heap.cc revision 2796a1669ae0f3b96db8432fbd8be1b93bf335c4
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 "os.h" 62#include "reflection.h" 63#include "runtime.h" 64#include "ScopedLocalRef.h" 65#include "scoped_thread_state_change.h" 66#include "handle_scope-inl.h" 67#include "thread_list.h" 68#include "well_known_classes.h" 69 70namespace art { 71 72namespace gc { 73 74static constexpr size_t kCollectorTransitionStressIterations = 0; 75static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 76static constexpr bool kGCALotMode = false; 77static constexpr size_t kGcAlotInterval = KB; 78// Minimum amount of remaining bytes before a concurrent GC is triggered. 79static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 80static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 81// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 82// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 83// threads (lower pauses, use less memory bandwidth). 84static constexpr double kStickyGcThroughputAdjustment = 1.0; 85// Whether or not we use the free list large object space. 86static constexpr bool kUseFreeListSpaceForLOS = false; 87// Whether or not we compact the zygote in PreZygoteFork. 88static constexpr bool kCompactZygote = kMovingCollector; 89static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 90// How many reserve entries are at the end of the allocation stack, these are only needed if the 91// allocation stack overflows. 92static constexpr size_t kAllocationStackReserveSize = 1024; 93// Default mark stack size in bytes. 94static const size_t kDefaultMarkStackSize = 64 * KB; 95// Define space name. 96static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 97static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 98static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 99static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 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_( 184 min_interval_homogeneous_space_compaction_by_oom), 185 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 186 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 187 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 188 LOG(INFO) << "Heap() entering"; 189 } 190 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 191 // entrypoints. 192 if (!Runtime::Current()->IsZygote()) { 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 live_bitmap_.reset(new accounting::HeapBitmap(this)); 202 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 203 // Requested begin for the alloc space, to follow the mapped image and oat files 204 byte* requested_alloc_space_begin = nullptr; 205 if (!image_file_name.empty()) { 206 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 207 image_instruction_set); 208 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 209 AddSpace(image_space); 210 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 211 // isn't going to get in the middle 212 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 213 CHECK_GT(oat_file_end_addr, image_space->End()); 214 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 215 } 216 /* 217 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 218 +- nonmoving space (kNonMovingSpaceCapacity) +- 219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 220 +-main alloc space / bump space 1 (capacity_) +- 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 222 +-????????????????????????????????????????????+- 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 224 +-main alloc space2 / bump space 2 (capacity_)+- 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 226 */ 227 bool support_homogeneous_space_compaction = 228 background_collector_type == gc::kCollectorTypeHomogeneousSpaceCompact || 229 use_homogeneous_space_compaction_for_oom; 230 // We may use the same space the main space for the non moving space if we don't need to compact 231 // from the main space. 232 // This is not the case if we support homogeneous compaction or have a moving background 233 // collector type. 234 const bool is_zygote = Runtime::Current()->IsZygote(); 235 bool separate_non_moving_space = is_zygote || 236 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 237 IsMovingGc(background_collector_type_); 238 if (foreground_collector_type == kCollectorTypeGSS) { 239 separate_non_moving_space = false; 240 } 241 std::unique_ptr<MemMap> main_mem_map_1; 242 std::unique_ptr<MemMap> main_mem_map_2; 243 byte* request_begin = requested_alloc_space_begin; 244 if (request_begin != nullptr && separate_non_moving_space) { 245 request_begin += kNonMovingSpaceCapacity; 246 } 247 std::string error_str; 248 std::unique_ptr<MemMap> non_moving_space_mem_map; 249 if (separate_non_moving_space) { 250 // Reserve the non moving mem map before the other two since it needs to be at a specific 251 // address. 252 non_moving_space_mem_map.reset( 253 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 254 kNonMovingSpaceCapacity, PROT_READ | PROT_WRITE, true, &error_str)); 255 CHECK(non_moving_space_mem_map != nullptr) << error_str; 256 } 257 // Attempt to create 2 mem maps at or after the requested begin. 258 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 259 PROT_READ | PROT_WRITE, &error_str)); 260 CHECK(main_mem_map_1.get() != nullptr) << error_str; 261 if (support_homogeneous_space_compaction || 262 background_collector_type_ == kCollectorTypeSS || 263 foreground_collector_type_ == kCollectorTypeSS) { 264 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 265 capacity_, PROT_READ | PROT_WRITE, 266 &error_str)); 267 CHECK(main_mem_map_2.get() != nullptr) << error_str; 268 } 269 // Create the non moving space first so that bitmaps don't take up the address range. 270 if (separate_non_moving_space) { 271 // Non moving space is always dlmalloc since we currently don't have support for multiple 272 // active rosalloc spaces. 273 const size_t size = non_moving_space_mem_map->Size(); 274 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 275 non_moving_space_mem_map.release(), "zygote / non moving space", initial_size, 276 initial_size, size, size, false); 277 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 278 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 279 << requested_alloc_space_begin; 280 AddSpace(non_moving_space_); 281 } 282 // Create other spaces based on whether or not we have a moving GC. 283 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 284 // Create bump pointer spaces. 285 // We only to create the bump pointer if the foreground collector is a compacting GC. 286 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 287 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 288 main_mem_map_1.release()); 289 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 290 AddSpace(bump_pointer_space_); 291 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 292 main_mem_map_2.release()); 293 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 294 AddSpace(temp_space_); 295 CHECK(separate_non_moving_space); 296 } else { 297 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 298 CHECK(main_space_ != nullptr); 299 AddSpace(main_space_); 300 if (!separate_non_moving_space) { 301 non_moving_space_ = main_space_; 302 CHECK(!non_moving_space_->CanMoveObjects()); 303 } 304 if (foreground_collector_type_ == kCollectorTypeGSS) { 305 CHECK_EQ(foreground_collector_type_, background_collector_type_); 306 // Create bump pointer spaces instead of a backup space. 307 main_mem_map_2.release(); 308 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 309 kGSSBumpPointerSpaceCapacity, nullptr); 310 CHECK(bump_pointer_space_ != nullptr); 311 AddSpace(bump_pointer_space_); 312 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 313 kGSSBumpPointerSpaceCapacity, nullptr); 314 CHECK(temp_space_ != nullptr); 315 AddSpace(temp_space_); 316 } else if (main_mem_map_2.get() != nullptr) { 317 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 318 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 319 growth_limit_, capacity_, name, true)); 320 CHECK(main_space_backup_.get() != nullptr); 321 // Add the space so its accounted for in the heap_begin and heap_end. 322 AddSpace(main_space_backup_.get()); 323 } 324 } 325 CHECK(non_moving_space_ != nullptr); 326 CHECK(!non_moving_space_->CanMoveObjects()); 327 // Allocate the large object space. 328 if (kUseFreeListSpaceForLOS) { 329 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 330 } else { 331 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 332 } 333 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 334 AddSpace(large_object_space_); 335 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 336 CHECK(!continuous_spaces_.empty()); 337 // Relies on the spaces being sorted. 338 byte* heap_begin = continuous_spaces_.front()->Begin(); 339 byte* heap_end = continuous_spaces_.back()->Limit(); 340 size_t heap_capacity = heap_end - heap_begin; 341 // Remove the main backup space since it slows down the GC to have unused extra spaces. 342 if (main_space_backup_.get() != nullptr) { 343 RemoveSpace(main_space_backup_.get()); 344 } 345 // Allocate the card table. 346 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 347 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 348 // Card cache for now since it makes it easier for us to update the references to the copying 349 // spaces. 350 accounting::ModUnionTable* mod_union_table = 351 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 352 GetImageSpace()); 353 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 354 AddModUnionTable(mod_union_table); 355 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 356 accounting::RememberedSet* non_moving_space_rem_set = 357 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 358 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 359 AddRememberedSet(non_moving_space_rem_set); 360 } 361 // TODO: Count objects in the image space here? 362 num_bytes_allocated_.StoreRelaxed(0); 363 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 364 kDefaultMarkStackSize)); 365 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 366 allocation_stack_.reset(accounting::ObjectStack::Create( 367 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 368 live_stack_.reset(accounting::ObjectStack::Create( 369 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 370 // It's still too early to take a lock because there are no threads yet, but we can create locks 371 // now. We don't create it earlier to make it clear that you can't use locks during heap 372 // initialization. 373 gc_complete_lock_ = new Mutex("GC complete lock"); 374 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 375 *gc_complete_lock_)); 376 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 377 last_gc_size_ = GetBytesAllocated(); 378 if (ignore_max_footprint_) { 379 SetIdealFootprint(std::numeric_limits<size_t>::max()); 380 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 381 } 382 CHECK_NE(max_allowed_footprint_, 0U); 383 // Create our garbage collectors. 384 for (size_t i = 0; i < 2; ++i) { 385 const bool concurrent = i != 0; 386 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 387 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 388 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 389 } 390 if (kMovingCollector) { 391 // TODO: Clean this up. 392 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 393 semi_space_collector_ = new collector::SemiSpace(this, generational, 394 generational ? "generational" : ""); 395 garbage_collectors_.push_back(semi_space_collector_); 396 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 397 garbage_collectors_.push_back(concurrent_copying_collector_); 398 mark_compact_collector_ = new collector::MarkCompact(this); 399 garbage_collectors_.push_back(mark_compact_collector_); 400 } 401 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr) { 402 // Check that there's no gap between the image space and the non moving space so that the 403 // immune region won't break (eg. due to a large object allocated in the gap). 404 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 405 non_moving_space_->GetMemMap()); 406 if (!no_gap) { 407 MemMap::DumpMaps(LOG(ERROR)); 408 LOG(FATAL) << "There's a gap between the image space and the main space"; 409 } 410 } 411 if (running_on_valgrind_) { 412 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 413 } 414 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 415 LOG(INFO) << "Heap() exiting"; 416 } 417} 418 419MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 420 int prot_flags, std::string* out_error_str) { 421 while (true) { 422 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 423 PROT_READ | PROT_WRITE, true, out_error_str); 424 if (map != nullptr || request_begin == nullptr) { 425 return map; 426 } 427 // Retry a second time with no specified request begin. 428 request_begin = nullptr; 429 } 430 return nullptr; 431} 432 433space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 434 size_t growth_limit, size_t capacity, 435 const char* name, bool can_move_objects) { 436 space::MallocSpace* malloc_space = nullptr; 437 if (kUseRosAlloc) { 438 // Create rosalloc space. 439 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 440 initial_size, growth_limit, capacity, 441 low_memory_mode_, can_move_objects); 442 } else { 443 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 444 initial_size, growth_limit, capacity, 445 can_move_objects); 446 } 447 if (collector::SemiSpace::kUseRememberedSet) { 448 accounting::RememberedSet* rem_set = 449 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 450 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 451 AddRememberedSet(rem_set); 452 } 453 CHECK(malloc_space != nullptr) << "Failed to create " << name; 454 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 455 return malloc_space; 456} 457 458void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 459 size_t capacity) { 460 // Is background compaction is enabled? 461 bool can_move_objects = IsMovingGc(background_collector_type_) != 462 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 463 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 464 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 465 // from the main space to the zygote space. If background compaction is enabled, always pass in 466 // that we can move objets. 467 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 468 // After the zygote we want this to be false if we don't have background compaction enabled so 469 // that getting primitive array elements is faster. 470 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 471 can_move_objects = !have_zygote_space_ && foreground_collector_type_ != kCollectorTypeGSS; 472 } 473 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 474 RemoveRememberedSet(main_space_); 475 } 476 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 477 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 478 can_move_objects); 479 SetSpaceAsDefault(main_space_); 480 VLOG(heap) << "Created main space " << main_space_; 481} 482 483void Heap::ChangeAllocator(AllocatorType allocator) { 484 if (current_allocator_ != allocator) { 485 // These two allocators are only used internally and don't have any entrypoints. 486 CHECK_NE(allocator, kAllocatorTypeLOS); 487 CHECK_NE(allocator, kAllocatorTypeNonMoving); 488 current_allocator_ = allocator; 489 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 490 SetQuickAllocEntryPointsAllocator(current_allocator_); 491 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 492 } 493} 494 495void Heap::DisableCompaction() { 496 if (IsMovingGc(foreground_collector_type_)) { 497 foreground_collector_type_ = kCollectorTypeCMS; 498 } 499 if (IsMovingGc(background_collector_type_)) { 500 background_collector_type_ = foreground_collector_type_; 501 } 502 TransitionCollector(foreground_collector_type_); 503} 504 505std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 506 if (!IsValidContinuousSpaceObjectAddress(klass)) { 507 return StringPrintf("<non heap address klass %p>", klass); 508 } 509 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 510 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 511 std::string result("["); 512 result += SafeGetClassDescriptor(component_type); 513 return result; 514 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 515 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 516 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 517 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 518 } else { 519 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 520 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 521 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 522 } 523 const DexFile* dex_file = dex_cache->GetDexFile(); 524 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 525 if (class_def_idx == DexFile::kDexNoIndex16) { 526 return "<class def not found>"; 527 } 528 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 529 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 530 return dex_file->GetTypeDescriptor(type_id); 531 } 532} 533 534std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 535 if (obj == nullptr) { 536 return "null"; 537 } 538 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 539 if (klass == nullptr) { 540 return "(class=null)"; 541 } 542 std::string result(SafeGetClassDescriptor(klass)); 543 if (obj->IsClass()) { 544 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 545 } 546 return result; 547} 548 549void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 550 if (obj == nullptr) { 551 stream << "(obj=null)"; 552 return; 553 } 554 if (IsAligned<kObjectAlignment>(obj)) { 555 space::Space* space = nullptr; 556 // Don't use find space since it only finds spaces which actually contain objects instead of 557 // spaces which may contain objects (e.g. cleared bump pointer spaces). 558 for (const auto& cur_space : continuous_spaces_) { 559 if (cur_space->HasAddress(obj)) { 560 space = cur_space; 561 break; 562 } 563 } 564 // Unprotect all the spaces. 565 for (const auto& space : continuous_spaces_) { 566 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 567 } 568 stream << "Object " << obj; 569 if (space != nullptr) { 570 stream << " in space " << *space; 571 } 572 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 573 stream << "\nclass=" << klass; 574 if (klass != nullptr) { 575 stream << " type= " << SafePrettyTypeOf(obj); 576 } 577 // Re-protect the address we faulted on. 578 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 579 } 580} 581 582bool Heap::IsCompilingBoot() const { 583 for (const auto& space : continuous_spaces_) { 584 if (space->IsImageSpace() || space->IsZygoteSpace()) { 585 return false; 586 } 587 } 588 return true; 589} 590 591bool Heap::HasImageSpace() const { 592 for (const auto& space : continuous_spaces_) { 593 if (space->IsImageSpace()) { 594 return true; 595 } 596 } 597 return false; 598} 599 600void Heap::IncrementDisableMovingGC(Thread* self) { 601 // Need to do this holding the lock to prevent races where the GC is about to run / running when 602 // we attempt to disable it. 603 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 604 MutexLock mu(self, *gc_complete_lock_); 605 ++disable_moving_gc_count_; 606 if (IsMovingGc(collector_type_running_)) { 607 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 608 } 609} 610 611void Heap::DecrementDisableMovingGC(Thread* self) { 612 MutexLock mu(self, *gc_complete_lock_); 613 CHECK_GE(disable_moving_gc_count_, 0U); 614 --disable_moving_gc_count_; 615} 616 617void Heap::UpdateProcessState(ProcessState process_state) { 618 if (process_state_ != process_state) { 619 process_state_ = process_state; 620 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 621 // Start at index 1 to avoid "is always false" warning. 622 // Have iteration 1 always transition the collector. 623 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 624 ? foreground_collector_type_ : background_collector_type_); 625 usleep(kCollectorTransitionStressWait); 626 } 627 if (process_state_ == kProcessStateJankPerceptible) { 628 // Transition back to foreground right away to prevent jank. 629 RequestCollectorTransition(foreground_collector_type_, 0); 630 } else { 631 // Don't delay for debug builds since we may want to stress test the GC. 632 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 633 // special handling which does a homogenous space compaction once but then doesn't transition 634 // the collector. 635 RequestCollectorTransition(background_collector_type_, 636 kIsDebugBuild ? 0 : kCollectorTransitionWait); 637 } 638 } 639} 640 641void Heap::CreateThreadPool() { 642 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 643 if (num_threads != 0) { 644 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 645 } 646} 647 648void Heap::VisitObjects(ObjectCallback callback, void* arg) { 649 Thread* self = Thread::Current(); 650 // GCs can move objects, so don't allow this. 651 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 652 if (bump_pointer_space_ != nullptr) { 653 // Visit objects in bump pointer space. 654 bump_pointer_space_->Walk(callback, arg); 655 } 656 // TODO: Switch to standard begin and end to use ranged a based loop. 657 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 658 it < end; ++it) { 659 mirror::Object* obj = *it; 660 if (obj != nullptr && obj->GetClass() != nullptr) { 661 // Avoid the race condition caused by the object not yet being written into the allocation 662 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 663 // there can be nulls on the allocation stack. 664 callback(obj, arg); 665 } 666 } 667 GetLiveBitmap()->Walk(callback, arg); 668 self->EndAssertNoThreadSuspension(old_cause); 669} 670 671void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 672 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 673 space::ContinuousSpace* space2 = non_moving_space_; 674 // TODO: Generalize this to n bitmaps? 675 CHECK(space1 != nullptr); 676 CHECK(space2 != nullptr); 677 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 678 large_object_space_->GetLiveBitmap(), stack); 679} 680 681void Heap::DeleteThreadPool() { 682 thread_pool_.reset(nullptr); 683} 684 685void Heap::AddSpace(space::Space* space) { 686 CHECK(space != nullptr); 687 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 688 if (space->IsContinuousSpace()) { 689 DCHECK(!space->IsDiscontinuousSpace()); 690 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 691 // Continuous spaces don't necessarily have bitmaps. 692 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 693 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 694 if (live_bitmap != nullptr) { 695 CHECK(mark_bitmap != nullptr); 696 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 697 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 698 } 699 continuous_spaces_.push_back(continuous_space); 700 // Ensure that spaces remain sorted in increasing order of start address. 701 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 702 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 703 return a->Begin() < b->Begin(); 704 }); 705 } else { 706 CHECK(space->IsDiscontinuousSpace()); 707 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 708 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 709 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 710 discontinuous_spaces_.push_back(discontinuous_space); 711 } 712 if (space->IsAllocSpace()) { 713 alloc_spaces_.push_back(space->AsAllocSpace()); 714 } 715} 716 717void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 718 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 719 if (continuous_space->IsDlMallocSpace()) { 720 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 721 } else if (continuous_space->IsRosAllocSpace()) { 722 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 723 } 724} 725 726void Heap::RemoveSpace(space::Space* space) { 727 DCHECK(space != nullptr); 728 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 729 if (space->IsContinuousSpace()) { 730 DCHECK(!space->IsDiscontinuousSpace()); 731 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 732 // Continuous spaces don't necessarily have bitmaps. 733 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 734 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 735 if (live_bitmap != nullptr) { 736 DCHECK(mark_bitmap != nullptr); 737 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 738 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 739 } 740 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 741 DCHECK(it != continuous_spaces_.end()); 742 continuous_spaces_.erase(it); 743 } else { 744 DCHECK(space->IsDiscontinuousSpace()); 745 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 746 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 747 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 748 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 749 discontinuous_space); 750 DCHECK(it != discontinuous_spaces_.end()); 751 discontinuous_spaces_.erase(it); 752 } 753 if (space->IsAllocSpace()) { 754 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 755 DCHECK(it != alloc_spaces_.end()); 756 alloc_spaces_.erase(it); 757 } 758} 759 760void Heap::RegisterGCAllocation(size_t bytes) { 761 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 762} 763 764void Heap::RegisterGCDeAllocation(size_t bytes) { 765 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 766} 767 768void Heap::DumpGcPerformanceInfo(std::ostream& os) { 769 // Dump cumulative timings. 770 os << "Dumping cumulative Gc timings\n"; 771 uint64_t total_duration = 0; 772 // Dump cumulative loggers for each GC type. 773 uint64_t total_paused_time = 0; 774 for (auto& collector : garbage_collectors_) { 775 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 776 const size_t iterations = logger.GetIterations(); 777 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 778 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 779 os << ConstDumpable<CumulativeLogger>(logger); 780 const uint64_t total_ns = logger.GetTotalNs(); 781 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 782 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 783 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 784 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 785 Histogram<uint64_t>::CumulativeData cumulative_data; 786 pause_histogram.CreateHistogram(&cumulative_data); 787 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 788 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 789 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 790 << collector->GetName() << " freed: " << freed_objects 791 << " objects with total size " << PrettySize(freed_bytes) << "\n" 792 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 793 << PrettySize(freed_bytes / seconds) << "/s\n"; 794 total_duration += total_ns; 795 total_paused_time += total_pause_ns; 796 } 797 collector->ResetMeasurements(); 798 } 799 uint64_t allocation_time = 800 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 801 if (total_duration != 0) { 802 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 803 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 804 os << "Mean GC size throughput: " 805 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 806 os << "Mean GC object throughput: " 807 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 808 } 809 size_t total_objects_allocated = GetObjectsAllocatedEver(); 810 os << "Total number of allocations: " << total_objects_allocated << "\n"; 811 size_t total_bytes_allocated = GetBytesAllocatedEver(); 812 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 813 if (kMeasureAllocationTime) { 814 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 815 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 816 << "\n"; 817 } 818 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 819 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 820 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 821 BaseMutex::DumpAll(os); 822} 823 824Heap::~Heap() { 825 VLOG(heap) << "Starting ~Heap()"; 826 STLDeleteElements(&garbage_collectors_); 827 // If we don't reset then the mark stack complains in its destructor. 828 allocation_stack_->Reset(); 829 live_stack_->Reset(); 830 STLDeleteValues(&mod_union_tables_); 831 STLDeleteValues(&remembered_sets_); 832 STLDeleteElements(&continuous_spaces_); 833 STLDeleteElements(&discontinuous_spaces_); 834 delete gc_complete_lock_; 835 delete heap_trim_request_lock_; 836 VLOG(heap) << "Finished ~Heap()"; 837} 838 839space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 840 bool fail_ok) const { 841 for (const auto& space : continuous_spaces_) { 842 if (space->Contains(obj)) { 843 return space; 844 } 845 } 846 if (!fail_ok) { 847 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 848 } 849 return NULL; 850} 851 852space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 853 bool fail_ok) const { 854 for (const auto& space : discontinuous_spaces_) { 855 if (space->Contains(obj)) { 856 return space; 857 } 858 } 859 if (!fail_ok) { 860 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 861 } 862 return NULL; 863} 864 865space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 866 space::Space* result = FindContinuousSpaceFromObject(obj, true); 867 if (result != NULL) { 868 return result; 869 } 870 return FindDiscontinuousSpaceFromObject(obj, true); 871} 872 873space::ImageSpace* Heap::GetImageSpace() const { 874 for (const auto& space : continuous_spaces_) { 875 if (space->IsImageSpace()) { 876 return space->AsImageSpace(); 877 } 878 } 879 return NULL; 880} 881 882void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 883 std::ostringstream oss; 884 size_t total_bytes_free = GetFreeMemory(); 885 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 886 << " free bytes"; 887 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 888 if (total_bytes_free >= byte_count) { 889 space::AllocSpace* space = nullptr; 890 if (allocator_type == kAllocatorTypeNonMoving) { 891 space = non_moving_space_; 892 } else if (allocator_type == kAllocatorTypeRosAlloc || 893 allocator_type == kAllocatorTypeDlMalloc) { 894 space = main_space_; 895 } else if (allocator_type == kAllocatorTypeBumpPointer || 896 allocator_type == kAllocatorTypeTLAB) { 897 space = bump_pointer_space_; 898 } 899 if (space != nullptr) { 900 space->LogFragmentationAllocFailure(oss, byte_count); 901 } 902 } 903 self->ThrowOutOfMemoryError(oss.str().c_str()); 904} 905 906void Heap::DoPendingTransitionOrTrim() { 907 Thread* self = Thread::Current(); 908 CollectorType desired_collector_type; 909 // Wait until we reach the desired transition time. 910 while (true) { 911 uint64_t wait_time; 912 { 913 MutexLock mu(self, *heap_trim_request_lock_); 914 desired_collector_type = desired_collector_type_; 915 uint64_t current_time = NanoTime(); 916 if (current_time >= heap_transition_or_trim_target_time_) { 917 break; 918 } 919 wait_time = heap_transition_or_trim_target_time_ - current_time; 920 } 921 ScopedThreadStateChange tsc(self, kSleeping); 922 usleep(wait_time / 1000); // Usleep takes microseconds. 923 } 924 // Launch homogeneous space compaction if it is desired. 925 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 926 if (!CareAboutPauseTimes()) { 927 PerformHomogeneousSpaceCompact(); 928 } 929 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 930 desired_collector_type = collector_type_; 931 return; 932 } 933 // Transition the collector if the desired collector type is not the same as the current 934 // collector type. 935 TransitionCollector(desired_collector_type); 936 if (!CareAboutPauseTimes()) { 937 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 938 // about pauses. 939 Runtime* runtime = Runtime::Current(); 940 runtime->GetThreadList()->SuspendAll(); 941 uint64_t start_time = NanoTime(); 942 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 943 VLOG(heap) << "Deflating " << count << " monitors took " 944 << PrettyDuration(NanoTime() - start_time); 945 runtime->GetThreadList()->ResumeAll(); 946 } 947 // Do a heap trim if it is needed. 948 Trim(); 949} 950 951void Heap::Trim() { 952 Thread* self = Thread::Current(); 953 { 954 MutexLock mu(self, *heap_trim_request_lock_); 955 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 956 return; 957 } 958 last_trim_time_ = NanoTime(); 959 heap_trim_request_pending_ = false; 960 } 961 { 962 // Need to do this before acquiring the locks since we don't want to get suspended while 963 // holding any locks. 964 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 965 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 966 // trimming. 967 MutexLock mu(self, *gc_complete_lock_); 968 // Ensure there is only one GC at a time. 969 WaitForGcToCompleteLocked(kGcCauseTrim, self); 970 collector_type_running_ = kCollectorTypeHeapTrim; 971 } 972 uint64_t start_ns = NanoTime(); 973 // Trim the managed spaces. 974 uint64_t total_alloc_space_allocated = 0; 975 uint64_t total_alloc_space_size = 0; 976 uint64_t managed_reclaimed = 0; 977 for (const auto& space : continuous_spaces_) { 978 if (space->IsMallocSpace()) { 979 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 980 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 981 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 982 // for a long period of time. 983 managed_reclaimed += malloc_space->Trim(); 984 } 985 total_alloc_space_size += malloc_space->Size(); 986 } 987 } 988 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 989 if (bump_pointer_space_ != nullptr) { 990 total_alloc_space_allocated -= bump_pointer_space_->Size(); 991 } 992 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 993 static_cast<float>(total_alloc_space_size); 994 uint64_t gc_heap_end_ns = NanoTime(); 995 // We never move things in the native heap, so we can finish the GC at this point. 996 FinishGC(self, collector::kGcTypeNone); 997 size_t native_reclaimed = 0; 998 // Only trim the native heap if we don't care about pauses. 999 if (!CareAboutPauseTimes()) { 1000#if defined(USE_DLMALLOC) 1001 // Trim the native heap. 1002 dlmalloc_trim(0); 1003 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1004#elif defined(USE_JEMALLOC) 1005 // Jemalloc does it's own internal trimming. 1006#else 1007 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1008#endif 1009 } 1010 uint64_t end_ns = NanoTime(); 1011 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1012 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1013 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1014 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1015 << "%."; 1016} 1017 1018bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1019 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1020 // taking the lock. 1021 if (obj == nullptr) { 1022 return true; 1023 } 1024 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1025} 1026 1027bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1028 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1029} 1030 1031bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1032 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1033 return false; 1034 } 1035 for (const auto& space : continuous_spaces_) { 1036 if (space->HasAddress(obj)) { 1037 return true; 1038 } 1039 } 1040 return false; 1041} 1042 1043bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1044 bool search_live_stack, bool sorted) { 1045 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1046 return false; 1047 } 1048 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1049 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1050 if (obj == klass) { 1051 // This case happens for java.lang.Class. 1052 return true; 1053 } 1054 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1055 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1056 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1057 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1058 return temp_space_->Contains(obj); 1059 } 1060 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1061 space::DiscontinuousSpace* d_space = nullptr; 1062 if (c_space != nullptr) { 1063 if (c_space->GetLiveBitmap()->Test(obj)) { 1064 return true; 1065 } 1066 } else { 1067 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1068 if (d_space != nullptr) { 1069 if (d_space->GetLiveBitmap()->Test(obj)) { 1070 return true; 1071 } 1072 } 1073 } 1074 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1075 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1076 if (i > 0) { 1077 NanoSleep(MsToNs(10)); 1078 } 1079 if (search_allocation_stack) { 1080 if (sorted) { 1081 if (allocation_stack_->ContainsSorted(obj)) { 1082 return true; 1083 } 1084 } else if (allocation_stack_->Contains(obj)) { 1085 return true; 1086 } 1087 } 1088 1089 if (search_live_stack) { 1090 if (sorted) { 1091 if (live_stack_->ContainsSorted(obj)) { 1092 return true; 1093 } 1094 } else if (live_stack_->Contains(obj)) { 1095 return true; 1096 } 1097 } 1098 } 1099 // We need to check the bitmaps again since there is a race where we mark something as live and 1100 // then clear the stack containing it. 1101 if (c_space != nullptr) { 1102 if (c_space->GetLiveBitmap()->Test(obj)) { 1103 return true; 1104 } 1105 } else { 1106 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1107 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1108 return true; 1109 } 1110 } 1111 return false; 1112} 1113 1114std::string Heap::DumpSpaces() const { 1115 std::ostringstream oss; 1116 DumpSpaces(oss); 1117 return oss.str(); 1118} 1119 1120void Heap::DumpSpaces(std::ostream& stream) const { 1121 for (const auto& space : continuous_spaces_) { 1122 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1123 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1124 stream << space << " " << *space << "\n"; 1125 if (live_bitmap != nullptr) { 1126 stream << live_bitmap << " " << *live_bitmap << "\n"; 1127 } 1128 if (mark_bitmap != nullptr) { 1129 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1130 } 1131 } 1132 for (const auto& space : discontinuous_spaces_) { 1133 stream << space << " " << *space << "\n"; 1134 } 1135} 1136 1137void Heap::VerifyObjectBody(mirror::Object* obj) { 1138 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1139 return; 1140 } 1141 1142 // Ignore early dawn of the universe verifications. 1143 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1144 return; 1145 } 1146 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1147 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1148 CHECK(c != nullptr) << "Null class in object " << obj; 1149 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1150 CHECK(VerifyClassClass(c)); 1151 1152 if (verify_object_mode_ > kVerifyObjectModeFast) { 1153 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1154 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1155 } 1156} 1157 1158void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1159 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1160} 1161 1162void Heap::VerifyHeap() { 1163 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1164 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1165} 1166 1167void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1168 // Use signed comparison since freed bytes can be negative when background compaction foreground 1169 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1170 // free list backed space typically increasing memory footprint due to padding and binning. 1171 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1172 // Note: This relies on 2s complement for handling negative freed_bytes. 1173 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1174 if (Runtime::Current()->HasStatsEnabled()) { 1175 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1176 thread_stats->freed_objects += freed_objects; 1177 thread_stats->freed_bytes += freed_bytes; 1178 // TODO: Do this concurrently. 1179 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1180 global_stats->freed_objects += freed_objects; 1181 global_stats->freed_bytes += freed_bytes; 1182 } 1183} 1184 1185space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1186 for (const auto& space : continuous_spaces_) { 1187 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1188 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1189 return space->AsContinuousSpace()->AsRosAllocSpace(); 1190 } 1191 } 1192 } 1193 return nullptr; 1194} 1195 1196mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1197 size_t alloc_size, size_t* bytes_allocated, 1198 size_t* usable_size, 1199 mirror::Class** klass) { 1200 bool was_default_allocator = allocator == GetCurrentAllocator(); 1201 DCHECK(klass != nullptr); 1202 StackHandleScope<1> hs(self); 1203 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1204 klass = nullptr; // Invalidate for safety. 1205 // The allocation failed. If the GC is running, block until it completes, and then retry the 1206 // allocation. 1207 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1208 if (last_gc != collector::kGcTypeNone) { 1209 // If we were the default allocator but the allocator changed while we were suspended, 1210 // abort the allocation. 1211 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1212 return nullptr; 1213 } 1214 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1215 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1216 usable_size); 1217 if (ptr != nullptr) { 1218 return ptr; 1219 } 1220 } 1221 1222 collector::GcType tried_type = next_gc_type_; 1223 const bool gc_ran = 1224 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1225 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1226 return nullptr; 1227 } 1228 if (gc_ran) { 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 // Loop through our different Gc types and try to Gc until we get enough free memory. 1237 for (collector::GcType gc_type : gc_plan_) { 1238 if (gc_type == tried_type) { 1239 continue; 1240 } 1241 // Attempt to run the collector, if we succeed, re-try the allocation. 1242 const bool gc_ran = 1243 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1244 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1245 return nullptr; 1246 } 1247 if (gc_ran) { 1248 // Did we free sufficient memory for the allocation to succeed? 1249 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1250 usable_size); 1251 if (ptr != nullptr) { 1252 return ptr; 1253 } 1254 } 1255 } 1256 // Allocations have failed after GCs; this is an exceptional state. 1257 // Try harder, growing the heap if necessary. 1258 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1259 usable_size); 1260 if (ptr != nullptr) { 1261 return ptr; 1262 } 1263 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1264 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1265 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1266 // OOME. 1267 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1268 << " allocation"; 1269 // TODO: Run finalization, but this may cause more allocations to occur. 1270 // We don't need a WaitForGcToComplete here either. 1271 DCHECK(!gc_plan_.empty()); 1272 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1273 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1274 return nullptr; 1275 } 1276 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1277 if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) { 1278 const uint64_t current_time = NanoTime(); 1279 if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) && 1280 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1281 min_interval_homogeneous_space_compaction_by_oom_) { 1282 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1283 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1284 switch (result) { 1285 case HomogeneousSpaceCompactResult::kSuccess: 1286 // If the allocation succeeded, we delayed an oom. 1287 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1288 if (ptr != nullptr) { 1289 count_delayed_oom_++; 1290 } 1291 break; 1292 case HomogeneousSpaceCompactResult::kErrorReject: 1293 // Reject due to disabled moving GC. 1294 break; 1295 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1296 // Throw OOM by default. 1297 break; 1298 default: { 1299 LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result); 1300 } 1301 } 1302 // Always print that we ran homogeneous space compation since this can cause jank. 1303 VLOG(heap) << "Ran heap homogeneous space compaction, " 1304 << " requested defragmentation " 1305 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1306 << " performed defragmentation " 1307 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1308 << " ignored homogeneous space compaction " 1309 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1310 << " delayed count = " 1311 << count_delayed_oom_.LoadSequentiallyConsistent(); 1312 } 1313 } 1314 // If the allocation hasn't succeeded by this point, throw an OOM error. 1315 if (ptr == nullptr) { 1316 ThrowOutOfMemoryError(self, alloc_size, allocator); 1317 } 1318 return ptr; 1319} 1320 1321void Heap::SetTargetHeapUtilization(float target) { 1322 DCHECK_GT(target, 0.0f); // asserted in Java code 1323 DCHECK_LT(target, 1.0f); 1324 target_utilization_ = target; 1325} 1326 1327size_t Heap::GetObjectsAllocated() const { 1328 size_t total = 0; 1329 for (space::AllocSpace* space : alloc_spaces_) { 1330 total += space->GetObjectsAllocated(); 1331 } 1332 return total; 1333} 1334 1335size_t Heap::GetObjectsAllocatedEver() const { 1336 return GetObjectsFreedEver() + GetObjectsAllocated(); 1337} 1338 1339size_t Heap::GetBytesAllocatedEver() const { 1340 return GetBytesFreedEver() + GetBytesAllocated(); 1341} 1342 1343class InstanceCounter { 1344 public: 1345 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1346 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1347 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1348 } 1349 static void Callback(mirror::Object* obj, void* arg) 1350 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1351 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1352 mirror::Class* instance_class = obj->GetClass(); 1353 CHECK(instance_class != nullptr); 1354 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1355 if (instance_counter->use_is_assignable_from_) { 1356 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1357 ++instance_counter->counts_[i]; 1358 } 1359 } else if (instance_class == instance_counter->classes_[i]) { 1360 ++instance_counter->counts_[i]; 1361 } 1362 } 1363 } 1364 1365 private: 1366 const std::vector<mirror::Class*>& classes_; 1367 bool use_is_assignable_from_; 1368 uint64_t* const counts_; 1369 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1370}; 1371 1372void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1373 uint64_t* counts) { 1374 // Can't do any GC in this function since this may move classes. 1375 Thread* self = Thread::Current(); 1376 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1377 InstanceCounter counter(classes, use_is_assignable_from, counts); 1378 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1379 VisitObjects(InstanceCounter::Callback, &counter); 1380 self->EndAssertNoThreadSuspension(old_cause); 1381} 1382 1383class InstanceCollector { 1384 public: 1385 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1386 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1387 : class_(c), max_count_(max_count), instances_(instances) { 1388 } 1389 static void Callback(mirror::Object* obj, void* arg) 1390 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1391 DCHECK(arg != nullptr); 1392 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1393 mirror::Class* instance_class = obj->GetClass(); 1394 if (instance_class == instance_collector->class_) { 1395 if (instance_collector->max_count_ == 0 || 1396 instance_collector->instances_.size() < instance_collector->max_count_) { 1397 instance_collector->instances_.push_back(obj); 1398 } 1399 } 1400 } 1401 1402 private: 1403 mirror::Class* class_; 1404 uint32_t max_count_; 1405 std::vector<mirror::Object*>& instances_; 1406 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1407}; 1408 1409void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1410 std::vector<mirror::Object*>& instances) { 1411 // Can't do any GC in this function since this may move classes. 1412 Thread* self = Thread::Current(); 1413 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1414 InstanceCollector collector(c, max_count, instances); 1415 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1416 VisitObjects(&InstanceCollector::Callback, &collector); 1417 self->EndAssertNoThreadSuspension(old_cause); 1418} 1419 1420class ReferringObjectsFinder { 1421 public: 1422 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1423 std::vector<mirror::Object*>& referring_objects) 1424 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1425 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1426 } 1427 1428 static void Callback(mirror::Object* obj, void* arg) 1429 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1430 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1431 } 1432 1433 // For bitmap Visit. 1434 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1435 // annotalysis on visitors. 1436 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1437 o->VisitReferences<true>(*this, VoidFunctor()); 1438 } 1439 1440 // For Object::VisitReferences. 1441 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1442 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1443 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1444 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1445 referring_objects_.push_back(obj); 1446 } 1447 } 1448 1449 private: 1450 mirror::Object* object_; 1451 uint32_t max_count_; 1452 std::vector<mirror::Object*>& referring_objects_; 1453 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1454}; 1455 1456void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1457 std::vector<mirror::Object*>& referring_objects) { 1458 // Can't do any GC in this function since this may move the object o. 1459 Thread* self = Thread::Current(); 1460 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1461 ReferringObjectsFinder finder(o, max_count, referring_objects); 1462 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1463 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1464 self->EndAssertNoThreadSuspension(old_cause); 1465} 1466 1467void Heap::CollectGarbage(bool clear_soft_references) { 1468 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1469 // last GC will not have necessarily been cleared. 1470 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1471} 1472 1473HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1474 Thread* self = Thread::Current(); 1475 // Inc requested homogeneous space compaction. 1476 count_requested_homogeneous_space_compaction_++; 1477 // Store performed homogeneous space compaction at a new request arrival. 1478 ThreadList* tl = Runtime::Current()->GetThreadList(); 1479 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1480 Locks::mutator_lock_->AssertNotHeld(self); 1481 { 1482 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1483 MutexLock mu(self, *gc_complete_lock_); 1484 // Ensure there is only one GC at a time. 1485 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1486 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1487 // is non zero. 1488 // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction, 1489 // exit. 1490 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) { 1491 return HomogeneousSpaceCompactResult::kErrorReject; 1492 } 1493 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1494 } 1495 if (Runtime::Current()->IsShuttingDown(self)) { 1496 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1497 // cause objects to get finalized. 1498 FinishGC(self, collector::kGcTypeNone); 1499 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1500 } 1501 // Suspend all threads. 1502 tl->SuspendAll(); 1503 uint64_t start_time = NanoTime(); 1504 // Launch compaction. 1505 space::MallocSpace* to_space = main_space_backup_.release(); 1506 space::MallocSpace* from_space = main_space_; 1507 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1508 const uint64_t space_size_before_compaction = from_space->Size(); 1509 AddSpace(to_space); 1510 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1511 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1512 from_space->GetMemMap()->Protect(PROT_READ); 1513 const uint64_t space_size_after_compaction = to_space->Size(); 1514 main_space_ = to_space; 1515 main_space_backup_.reset(from_space); 1516 RemoveSpace(from_space); 1517 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1518 // Update performed homogeneous space compaction count. 1519 count_performed_homogeneous_space_compaction_++; 1520 // Print statics log and resume all threads. 1521 uint64_t duration = NanoTime() - start_time; 1522 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1523 << PrettySize(space_size_before_compaction) << " -> " 1524 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1525 << std::fixed << static_cast<double>(space_size_after_compaction) / 1526 static_cast<double>(space_size_before_compaction); 1527 tl->ResumeAll(); 1528 // Finish GC. 1529 reference_processor_.EnqueueClearedReferences(self); 1530 GrowForUtilization(semi_space_collector_); 1531 FinishGC(self, collector::kGcTypeFull); 1532 return HomogeneousSpaceCompactResult::kSuccess; 1533} 1534 1535 1536void Heap::TransitionCollector(CollectorType collector_type) { 1537 if (collector_type == collector_type_) { 1538 return; 1539 } 1540 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1541 << " -> " << static_cast<int>(collector_type); 1542 uint64_t start_time = NanoTime(); 1543 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1544 Runtime* const runtime = Runtime::Current(); 1545 ThreadList* const tl = runtime->GetThreadList(); 1546 Thread* const self = Thread::Current(); 1547 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1548 Locks::mutator_lock_->AssertNotHeld(self); 1549 const bool copying_transition = 1550 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1551 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1552 // compacting_gc_disable_count_, this should rarely occurs). 1553 for (;;) { 1554 { 1555 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1556 MutexLock mu(self, *gc_complete_lock_); 1557 // Ensure there is only one GC at a time. 1558 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1559 // If someone else beat us to it and changed the collector before we could, exit. 1560 // This is safe to do before the suspend all since we set the collector_type_running_ before 1561 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1562 // then it would get blocked on WaitForGcToCompleteLocked. 1563 if (collector_type == collector_type_) { 1564 return; 1565 } 1566 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1567 if (!copying_transition || disable_moving_gc_count_ == 0) { 1568 // TODO: Not hard code in semi-space collector? 1569 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1570 break; 1571 } 1572 } 1573 usleep(1000); 1574 } 1575 if (runtime->IsShuttingDown(self)) { 1576 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1577 // cause objects to get finalized. 1578 FinishGC(self, collector::kGcTypeNone); 1579 return; 1580 } 1581 tl->SuspendAll(); 1582 switch (collector_type) { 1583 case kCollectorTypeSS: { 1584 if (!IsMovingGc(collector_type_)) { 1585 // Create the bump pointer space from the backup space. 1586 CHECK(main_space_backup_ != nullptr); 1587 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1588 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1589 // pointer space last transition it will be protected. 1590 CHECK(mem_map != nullptr); 1591 mem_map->Protect(PROT_READ | PROT_WRITE); 1592 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1593 mem_map.release()); 1594 AddSpace(bump_pointer_space_); 1595 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1596 // Use the now empty main space mem map for the bump pointer temp space. 1597 mem_map.reset(main_space_->ReleaseMemMap()); 1598 // Unset the pointers just in case. 1599 if (dlmalloc_space_ == main_space_) { 1600 dlmalloc_space_ = nullptr; 1601 } else if (rosalloc_space_ == main_space_) { 1602 rosalloc_space_ = nullptr; 1603 } 1604 // Remove the main space so that we don't try to trim it, this doens't work for debug 1605 // builds since RosAlloc attempts to read the magic number from a protected page. 1606 RemoveSpace(main_space_); 1607 RemoveRememberedSet(main_space_); 1608 delete main_space_; // Delete the space since it has been removed. 1609 main_space_ = nullptr; 1610 RemoveRememberedSet(main_space_backup_.get()); 1611 main_space_backup_.reset(nullptr); // Deletes the space. 1612 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1613 mem_map.release()); 1614 AddSpace(temp_space_); 1615 } 1616 break; 1617 } 1618 case kCollectorTypeMS: 1619 // Fall through. 1620 case kCollectorTypeCMS: { 1621 if (IsMovingGc(collector_type_)) { 1622 CHECK(temp_space_ != nullptr); 1623 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1624 RemoveSpace(temp_space_); 1625 temp_space_ = nullptr; 1626 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1627 mem_map->Size()); 1628 mem_map.release(); 1629 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1630 AddSpace(main_space_); 1631 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1632 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1633 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1634 RemoveSpace(bump_pointer_space_); 1635 bump_pointer_space_ = nullptr; 1636 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1637 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1638 mem_map->Size(), mem_map->Size(), 1639 name, true)); 1640 mem_map.release(); 1641 } 1642 break; 1643 } 1644 default: { 1645 LOG(FATAL) << "Attempted to transition to invalid collector type " 1646 << static_cast<size_t>(collector_type); 1647 break; 1648 } 1649 } 1650 ChangeCollector(collector_type); 1651 tl->ResumeAll(); 1652 // Can't call into java code with all threads suspended. 1653 reference_processor_.EnqueueClearedReferences(self); 1654 uint64_t duration = NanoTime() - start_time; 1655 GrowForUtilization(semi_space_collector_); 1656 FinishGC(self, collector::kGcTypeFull); 1657 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1658 int32_t delta_allocated = before_allocated - after_allocated; 1659 std::string saved_str; 1660 if (delta_allocated >= 0) { 1661 saved_str = " saved at least " + PrettySize(delta_allocated); 1662 } else { 1663 saved_str = " expanded " + PrettySize(-delta_allocated); 1664 } 1665 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1666 << PrettyDuration(duration) << saved_str; 1667} 1668 1669void Heap::ChangeCollector(CollectorType collector_type) { 1670 // TODO: Only do this with all mutators suspended to avoid races. 1671 if (collector_type != collector_type_) { 1672 if (collector_type == kCollectorTypeMC) { 1673 // Don't allow mark compact unless support is compiled in. 1674 CHECK(kMarkCompactSupport); 1675 } 1676 collector_type_ = collector_type; 1677 gc_plan_.clear(); 1678 switch (collector_type_) { 1679 case kCollectorTypeCC: // Fall-through. 1680 case kCollectorTypeMC: // Fall-through. 1681 case kCollectorTypeSS: // Fall-through. 1682 case kCollectorTypeGSS: { 1683 gc_plan_.push_back(collector::kGcTypeFull); 1684 if (use_tlab_) { 1685 ChangeAllocator(kAllocatorTypeTLAB); 1686 } else { 1687 ChangeAllocator(kAllocatorTypeBumpPointer); 1688 } 1689 break; 1690 } 1691 case kCollectorTypeMS: { 1692 gc_plan_.push_back(collector::kGcTypeSticky); 1693 gc_plan_.push_back(collector::kGcTypePartial); 1694 gc_plan_.push_back(collector::kGcTypeFull); 1695 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1696 break; 1697 } 1698 case kCollectorTypeCMS: { 1699 gc_plan_.push_back(collector::kGcTypeSticky); 1700 gc_plan_.push_back(collector::kGcTypePartial); 1701 gc_plan_.push_back(collector::kGcTypeFull); 1702 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1703 break; 1704 } 1705 default: { 1706 LOG(FATAL) << "Unimplemented"; 1707 } 1708 } 1709 if (IsGcConcurrent()) { 1710 concurrent_start_bytes_ = 1711 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1712 } else { 1713 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1714 } 1715 } 1716} 1717 1718// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1719class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1720 public: 1721 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1722 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1723 } 1724 1725 void BuildBins(space::ContinuousSpace* space) { 1726 bin_live_bitmap_ = space->GetLiveBitmap(); 1727 bin_mark_bitmap_ = space->GetMarkBitmap(); 1728 BinContext context; 1729 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1730 context.collector_ = this; 1731 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1732 // Note: This requires traversing the space in increasing order of object addresses. 1733 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1734 // Add the last bin which spans after the last object to the end of the space. 1735 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1736 } 1737 1738 private: 1739 struct BinContext { 1740 uintptr_t prev_; // The end of the previous object. 1741 ZygoteCompactingCollector* collector_; 1742 }; 1743 // Maps from bin sizes to locations. 1744 std::multimap<size_t, uintptr_t> bins_; 1745 // Live bitmap of the space which contains the bins. 1746 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1747 // Mark bitmap of the space which contains the bins. 1748 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1749 1750 static void Callback(mirror::Object* obj, void* arg) 1751 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1752 DCHECK(arg != nullptr); 1753 BinContext* context = reinterpret_cast<BinContext*>(arg); 1754 ZygoteCompactingCollector* collector = context->collector_; 1755 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1756 size_t bin_size = object_addr - context->prev_; 1757 // Add the bin consisting of the end of the previous object to the start of the current object. 1758 collector->AddBin(bin_size, context->prev_); 1759 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1760 } 1761 1762 void AddBin(size_t size, uintptr_t position) { 1763 if (size != 0) { 1764 bins_.insert(std::make_pair(size, position)); 1765 } 1766 } 1767 1768 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1769 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1770 // allocator. 1771 return false; 1772 } 1773 1774 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1775 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1776 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1777 mirror::Object* forward_address; 1778 // Find the smallest bin which we can move obj in. 1779 auto it = bins_.lower_bound(object_size); 1780 if (it == bins_.end()) { 1781 // No available space in the bins, place it in the target space instead (grows the zygote 1782 // space). 1783 size_t bytes_allocated; 1784 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1785 if (to_space_live_bitmap_ != nullptr) { 1786 to_space_live_bitmap_->Set(forward_address); 1787 } else { 1788 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1789 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1790 } 1791 } else { 1792 size_t size = it->first; 1793 uintptr_t pos = it->second; 1794 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1795 forward_address = reinterpret_cast<mirror::Object*>(pos); 1796 // Set the live and mark bits so that sweeping system weaks works properly. 1797 bin_live_bitmap_->Set(forward_address); 1798 bin_mark_bitmap_->Set(forward_address); 1799 DCHECK_GE(size, object_size); 1800 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1801 } 1802 // Copy the object over to its new location. 1803 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1804 if (kUseBakerOrBrooksReadBarrier) { 1805 obj->AssertReadBarrierPointer(); 1806 if (kUseBrooksReadBarrier) { 1807 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1808 forward_address->SetReadBarrierPointer(forward_address); 1809 } 1810 forward_address->AssertReadBarrierPointer(); 1811 } 1812 return forward_address; 1813 } 1814}; 1815 1816void Heap::UnBindBitmaps() { 1817 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1818 for (const auto& space : GetContinuousSpaces()) { 1819 if (space->IsContinuousMemMapAllocSpace()) { 1820 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1821 if (alloc_space->HasBoundBitmaps()) { 1822 alloc_space->UnBindBitmaps(); 1823 } 1824 } 1825 } 1826} 1827 1828void Heap::PreZygoteFork() { 1829 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1830 Thread* self = Thread::Current(); 1831 MutexLock mu(self, zygote_creation_lock_); 1832 // Try to see if we have any Zygote spaces. 1833 if (have_zygote_space_) { 1834 return; 1835 } 1836 VLOG(heap) << "Starting PreZygoteFork"; 1837 // Trim the pages at the end of the non moving space. 1838 non_moving_space_->Trim(); 1839 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1840 // there. 1841 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1842 // Change the collector to the post zygote one. 1843 bool same_space = non_moving_space_ == main_space_; 1844 if (kCompactZygote) { 1845 DCHECK(semi_space_collector_ != nullptr); 1846 // Temporarily disable rosalloc verification because the zygote 1847 // compaction will mess up the rosalloc internal metadata. 1848 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1849 ZygoteCompactingCollector zygote_collector(this); 1850 zygote_collector.BuildBins(non_moving_space_); 1851 // Create a new bump pointer space which we will compact into. 1852 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1853 non_moving_space_->Limit()); 1854 // Compact the bump pointer space to a new zygote bump pointer space. 1855 bool reset_main_space = false; 1856 if (IsMovingGc(collector_type_)) { 1857 zygote_collector.SetFromSpace(bump_pointer_space_); 1858 } else { 1859 CHECK(main_space_ != nullptr); 1860 // Copy from the main space. 1861 zygote_collector.SetFromSpace(main_space_); 1862 reset_main_space = true; 1863 } 1864 zygote_collector.SetToSpace(&target_space); 1865 zygote_collector.SetSwapSemiSpaces(false); 1866 zygote_collector.Run(kGcCauseCollectorTransition, false); 1867 if (reset_main_space) { 1868 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1869 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1870 MemMap* mem_map = main_space_->ReleaseMemMap(); 1871 RemoveSpace(main_space_); 1872 space::Space* old_main_space = main_space_; 1873 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1874 delete old_main_space; 1875 AddSpace(main_space_); 1876 } else { 1877 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1878 } 1879 if (temp_space_ != nullptr) { 1880 CHECK(temp_space_->IsEmpty()); 1881 } 1882 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1883 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1884 // Update the end and write out image. 1885 non_moving_space_->SetEnd(target_space.End()); 1886 non_moving_space_->SetLimit(target_space.Limit()); 1887 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1888 } 1889 ChangeCollector(foreground_collector_type_); 1890 // Save the old space so that we can remove it after we complete creating the zygote space. 1891 space::MallocSpace* old_alloc_space = non_moving_space_; 1892 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1893 // the remaining available space. 1894 // Remove the old space before creating the zygote space since creating the zygote space sets 1895 // the old alloc space's bitmaps to nullptr. 1896 RemoveSpace(old_alloc_space); 1897 if (collector::SemiSpace::kUseRememberedSet) { 1898 // Sanity bound check. 1899 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1900 // Remove the remembered set for the now zygote space (the old 1901 // non-moving space). Note now that we have compacted objects into 1902 // the zygote space, the data in the remembered set is no longer 1903 // needed. The zygote space will instead have a mod-union table 1904 // from this point on. 1905 RemoveRememberedSet(old_alloc_space); 1906 } 1907 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1908 low_memory_mode_, 1909 &non_moving_space_); 1910 CHECK(!non_moving_space_->CanMoveObjects()); 1911 if (same_space) { 1912 main_space_ = non_moving_space_; 1913 SetSpaceAsDefault(main_space_); 1914 } 1915 delete old_alloc_space; 1916 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1917 AddSpace(zygote_space); 1918 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1919 AddSpace(non_moving_space_); 1920 have_zygote_space_ = true; 1921 // Enable large object space allocations. 1922 large_object_threshold_ = kDefaultLargeObjectThreshold; 1923 // Create the zygote space mod union table. 1924 accounting::ModUnionTable* mod_union_table = 1925 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1926 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1927 AddModUnionTable(mod_union_table); 1928 if (collector::SemiSpace::kUseRememberedSet) { 1929 // Add a new remembered set for the post-zygote non-moving space. 1930 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1931 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1932 non_moving_space_); 1933 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1934 << "Failed to create post-zygote non-moving space remembered set"; 1935 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1936 } 1937} 1938 1939void Heap::FlushAllocStack() { 1940 MarkAllocStackAsLive(allocation_stack_.get()); 1941 allocation_stack_->Reset(); 1942} 1943 1944void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1945 accounting::ContinuousSpaceBitmap* bitmap2, 1946 accounting::LargeObjectBitmap* large_objects, 1947 accounting::ObjectStack* stack) { 1948 DCHECK(bitmap1 != nullptr); 1949 DCHECK(bitmap2 != nullptr); 1950 mirror::Object** limit = stack->End(); 1951 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1952 const mirror::Object* obj = *it; 1953 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1954 if (bitmap1->HasAddress(obj)) { 1955 bitmap1->Set(obj); 1956 } else if (bitmap2->HasAddress(obj)) { 1957 bitmap2->Set(obj); 1958 } else { 1959 large_objects->Set(obj); 1960 } 1961 } 1962 } 1963} 1964 1965void Heap::SwapSemiSpaces() { 1966 CHECK(bump_pointer_space_ != nullptr); 1967 CHECK(temp_space_ != nullptr); 1968 std::swap(bump_pointer_space_, temp_space_); 1969} 1970 1971void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1972 space::ContinuousMemMapAllocSpace* source_space, 1973 GcCause gc_cause) { 1974 CHECK(kMovingCollector); 1975 if (target_space != source_space) { 1976 // Don't swap spaces since this isn't a typical semi space collection. 1977 semi_space_collector_->SetSwapSemiSpaces(false); 1978 semi_space_collector_->SetFromSpace(source_space); 1979 semi_space_collector_->SetToSpace(target_space); 1980 semi_space_collector_->Run(gc_cause, false); 1981 } else { 1982 CHECK(target_space->IsBumpPointerSpace()) 1983 << "In-place compaction is only supported for bump pointer spaces"; 1984 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1985 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1986 } 1987} 1988 1989collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1990 bool clear_soft_references) { 1991 Thread* self = Thread::Current(); 1992 Runtime* runtime = Runtime::Current(); 1993 // If the heap can't run the GC, silently fail and return that no GC was run. 1994 switch (gc_type) { 1995 case collector::kGcTypePartial: { 1996 if (!have_zygote_space_) { 1997 return collector::kGcTypeNone; 1998 } 1999 break; 2000 } 2001 default: { 2002 // Other GC types don't have any special cases which makes them not runnable. The main case 2003 // here is full GC. 2004 } 2005 } 2006 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2007 Locks::mutator_lock_->AssertNotHeld(self); 2008 if (self->IsHandlingStackOverflow()) { 2009 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2010 } 2011 bool compacting_gc; 2012 { 2013 gc_complete_lock_->AssertNotHeld(self); 2014 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2015 MutexLock mu(self, *gc_complete_lock_); 2016 // Ensure there is only one GC at a time. 2017 WaitForGcToCompleteLocked(gc_cause, self); 2018 compacting_gc = IsMovingGc(collector_type_); 2019 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2020 if (compacting_gc && disable_moving_gc_count_ != 0) { 2021 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2022 return collector::kGcTypeNone; 2023 } 2024 collector_type_running_ = collector_type_; 2025 } 2026 2027 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2028 ++runtime->GetStats()->gc_for_alloc_count; 2029 ++self->GetStats()->gc_for_alloc_count; 2030 } 2031 uint64_t gc_start_time_ns = NanoTime(); 2032 uint64_t gc_start_size = GetBytesAllocated(); 2033 // Approximate allocation rate in bytes / second. 2034 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2035 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2036 if (LIKELY(ms_delta != 0)) { 2037 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2038 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2039 } 2040 2041 DCHECK_LT(gc_type, collector::kGcTypeMax); 2042 DCHECK_NE(gc_type, collector::kGcTypeNone); 2043 2044 collector::GarbageCollector* collector = nullptr; 2045 // TODO: Clean this up. 2046 if (compacting_gc) { 2047 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2048 current_allocator_ == kAllocatorTypeTLAB); 2049 switch (collector_type_) { 2050 case kCollectorTypeSS: 2051 // Fall-through. 2052 case kCollectorTypeGSS: 2053 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2054 semi_space_collector_->SetToSpace(temp_space_); 2055 semi_space_collector_->SetSwapSemiSpaces(true); 2056 collector = semi_space_collector_; 2057 break; 2058 case kCollectorTypeCC: 2059 collector = concurrent_copying_collector_; 2060 break; 2061 case kCollectorTypeMC: 2062 mark_compact_collector_->SetSpace(bump_pointer_space_); 2063 collector = mark_compact_collector_; 2064 break; 2065 default: 2066 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2067 } 2068 if (collector != mark_compact_collector_) { 2069 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2070 CHECK(temp_space_->IsEmpty()); 2071 } 2072 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2073 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2074 current_allocator_ == kAllocatorTypeDlMalloc) { 2075 collector = FindCollectorByGcType(gc_type); 2076 } else { 2077 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2078 } 2079 CHECK(collector != nullptr) 2080 << "Could not find garbage collector with collector_type=" 2081 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2082 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2083 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2084 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2085 RequestHeapTrim(); 2086 // Enqueue cleared references. 2087 reference_processor_.EnqueueClearedReferences(self); 2088 // Grow the heap so that we know when to perform the next GC. 2089 GrowForUtilization(collector); 2090 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2091 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2092 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2093 // (mutator time blocked >= long_pause_log_threshold_). 2094 bool log_gc = gc_cause == kGcCauseExplicit; 2095 if (!log_gc && CareAboutPauseTimes()) { 2096 // GC for alloc pauses the allocating thread, so consider it as a pause. 2097 log_gc = duration > long_gc_log_threshold_ || 2098 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2099 for (uint64_t pause : pause_times) { 2100 log_gc = log_gc || pause >= long_pause_log_threshold_; 2101 } 2102 } 2103 if (log_gc) { 2104 const size_t percent_free = GetPercentFree(); 2105 const size_t current_heap_size = GetBytesAllocated(); 2106 const size_t total_memory = GetTotalMemory(); 2107 std::ostringstream pause_string; 2108 for (size_t i = 0; i < pause_times.size(); ++i) { 2109 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2110 << ((i != pause_times.size() - 1) ? "," : ""); 2111 } 2112 LOG(INFO) << gc_cause << " " << collector->GetName() 2113 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2114 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2115 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2116 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2117 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2118 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2119 << " total " << PrettyDuration((duration / 1000) * 1000); 2120 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2121 } 2122 FinishGC(self, gc_type); 2123 // Inform DDMS that a GC completed. 2124 Dbg::GcDidFinish(); 2125 return gc_type; 2126} 2127 2128void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2129 MutexLock mu(self, *gc_complete_lock_); 2130 collector_type_running_ = kCollectorTypeNone; 2131 if (gc_type != collector::kGcTypeNone) { 2132 last_gc_type_ = gc_type; 2133 } 2134 // Wake anyone who may have been waiting for the GC to complete. 2135 gc_complete_cond_->Broadcast(self); 2136} 2137 2138static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2139 RootType /*root_type*/) { 2140 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2141 if (*root == obj) { 2142 LOG(INFO) << "Object " << obj << " is a root"; 2143 } 2144} 2145 2146class ScanVisitor { 2147 public: 2148 void operator()(const mirror::Object* obj) const { 2149 LOG(ERROR) << "Would have rescanned object " << obj; 2150 } 2151}; 2152 2153// Verify a reference from an object. 2154class VerifyReferenceVisitor { 2155 public: 2156 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2157 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2158 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2159 2160 size_t GetFailureCount() const { 2161 return fail_count_->LoadSequentiallyConsistent(); 2162 } 2163 2164 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2165 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2166 if (verify_referent_) { 2167 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2168 } 2169 } 2170 2171 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2172 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2173 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2174 } 2175 2176 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2177 return heap_->IsLiveObjectLocked(obj, true, false, true); 2178 } 2179 2180 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2181 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2182 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2183 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2184 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2185 << " thread_id= " << thread_id << " root_type= " << root_type; 2186 } 2187 } 2188 2189 private: 2190 // TODO: Fix the no thread safety analysis. 2191 // Returns false on failure. 2192 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2193 NO_THREAD_SAFETY_ANALYSIS { 2194 if (ref == nullptr || IsLive(ref)) { 2195 // Verify that the reference is live. 2196 return true; 2197 } 2198 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2199 // Print message on only on first failure to prevent spam. 2200 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2201 } 2202 if (obj != nullptr) { 2203 // Only do this part for non roots. 2204 accounting::CardTable* card_table = heap_->GetCardTable(); 2205 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2206 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2207 byte* card_addr = card_table->CardFromAddr(obj); 2208 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2209 << offset << "\n card value = " << static_cast<int>(*card_addr); 2210 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2211 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2212 } else { 2213 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2214 } 2215 2216 // Attempt to find the class inside of the recently freed objects. 2217 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2218 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2219 space::MallocSpace* space = ref_space->AsMallocSpace(); 2220 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2221 if (ref_class != nullptr) { 2222 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2223 << PrettyClass(ref_class); 2224 } else { 2225 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2226 } 2227 } 2228 2229 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2230 ref->GetClass()->IsClass()) { 2231 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2232 } else { 2233 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2234 << ") is not a valid heap address"; 2235 } 2236 2237 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2238 void* cover_begin = card_table->AddrFromCard(card_addr); 2239 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2240 accounting::CardTable::kCardSize); 2241 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2242 << "-" << cover_end; 2243 accounting::ContinuousSpaceBitmap* bitmap = 2244 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2245 2246 if (bitmap == nullptr) { 2247 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2248 if (!VerifyClassClass(obj->GetClass())) { 2249 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2250 } 2251 } else { 2252 // Print out how the object is live. 2253 if (bitmap->Test(obj)) { 2254 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2255 } 2256 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2257 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2258 } 2259 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2260 LOG(ERROR) << "Object " << obj << " found in live stack"; 2261 } 2262 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2263 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2264 } 2265 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2266 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2267 } 2268 // Attempt to see if the card table missed the reference. 2269 ScanVisitor scan_visitor; 2270 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2271 card_table->Scan(bitmap, byte_cover_begin, 2272 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2273 } 2274 2275 // Search to see if any of the roots reference our object. 2276 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2277 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2278 2279 // Search to see if any of the roots reference our reference. 2280 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2281 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2282 } 2283 return false; 2284 } 2285 2286 Heap* const heap_; 2287 Atomic<size_t>* const fail_count_; 2288 const bool verify_referent_; 2289}; 2290 2291// Verify all references within an object, for use with HeapBitmap::Visit. 2292class VerifyObjectVisitor { 2293 public: 2294 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2295 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2296 } 2297 2298 void operator()(mirror::Object* obj) const 2299 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2300 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2301 // be live or else how did we find it in the live bitmap? 2302 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2303 // The class doesn't count as a reference but we should verify it anyways. 2304 obj->VisitReferences<true>(visitor, visitor); 2305 } 2306 2307 static void VisitCallback(mirror::Object* obj, void* arg) 2308 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2309 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2310 visitor->operator()(obj); 2311 } 2312 2313 size_t GetFailureCount() const { 2314 return fail_count_->LoadSequentiallyConsistent(); 2315 } 2316 2317 private: 2318 Heap* const heap_; 2319 Atomic<size_t>* const fail_count_; 2320 const bool verify_referent_; 2321}; 2322 2323void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2324 // Slow path, the allocation stack push back must have already failed. 2325 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2326 do { 2327 // TODO: Add handle VerifyObject. 2328 StackHandleScope<1> hs(self); 2329 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2330 // Push our object into the reserve region of the allocaiton stack. This is only required due 2331 // to heap verification requiring that roots are live (either in the live bitmap or in the 2332 // allocation stack). 2333 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2334 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2335 } while (!allocation_stack_->AtomicPushBack(*obj)); 2336} 2337 2338void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2339 // Slow path, the allocation stack push back must have already failed. 2340 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2341 mirror::Object** start_address; 2342 mirror::Object** end_address; 2343 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2344 &end_address)) { 2345 // TODO: Add handle VerifyObject. 2346 StackHandleScope<1> hs(self); 2347 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2348 // Push our object into the reserve region of the allocaiton stack. This is only required due 2349 // to heap verification requiring that roots are live (either in the live bitmap or in the 2350 // allocation stack). 2351 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2352 // Push into the reserve allocation stack. 2353 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2354 } 2355 self->SetThreadLocalAllocationStack(start_address, end_address); 2356 // Retry on the new thread-local allocation stack. 2357 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2358} 2359 2360// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2361size_t Heap::VerifyHeapReferences(bool verify_referents) { 2362 Thread* self = Thread::Current(); 2363 Locks::mutator_lock_->AssertExclusiveHeld(self); 2364 // Lets sort our allocation stacks so that we can efficiently binary search them. 2365 allocation_stack_->Sort(); 2366 live_stack_->Sort(); 2367 // Since we sorted the allocation stack content, need to revoke all 2368 // thread-local allocation stacks. 2369 RevokeAllThreadLocalAllocationStacks(self); 2370 Atomic<size_t> fail_count_(0); 2371 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2372 // Verify objects in the allocation stack since these will be objects which were: 2373 // 1. Allocated prior to the GC (pre GC verification). 2374 // 2. Allocated during the GC (pre sweep GC verification). 2375 // We don't want to verify the objects in the live stack since they themselves may be 2376 // pointing to dead objects if they are not reachable. 2377 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2378 // Verify the roots: 2379 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2380 if (visitor.GetFailureCount() > 0) { 2381 // Dump mod-union tables. 2382 for (const auto& table_pair : mod_union_tables_) { 2383 accounting::ModUnionTable* mod_union_table = table_pair.second; 2384 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2385 } 2386 // Dump remembered sets. 2387 for (const auto& table_pair : remembered_sets_) { 2388 accounting::RememberedSet* remembered_set = table_pair.second; 2389 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2390 } 2391 DumpSpaces(LOG(ERROR)); 2392 } 2393 return visitor.GetFailureCount(); 2394} 2395 2396class VerifyReferenceCardVisitor { 2397 public: 2398 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2399 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2400 Locks::heap_bitmap_lock_) 2401 : heap_(heap), failed_(failed) { 2402 } 2403 2404 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2405 // annotalysis on visitors. 2406 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2407 NO_THREAD_SAFETY_ANALYSIS { 2408 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2409 // Filter out class references since changing an object's class does not mark the card as dirty. 2410 // Also handles large objects, since the only reference they hold is a class reference. 2411 if (ref != nullptr && !ref->IsClass()) { 2412 accounting::CardTable* card_table = heap_->GetCardTable(); 2413 // If the object is not dirty and it is referencing something in the live stack other than 2414 // class, then it must be on a dirty card. 2415 if (!card_table->AddrIsInCardTable(obj)) { 2416 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2417 *failed_ = true; 2418 } else if (!card_table->IsDirty(obj)) { 2419 // TODO: Check mod-union tables. 2420 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2421 // kCardDirty - 1 if it didnt get touched since we aged it. 2422 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2423 if (live_stack->ContainsSorted(ref)) { 2424 if (live_stack->ContainsSorted(obj)) { 2425 LOG(ERROR) << "Object " << obj << " found in live stack"; 2426 } 2427 if (heap_->GetLiveBitmap()->Test(obj)) { 2428 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2429 } 2430 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2431 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2432 2433 // Print which field of the object is dead. 2434 if (!obj->IsObjectArray()) { 2435 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2436 CHECK(klass != NULL); 2437 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2438 : klass->GetIFields(); 2439 CHECK(fields != NULL); 2440 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2441 mirror::ArtField* cur = fields->Get(i); 2442 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2443 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2444 << PrettyField(cur); 2445 break; 2446 } 2447 } 2448 } else { 2449 mirror::ObjectArray<mirror::Object>* object_array = 2450 obj->AsObjectArray<mirror::Object>(); 2451 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2452 if (object_array->Get(i) == ref) { 2453 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2454 } 2455 } 2456 } 2457 2458 *failed_ = true; 2459 } 2460 } 2461 } 2462 } 2463 2464 private: 2465 Heap* const heap_; 2466 bool* const failed_; 2467}; 2468 2469class VerifyLiveStackReferences { 2470 public: 2471 explicit VerifyLiveStackReferences(Heap* heap) 2472 : heap_(heap), 2473 failed_(false) {} 2474 2475 void operator()(mirror::Object* obj) const 2476 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2477 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2478 obj->VisitReferences<true>(visitor, VoidFunctor()); 2479 } 2480 2481 bool Failed() const { 2482 return failed_; 2483 } 2484 2485 private: 2486 Heap* const heap_; 2487 bool failed_; 2488}; 2489 2490bool Heap::VerifyMissingCardMarks() { 2491 Thread* self = Thread::Current(); 2492 Locks::mutator_lock_->AssertExclusiveHeld(self); 2493 2494 // We need to sort the live stack since we binary search it. 2495 live_stack_->Sort(); 2496 // Since we sorted the allocation stack content, need to revoke all 2497 // thread-local allocation stacks. 2498 RevokeAllThreadLocalAllocationStacks(self); 2499 VerifyLiveStackReferences visitor(this); 2500 GetLiveBitmap()->Visit(visitor); 2501 2502 // We can verify objects in the live stack since none of these should reference dead objects. 2503 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2504 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2505 visitor(*it); 2506 } 2507 } 2508 return !visitor.Failed(); 2509} 2510 2511void Heap::SwapStacks(Thread* self) { 2512 if (kUseThreadLocalAllocationStack) { 2513 live_stack_->AssertAllZero(); 2514 } 2515 allocation_stack_.swap(live_stack_); 2516} 2517 2518void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2519 // This must be called only during the pause. 2520 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2521 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2522 MutexLock mu2(self, *Locks::thread_list_lock_); 2523 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2524 for (Thread* t : thread_list) { 2525 t->RevokeThreadLocalAllocationStack(); 2526 } 2527} 2528 2529void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2530 if (kIsDebugBuild) { 2531 if (bump_pointer_space_ != nullptr) { 2532 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2533 } 2534 } 2535} 2536 2537accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2538 auto it = mod_union_tables_.find(space); 2539 if (it == mod_union_tables_.end()) { 2540 return nullptr; 2541 } 2542 return it->second; 2543} 2544 2545accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2546 auto it = remembered_sets_.find(space); 2547 if (it == remembered_sets_.end()) { 2548 return nullptr; 2549 } 2550 return it->second; 2551} 2552 2553void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2554 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2555 // Clear cards and keep track of cards cleared in the mod-union table. 2556 for (const auto& space : continuous_spaces_) { 2557 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2558 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2559 if (table != nullptr) { 2560 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2561 "ImageModUnionClearCards"; 2562 TimingLogger::ScopedTiming t(name, timings); 2563 table->ClearCards(); 2564 } else if (use_rem_sets && rem_set != nullptr) { 2565 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2566 << static_cast<int>(collector_type_); 2567 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2568 rem_set->ClearCards(); 2569 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2570 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2571 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2572 // were dirty before the GC started. 2573 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2574 // -> clean(cleaning thread). 2575 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2576 // roots and then we scan / update mod union tables after. We will always scan either card. 2577 // If we end up with the non aged card, we scan it it in the pause. 2578 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2579 VoidFunctor()); 2580 } 2581 } 2582} 2583 2584static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2585} 2586 2587void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2588 Thread* const self = Thread::Current(); 2589 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2590 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2591 if (verify_pre_gc_heap_) { 2592 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2593 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2594 size_t failures = VerifyHeapReferences(); 2595 if (failures > 0) { 2596 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2597 << " failures"; 2598 } 2599 } 2600 // Check that all objects which reference things in the live stack are on dirty cards. 2601 if (verify_missing_card_marks_) { 2602 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2603 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2604 SwapStacks(self); 2605 // Sort the live stack so that we can quickly binary search it later. 2606 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2607 << " missing card mark verification failed\n" << DumpSpaces(); 2608 SwapStacks(self); 2609 } 2610 if (verify_mod_union_table_) { 2611 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2612 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2613 for (const auto& table_pair : mod_union_tables_) { 2614 accounting::ModUnionTable* mod_union_table = table_pair.second; 2615 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2616 mod_union_table->Verify(); 2617 } 2618 } 2619} 2620 2621void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2622 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2623 collector::GarbageCollector::ScopedPause pause(gc); 2624 PreGcVerificationPaused(gc); 2625 } 2626} 2627 2628void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2629 // TODO: Add a new runtime option for this? 2630 if (verify_pre_gc_rosalloc_) { 2631 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2632 } 2633} 2634 2635void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2636 Thread* const self = Thread::Current(); 2637 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2638 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2639 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2640 // reachable objects. 2641 if (verify_pre_sweeping_heap_) { 2642 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2643 CHECK_NE(self->GetState(), kRunnable); 2644 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2645 // Swapping bound bitmaps does nothing. 2646 gc->SwapBitmaps(); 2647 // Pass in false since concurrent reference processing can mean that the reference referents 2648 // may point to dead objects at the point which PreSweepingGcVerification is called. 2649 size_t failures = VerifyHeapReferences(false); 2650 if (failures > 0) { 2651 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2652 << " failures"; 2653 } 2654 gc->SwapBitmaps(); 2655 } 2656 if (verify_pre_sweeping_rosalloc_) { 2657 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2658 } 2659} 2660 2661void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2662 // Only pause if we have to do some verification. 2663 Thread* const self = Thread::Current(); 2664 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2665 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2666 if (verify_system_weaks_) { 2667 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2668 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2669 mark_sweep->VerifySystemWeaks(); 2670 } 2671 if (verify_post_gc_rosalloc_) { 2672 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2673 } 2674 if (verify_post_gc_heap_) { 2675 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2676 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2677 size_t failures = VerifyHeapReferences(); 2678 if (failures > 0) { 2679 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2680 << " failures"; 2681 } 2682 } 2683} 2684 2685void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2686 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2687 collector::GarbageCollector::ScopedPause pause(gc); 2688 PreGcVerificationPaused(gc); 2689 } 2690} 2691 2692void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2693 TimingLogger::ScopedTiming t(name, timings); 2694 for (const auto& space : continuous_spaces_) { 2695 if (space->IsRosAllocSpace()) { 2696 VLOG(heap) << name << " : " << space->GetName(); 2697 space->AsRosAllocSpace()->Verify(); 2698 } 2699 } 2700} 2701 2702collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2703 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2704 MutexLock mu(self, *gc_complete_lock_); 2705 return WaitForGcToCompleteLocked(cause, self); 2706} 2707 2708collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2709 collector::GcType last_gc_type = collector::kGcTypeNone; 2710 uint64_t wait_start = NanoTime(); 2711 while (collector_type_running_ != kCollectorTypeNone) { 2712 ATRACE_BEGIN("GC: Wait For Completion"); 2713 // We must wait, change thread state then sleep on gc_complete_cond_; 2714 gc_complete_cond_->Wait(self); 2715 last_gc_type = last_gc_type_; 2716 ATRACE_END(); 2717 } 2718 uint64_t wait_time = NanoTime() - wait_start; 2719 total_wait_time_ += wait_time; 2720 if (wait_time > long_pause_log_threshold_) { 2721 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2722 << " for cause " << cause; 2723 } 2724 return last_gc_type; 2725} 2726 2727void Heap::DumpForSigQuit(std::ostream& os) { 2728 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2729 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2730 DumpGcPerformanceInfo(os); 2731} 2732 2733size_t Heap::GetPercentFree() { 2734 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2735} 2736 2737void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2738 if (max_allowed_footprint > GetMaxMemory()) { 2739 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2740 << PrettySize(GetMaxMemory()); 2741 max_allowed_footprint = GetMaxMemory(); 2742 } 2743 max_allowed_footprint_ = max_allowed_footprint; 2744} 2745 2746bool Heap::IsMovableObject(const mirror::Object* obj) const { 2747 if (kMovingCollector) { 2748 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2749 if (space != nullptr) { 2750 // TODO: Check large object? 2751 return space->CanMoveObjects(); 2752 } 2753 } 2754 return false; 2755} 2756 2757void Heap::UpdateMaxNativeFootprint() { 2758 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2759 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2760 size_t target_size = native_size / GetTargetHeapUtilization(); 2761 if (target_size > native_size + max_free_) { 2762 target_size = native_size + max_free_; 2763 } else if (target_size < native_size + min_free_) { 2764 target_size = native_size + min_free_; 2765 } 2766 native_footprint_gc_watermark_ = target_size; 2767 native_footprint_limit_ = 2 * target_size - native_size; 2768} 2769 2770collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2771 for (const auto& collector : garbage_collectors_) { 2772 if (collector->GetCollectorType() == collector_type_ && 2773 collector->GetGcType() == gc_type) { 2774 return collector; 2775 } 2776 } 2777 return nullptr; 2778} 2779 2780double Heap::HeapGrowthMultiplier() const { 2781 // If we don't care about pause times we are background, so return 1.0. 2782 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2783 return 1.0; 2784 } 2785 return foreground_heap_growth_multiplier_; 2786} 2787 2788void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2789 // We know what our utilization is at this moment. 2790 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2791 const uint64_t bytes_allocated = GetBytesAllocated(); 2792 last_gc_size_ = bytes_allocated; 2793 last_gc_time_ns_ = NanoTime(); 2794 uint64_t target_size; 2795 collector::GcType gc_type = collector_ran->GetGcType(); 2796 if (gc_type != collector::kGcTypeSticky) { 2797 // Grow the heap for non sticky GC. 2798 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2799 // foreground. 2800 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2801 CHECK_GE(delta, 0); 2802 target_size = bytes_allocated + delta * multiplier; 2803 target_size = std::min(target_size, 2804 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2805 target_size = std::max(target_size, 2806 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2807 native_need_to_run_finalization_ = true; 2808 next_gc_type_ = collector::kGcTypeSticky; 2809 } else { 2810 collector::GcType non_sticky_gc_type = 2811 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2812 // Find what the next non sticky collector will be. 2813 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2814 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2815 // do another sticky collection next. 2816 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2817 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2818 // if the sticky GC throughput always remained >= the full/partial throughput. 2819 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2820 non_sticky_collector->GetEstimatedMeanThroughput() && 2821 non_sticky_collector->NumberOfIterations() > 0 && 2822 bytes_allocated <= max_allowed_footprint_) { 2823 next_gc_type_ = collector::kGcTypeSticky; 2824 } else { 2825 next_gc_type_ = non_sticky_gc_type; 2826 } 2827 // If we have freed enough memory, shrink the heap back down. 2828 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2829 target_size = bytes_allocated + max_free_; 2830 } else { 2831 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2832 } 2833 } 2834 if (!ignore_max_footprint_) { 2835 SetIdealFootprint(target_size); 2836 if (IsGcConcurrent()) { 2837 // Calculate when to perform the next ConcurrentGC. 2838 // Calculate the estimated GC duration. 2839 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2840 // Estimate how many remaining bytes we will have when we need to start the next GC. 2841 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2842 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2843 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2844 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2845 // A never going to happen situation that from the estimated allocation rate we will exceed 2846 // the applications entire footprint with the given estimated allocation rate. Schedule 2847 // another GC nearly straight away. 2848 remaining_bytes = kMinConcurrentRemainingBytes; 2849 } 2850 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2851 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2852 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2853 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2854 // right away. 2855 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2856 static_cast<size_t>(bytes_allocated)); 2857 } 2858 } 2859} 2860 2861void Heap::ClearGrowthLimit() { 2862 growth_limit_ = capacity_; 2863 non_moving_space_->ClearGrowthLimit(); 2864} 2865 2866void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2867 ScopedObjectAccess soa(self); 2868 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2869 jvalue args[1]; 2870 args[0].l = arg.get(); 2871 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2872 // Restore object in case it gets moved. 2873 *object = soa.Decode<mirror::Object*>(arg.get()); 2874} 2875 2876void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2877 StackHandleScope<1> hs(self); 2878 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2879 RequestConcurrentGC(self); 2880} 2881 2882void Heap::RequestConcurrentGC(Thread* self) { 2883 // Make sure that we can do a concurrent GC. 2884 Runtime* runtime = Runtime::Current(); 2885 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2886 self->IsHandlingStackOverflow()) { 2887 return; 2888 } 2889 // We already have a request pending, no reason to start more until we update 2890 // concurrent_start_bytes_. 2891 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2892 JNIEnv* env = self->GetJniEnv(); 2893 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2894 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2895 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2896 WellKnownClasses::java_lang_Daemons_requestGC); 2897 CHECK(!env->ExceptionCheck()); 2898} 2899 2900void Heap::ConcurrentGC(Thread* self) { 2901 if (Runtime::Current()->IsShuttingDown(self)) { 2902 return; 2903 } 2904 // Wait for any GCs currently running to finish. 2905 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2906 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2907 // instead. E.g. can't do partial, so do full instead. 2908 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2909 collector::kGcTypeNone) { 2910 for (collector::GcType gc_type : gc_plan_) { 2911 // Attempt to run the collector, if we succeed, we are done. 2912 if (gc_type > next_gc_type_ && 2913 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2914 break; 2915 } 2916 } 2917 } 2918 } 2919} 2920 2921void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2922 Thread* self = Thread::Current(); 2923 { 2924 MutexLock mu(self, *heap_trim_request_lock_); 2925 if (desired_collector_type_ == desired_collector_type) { 2926 return; 2927 } 2928 heap_transition_or_trim_target_time_ = 2929 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2930 desired_collector_type_ = desired_collector_type; 2931 } 2932 SignalHeapTrimDaemon(self); 2933} 2934 2935void Heap::RequestHeapTrim() { 2936 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2937 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2938 // a space it will hold its lock and can become a cause of jank. 2939 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2940 // forking. 2941 2942 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2943 // because that only marks object heads, so a large array looks like lots of empty space. We 2944 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2945 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2946 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2947 // not how much use we're making of those pages. 2948 2949 Thread* self = Thread::Current(); 2950 Runtime* runtime = Runtime::Current(); 2951 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2952 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2953 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2954 // as we don't hold the lock while requesting the trim). 2955 return; 2956 } 2957 { 2958 MutexLock mu(self, *heap_trim_request_lock_); 2959 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2960 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2961 // just yet. 2962 return; 2963 } 2964 heap_trim_request_pending_ = true; 2965 uint64_t current_time = NanoTime(); 2966 if (heap_transition_or_trim_target_time_ < current_time) { 2967 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2968 } 2969 } 2970 // Notify the daemon thread which will actually do the heap trim. 2971 SignalHeapTrimDaemon(self); 2972} 2973 2974void Heap::SignalHeapTrimDaemon(Thread* self) { 2975 JNIEnv* env = self->GetJniEnv(); 2976 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2977 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2978 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2979 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2980 CHECK(!env->ExceptionCheck()); 2981} 2982 2983void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2984 if (rosalloc_space_ != nullptr) { 2985 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2986 } 2987 if (bump_pointer_space_ != nullptr) { 2988 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2989 } 2990} 2991 2992void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2993 if (rosalloc_space_ != nullptr) { 2994 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2995 } 2996} 2997 2998void Heap::RevokeAllThreadLocalBuffers() { 2999 if (rosalloc_space_ != nullptr) { 3000 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3001 } 3002 if (bump_pointer_space_ != nullptr) { 3003 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3004 } 3005} 3006 3007bool Heap::IsGCRequestPending() const { 3008 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3009} 3010 3011void Heap::RunFinalization(JNIEnv* env) { 3012 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3013 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3014 CHECK(WellKnownClasses::java_lang_System != nullptr); 3015 WellKnownClasses::java_lang_System_runFinalization = 3016 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3017 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3018 } 3019 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3020 WellKnownClasses::java_lang_System_runFinalization); 3021} 3022 3023void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3024 Thread* self = ThreadForEnv(env); 3025 if (native_need_to_run_finalization_) { 3026 RunFinalization(env); 3027 UpdateMaxNativeFootprint(); 3028 native_need_to_run_finalization_ = false; 3029 } 3030 // Total number of native bytes allocated. 3031 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3032 new_native_bytes_allocated += bytes; 3033 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3034 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3035 collector::kGcTypeFull; 3036 3037 // The second watermark is higher than the gc watermark. If you hit this it means you are 3038 // allocating native objects faster than the GC can keep up with. 3039 if (new_native_bytes_allocated > native_footprint_limit_) { 3040 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3041 // Just finished a GC, attempt to run finalizers. 3042 RunFinalization(env); 3043 CHECK(!env->ExceptionCheck()); 3044 } 3045 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3046 if (new_native_bytes_allocated > native_footprint_limit_) { 3047 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3048 RunFinalization(env); 3049 native_need_to_run_finalization_ = false; 3050 CHECK(!env->ExceptionCheck()); 3051 } 3052 // We have just run finalizers, update the native watermark since it is very likely that 3053 // finalizers released native managed allocations. 3054 UpdateMaxNativeFootprint(); 3055 } else if (!IsGCRequestPending()) { 3056 if (IsGcConcurrent()) { 3057 RequestConcurrentGC(self); 3058 } else { 3059 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3060 } 3061 } 3062 } 3063} 3064 3065void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3066 int expected_size, new_size; 3067 do { 3068 expected_size = native_bytes_allocated_.LoadRelaxed(); 3069 new_size = expected_size - bytes; 3070 if (UNLIKELY(new_size < 0)) { 3071 ScopedObjectAccess soa(env); 3072 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3073 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3074 "registered as allocated", bytes, expected_size).c_str()); 3075 break; 3076 } 3077 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3078} 3079 3080size_t Heap::GetTotalMemory() const { 3081 size_t ret = 0; 3082 for (const auto& space : continuous_spaces_) { 3083 // Currently don't include the image space. 3084 if (!space->IsImageSpace()) { 3085 ret += space->Size(); 3086 } 3087 } 3088 for (const auto& space : discontinuous_spaces_) { 3089 if (space->IsLargeObjectSpace()) { 3090 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3091 } 3092 } 3093 return ret; 3094} 3095 3096void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3097 DCHECK(mod_union_table != nullptr); 3098 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3099} 3100 3101void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3102 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3103 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3104 c->GetDescriptor().empty()); 3105 CHECK_GE(byte_count, sizeof(mirror::Object)); 3106} 3107 3108void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3109 CHECK(remembered_set != nullptr); 3110 space::Space* space = remembered_set->GetSpace(); 3111 CHECK(space != nullptr); 3112 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3113 remembered_sets_.Put(space, remembered_set); 3114 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3115} 3116 3117void Heap::RemoveRememberedSet(space::Space* space) { 3118 CHECK(space != nullptr); 3119 auto it = remembered_sets_.find(space); 3120 CHECK(it != remembered_sets_.end()); 3121 delete it->second; 3122 remembered_sets_.erase(it); 3123 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3124} 3125 3126void Heap::ClearMarkedObjects() { 3127 // Clear all of the spaces' mark bitmaps. 3128 for (const auto& space : GetContinuousSpaces()) { 3129 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3130 if (space->GetLiveBitmap() != mark_bitmap) { 3131 mark_bitmap->Clear(); 3132 } 3133 } 3134 // Clear the marked objects in the discontinous space object sets. 3135 for (const auto& space : GetDiscontinuousSpaces()) { 3136 space->GetMarkBitmap()->Clear(); 3137 } 3138} 3139 3140} // namespace gc 3141} // namespace art 3142