); 1836 reset_main_space = true; 1837 } 1838 zygote_collector.SetToSpace(&target_space); 1839 zygote_collector.SetSwapSemiSpaces(false); 1840 zygote_collector.Run(kGcCauseCollectorTransition, false); 1841 if (reset_main_space) { 1842 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1843 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1844 MemMap* mem_map = main_space_->ReleaseMemMap(); 1845 RemoveSpace(main_space_); 1846 space::Space* old_main_space = main_space_; 1847 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1848 delete old_main_space; 1849 AddSpace(main_space_); 1850 } else { 1851 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1852 } 1853 if (temp_space_ != nullptr) { 1854 CHECK(temp_space_->IsEmpty()); 1855 } 1856 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1857 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1858 // Update the end and write out image. 1859 non_moving_space_->SetEnd(target_space.End()); 1860 non_moving_space_->SetLimit(target_space.Limit()); 1861 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1862 } 1863 ChangeCollector(foreground_collector_type_); 1864 // Save the old space so that we can remove it after we complete creating the zygote space. 1865 space::MallocSpace* old_alloc_space = non_moving_space_; 1866 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1867 // the remaining available space. 1868 // Remove the old space before creating the zygote space since creating the zygote space sets 1869 // the old alloc space's bitmaps to nullptr. 1870 RemoveSpace(old_alloc_space); 1871 if (collector::SemiSpace::kUseRememberedSet) { 1872 // Sanity bound check. 1873 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1874 // Remove the remembered set for the now zygote space (the old 1875 // non-moving space). Note now that we have compacted objects into 1876 // the zygote space, the data in the remembered set is no longer 1877 // needed. The zygote space will instead have a mod-union table 1878 // from this point on. 1879 RemoveRememberedSet(old_alloc_space); 1880 } 1881 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1882 low_memory_mode_, 1883 &non_moving_space_); 1884 delete old_alloc_space; 1885 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1886 AddSpace(zygote_space); 1887 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1888 AddSpace(non_moving_space_); 1889 have_zygote_space_ = true; 1890 // Enable large object space allocations. 1891 large_object_threshold_ = kDefaultLargeObjectThreshold; 1892 // Create the zygote space mod union table. 1893 accounting::ModUnionTable* mod_union_table = 1894 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1895 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1896 AddModUnionTable(mod_union_table); 1897 if (collector::SemiSpace::kUseRememberedSet) { 1898 // Add a new remembered set for the post-zygote non-moving space. 1899 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1900 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1901 non_moving_space_); 1902 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1903 << "Failed to create post-zygote non-moving space remembered set"; 1904 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1905 } 1906} 1907 1908void Heap::FlushAllocStack() { 1909 MarkAllocStackAsLive(allocation_stack_.get()); 1910 allocation_stack_->Reset(); 1911} 1912 1913void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1914 accounting::ContinuousSpaceBitmap* bitmap2, 1915 accounting::LargeObjectBitmap* large_objects, 1916 accounting::ObjectStack* stack) { 1917 DCHECK(bitmap1 != nullptr); 1918 DCHECK(bitmap2 != nullptr); 1919 mirror::Object** limit = stack->End(); 1920 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1921 const mirror::Object* obj = *it; 1922 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1923 if (bitmap1->HasAddress(obj)) { 1924 bitmap1->Set(obj); 1925 } else if (bitmap2->HasAddress(obj)) { 1926 bitmap2->Set(obj); 1927 } else { 1928 large_objects->Set(obj); 1929 } 1930 } 1931 } 1932} 1933 1934void Heap::SwapSemiSpaces() { 1935 CHECK(bump_pointer_space_ != nullptr); 1936 CHECK(temp_space_ != nullptr); 1937 std::swap(bump_pointer_space_, temp_space_); 1938} 1939 1940void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1941 space::ContinuousMemMapAllocSpace* source_space, 1942 GcCause gc_cause) { 1943 CHECK(kMovingCollector); 1944 if (target_space != source_space) { 1945 // Don't swap spaces since this isn't a typical semi space collection. 1946 semi_space_collector_->SetSwapSemiSpaces(false); 1947 semi_space_collector_->SetFromSpace(source_space); 1948 semi_space_collector_->SetToSpace(target_space); 1949 semi_space_collector_->Run(gc_cause, false); 1950 } else { 1951 CHECK(target_space->IsBumpPointerSpace()) 1952 << "In-place compaction is only supported for bump pointer spaces"; 1953 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1954 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1955 } 1956} 1957 1958collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1959 bool clear_soft_references) { 1960 Thread* self = Thread::Current(); 1961 Runtime* runtime = Runtime::Current(); 1962 // If the heap can't run the GC, silently fail and return that no GC was run. 1963 switch (gc_type) { 1964 case collector::kGcTypePartial: { 1965 if (!have_zygote_space_) { 1966 return collector::kGcTypeNone; 1967 } 1968 break; 1969 } 1970 default: { 1971 // Other GC types don't have any special cases which makes them not runnable. The main case 1972 // here is full GC. 1973 } 1974 } 1975 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1976 Locks::mutator_lock_->AssertNotHeld(self); 1977 if (self->IsHandlingStackOverflow()) { 1978 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 1979 } 1980 bool compacting_gc; 1981 { 1982 gc_complete_lock_->AssertNotHeld(self); 1983 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1984 MutexLock mu(self, *gc_complete_lock_); 1985 // Ensure there is only one GC at a time. 1986 WaitForGcToCompleteLocked(gc_cause, self); 1987 compacting_gc = IsMovingGc(collector_type_); 1988 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 1989 if (compacting_gc && disable_moving_gc_count_ != 0) { 1990 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 1991 return collector::kGcTypeNone; 1992 } 1993 collector_type_running_ = collector_type_; 1994 } 1995 1996 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 1997 ++runtime->GetStats()->gc_for_alloc_count; 1998 ++self->GetStats()->gc_for_alloc_count; 1999 } 2000 uint64_t gc_start_time_ns = NanoTime(); 2001 uint64_t gc_start_size = GetBytesAllocated(); 2002 // Approximate allocation rate in bytes / second. 2003 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2004 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2005 if (LIKELY(ms_delta != 0)) { 2006 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2007 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2008 } 2009 2010 DCHECK_LT(gc_type, collector::kGcTypeMax); 2011 DCHECK_NE(gc_type, collector::kGcTypeNone); 2012 2013 collector::GarbageCollector* collector = nullptr; 2014 // TODO: Clean this up. 2015 if (compacting_gc) { 2016 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2017 current_allocator_ == kAllocatorTypeTLAB); 2018 switch (collector_type_) { 2019 case kCollectorTypeSS: 2020 // Fall-through. 2021 case kCollectorTypeGSS: 2022 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2023 semi_space_collector_->SetToSpace(temp_space_); 2024 semi_space_collector_->SetSwapSemiSpaces(true); 2025 collector = semi_space_collector_; 2026 break; 2027 case kCollectorTypeCC: 2028 collector = concurrent_copying_collector_; 2029 break; 2030 case kCollectorTypeMC: 2031 mark_compact_collector_->SetSpace(bump_pointer_space_); 2032 collector = mark_compact_collector_; 2033 break; 2034 default: 2035 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2036 } 2037 if (collector != mark_compact_collector_) { 2038 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2039 CHECK(temp_space_->IsEmpty()); 2040 } 2041 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2042 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2043 current_allocator_ == kAllocatorTypeDlMalloc) { 2044 collector = FindCollectorByGcType(gc_type); 2045 } else { 2046 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2047 } 2048 CHECK(collector != nullptr) 2049 << "Could not find garbage collector with collector_type=" 2050 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2051 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2052 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2053 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2054 RequestHeapTrim(); 2055 // Enqueue cleared references. 2056 reference_processor_.EnqueueClearedReferences(self); 2057 // Grow the heap so that we know when to perform the next GC. 2058 GrowForUtilization(collector); 2059 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2060 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2061 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2062 // (mutator time blocked >= long_pause_log_threshold_). 2063 bool log_gc = gc_cause == kGcCauseExplicit; 2064 if (!log_gc && CareAboutPauseTimes()) { 2065 // GC for alloc pauses the allocating thread, so consider it as a pause. 2066 log_gc = duration > long_gc_log_threshold_ || 2067 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2068 for (uint64_t pause : pause_times) { 2069 log_gc = log_gc || pause >= long_pause_log_threshold_; 2070 } 2071 } 2072 if (log_gc) { 2073 const size_t percent_free = GetPercentFree(); 2074 const size_t current_heap_size = GetBytesAllocated(); 2075 const size_t total_memory = GetTotalMemory(); 2076 std::ostringstream pause_string; 2077 for (size_t i = 0; i < pause_times.size(); ++i) { 2078 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2079 << ((i != pause_times.size() - 1) ? "," : ""); 2080 } 2081 LOG(INFO) << gc_cause << " " << collector->GetName() 2082 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2083 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2084 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2085 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2086 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2087 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2088 << " total " << PrettyDuration((duration / 1000) * 1000); 2089 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2090 } 2091 FinishGC(self, gc_type); 2092 // Inform DDMS that a GC completed. 2093 Dbg::GcDidFinish(); 2094 return gc_type; 2095} 2096 2097void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2098 MutexLock mu(self, *gc_complete_lock_); 2099 collector_type_running_ = kCollectorTypeNone; 2100 if (gc_type != collector::kGcTypeNone) { 2101 last_gc_type_ = gc_type; 2102 } 2103 // Wake anyone who may have been waiting for the GC to complete. 2104 gc_complete_cond_->Broadcast(self); 2105} 2106 2107static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2108 RootType /*root_type*/) { 2109 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2110 if (*root == obj) { 2111 LOG(INFO) << "Object " << obj << " is a root"; 2112 } 2113} 2114 2115class ScanVisitor { 2116 public: 2117 void operator()(const mirror::Object* obj) const { 2118 LOG(ERROR) << "Would have rescanned object " << obj; 2119 } 2120}; 2121 2122// Verify a reference from an object. 2123class VerifyReferenceVisitor { 2124 public: 2125 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2126 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2127 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2128 2129 size_t GetFailureCount() const { 2130 return fail_count_->LoadSequentiallyConsistent(); 2131 } 2132 2133 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2134 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2135 if (verify_referent_) { 2136 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2137 } 2138 } 2139 2140 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2141 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2142 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2143 } 2144 2145 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2146 return heap_->IsLiveObjectLocked(obj, true, false, true); 2147 } 2148 2149 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2150 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2151 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2152 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2153 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2154 << " thread_id= " << thread_id << " root_type= " << root_type; 2155 } 2156 } 2157 2158 private: 2159 // TODO: Fix the no thread safety analysis. 2160 // Returns false on failure. 2161 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2162 NO_THREAD_SAFETY_ANALYSIS { 2163 if (ref == nullptr || IsLive(ref)) { 2164 // Verify that the reference is live. 2165 return true; 2166 } 2167 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2168 // Print message on only on first failure to prevent spam. 2169 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2170 } 2171 if (obj != nullptr) { 2172 // Only do this part for non roots. 2173 accounting::CardTable* card_table = heap_->GetCardTable(); 2174 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2175 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2176 byte* card_addr = card_table->CardFromAddr(obj); 2177 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2178 << offset << "\n card value = " << static_cast<int>(*card_addr); 2179 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2180 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2181 } else { 2182 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2183 } 2184 2185 // Attmept to find the class inside of the recently freed objects. 2186 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2187 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2188 space::MallocSpace* space = ref_space->AsMallocSpace(); 2189 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2190 if (ref_class != nullptr) { 2191 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2192 << PrettyClass(ref_class); 2193 } else { 2194 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2195 } 2196 } 2197 2198 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2199 ref->GetClass()->IsClass()) { 2200 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2201 } else { 2202 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2203 << ") is not a valid heap address"; 2204 } 2205 2206 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2207 void* cover_begin = card_table->AddrFromCard(card_addr); 2208 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2209 accounting::CardTable::kCardSize); 2210 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2211 << "-" << cover_end; 2212 accounting::ContinuousSpaceBitmap* bitmap = 2213 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2214 2215 if (bitmap == nullptr) { 2216 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2217 if (!VerifyClassClass(obj->GetClass())) { 2218 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2219 } 2220 } else { 2221 // Print out how the object is live. 2222 if (bitmap->Test(obj)) { 2223 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2224 } 2225 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2226 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2227 } 2228 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2229 LOG(ERROR) << "Object " << obj << " found in live stack"; 2230 } 2231 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2232 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2233 } 2234 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2235 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2236 } 2237 // Attempt to see if the card table missed the reference. 2238 ScanVisitor scan_visitor; 2239 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2240 card_table->Scan(bitmap, byte_cover_begin, 2241 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2242 } 2243 2244 // Search to see if any of the roots reference our object. 2245 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2246 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2247 2248 // Search to see if any of the roots reference our reference. 2249 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2250 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2251 } 2252 return false; 2253 } 2254 2255 Heap* const heap_; 2256 Atomic<size_t>* const fail_count_; 2257 const bool verify_referent_; 2258}; 2259 2260// Verify all references within an object, for use with HeapBitmap::Visit. 2261class VerifyObjectVisitor { 2262 public: 2263 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2264 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2265 } 2266 2267 void operator()(mirror::Object* obj) const 2268 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2269 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2270 // be live or else how did we find it in the live bitmap? 2271 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2272 // The class doesn't count as a reference but we should verify it anyways. 2273 obj->VisitReferences<true>(visitor, visitor); 2274 } 2275 2276 static void VisitCallback(mirror::Object* obj, void* arg) 2277 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2278 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2279 visitor->operator()(obj); 2280 } 2281 2282 size_t GetFailureCount() const { 2283 return fail_count_->LoadSequentiallyConsistent(); 2284 } 2285 2286 private: 2287 Heap* const heap_; 2288 Atomic<size_t>* const fail_count_; 2289 const bool verify_referent_; 2290}; 2291 2292void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2293 // Slow path, the allocation stack push back must have already failed. 2294 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2295 do { 2296 // TODO: Add handle VerifyObject. 2297 StackHandleScope<1> hs(self); 2298 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2299 // Push our object into the reserve region of the allocaiton stack. This is only required due 2300 // to heap verification requiring that roots are live (either in the live bitmap or in the 2301 // allocation stack). 2302 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2303 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2304 } while (!allocation_stack_->AtomicPushBack(*obj)); 2305} 2306 2307void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2308 // Slow path, the allocation stack push back must have already failed. 2309 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2310 mirror::Object** start_address; 2311 mirror::Object** end_address; 2312 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2313 &end_address)) { 2314 // TODO: Add handle VerifyObject. 2315 StackHandleScope<1> hs(self); 2316 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2317 // Push our object into the reserve region of the allocaiton stack. This is only required due 2318 // to heap verification requiring that roots are live (either in the live bitmap or in the 2319 // allocation stack). 2320 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2321 // Push into the reserve allocation stack. 2322 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2323 } 2324 self->SetThreadLocalAllocationStack(start_address, end_address); 2325 // Retry on the new thread-local allocation stack. 2326 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2327} 2328 2329// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2330size_t Heap::VerifyHeapReferences(bool verify_referents) { 2331 Thread* self = Thread::Current(); 2332 Locks::mutator_lock_->AssertExclusiveHeld(self); 2333 // Lets sort our allocation stacks so that we can efficiently binary search them. 2334 allocation_stack_->Sort(); 2335 live_stack_->Sort(); 2336 // Since we sorted the allocation stack content, need to revoke all 2337 // thread-local allocation stacks. 2338 RevokeAllThreadLocalAllocationStacks(self); 2339 Atomic<size_t> fail_count_(0); 2340 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2341 // Verify objects in the allocation stack since these will be objects which were: 2342 // 1. Allocated prior to the GC (pre GC verification). 2343 // 2. Allocated during the GC (pre sweep GC verification). 2344 // We don't want to verify the objects in the live stack since they themselves may be 2345 // pointing to dead objects if they are not reachable. 2346 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2347 // Verify the roots: 2348 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2349 if (visitor.GetFailureCount() > 0) { 2350 // Dump mod-union tables. 2351 for (const auto& table_pair : mod_union_tables_) { 2352 accounting::ModUnionTable* mod_union_table = table_pair.second; 2353 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2354 } 2355 // Dump remembered sets. 2356 for (const auto& table_pair : remembered_sets_) { 2357 accounting::RememberedSet* remembered_set = table_pair.second; 2358 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2359 } 2360 DumpSpaces(LOG(ERROR)); 2361 } 2362 return visitor.GetFailureCount(); 2363} 2364 2365class VerifyReferenceCardVisitor { 2366 public: 2367 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2368 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2369 Locks::heap_bitmap_lock_) 2370 : heap_(heap), failed_(failed) { 2371 } 2372 2373 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2374 // annotalysis on visitors. 2375 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2376 NO_THREAD_SAFETY_ANALYSIS { 2377 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2378 // Filter out class references since changing an object's class does not mark the card as dirty. 2379 // Also handles large objects, since the only reference they hold is a class reference. 2380 if (ref != nullptr && !ref->IsClass()) { 2381 accounting::CardTable* card_table = heap_->GetCardTable(); 2382 // If the object is not dirty and it is referencing something in the live stack other than 2383 // class, then it must be on a dirty card. 2384 if (!card_table->AddrIsInCardTable(obj)) { 2385 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2386 *failed_ = true; 2387 } else if (!card_table->IsDirty(obj)) { 2388 // TODO: Check mod-union tables. 2389 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2390 // kCardDirty - 1 if it didnt get touched since we aged it. 2391 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2392 if (live_stack->ContainsSorted(ref)) { 2393 if (live_stack->ContainsSorted(obj)) { 2394 LOG(ERROR) << "Object " << obj << " found in live stack"; 2395 } 2396 if (heap_->GetLiveBitmap()->Test(obj)) { 2397 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2398 } 2399 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2400 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2401 2402 // Print which field of the object is dead. 2403 if (!obj->IsObjectArray()) { 2404 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2405 CHECK(klass != NULL); 2406 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2407 : klass->GetIFields(); 2408 CHECK(fields != NULL); 2409 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2410 mirror::ArtField* cur = fields->Get(i); 2411 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2412 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2413 << PrettyField(cur); 2414 break; 2415 } 2416 } 2417 } else { 2418 mirror::ObjectArray<mirror::Object>* object_array = 2419 obj->AsObjectArray<mirror::Object>(); 2420 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2421 if (object_array->Get(i) == ref) { 2422 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2423 } 2424 } 2425 } 2426 2427 *failed_ = true; 2428 } 2429 } 2430 } 2431 } 2432 2433 private: 2434 Heap* const heap_; 2435 bool* const failed_; 2436}; 2437 2438class VerifyLiveStackReferences { 2439 public: 2440 explicit VerifyLiveStackReferences(Heap* heap) 2441 : heap_(heap), 2442 failed_(false) {} 2443 2444 void operator()(mirror::Object* obj) const 2445 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2446 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2447 obj->VisitReferences<true>(visitor, VoidFunctor()); 2448 } 2449 2450 bool Failed() const { 2451 return failed_; 2452 } 2453 2454 private: 2455 Heap* const heap_; 2456 bool failed_; 2457}; 2458 2459bool Heap::VerifyMissingCardMarks() { 2460 Thread* self = Thread::Current(); 2461 Locks::mutator_lock_->AssertExclusiveHeld(self); 2462 2463 // We need to sort the live stack since we binary search it. 2464 live_stack_->Sort(); 2465 // Since we sorted the allocation stack content, need to revoke all 2466 // thread-local allocation stacks. 2467 RevokeAllThreadLocalAllocationStacks(self); 2468 VerifyLiveStackReferences visitor(this); 2469 GetLiveBitmap()->Visit(visitor); 2470 2471 // We can verify objects in the live stack since none of these should reference dead objects. 2472 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2473 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2474 visitor(*it); 2475 } 2476 } 2477 return !visitor.Failed(); 2478} 2479 2480void Heap::SwapStacks(Thread* self) { 2481 if (kUseThreadLocalAllocationStack) { 2482 live_stack_->AssertAllZero(); 2483 } 2484 allocation_stack_.swap(live_stack_); 2485} 2486 2487void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2488 // This must be called only during the pause. 2489 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2490 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2491 MutexLock mu2(self, *Locks::thread_list_lock_); 2492 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2493 for (Thread* t : thread_list) { 2494 t->RevokeThreadLocalAllocationStack(); 2495 } 2496} 2497 2498void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2499 if (kIsDebugBuild) { 2500 if (bump_pointer_space_ != nullptr) { 2501 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2502 } 2503 } 2504} 2505 2506accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2507 auto it = mod_union_tables_.find(space); 2508 if (it == mod_union_tables_.end()) { 2509 return nullptr; 2510 } 2511 return it->second; 2512} 2513 2514accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2515 auto it = remembered_sets_.find(space); 2516 if (it == remembered_sets_.end()) { 2517 return nullptr; 2518 } 2519 return it->second; 2520} 2521 2522void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2523 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2524 // Clear cards and keep track of cards cleared in the mod-union table. 2525 for (const auto& space : continuous_spaces_) { 2526 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2527 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2528 if (table != nullptr) { 2529 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2530 "ImageModUnionClearCards"; 2531 TimingLogger::ScopedTiming t(name, timings); 2532 table->ClearCards(); 2533 } else if (use_rem_sets && rem_set != nullptr) { 2534 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2535 << static_cast<int>(collector_type_); 2536 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2537 rem_set->ClearCards(); 2538 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2539 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2540 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2541 // were dirty before the GC started. 2542 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2543 // -> clean(cleaning thread). 2544 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2545 // roots and then we scan / update mod union tables after. We will always scan either card. 2546 // If we end up with the non aged card, we scan it it in the pause. 2547 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2548 VoidFunctor()); 2549 } 2550 } 2551} 2552 2553static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2554} 2555 2556void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2557 Thread* const self = Thread::Current(); 2558 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2559 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2560 if (verify_pre_gc_heap_) { 2561 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2562 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2563 size_t failures = VerifyHeapReferences(); 2564 if (failures > 0) { 2565 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2566 << " failures"; 2567 } 2568 } 2569 // Check that all objects which reference things in the live stack are on dirty cards. 2570 if (verify_missing_card_marks_) { 2571 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2572 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2573 SwapStacks(self); 2574 // Sort the live stack so that we can quickly binary search it later. 2575 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2576 << " missing card mark verification failed\n" << DumpSpaces(); 2577 SwapStacks(self); 2578 } 2579 if (verify_mod_union_table_) { 2580 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2581 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2582 for (const auto& table_pair : mod_union_tables_) { 2583 accounting::ModUnionTable* mod_union_table = table_pair.second; 2584 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2585 mod_union_table->Verify(); 2586 } 2587 } 2588} 2589 2590void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2591 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2592 collector::GarbageCollector::ScopedPause pause(gc); 2593 PreGcVerificationPaused(gc); 2594 } 2595} 2596 2597void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2598 // TODO: Add a new runtime option for this? 2599 if (verify_pre_gc_rosalloc_) { 2600 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2601 } 2602} 2603 2604void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2605 Thread* const self = Thread::Current(); 2606 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2607 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2608 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2609 // reachable objects. 2610 if (verify_pre_sweeping_heap_) { 2611 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2612 CHECK_NE(self->GetState(), kRunnable); 2613 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2614 // Swapping bound bitmaps does nothing. 2615 gc->SwapBitmaps(); 2616 // Pass in false since concurrent reference processing can mean that the reference referents 2617 // may point to dead objects at the point which PreSweepingGcVerification is called. 2618 size_t failures = VerifyHeapReferences(false); 2619 if (failures > 0) { 2620 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2621 << " failures"; 2622 } 2623 gc->SwapBitmaps(); 2624 } 2625 if (verify_pre_sweeping_rosalloc_) { 2626 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2627 } 2628} 2629 2630void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2631 // Only pause if we have to do some verification. 2632 Thread* const self = Thread::Current(); 2633 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2634 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2635 if (verify_system_weaks_) { 2636 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2637 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2638 mark_sweep->VerifySystemWeaks(); 2639 } 2640 if (verify_post_gc_rosalloc_) { 2641 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2642 } 2643 if (verify_post_gc_heap_) { 2644 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2645 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2646 size_t failures = VerifyHeapReferences(); 2647 if (failures > 0) { 2648 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2649 << " failures"; 2650 } 2651 } 2652} 2653 2654void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2655 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2656 collector::GarbageCollector::ScopedPause pause(gc); 2657 PreGcVerificationPaused(gc); 2658 } 2659} 2660 2661void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2662 TimingLogger::ScopedTiming t(name, timings); 2663 for (const auto& space : continuous_spaces_) { 2664 if (space->IsRosAllocSpace()) { 2665 VLOG(heap) << name << " : " << space->GetName(); 2666 space->AsRosAllocSpace()->Verify(); 2667 } 2668 } 2669} 2670 2671collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2672 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2673 MutexLock mu(self, *gc_complete_lock_); 2674 return WaitForGcToCompleteLocked(cause, self); 2675} 2676 2677collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2678 collector::GcType last_gc_type = collector::kGcTypeNone; 2679 uint64_t wait_start = NanoTime(); 2680 while (collector_type_running_ != kCollectorTypeNone) { 2681 ATRACE_BEGIN("GC: Wait For Completion"); 2682 // We must wait, change thread state then sleep on gc_complete_cond_; 2683 gc_complete_cond_->Wait(self); 2684 last_gc_type = last_gc_type_; 2685 ATRACE_END(); 2686 } 2687 uint64_t wait_time = NanoTime() - wait_start; 2688 total_wait_time_ += wait_time; 2689 if (wait_time > long_pause_log_threshold_) { 2690 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2691 << " for cause " << cause; 2692 } 2693 return last_gc_type; 2694} 2695 2696void Heap::DumpForSigQuit(std::ostream& os) { 2697 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2698 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2699 DumpGcPerformanceInfo(os); 2700} 2701 2702size_t Heap::GetPercentFree() { 2703 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2704} 2705 2706void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2707 if (max_allowed_footprint > GetMaxMemory()) { 2708 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2709 << PrettySize(GetMaxMemory()); 2710 max_allowed_footprint = GetMaxMemory(); 2711 } 2712 max_allowed_footprint_ = max_allowed_footprint; 2713} 2714 2715bool Heap::IsMovableObject(const mirror::Object* obj) const { 2716 if (kMovingCollector) { 2717 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2718 if (space != nullptr) { 2719 // TODO: Check large object? 2720 return space->CanMoveObjects(); 2721 } 2722 } 2723 return false; 2724} 2725 2726void Heap::UpdateMaxNativeFootprint() { 2727 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2728 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2729 size_t target_size = native_size / GetTargetHeapUtilization(); 2730 if (target_size > native_size + max_free_) { 2731 target_size = native_size + max_free_; 2732 } else if (target_size < native_size + min_free_) { 2733 target_size = native_size + min_free_; 2734 } 2735 native_footprint_gc_watermark_ = target_size; 2736 native_footprint_limit_ = 2 * target_size - native_size; 2737} 2738 2739collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2740 for (const auto& collector : garbage_collectors_) { 2741 if (collector->GetCollectorType() == collector_type_ && 2742 collector->GetGcType() == gc_type) { 2743 return collector; 2744 } 2745 } 2746 return nullptr; 2747} 2748 2749double Heap::HeapGrowthMultiplier() const { 2750 // If we don't care about pause times we are background, so return 1.0. 2751 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2752 return 1.0; 2753 } 2754 return foreground_heap_growth_multiplier_; 2755} 2756 2757void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2758 // We know what our utilization is at this moment. 2759 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2760 const uint64_t bytes_allocated = GetBytesAllocated(); 2761 last_gc_size_ = bytes_allocated; 2762 last_gc_time_ns_ = NanoTime(); 2763 uint64_t target_size; 2764 collector::GcType gc_type = collector_ran->GetGcType(); 2765 if (gc_type != collector::kGcTypeSticky) { 2766 // Grow the heap for non sticky GC. 2767 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2768 // foreground. 2769 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2770 CHECK_GE(delta, 0); 2771 target_size = bytes_allocated + delta * multiplier; 2772 target_size = std::min(target_size, 2773 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2774 target_size = std::max(target_size, 2775 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2776 native_need_to_run_finalization_ = true; 2777 next_gc_type_ = collector::kGcTypeSticky; 2778 } else { 2779 collector::GcType non_sticky_gc_type = 2780 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2781 // Find what the next non sticky collector will be. 2782 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2783 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2784 // do another sticky collection next. 2785 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2786 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2787 // if the sticky GC throughput always remained >= the full/partial throughput. 2788 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2789 non_sticky_collector->GetEstimatedMeanThroughput() && 2790 non_sticky_collector->NumberOfIterations() > 0 && 2791 bytes_allocated <= max_allowed_footprint_) { 2792 next_gc_type_ = collector::kGcTypeSticky; 2793 } else { 2794 next_gc_type_ = non_sticky_gc_type; 2795 } 2796 // If we have freed enough memory, shrink the heap back down. 2797 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2798 target_size = bytes_allocated + max_free_; 2799 } else { 2800 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2801 } 2802 } 2803 if (!ignore_max_footprint_) { 2804 SetIdealFootprint(target_size); 2805 if (IsGcConcurrent()) { 2806 // Calculate when to perform the next ConcurrentGC. 2807 // Calculate the estimated GC duration. 2808 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2809 // Estimate how many remaining bytes we will have when we need to start the next GC. 2810 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2811 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2812 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2813 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2814 // A never going to happen situation that from the estimated allocation rate we will exceed 2815 // the applications entire footprint with the given estimated allocation rate. Schedule 2816 // another GC nearly straight away. 2817 remaining_bytes = kMinConcurrentRemainingBytes; 2818 } 2819 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2820 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2821 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2822 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2823 // right away. 2824 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2825 static_cast<size_t>(bytes_allocated)); 2826 } 2827 } 2828} 2829 2830void Heap::ClearGrowthLimit() { 2831 growth_limit_ = capacity_; 2832 non_moving_space_->ClearGrowthLimit(); 2833} 2834 2835void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2836 ScopedObjectAccess soa(self); 2837 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2838 jvalue args[1]; 2839 args[0].l = arg.get(); 2840 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2841 // Restore object in case it gets moved. 2842 *object = soa.Decode<mirror::Object*>(arg.get()); 2843} 2844 2845void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2846 StackHandleScope<1> hs(self); 2847 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2848 RequestConcurrentGC(self); 2849} 2850 2851void Heap::RequestConcurrentGC(Thread* self) { 2852 // Make sure that we can do a concurrent GC. 2853 Runtime* runtime = Runtime::Current(); 2854 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2855 self->IsHandlingStackOverflow()) { 2856 return; 2857 } 2858 // We already have a request pending, no reason to start more until we update 2859 // concurrent_start_bytes_. 2860 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2861 JNIEnv* env = self->GetJniEnv(); 2862 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2863 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2864 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2865 WellKnownClasses::java_lang_Daemons_requestGC); 2866 CHECK(!env->ExceptionCheck()); 2867} 2868 2869void Heap::ConcurrentGC(Thread* self) { 2870 if (Runtime::Current()->IsShuttingDown(self)) { 2871 return; 2872 } 2873 // Wait for any GCs currently running to finish. 2874 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2875 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2876 // instead. E.g. can't do partial, so do full instead. 2877 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2878 collector::kGcTypeNone) { 2879 for (collector::GcType gc_type : gc_plan_) { 2880 // Attempt to run the collector, if we succeed, we are done. 2881 if (gc_type > next_gc_type_ && 2882 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2883 break; 2884 } 2885 } 2886 } 2887 } 2888} 2889 2890void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2891 Thread* self = Thread::Current(); 2892 { 2893 MutexLock mu(self, *heap_trim_request_lock_); 2894 if (desired_collector_type_ == desired_collector_type) { 2895 return; 2896 } 2897 heap_transition_or_trim_target_time_ = 2898 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2899 desired_collector_type_ = desired_collector_type; 2900 } 2901 SignalHeapTrimDaemon(self); 2902} 2903 2904void Heap::RequestHeapTrim() { 2905 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2906 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2907 // a space it will hold its lock and can become a cause of jank. 2908 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2909 // forking. 2910 2911 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2912 // because that only marks object heads, so a large array looks like lots of empty space. We 2913 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2914 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2915 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2916 // not how much use we're making of those pages. 2917 2918 Thread* self = Thread::Current(); 2919 Runtime* runtime = Runtime::Current(); 2920 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2921 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2922 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2923 // as we don't hold the lock while requesting the trim). 2924 return; 2925 } 2926 { 2927 MutexLock mu(self, *heap_trim_request_lock_); 2928 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2929 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2930 // just yet. 2931 return; 2932 } 2933 heap_trim_request_pending_ = true; 2934 uint64_t current_time = NanoTime(); 2935 if (heap_transition_or_trim_target_time_ < current_time) { 2936 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2937 } 2938 } 2939 // Notify the daemon thread which will actually do the heap trim. 2940 SignalHeapTrimDaemon(self); 2941} 2942 2943void Heap::SignalHeapTrimDaemon(Thread* self) { 2944 JNIEnv* env = self->GetJniEnv(); 2945 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2946 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2947 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2948 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2949 CHECK(!env->ExceptionCheck()); 2950} 2951 2952void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2953 if (rosalloc_space_ != nullptr) { 2954 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2955 } 2956 if (bump_pointer_space_ != nullptr) { 2957 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2958 } 2959} 2960 2961void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2962 if (rosalloc_space_ != nullptr) { 2963 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2964 } 2965} 2966 2967void Heap::RevokeAllThreadLocalBuffers() { 2968 if (rosalloc_space_ != nullptr) { 2969 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2970 } 2971 if (bump_pointer_space_ != nullptr) { 2972 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 2973 } 2974} 2975 2976bool Heap::IsGCRequestPending() const { 2977 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 2978} 2979 2980void Heap::RunFinalization(JNIEnv* env) { 2981 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 2982 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 2983 CHECK(WellKnownClasses::java_lang_System != nullptr); 2984 WellKnownClasses::java_lang_System_runFinalization = 2985 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 2986 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 2987 } 2988 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 2989 WellKnownClasses::java_lang_System_runFinalization); 2990} 2991 2992void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 2993 Thread* self = ThreadForEnv(env); 2994 if (native_need_to_run_finalization_) { 2995 RunFinalization(env); 2996 UpdateMaxNativeFootprint(); 2997 native_need_to_run_finalization_ = false; 2998 } 2999 // Total number of native bytes allocated. 3000 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3001 new_native_bytes_allocated += bytes; 3002 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3003 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3004 collector::kGcTypeFull; 3005 3006 // The second watermark is higher than the gc watermark. If you hit this it means you are 3007 // allocating native objects faster than the GC can keep up with. 3008 if (new_native_bytes_allocated > native_footprint_limit_) { 3009 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3010 // Just finished a GC, attempt to run finalizers. 3011 RunFinalization(env); 3012 CHECK(!env->ExceptionCheck()); 3013 } 3014 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3015 if (new_native_bytes_allocated > native_footprint_limit_) { 3016 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3017 RunFinalization(env); 3018 native_need_to_run_finalization_ = false; 3019 CHECK(!env->ExceptionCheck()); 3020 } 3021 // We have just run finalizers, update the native watermark since it is very likely that 3022 // finalizers released native managed allocations. 3023 UpdateMaxNativeFootprint(); 3024 } else if (!IsGCRequestPending()) { 3025 if (IsGcConcurrent()) { 3026 RequestConcurrentGC(self); 3027 } else { 3028 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3029 } 3030 } 3031 } 3032} 3033 3034void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3035 int expected_size, new_size; 3036 do { 3037 expected_size = native_bytes_allocated_.LoadRelaxed(); 3038 new_size = expected_size - bytes; 3039 if (UNLIKELY(new_size < 0)) { 3040 ScopedObjectAccess soa(env); 3041 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3042 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3043 "registered as allocated", bytes, expected_size).c_str()); 3044 break; 3045 } 3046 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3047} 3048 3049size_t Heap::GetTotalMemory() const { 3050 size_t ret = 0; 3051 for (const auto& space : continuous_spaces_) { 3052 // Currently don't include the image space. 3053 if (!space->IsImageSpace()) { 3054 ret += space->Size(); 3055 } 3056 } 3057 for (const auto& space : discontinuous_spaces_) { 3058 if (space->IsLargeObjectSpace()) { 3059 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3060 } 3061 } 3062 return ret; 3063} 3064 3065void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3066 DCHECK(mod_union_table != nullptr); 3067 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3068} 3069 3070void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3071 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3072 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3073 c->GetDescriptor().empty()); 3074 CHECK_GE(byte_count, sizeof(mirror::Object)); 3075} 3076 3077void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3078 CHECK(remembered_set != nullptr); 3079 space::Space* space = remembered_set->GetSpace(); 3080 CHECK(space != nullptr); 3081 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3082 remembered_sets_.Put(space, remembered_set); 3083 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3084} 3085 3086void Heap::RemoveRememberedSet(space::Space* space) { 3087 CHECK(space != nullptr); 3088 auto it = remembered_sets_.find(space); 3089 CHECK(it != remembered_sets_.end()); 3090 remembered_sets_.erase(it); 3091 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3092} 3093 3094void Heap::ClearMarkedObjects() { 3095 // Clear all of the spaces' mark bitmaps. 3096 for (const auto& space : GetContinuousSpaces()) { 3097 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3098 if (space->GetLiveBitmap() != mark_bitmap) { 3099 mark_bitmap->Clear(); 3100 } 3101 } 3102 // Clear the marked objects in the discontinous space object sets. 3103 for (const auto& space : GetDiscontinuousSpaces()) { 3104 space->GetMarkBitmap()->Clear(); 3105 } 3106} 3107 3108} // namespace gc 3109} // namespace art 3110