heap.cc revision 27c84b64bdd3302d8260c6f330513e484d97fc98
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/concurrent_copying.h" 39#include "gc/collector/mark_compact.h" 40#include "gc/collector/mark_sweep-inl.h" 41#include "gc/collector/partial_mark_sweep.h" 42#include "gc/collector/semi_space.h" 43#include "gc/collector/sticky_mark_sweep.h" 44#include "gc/reference_processor.h" 45#include "gc/space/bump_pointer_space.h" 46#include "gc/space/dlmalloc_space-inl.h" 47#include "gc/space/image_space.h" 48#include "gc/space/large_object_space.h" 49#include "gc/space/rosalloc_space-inl.h" 50#include "gc/space/space-inl.h" 51#include "gc/space/zygote_space.h" 52#include "entrypoints/quick/quick_alloc_entrypoints.h" 53#include "heap-inl.h" 54#include "image.h" 55#include "mirror/art_field-inl.h" 56#include "mirror/class-inl.h" 57#include "mirror/object.h" 58#include "mirror/object-inl.h" 59#include "mirror/object_array-inl.h" 60#include "mirror/reference-inl.h" 61#include "object_utils.h" 62#include "os.h" 63#include "reflection.h" 64#include "runtime.h" 65#include "ScopedLocalRef.h" 66#include "scoped_thread_state_change.h" 67#include "handle_scope-inl.h" 68#include "thread_list.h" 69#include "well_known_classes.h" 70 71namespace art { 72 73namespace gc { 74 75static constexpr size_t kCollectorTransitionStressIterations = 0; 76static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 77static constexpr bool kGCALotMode = false; 78static constexpr size_t kGcAlotInterval = KB; 79// Minimum amount of remaining bytes before a concurrent GC is triggered. 80static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 81static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 82// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 83// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 84// threads (lower pauses, use less memory bandwidth). 85static constexpr double kStickyGcThroughputAdjustment = 1.0; 86// Whether or not we use the free list large object space. 87static constexpr bool kUseFreeListSpaceForLOS = false; 88// Whether or not we compact the zygote in PreZygoteFork. 89static constexpr bool kCompactZygote = kMovingCollector; 90static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 91// How many reserve entries are at the end of the allocation stack, these are only needed if the 92// allocation stack overflows. 93static constexpr size_t kAllocationStackReserveSize = 1024; 94// Default mark stack size in bytes. 95static const size_t kDefaultMarkStackSize = 64 * KB; 96// Define space name. 97static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 98static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 99static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 100static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 101 102Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 103 double target_utilization, double foreground_heap_growth_multiplier, size_t capacity, 104 const std::string& image_file_name, const InstructionSet image_instruction_set, 105 CollectorType foreground_collector_type, CollectorType background_collector_type, 106 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 107 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 108 bool ignore_max_footprint, bool use_tlab, 109 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 110 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 111 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 112 uint64_t min_interval_homogeneous_space_compaction_by_oom) 113 : non_moving_space_(nullptr), 114 rosalloc_space_(nullptr), 115 dlmalloc_space_(nullptr), 116 main_space_(nullptr), 117 collector_type_(kCollectorTypeNone), 118 foreground_collector_type_(foreground_collector_type), 119 background_collector_type_(background_collector_type), 120 desired_collector_type_(foreground_collector_type_), 121 heap_trim_request_lock_(nullptr), 122 last_trim_time_(0), 123 heap_transition_or_trim_target_time_(0), 124 heap_trim_request_pending_(false), 125 parallel_gc_threads_(parallel_gc_threads), 126 conc_gc_threads_(conc_gc_threads), 127 low_memory_mode_(low_memory_mode), 128 long_pause_log_threshold_(long_pause_log_threshold), 129 long_gc_log_threshold_(long_gc_log_threshold), 130 ignore_max_footprint_(ignore_max_footprint), 131 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 132 have_zygote_space_(false), 133 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 134 collector_type_running_(kCollectorTypeNone), 135 last_gc_type_(collector::kGcTypeNone), 136 next_gc_type_(collector::kGcTypePartial), 137 capacity_(capacity), 138 growth_limit_(growth_limit), 139 max_allowed_footprint_(initial_size), 140 native_footprint_gc_watermark_(initial_size), 141 native_footprint_limit_(2 * initial_size), 142 native_need_to_run_finalization_(false), 143 // Initially assume we perceive jank in case the process state is never updated. 144 process_state_(kProcessStateJankPerceptible), 145 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 146 total_bytes_freed_ever_(0), 147 total_objects_freed_ever_(0), 148 num_bytes_allocated_(0), 149 native_bytes_allocated_(0), 150 gc_memory_overhead_(0), 151 verify_missing_card_marks_(false), 152 verify_system_weaks_(false), 153 verify_pre_gc_heap_(verify_pre_gc_heap), 154 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 155 verify_post_gc_heap_(verify_post_gc_heap), 156 verify_mod_union_table_(false), 157 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 158 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 159 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 160 last_gc_time_ns_(NanoTime()), 161 allocation_rate_(0), 162 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 163 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 164 * verification is enabled, we limit the size of allocation stacks to speed up their 165 * searching. 166 */ 167 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 168 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 169 current_allocator_(kAllocatorTypeDlMalloc), 170 current_non_moving_allocator_(kAllocatorTypeNonMoving), 171 bump_pointer_space_(nullptr), 172 temp_space_(nullptr), 173 min_free_(min_free), 174 max_free_(max_free), 175 target_utilization_(target_utilization), 176 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 177 total_wait_time_(0), 178 total_allocation_time_(0), 179 verify_object_mode_(kVerifyObjectModeDisabled), 180 disable_moving_gc_count_(0), 181 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 182 use_tlab_(use_tlab), 183 main_space_backup_(nullptr), 184 min_interval_homogeneous_space_compaction_by_oom_( 185 min_interval_homogeneous_space_compaction_by_oom), 186 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 187 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 188 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 189 LOG(INFO) << "Heap() entering"; 190 } 191 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 192 // entrypoints. 193 if (!Runtime::Current()->IsZygote()) { 194 large_object_threshold_ = kDefaultLargeObjectThreshold; 195 // Background compaction is currently not supported for command line runs. 196 if (background_collector_type_ != foreground_collector_type_) { 197 VLOG(heap) << "Disabling background compaction for non zygote"; 198 background_collector_type_ = foreground_collector_type_; 199 } 200 } 201 ChangeCollector(desired_collector_type_); 202 live_bitmap_.reset(new accounting::HeapBitmap(this)); 203 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 204 // Requested begin for the alloc space, to follow the mapped image and oat files 205 byte* requested_alloc_space_begin = nullptr; 206 if (!image_file_name.empty()) { 207 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 208 image_instruction_set); 209 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 210 AddSpace(image_space); 211 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 212 // isn't going to get in the middle 213 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 214 CHECK_GT(oat_file_end_addr, image_space->End()); 215 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 216 } 217 /* 218 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 219 +- nonmoving space (kNonMovingSpaceCapacity) +- 220 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 221 +-main alloc space / bump space 1 (capacity_) +- 222 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 223 +-????????????????????????????????????????????+- 224 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 225 +-main alloc space2 / bump space 2 (capacity_)+- 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 227 */ 228 bool support_homogeneous_space_compaction = 229 background_collector_type == gc::kCollectorTypeHomogeneousSpaceCompact || 230 use_homogeneous_space_compaction_for_oom; 231 // We may use the same space the main space for the non moving space if we don't need to compact 232 // from the main space. 233 // This is not the case if we support homogeneous compaction or have a moving background 234 // collector type. 235 const bool is_zygote = Runtime::Current()->IsZygote(); 236 bool separate_non_moving_space = is_zygote || 237 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 238 IsMovingGc(background_collector_type_); 239 if (foreground_collector_type == kCollectorTypeGSS) { 240 separate_non_moving_space = false; 241 } 242 std::unique_ptr<MemMap> main_mem_map_1; 243 std::unique_ptr<MemMap> main_mem_map_2; 244 byte* request_begin = requested_alloc_space_begin; 245 if (request_begin != nullptr && separate_non_moving_space) { 246 request_begin += kNonMovingSpaceCapacity; 247 } 248 std::string error_str; 249 std::unique_ptr<MemMap> non_moving_space_mem_map; 250 if (separate_non_moving_space) { 251 // Reserve the non moving mem map before the other two since it needs to be at a specific 252 // address. 253 non_moving_space_mem_map.reset( 254 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 255 kNonMovingSpaceCapacity, PROT_READ | PROT_WRITE, true, &error_str)); 256 CHECK(non_moving_space_mem_map != nullptr) << error_str; 257 } 258 // Attempt to create 2 mem maps at or after the requested begin. 259 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 260 PROT_READ | PROT_WRITE, &error_str)); 261 CHECK(main_mem_map_1.get() != nullptr) << error_str; 262 if (support_homogeneous_space_compaction || 263 background_collector_type_ == kCollectorTypeSS || 264 foreground_collector_type_ == kCollectorTypeSS) { 265 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 266 capacity_, PROT_READ | PROT_WRITE, 267 &error_str)); 268 CHECK(main_mem_map_2.get() != nullptr) << error_str; 269 } 270 // Create the non moving space first so that bitmaps don't take up the address range. 271 if (separate_non_moving_space) { 272 // Non moving space is always dlmalloc since we currently don't have support for multiple 273 // active rosalloc spaces. 274 const size_t size = non_moving_space_mem_map->Size(); 275 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 276 non_moving_space_mem_map.release(), "zygote / non moving space", initial_size, 277 initial_size, size, size, false); 278 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 279 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 280 << requested_alloc_space_begin; 281 AddSpace(non_moving_space_); 282 } 283 // Create other spaces based on whether or not we have a moving GC. 284 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 285 // Create bump pointer spaces. 286 // We only to create the bump pointer if the foreground collector is a compacting GC. 287 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 288 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 289 main_mem_map_1.release()); 290 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 291 AddSpace(bump_pointer_space_); 292 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 293 main_mem_map_2.release()); 294 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 295 AddSpace(temp_space_); 296 CHECK(separate_non_moving_space); 297 } else { 298 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 299 CHECK(main_space_ != nullptr); 300 AddSpace(main_space_); 301 if (!separate_non_moving_space) { 302 non_moving_space_ = main_space_; 303 CHECK(!non_moving_space_->CanMoveObjects()); 304 } 305 if (foreground_collector_type_ == kCollectorTypeGSS) { 306 CHECK_EQ(foreground_collector_type_, background_collector_type_); 307 // Create bump pointer spaces instead of a backup space. 308 main_mem_map_2.release(); 309 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 310 kGSSBumpPointerSpaceCapacity, nullptr); 311 CHECK(bump_pointer_space_ != nullptr); 312 AddSpace(bump_pointer_space_); 313 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 314 kGSSBumpPointerSpaceCapacity, nullptr); 315 CHECK(temp_space_ != nullptr); 316 AddSpace(temp_space_); 317 } else if (main_mem_map_2.get() != nullptr) { 318 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 319 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 320 growth_limit_, capacity_, name, true)); 321 CHECK(main_space_backup_.get() != nullptr); 322 // Add the space so its accounted for in the heap_begin and heap_end. 323 AddSpace(main_space_backup_.get()); 324 } 325 } 326 CHECK(non_moving_space_ != nullptr); 327 CHECK(!non_moving_space_->CanMoveObjects()); 328 // Allocate the large object space. 329 if (kUseFreeListSpaceForLOS) { 330 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 331 } else { 332 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 333 } 334 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 335 AddSpace(large_object_space_); 336 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 337 CHECK(!continuous_spaces_.empty()); 338 // Relies on the spaces being sorted. 339 byte* heap_begin = continuous_spaces_.front()->Begin(); 340 byte* heap_end = continuous_spaces_.back()->Limit(); 341 size_t heap_capacity = heap_end - heap_begin; 342 // Remove the main backup space since it slows down the GC to have unused extra spaces. 343 if (main_space_backup_.get() != nullptr) { 344 RemoveSpace(main_space_backup_.get()); 345 } 346 // Allocate the card table. 347 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 348 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 349 // Card cache for now since it makes it easier for us to update the references to the copying 350 // spaces. 351 accounting::ModUnionTable* mod_union_table = 352 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 353 GetImageSpace()); 354 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 355 AddModUnionTable(mod_union_table); 356 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 357 accounting::RememberedSet* non_moving_space_rem_set = 358 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 359 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 360 AddRememberedSet(non_moving_space_rem_set); 361 } 362 // TODO: Count objects in the image space here? 363 num_bytes_allocated_.StoreRelaxed(0); 364 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 365 kDefaultMarkStackSize)); 366 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 367 allocation_stack_.reset(accounting::ObjectStack::Create( 368 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 369 live_stack_.reset(accounting::ObjectStack::Create( 370 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 371 // It's still too early to take a lock because there are no threads yet, but we can create locks 372 // now. We don't create it earlier to make it clear that you can't use locks during heap 373 // initialization. 374 gc_complete_lock_ = new Mutex("GC complete lock"); 375 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 376 *gc_complete_lock_)); 377 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 378 last_gc_size_ = GetBytesAllocated(); 379 if (ignore_max_footprint_) { 380 SetIdealFootprint(std::numeric_limits<size_t>::max()); 381 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 382 } 383 CHECK_NE(max_allowed_footprint_, 0U); 384 // Create our garbage collectors. 385 for (size_t i = 0; i < 2; ++i) { 386 const bool concurrent = i != 0; 387 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 388 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 389 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 390 } 391 if (kMovingCollector) { 392 // TODO: Clean this up. 393 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 394 semi_space_collector_ = new collector::SemiSpace(this, generational, 395 generational ? "generational" : ""); 396 garbage_collectors_.push_back(semi_space_collector_); 397 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 398 garbage_collectors_.push_back(concurrent_copying_collector_); 399 mark_compact_collector_ = new collector::MarkCompact(this); 400 garbage_collectors_.push_back(mark_compact_collector_); 401 } 402 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr) { 403 // Check that there's no gap between the image space and the non moving space so that the 404 // immune region won't break (eg. due to a large object allocated in the gap). 405 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 406 non_moving_space_->GetMemMap()); 407 if (!no_gap) { 408 MemMap::DumpMaps(LOG(ERROR)); 409 LOG(FATAL) << "There's a gap between the image space and the main space"; 410 } 411 } 412 if (running_on_valgrind_) { 413 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 414 } 415 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 416 LOG(INFO) << "Heap() exiting"; 417 } 418} 419 420MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 421 int prot_flags, std::string* out_error_str) { 422 while (true) { 423 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 424 PROT_READ | PROT_WRITE, true, out_error_str); 425 if (map != nullptr || request_begin == nullptr) { 426 return map; 427 } 428 // Retry a second time with no specified request begin. 429 request_begin = nullptr; 430 } 431 return nullptr; 432} 433 434space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 435 size_t growth_limit, size_t capacity, 436 const char* name, bool can_move_objects) { 437 space::MallocSpace* malloc_space = nullptr; 438 if (kUseRosAlloc) { 439 // Create rosalloc space. 440 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 441 initial_size, growth_limit, capacity, 442 low_memory_mode_, can_move_objects); 443 } else { 444 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 445 initial_size, growth_limit, capacity, 446 can_move_objects); 447 } 448 if (collector::SemiSpace::kUseRememberedSet) { 449 accounting::RememberedSet* rem_set = 450 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 451 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 452 AddRememberedSet(rem_set); 453 } 454 CHECK(malloc_space != nullptr) << "Failed to create " << name; 455 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 456 return malloc_space; 457} 458 459void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 460 size_t capacity) { 461 // Is background compaction is enabled? 462 bool can_move_objects = IsMovingGc(background_collector_type_) != 463 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 464 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 465 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 466 // from the main space to the zygote space. If background compaction is enabled, always pass in 467 // that we can move objets. 468 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 469 // After the zygote we want this to be false if we don't have background compaction enabled so 470 // that getting primitive array elements is faster. 471 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 472 can_move_objects = !have_zygote_space_ && foreground_collector_type_ != kCollectorTypeGSS; 473 } 474 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 475 RemoveRememberedSet(main_space_); 476 } 477 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 478 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 479 can_move_objects); 480 SetSpaceAsDefault(main_space_); 481 VLOG(heap) << "Created main space " << main_space_; 482} 483 484void Heap::ChangeAllocator(AllocatorType allocator) { 485 if (current_allocator_ != allocator) { 486 // These two allocators are only used internally and don't have any entrypoints. 487 CHECK_NE(allocator, kAllocatorTypeLOS); 488 CHECK_NE(allocator, kAllocatorTypeNonMoving); 489 current_allocator_ = allocator; 490 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 491 SetQuickAllocEntryPointsAllocator(current_allocator_); 492 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 493 } 494} 495 496void Heap::DisableCompaction() { 497 if (IsMovingGc(foreground_collector_type_)) { 498 foreground_collector_type_ = kCollectorTypeCMS; 499 } 500 if (IsMovingGc(background_collector_type_)) { 501 background_collector_type_ = foreground_collector_type_; 502 } 503 TransitionCollector(foreground_collector_type_); 504} 505 506std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 507 if (!IsValidContinuousSpaceObjectAddress(klass)) { 508 return StringPrintf("<non heap address klass %p>", klass); 509 } 510 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 511 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 512 std::string result("["); 513 result += SafeGetClassDescriptor(component_type); 514 return result; 515 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 516 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 517 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 518 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 519 } else { 520 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 521 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 522 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 523 } 524 const DexFile* dex_file = dex_cache->GetDexFile(); 525 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 526 if (class_def_idx == DexFile::kDexNoIndex16) { 527 return "<class def not found>"; 528 } 529 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 530 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 531 return dex_file->GetTypeDescriptor(type_id); 532 } 533} 534 535std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 536 if (obj == nullptr) { 537 return "null"; 538 } 539 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 540 if (klass == nullptr) { 541 return "(class=null)"; 542 } 543 std::string result(SafeGetClassDescriptor(klass)); 544 if (obj->IsClass()) { 545 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 546 } 547 return result; 548} 549 550void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 551 if (obj == nullptr) { 552 stream << "(obj=null)"; 553 return; 554 } 555 if (IsAligned<kObjectAlignment>(obj)) { 556 space::Space* space = nullptr; 557 // Don't use find space since it only finds spaces which actually contain objects instead of 558 // spaces which may contain objects (e.g. cleared bump pointer spaces). 559 for (const auto& cur_space : continuous_spaces_) { 560 if (cur_space->HasAddress(obj)) { 561 space = cur_space; 562 break; 563 } 564 } 565 // Unprotect all the spaces. 566 for (const auto& space : continuous_spaces_) { 567 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 568 } 569 stream << "Object " << obj; 570 if (space != nullptr) { 571 stream << " in space " << *space; 572 } 573 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 574 stream << "\nclass=" << klass; 575 if (klass != nullptr) { 576 stream << " type= " << SafePrettyTypeOf(obj); 577 } 578 // Re-protect the address we faulted on. 579 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 580 } 581} 582 583bool Heap::IsCompilingBoot() const { 584 for (const auto& space : continuous_spaces_) { 585 if (space->IsImageSpace() || space->IsZygoteSpace()) { 586 return false; 587 } 588 } 589 return true; 590} 591 592bool Heap::HasImageSpace() const { 593 for (const auto& space : continuous_spaces_) { 594 if (space->IsImageSpace()) { 595 return true; 596 } 597 } 598 return false; 599} 600 601void Heap::IncrementDisableMovingGC(Thread* self) { 602 // Need to do this holding the lock to prevent races where the GC is about to run / running when 603 // we attempt to disable it. 604 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 605 MutexLock mu(self, *gc_complete_lock_); 606 ++disable_moving_gc_count_; 607 if (IsMovingGc(collector_type_running_)) { 608 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 609 } 610} 611 612void Heap::DecrementDisableMovingGC(Thread* self) { 613 MutexLock mu(self, *gc_complete_lock_); 614 CHECK_GE(disable_moving_gc_count_, 0U); 615 --disable_moving_gc_count_; 616} 617 618void Heap::UpdateProcessState(ProcessState process_state) { 619 if (process_state_ != process_state) { 620 process_state_ = process_state; 621 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 622 // Start at index 1 to avoid "is always false" warning. 623 // Have iteration 1 always transition the collector. 624 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 625 ? foreground_collector_type_ : background_collector_type_); 626 usleep(kCollectorTransitionStressWait); 627 } 628 if (process_state_ == kProcessStateJankPerceptible) { 629 // Transition back to foreground right away to prevent jank. 630 RequestCollectorTransition(foreground_collector_type_, 0); 631 } else { 632 // Don't delay for debug builds since we may want to stress test the GC. 633 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 634 // special handling which does a homogenous space compaction once but then doesn't transition 635 // the collector. 636 RequestCollectorTransition(background_collector_type_, 637 kIsDebugBuild ? 0 : kCollectorTransitionWait); 638 } 639 } 640} 641 642void Heap::CreateThreadPool() { 643 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 644 if (num_threads != 0) { 645 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 646 } 647} 648 649void Heap::VisitObjects(ObjectCallback callback, void* arg) { 650 Thread* self = Thread::Current(); 651 // GCs can move objects, so don't allow this. 652 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 653 if (bump_pointer_space_ != nullptr) { 654 // Visit objects in bump pointer space. 655 bump_pointer_space_->Walk(callback, arg); 656 } 657 // TODO: Switch to standard begin and end to use ranged a based loop. 658 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 659 it < end; ++it) { 660 mirror::Object* obj = *it; 661 if (obj != nullptr && obj->GetClass() != nullptr) { 662 // Avoid the race condition caused by the object not yet being written into the allocation 663 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 664 // there can be nulls on the allocation stack. 665 callback(obj, arg); 666 } 667 } 668 GetLiveBitmap()->Walk(callback, arg); 669 self->EndAssertNoThreadSuspension(old_cause); 670} 671 672void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 673 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 674 space::ContinuousSpace* space2 = non_moving_space_; 675 // TODO: Generalize this to n bitmaps? 676 CHECK(space1 != nullptr); 677 CHECK(space2 != nullptr); 678 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 679 large_object_space_->GetLiveBitmap(), stack); 680} 681 682void Heap::DeleteThreadPool() { 683 thread_pool_.reset(nullptr); 684} 685 686void Heap::AddSpace(space::Space* space) { 687 CHECK(space != nullptr); 688 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 689 if (space->IsContinuousSpace()) { 690 DCHECK(!space->IsDiscontinuousSpace()); 691 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 692 // Continuous spaces don't necessarily have bitmaps. 693 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 694 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 695 if (live_bitmap != nullptr) { 696 DCHECK(mark_bitmap != nullptr); 697 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 698 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 699 } 700 continuous_spaces_.push_back(continuous_space); 701 // Ensure that spaces remain sorted in increasing order of start address. 702 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 703 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 704 return a->Begin() < b->Begin(); 705 }); 706 } else { 707 DCHECK(space->IsDiscontinuousSpace()); 708 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 709 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 710 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 711 discontinuous_spaces_.push_back(discontinuous_space); 712 } 713 if (space->IsAllocSpace()) { 714 alloc_spaces_.push_back(space->AsAllocSpace()); 715 } 716} 717 718void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 719 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 720 if (continuous_space->IsDlMallocSpace()) { 721 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 722 } else if (continuous_space->IsRosAllocSpace()) { 723 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 724 } 725} 726 727void Heap::RemoveSpace(space::Space* space) { 728 DCHECK(space != nullptr); 729 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 730 if (space->IsContinuousSpace()) { 731 DCHECK(!space->IsDiscontinuousSpace()); 732 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 733 // Continuous spaces don't necessarily have bitmaps. 734 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 735 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 736 if (live_bitmap != nullptr) { 737 DCHECK(mark_bitmap != nullptr); 738 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 739 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 740 } 741 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 742 DCHECK(it != continuous_spaces_.end()); 743 continuous_spaces_.erase(it); 744 } else { 745 DCHECK(space->IsDiscontinuousSpace()); 746 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 747 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 748 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 749 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 750 discontinuous_space); 751 DCHECK(it != discontinuous_spaces_.end()); 752 discontinuous_spaces_.erase(it); 753 } 754 if (space->IsAllocSpace()) { 755 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 756 DCHECK(it != alloc_spaces_.end()); 757 alloc_spaces_.erase(it); 758 } 759} 760 761void Heap::RegisterGCAllocation(size_t bytes) { 762 if (this != nullptr) { 763 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 764 } 765} 766 767void Heap::RegisterGCDeAllocation(size_t bytes) { 768 if (this != nullptr) { 769 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 770 } 771} 772 773void Heap::DumpGcPerformanceInfo(std::ostream& os) { 774 // Dump cumulative timings. 775 os << "Dumping cumulative Gc timings\n"; 776 uint64_t total_duration = 0; 777 // Dump cumulative loggers for each GC type. 778 uint64_t total_paused_time = 0; 779 for (auto& collector : garbage_collectors_) { 780 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 781 const size_t iterations = logger.GetIterations(); 782 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 783 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 784 os << ConstDumpable<CumulativeLogger>(logger); 785 const uint64_t total_ns = logger.GetTotalNs(); 786 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 787 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 788 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 789 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 790 Histogram<uint64_t>::CumulativeData cumulative_data; 791 pause_histogram.CreateHistogram(&cumulative_data); 792 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 793 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 794 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 795 << collector->GetName() << " freed: " << freed_objects 796 << " objects with total size " << PrettySize(freed_bytes) << "\n" 797 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 798 << PrettySize(freed_bytes / seconds) << "/s\n"; 799 total_duration += total_ns; 800 total_paused_time += total_pause_ns; 801 } 802 collector->ResetMeasurements(); 803 } 804 uint64_t allocation_time = 805 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 806 if (total_duration != 0) { 807 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 808 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 809 os << "Mean GC size throughput: " 810 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 811 os << "Mean GC object throughput: " 812 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 813 } 814 size_t total_objects_allocated = GetObjectsAllocatedEver(); 815 os << "Total number of allocations: " << total_objects_allocated << "\n"; 816 size_t total_bytes_allocated = GetBytesAllocatedEver(); 817 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 818 if (kMeasureAllocationTime) { 819 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 820 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 821 << "\n"; 822 } 823 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 824 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 825 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 826 BaseMutex::DumpAll(os); 827} 828 829Heap::~Heap() { 830 VLOG(heap) << "Starting ~Heap()"; 831 STLDeleteElements(&garbage_collectors_); 832 // If we don't reset then the mark stack complains in its destructor. 833 allocation_stack_->Reset(); 834 live_stack_->Reset(); 835 STLDeleteValues(&mod_union_tables_); 836 STLDeleteValues(&remembered_sets_); 837 STLDeleteElements(&continuous_spaces_); 838 STLDeleteElements(&discontinuous_spaces_); 839 delete gc_complete_lock_; 840 delete heap_trim_request_lock_; 841 VLOG(heap) << "Finished ~Heap()"; 842} 843 844space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 845 bool fail_ok) const { 846 for (const auto& space : continuous_spaces_) { 847 if (space->Contains(obj)) { 848 return space; 849 } 850 } 851 if (!fail_ok) { 852 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 853 } 854 return NULL; 855} 856 857space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 858 bool fail_ok) const { 859 for (const auto& space : discontinuous_spaces_) { 860 if (space->Contains(obj)) { 861 return space; 862 } 863 } 864 if (!fail_ok) { 865 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 866 } 867 return NULL; 868} 869 870space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 871 space::Space* result = FindContinuousSpaceFromObject(obj, true); 872 if (result != NULL) { 873 return result; 874 } 875 return FindDiscontinuousSpaceFromObject(obj, true); 876} 877 878space::ImageSpace* Heap::GetImageSpace() const { 879 for (const auto& space : continuous_spaces_) { 880 if (space->IsImageSpace()) { 881 return space->AsImageSpace(); 882 } 883 } 884 return NULL; 885} 886 887void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 888 std::ostringstream oss; 889 size_t total_bytes_free = GetFreeMemory(); 890 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 891 << " free bytes"; 892 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 893 if (total_bytes_free >= byte_count) { 894 space::AllocSpace* space = nullptr; 895 if (allocator_type == kAllocatorTypeNonMoving) { 896 space = non_moving_space_; 897 } else if (allocator_type == kAllocatorTypeRosAlloc || 898 allocator_type == kAllocatorTypeDlMalloc) { 899 space = main_space_; 900 } else if (allocator_type == kAllocatorTypeBumpPointer || 901 allocator_type == kAllocatorTypeTLAB) { 902 space = bump_pointer_space_; 903 } 904 if (space != nullptr) { 905 space->LogFragmentationAllocFailure(oss, byte_count); 906 } 907 } 908 self->ThrowOutOfMemoryError(oss.str().c_str()); 909} 910 911void Heap::DoPendingTransitionOrTrim() { 912 Thread* self = Thread::Current(); 913 CollectorType desired_collector_type; 914 // Wait until we reach the desired transition time. 915 while (true) { 916 uint64_t wait_time; 917 { 918 MutexLock mu(self, *heap_trim_request_lock_); 919 desired_collector_type = desired_collector_type_; 920 uint64_t current_time = NanoTime(); 921 if (current_time >= heap_transition_or_trim_target_time_) { 922 break; 923 } 924 wait_time = heap_transition_or_trim_target_time_ - current_time; 925 } 926 ScopedThreadStateChange tsc(self, kSleeping); 927 usleep(wait_time / 1000); // Usleep takes microseconds. 928 } 929 // Launch homogeneous space compaction if it is desired. 930 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 931 if (!CareAboutPauseTimes()) { 932 PerformHomogeneousSpaceCompact(); 933 } 934 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 935 desired_collector_type = collector_type_; 936 return; 937 } 938 // Transition the collector if the desired collector type is not the same as the current 939 // collector type. 940 TransitionCollector(desired_collector_type); 941 if (!CareAboutPauseTimes()) { 942 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 943 // about pauses. 944 Runtime* runtime = Runtime::Current(); 945 runtime->GetThreadList()->SuspendAll(); 946 uint64_t start_time = NanoTime(); 947 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 948 VLOG(heap) << "Deflating " << count << " monitors took " 949 << PrettyDuration(NanoTime() - start_time); 950 runtime->GetThreadList()->ResumeAll(); 951 } 952 // Do a heap trim if it is needed. 953 Trim(); 954} 955 956void Heap::Trim() { 957 Thread* self = Thread::Current(); 958 { 959 MutexLock mu(self, *heap_trim_request_lock_); 960 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 961 return; 962 } 963 last_trim_time_ = NanoTime(); 964 heap_trim_request_pending_ = false; 965 } 966 { 967 // Need to do this before acquiring the locks since we don't want to get suspended while 968 // holding any locks. 969 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 970 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 971 // trimming. 972 MutexLock mu(self, *gc_complete_lock_); 973 // Ensure there is only one GC at a time. 974 WaitForGcToCompleteLocked(kGcCauseTrim, self); 975 collector_type_running_ = kCollectorTypeHeapTrim; 976 } 977 uint64_t start_ns = NanoTime(); 978 // Trim the managed spaces. 979 uint64_t total_alloc_space_allocated = 0; 980 uint64_t total_alloc_space_size = 0; 981 uint64_t managed_reclaimed = 0; 982 for (const auto& space : continuous_spaces_) { 983 if (space->IsMallocSpace()) { 984 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 985 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 986 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 987 // for a long period of time. 988 managed_reclaimed += malloc_space->Trim(); 989 } 990 total_alloc_space_size += malloc_space->Size(); 991 } 992 } 993 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 994 if (bump_pointer_space_ != nullptr) { 995 total_alloc_space_allocated -= bump_pointer_space_->Size(); 996 } 997 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 998 static_cast<float>(total_alloc_space_size); 999 uint64_t gc_heap_end_ns = NanoTime(); 1000 // We never move things in the native heap, so we can finish the GC at this point. 1001 FinishGC(self, collector::kGcTypeNone); 1002 size_t native_reclaimed = 0; 1003 // Only trim the native heap if we don't care about pauses. 1004 if (!CareAboutPauseTimes()) { 1005#if defined(USE_DLMALLOC) 1006 // Trim the native heap. 1007 dlmalloc_trim(0); 1008 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1009#elif defined(USE_JEMALLOC) 1010 // Jemalloc does it's own internal trimming. 1011#else 1012 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1013#endif 1014 } 1015 uint64_t end_ns = NanoTime(); 1016 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1017 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1018 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1019 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1020 << "%."; 1021} 1022 1023bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1024 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1025 // taking the lock. 1026 if (obj == nullptr) { 1027 return true; 1028 } 1029 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1030} 1031 1032bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1033 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1034} 1035 1036bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1037 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1038 return false; 1039 } 1040 for (const auto& space : continuous_spaces_) { 1041 if (space->HasAddress(obj)) { 1042 return true; 1043 } 1044 } 1045 return false; 1046} 1047 1048bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1049 bool search_live_stack, bool sorted) { 1050 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1051 return false; 1052 } 1053 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1054 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1055 if (obj == klass) { 1056 // This case happens for java.lang.Class. 1057 return true; 1058 } 1059 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1060 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1061 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1062 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1063 return temp_space_->Contains(obj); 1064 } 1065 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1066 space::DiscontinuousSpace* d_space = nullptr; 1067 if (c_space != nullptr) { 1068 if (c_space->GetLiveBitmap()->Test(obj)) { 1069 return true; 1070 } 1071 } else { 1072 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1073 if (d_space != nullptr) { 1074 if (d_space->GetLiveBitmap()->Test(obj)) { 1075 return true; 1076 } 1077 } 1078 } 1079 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1080 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1081 if (i > 0) { 1082 NanoSleep(MsToNs(10)); 1083 } 1084 if (search_allocation_stack) { 1085 if (sorted) { 1086 if (allocation_stack_->ContainsSorted(obj)) { 1087 return true; 1088 } 1089 } else if (allocation_stack_->Contains(obj)) { 1090 return true; 1091 } 1092 } 1093 1094 if (search_live_stack) { 1095 if (sorted) { 1096 if (live_stack_->ContainsSorted(obj)) { 1097 return true; 1098 } 1099 } else if (live_stack_->Contains(obj)) { 1100 return true; 1101 } 1102 } 1103 } 1104 // We need to check the bitmaps again since there is a race where we mark something as live and 1105 // then clear the stack containing it. 1106 if (c_space != nullptr) { 1107 if (c_space->GetLiveBitmap()->Test(obj)) { 1108 return true; 1109 } 1110 } else { 1111 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1112 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1113 return true; 1114 } 1115 } 1116 return false; 1117} 1118 1119std::string Heap::DumpSpaces() const { 1120 std::ostringstream oss; 1121 DumpSpaces(oss); 1122 return oss.str(); 1123} 1124 1125void Heap::DumpSpaces(std::ostream& stream) const { 1126 for (const auto& space : continuous_spaces_) { 1127 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1128 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1129 stream << space << " " << *space << "\n"; 1130 if (live_bitmap != nullptr) { 1131 stream << live_bitmap << " " << *live_bitmap << "\n"; 1132 } 1133 if (mark_bitmap != nullptr) { 1134 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1135 } 1136 } 1137 for (const auto& space : discontinuous_spaces_) { 1138 stream << space << " " << *space << "\n"; 1139 } 1140} 1141 1142void Heap::VerifyObjectBody(mirror::Object* obj) { 1143 if (this == nullptr && verify_object_mode_ == kVerifyObjectModeDisabled) { 1144 return; 1145 } 1146 // Ignore early dawn of the universe verifications. 1147 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1148 return; 1149 } 1150 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1151 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1152 CHECK(c != nullptr) << "Null class in object " << obj; 1153 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1154 CHECK(VerifyClassClass(c)); 1155 1156 if (verify_object_mode_ > kVerifyObjectModeFast) { 1157 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1158 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1159 } 1160} 1161 1162void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1163 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1164} 1165 1166void Heap::VerifyHeap() { 1167 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1168 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1169} 1170 1171void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1172 // Use signed comparison since freed bytes can be negative when background compaction foreground 1173 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1174 // free list backed space typically increasing memory footprint due to padding and binning. 1175 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1176 // Note: This relies on 2s complement for handling negative freed_bytes. 1177 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1178 if (Runtime::Current()->HasStatsEnabled()) { 1179 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1180 thread_stats->freed_objects += freed_objects; 1181 thread_stats->freed_bytes += freed_bytes; 1182 // TODO: Do this concurrently. 1183 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1184 global_stats->freed_objects += freed_objects; 1185 global_stats->freed_bytes += freed_bytes; 1186 } 1187} 1188 1189space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1190 for (const auto& space : continuous_spaces_) { 1191 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1192 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1193 return space->AsContinuousSpace()->AsRosAllocSpace(); 1194 } 1195 } 1196 } 1197 return nullptr; 1198} 1199 1200mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1201 size_t alloc_size, size_t* bytes_allocated, 1202 size_t* usable_size, 1203 mirror::Class** klass) { 1204 bool was_default_allocator = allocator == GetCurrentAllocator(); 1205 DCHECK(klass != nullptr); 1206 StackHandleScope<1> hs(self); 1207 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1208 klass = nullptr; // Invalidate for safety. 1209 // The allocation failed. If the GC is running, block until it completes, and then retry the 1210 // allocation. 1211 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1212 if (last_gc != collector::kGcTypeNone) { 1213 // If we were the default allocator but the allocator changed while we were suspended, 1214 // abort the allocation. 1215 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1216 return nullptr; 1217 } 1218 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1219 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1220 usable_size); 1221 if (ptr != nullptr) { 1222 return ptr; 1223 } 1224 } 1225 1226 collector::GcType tried_type = next_gc_type_; 1227 const bool gc_ran = 1228 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1229 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1230 return nullptr; 1231 } 1232 if (gc_ran) { 1233 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1234 usable_size); 1235 if (ptr != nullptr) { 1236 return ptr; 1237 } 1238 } 1239 1240 // Loop through our different Gc types and try to Gc until we get enough free memory. 1241 for (collector::GcType gc_type : gc_plan_) { 1242 if (gc_type == tried_type) { 1243 continue; 1244 } 1245 // Attempt to run the collector, if we succeed, re-try the allocation. 1246 const bool gc_ran = 1247 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1248 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1249 return nullptr; 1250 } 1251 if (gc_ran) { 1252 // Did we free sufficient memory for the allocation to succeed? 1253 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1254 usable_size); 1255 if (ptr != nullptr) { 1256 return ptr; 1257 } 1258 } 1259 } 1260 // Allocations have failed after GCs; this is an exceptional state. 1261 // Try harder, growing the heap if necessary. 1262 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1263 usable_size); 1264 if (ptr != nullptr) { 1265 return ptr; 1266 } 1267 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1268 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1269 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1270 // OOME. 1271 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1272 << " allocation"; 1273 // TODO: Run finalization, but this may cause more allocations to occur. 1274 // We don't need a WaitForGcToComplete here either. 1275 DCHECK(!gc_plan_.empty()); 1276 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1277 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1278 return nullptr; 1279 } 1280 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1281 if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) { 1282 const uint64_t current_time = NanoTime(); 1283 if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) && 1284 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1285 min_interval_homogeneous_space_compaction_by_oom_) { 1286 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1287 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1288 switch (result) { 1289 case HomogeneousSpaceCompactResult::kSuccess: 1290 // If the allocation succeeded, we delayed an oom. 1291 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1292 if (ptr != nullptr) { 1293 count_delayed_oom_++; 1294 } 1295 break; 1296 case HomogeneousSpaceCompactResult::kErrorReject: 1297 // Reject due to disabled moving GC. 1298 break; 1299 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1300 // Throw OOM by default. 1301 break; 1302 default: { 1303 LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result); 1304 } 1305 } 1306 // Always print that we ran homogeneous space compation since this can cause jank. 1307 VLOG(heap) << "Ran heap homogeneous space compaction, " 1308 << " requested defragmentation " 1309 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1310 << " performed defragmentation " 1311 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1312 << " ignored homogeneous space compaction " 1313 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1314 << " delayed count = " 1315 << count_delayed_oom_.LoadSequentiallyConsistent(); 1316 } 1317 } 1318 // If the allocation hasn't succeeded by this point, throw an OOM error. 1319 if (ptr == nullptr) { 1320 ThrowOutOfMemoryError(self, alloc_size, allocator); 1321 } 1322 return ptr; 1323} 1324 1325void Heap::SetTargetHeapUtilization(float target) { 1326 DCHECK_GT(target, 0.0f); // asserted in Java code 1327 DCHECK_LT(target, 1.0f); 1328 target_utilization_ = target; 1329} 1330 1331size_t Heap::GetObjectsAllocated() const { 1332 size_t total = 0; 1333 for (space::AllocSpace* space : alloc_spaces_) { 1334 total += space->GetObjectsAllocated(); 1335 } 1336 return total; 1337} 1338 1339size_t Heap::GetObjectsAllocatedEver() const { 1340 return GetObjectsFreedEver() + GetObjectsAllocated(); 1341} 1342 1343size_t Heap::GetBytesAllocatedEver() const { 1344 return GetBytesFreedEver() + GetBytesAllocated(); 1345} 1346 1347class InstanceCounter { 1348 public: 1349 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1350 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1351 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1352 } 1353 static void Callback(mirror::Object* obj, void* arg) 1354 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1355 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1356 mirror::Class* instance_class = obj->GetClass(); 1357 CHECK(instance_class != nullptr); 1358 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1359 if (instance_counter->use_is_assignable_from_) { 1360 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1361 ++instance_counter->counts_[i]; 1362 } 1363 } else if (instance_class == instance_counter->classes_[i]) { 1364 ++instance_counter->counts_[i]; 1365 } 1366 } 1367 } 1368 1369 private: 1370 const std::vector<mirror::Class*>& classes_; 1371 bool use_is_assignable_from_; 1372 uint64_t* const counts_; 1373 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1374}; 1375 1376void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1377 uint64_t* counts) { 1378 // Can't do any GC in this function since this may move classes. 1379 Thread* self = Thread::Current(); 1380 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1381 InstanceCounter counter(classes, use_is_assignable_from, counts); 1382 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1383 VisitObjects(InstanceCounter::Callback, &counter); 1384 self->EndAssertNoThreadSuspension(old_cause); 1385} 1386 1387class InstanceCollector { 1388 public: 1389 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1390 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1391 : class_(c), max_count_(max_count), instances_(instances) { 1392 } 1393 static void Callback(mirror::Object* obj, void* arg) 1394 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1395 DCHECK(arg != nullptr); 1396 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1397 mirror::Class* instance_class = obj->GetClass(); 1398 if (instance_class == instance_collector->class_) { 1399 if (instance_collector->max_count_ == 0 || 1400 instance_collector->instances_.size() < instance_collector->max_count_) { 1401 instance_collector->instances_.push_back(obj); 1402 } 1403 } 1404 } 1405 1406 private: 1407 mirror::Class* class_; 1408 uint32_t max_count_; 1409 std::vector<mirror::Object*>& instances_; 1410 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1411}; 1412 1413void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1414 std::vector<mirror::Object*>& instances) { 1415 // Can't do any GC in this function since this may move classes. 1416 Thread* self = Thread::Current(); 1417 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1418 InstanceCollector collector(c, max_count, instances); 1419 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1420 VisitObjects(&InstanceCollector::Callback, &collector); 1421 self->EndAssertNoThreadSuspension(old_cause); 1422} 1423 1424class ReferringObjectsFinder { 1425 public: 1426 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1427 std::vector<mirror::Object*>& referring_objects) 1428 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1429 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1430 } 1431 1432 static void Callback(mirror::Object* obj, void* arg) 1433 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1434 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1435 } 1436 1437 // For bitmap Visit. 1438 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1439 // annotalysis on visitors. 1440 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1441 o->VisitReferences<true>(*this, VoidFunctor()); 1442 } 1443 1444 // For Object::VisitReferences. 1445 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1446 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1447 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1448 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1449 referring_objects_.push_back(obj); 1450 } 1451 } 1452 1453 private: 1454 mirror::Object* object_; 1455 uint32_t max_count_; 1456 std::vector<mirror::Object*>& referring_objects_; 1457 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1458}; 1459 1460void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1461 std::vector<mirror::Object*>& referring_objects) { 1462 // Can't do any GC in this function since this may move the object o. 1463 Thread* self = Thread::Current(); 1464 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1465 ReferringObjectsFinder finder(o, max_count, referring_objects); 1466 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1467 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1468 self->EndAssertNoThreadSuspension(old_cause); 1469} 1470 1471void Heap::CollectGarbage(bool clear_soft_references) { 1472 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1473 // last GC will not have necessarily been cleared. 1474 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1475} 1476 1477HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1478 Thread* self = Thread::Current(); 1479 // Inc requested homogeneous space compaction. 1480 count_requested_homogeneous_space_compaction_++; 1481 // Store performed homogeneous space compaction at a new request arrival. 1482 ThreadList* tl = Runtime::Current()->GetThreadList(); 1483 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1484 Locks::mutator_lock_->AssertNotHeld(self); 1485 { 1486 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1487 MutexLock mu(self, *gc_complete_lock_); 1488 // Ensure there is only one GC at a time. 1489 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1490 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1491 // is non zero. 1492 // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction, 1493 // exit. 1494 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) { 1495 return HomogeneousSpaceCompactResult::kErrorReject; 1496 } 1497 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1498 } 1499 if (Runtime::Current()->IsShuttingDown(self)) { 1500 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1501 // cause objects to get finalized. 1502 FinishGC(self, collector::kGcTypeNone); 1503 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1504 } 1505 // Suspend all threads. 1506 tl->SuspendAll(); 1507 uint64_t start_time = NanoTime(); 1508 // Launch compaction. 1509 space::MallocSpace* to_space = main_space_backup_.release(); 1510 space::MallocSpace* from_space = main_space_; 1511 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1512 const uint64_t space_size_before_compaction = from_space->Size(); 1513 AddSpace(to_space); 1514 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1515 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1516 from_space->GetMemMap()->Protect(PROT_READ); 1517 const uint64_t space_size_after_compaction = to_space->Size(); 1518 main_space_ = to_space; 1519 main_space_backup_.reset(from_space); 1520 RemoveSpace(from_space); 1521 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1522 // Update performed homogeneous space compaction count. 1523 count_performed_homogeneous_space_compaction_++; 1524 // Print statics log and resume all threads. 1525 uint64_t duration = NanoTime() - start_time; 1526 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1527 << PrettySize(space_size_before_compaction) << " -> " 1528 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1529 << std::fixed << static_cast<double>(space_size_after_compaction) / 1530 static_cast<double>(space_size_before_compaction); 1531 tl->ResumeAll(); 1532 // Finish GC. 1533 reference_processor_.EnqueueClearedReferences(self); 1534 GrowForUtilization(semi_space_collector_); 1535 FinishGC(self, collector::kGcTypeFull); 1536 return HomogeneousSpaceCompactResult::kSuccess; 1537} 1538 1539 1540void Heap::TransitionCollector(CollectorType collector_type) { 1541 if (collector_type == collector_type_) { 1542 return; 1543 } 1544 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1545 << " -> " << static_cast<int>(collector_type); 1546 uint64_t start_time = NanoTime(); 1547 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1548 Runtime* const runtime = Runtime::Current(); 1549 ThreadList* const tl = runtime->GetThreadList(); 1550 Thread* const self = Thread::Current(); 1551 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1552 Locks::mutator_lock_->AssertNotHeld(self); 1553 const bool copying_transition = 1554 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1555 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1556 // compacting_gc_disable_count_, this should rarely occurs). 1557 for (;;) { 1558 { 1559 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1560 MutexLock mu(self, *gc_complete_lock_); 1561 // Ensure there is only one GC at a time. 1562 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1563 // If someone else beat us to it and changed the collector before we could, exit. 1564 // This is safe to do before the suspend all since we set the collector_type_running_ before 1565 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1566 // then it would get blocked on WaitForGcToCompleteLocked. 1567 if (collector_type == collector_type_) { 1568 return; 1569 } 1570 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1571 if (!copying_transition || disable_moving_gc_count_ == 0) { 1572 // TODO: Not hard code in semi-space collector? 1573 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1574 break; 1575 } 1576 } 1577 usleep(1000); 1578 } 1579 if (runtime->IsShuttingDown(self)) { 1580 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1581 // cause objects to get finalized. 1582 FinishGC(self, collector::kGcTypeNone); 1583 return; 1584 } 1585 tl->SuspendAll(); 1586 switch (collector_type) { 1587 case kCollectorTypeSS: { 1588 if (!IsMovingGc(collector_type_)) { 1589 // Create the bump pointer space from the backup space. 1590 CHECK(main_space_backup_ != nullptr); 1591 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1592 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1593 // pointer space last transition it will be protected. 1594 CHECK(mem_map != nullptr); 1595 mem_map->Protect(PROT_READ | PROT_WRITE); 1596 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1597 mem_map.release()); 1598 AddSpace(bump_pointer_space_); 1599 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1600 // Use the now empty main space mem map for the bump pointer temp space. 1601 mem_map.reset(main_space_->ReleaseMemMap()); 1602 // Remove the main space so that we don't try to trim it, this doens't work for debug 1603 // builds since RosAlloc attempts to read the magic number from a protected page. 1604 RemoveSpace(main_space_); 1605 // Unset the pointers just in case. 1606 if (dlmalloc_space_ == main_space_) { 1607 dlmalloc_space_ = nullptr; 1608 } else if (rosalloc_space_ == main_space_) { 1609 rosalloc_space_ = nullptr; 1610 } 1611 RemoveRememberedSet(main_space_); 1612 RemoveRememberedSet(main_space_backup_.get()); 1613 main_space_backup_.reset(nullptr); 1614 main_space_ = nullptr; 1615 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1616 mem_map.release()); 1617 AddSpace(temp_space_); 1618 } 1619 break; 1620 } 1621 case kCollectorTypeMS: 1622 // Fall through. 1623 case kCollectorTypeCMS: { 1624 if (IsMovingGc(collector_type_)) { 1625 CHECK(temp_space_ != nullptr); 1626 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1627 RemoveSpace(temp_space_); 1628 temp_space_ = nullptr; 1629 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1630 mem_map->Size()); 1631 mem_map.release(); 1632 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1633 AddSpace(main_space_); 1634 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1635 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1636 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1637 RemoveSpace(bump_pointer_space_); 1638 bump_pointer_space_ = nullptr; 1639 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1640 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1641 mem_map->Size(), mem_map->Size(), 1642 name, true)); 1643 mem_map.release(); 1644 } 1645 break; 1646 } 1647 default: { 1648 LOG(FATAL) << "Attempted to transition to invalid collector type " 1649 << static_cast<size_t>(collector_type); 1650 break; 1651 } 1652 } 1653 ChangeCollector(collector_type); 1654 tl->ResumeAll(); 1655 // Can't call into java code with all threads suspended. 1656 reference_processor_.EnqueueClearedReferences(self); 1657 uint64_t duration = NanoTime() - start_time; 1658 GrowForUtilization(semi_space_collector_); 1659 FinishGC(self, collector::kGcTypeFull); 1660 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1661 int32_t delta_allocated = before_allocated - after_allocated; 1662 std::string saved_str; 1663 if (delta_allocated >= 0) { 1664 saved_str = " saved at least " + PrettySize(delta_allocated); 1665 } else { 1666 saved_str = " expanded " + PrettySize(-delta_allocated); 1667 } 1668 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1669 << PrettyDuration(duration) << saved_str; 1670} 1671 1672void Heap::ChangeCollector(CollectorType collector_type) { 1673 // TODO: Only do this with all mutators suspended to avoid races. 1674 if (collector_type != collector_type_) { 1675 if (collector_type == kCollectorTypeMC) { 1676 // Don't allow mark compact unless support is compiled in. 1677 CHECK(kMarkCompactSupport); 1678 } 1679 collector_type_ = collector_type; 1680 gc_plan_.clear(); 1681 switch (collector_type_) { 1682 case kCollectorTypeCC: // Fall-through. 1683 case kCollectorTypeMC: // Fall-through. 1684 case kCollectorTypeSS: // Fall-through. 1685 case kCollectorTypeGSS: { 1686 gc_plan_.push_back(collector::kGcTypeFull); 1687 if (use_tlab_) { 1688 ChangeAllocator(kAllocatorTypeTLAB); 1689 } else { 1690 ChangeAllocator(kAllocatorTypeBumpPointer); 1691 } 1692 break; 1693 } 1694 case kCollectorTypeMS: { 1695 gc_plan_.push_back(collector::kGcTypeSticky); 1696 gc_plan_.push_back(collector::kGcTypePartial); 1697 gc_plan_.push_back(collector::kGcTypeFull); 1698 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1699 break; 1700 } 1701 case kCollectorTypeCMS: { 1702 gc_plan_.push_back(collector::kGcTypeSticky); 1703 gc_plan_.push_back(collector::kGcTypePartial); 1704 gc_plan_.push_back(collector::kGcTypeFull); 1705 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1706 break; 1707 } 1708 default: { 1709 LOG(FATAL) << "Unimplemented"; 1710 } 1711 } 1712 if (IsGcConcurrent()) { 1713 concurrent_start_bytes_ = 1714 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1715 } else { 1716 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1717 } 1718 } 1719} 1720 1721// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1722class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1723 public: 1724 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1725 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1726 } 1727 1728 void BuildBins(space::ContinuousSpace* space) { 1729 bin_live_bitmap_ = space->GetLiveBitmap(); 1730 bin_mark_bitmap_ = space->GetMarkBitmap(); 1731 BinContext context; 1732 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1733 context.collector_ = this; 1734 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1735 // Note: This requires traversing the space in increasing order of object addresses. 1736 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1737 // Add the last bin which spans after the last object to the end of the space. 1738 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1739 } 1740 1741 private: 1742 struct BinContext { 1743 uintptr_t prev_; // The end of the previous object. 1744 ZygoteCompactingCollector* collector_; 1745 }; 1746 // Maps from bin sizes to locations. 1747 std::multimap<size_t, uintptr_t> bins_; 1748 // Live bitmap of the space which contains the bins. 1749 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1750 // Mark bitmap of the space which contains the bins. 1751 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1752 1753 static void Callback(mirror::Object* obj, void* arg) 1754 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1755 DCHECK(arg != nullptr); 1756 BinContext* context = reinterpret_cast<BinContext*>(arg); 1757 ZygoteCompactingCollector* collector = context->collector_; 1758 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1759 size_t bin_size = object_addr - context->prev_; 1760 // Add the bin consisting of the end of the previous object to the start of the current object. 1761 collector->AddBin(bin_size, context->prev_); 1762 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1763 } 1764 1765 void AddBin(size_t size, uintptr_t position) { 1766 if (size != 0) { 1767 bins_.insert(std::make_pair(size, position)); 1768 } 1769 } 1770 1771 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1772 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1773 // allocator. 1774 return false; 1775 } 1776 1777 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1778 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1779 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1780 mirror::Object* forward_address; 1781 // Find the smallest bin which we can move obj in. 1782 auto it = bins_.lower_bound(object_size); 1783 if (it == bins_.end()) { 1784 // No available space in the bins, place it in the target space instead (grows the zygote 1785 // space). 1786 size_t bytes_allocated; 1787 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1788 if (to_space_live_bitmap_ != nullptr) { 1789 to_space_live_bitmap_->Set(forward_address); 1790 } else { 1791 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1792 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1793 } 1794 } else { 1795 size_t size = it->first; 1796 uintptr_t pos = it->second; 1797 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1798 forward_address = reinterpret_cast<mirror::Object*>(pos); 1799 // Set the live and mark bits so that sweeping system weaks works properly. 1800 bin_live_bitmap_->Set(forward_address); 1801 bin_mark_bitmap_->Set(forward_address); 1802 DCHECK_GE(size, object_size); 1803 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1804 } 1805 // Copy the object over to its new location. 1806 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1807 if (kUseBakerOrBrooksReadBarrier) { 1808 obj->AssertReadBarrierPointer(); 1809 if (kUseBrooksReadBarrier) { 1810 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1811 forward_address->SetReadBarrierPointer(forward_address); 1812 } 1813 forward_address->AssertReadBarrierPointer(); 1814 } 1815 return forward_address; 1816 } 1817}; 1818 1819void Heap::UnBindBitmaps() { 1820 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1821 for (const auto& space : GetContinuousSpaces()) { 1822 if (space->IsContinuousMemMapAllocSpace()) { 1823 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1824 if (alloc_space->HasBoundBitmaps()) { 1825 alloc_space->UnBindBitmaps(); 1826 } 1827 } 1828 } 1829} 1830 1831void Heap::PreZygoteFork() { 1832 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1833 Thread* self = Thread::Current(); 1834 MutexLock mu(self, zygote_creation_lock_); 1835 // Try to see if we have any Zygote spaces. 1836 if (have_zygote_space_) { 1837 return; 1838 } 1839 VLOG(heap) << "Starting PreZygoteFork"; 1840 // Trim the pages at the end of the non moving space. 1841 non_moving_space_->Trim(); 1842 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1843 // there. 1844 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1845 // Change the collector to the post zygote one. 1846 bool same_space = non_moving_space_ == main_space_; 1847 if (kCompactZygote) { 1848 DCHECK(semi_space_collector_ != nullptr); 1849 // Temporarily disable rosalloc verification because the zygote 1850 // compaction will mess up the rosalloc internal metadata. 1851 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1852 ZygoteCompactingCollector zygote_collector(this); 1853 zygote_collector.BuildBins(non_moving_space_); 1854 // Create a new bump pointer space which we will compact into. 1855 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1856 non_moving_space_->Limit()); 1857 // Compact the bump pointer space to a new zygote bump pointer space. 1858 bool reset_main_space = false; 1859 if (IsMovingGc(collector_type_)) { 1860 zygote_collector.SetFromSpace(bump_pointer_space_); 1861 } else { 1862 CHECK(main_space_ != nullptr); 1863 // Copy from the main space. 1864 zygote_collector.SetFromSpace(main_space_); 1865 reset_main_space = true; 1866 } 1867 zygote_collector.SetToSpace(&target_space); 1868 zygote_collector.SetSwapSemiSpaces(false); 1869 zygote_collector.Run(kGcCauseCollectorTransition, false); 1870 if (reset_main_space) { 1871 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1872 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1873 MemMap* mem_map = main_space_->ReleaseMemMap(); 1874 RemoveSpace(main_space_); 1875 space::Space* old_main_space = main_space_; 1876 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1877 delete old_main_space; 1878 AddSpace(main_space_); 1879 } else { 1880 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1881 } 1882 if (temp_space_ != nullptr) { 1883 CHECK(temp_space_->IsEmpty()); 1884 } 1885 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1886 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1887 // Update the end and write out image. 1888 non_moving_space_->SetEnd(target_space.End()); 1889 non_moving_space_->SetLimit(target_space.Limit()); 1890 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1891 } 1892 ChangeCollector(foreground_collector_type_); 1893 // Save the old space so that we can remove it after we complete creating the zygote space. 1894 space::MallocSpace* old_alloc_space = non_moving_space_; 1895 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1896 // the remaining available space. 1897 // Remove the old space before creating the zygote space since creating the zygote space sets 1898 // the old alloc space's bitmaps to nullptr. 1899 RemoveSpace(old_alloc_space); 1900 if (collector::SemiSpace::kUseRememberedSet) { 1901 // Sanity bound check. 1902 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1903 // Remove the remembered set for the now zygote space (the old 1904 // non-moving space). Note now that we have compacted objects into 1905 // the zygote space, the data in the remembered set is no longer 1906 // needed. The zygote space will instead have a mod-union table 1907 // from this point on. 1908 RemoveRememberedSet(old_alloc_space); 1909 } 1910 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1911 low_memory_mode_, 1912 &non_moving_space_); 1913 CHECK(!non_moving_space_->CanMoveObjects()); 1914 if (same_space) { 1915 main_space_ = non_moving_space_; 1916 SetSpaceAsDefault(main_space_); 1917 } 1918 delete old_alloc_space; 1919 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1920 AddSpace(zygote_space); 1921 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1922 AddSpace(non_moving_space_); 1923 have_zygote_space_ = true; 1924 // Enable large object space allocations. 1925 large_object_threshold_ = kDefaultLargeObjectThreshold; 1926 // Create the zygote space mod union table. 1927 accounting::ModUnionTable* mod_union_table = 1928 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1929 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1930 AddModUnionTable(mod_union_table); 1931 if (collector::SemiSpace::kUseRememberedSet) { 1932 // Add a new remembered set for the post-zygote non-moving space. 1933 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1934 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1935 non_moving_space_); 1936 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1937 << "Failed to create post-zygote non-moving space remembered set"; 1938 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1939 } 1940} 1941 1942void Heap::FlushAllocStack() { 1943 MarkAllocStackAsLive(allocation_stack_.get()); 1944 allocation_stack_->Reset(); 1945} 1946 1947void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1948 accounting::ContinuousSpaceBitmap* bitmap2, 1949 accounting::LargeObjectBitmap* large_objects, 1950 accounting::ObjectStack* stack) { 1951 DCHECK(bitmap1 != nullptr); 1952 DCHECK(bitmap2 != nullptr); 1953 mirror::Object** limit = stack->End(); 1954 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1955 const mirror::Object* obj = *it; 1956 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1957 if (bitmap1->HasAddress(obj)) { 1958 bitmap1->Set(obj); 1959 } else if (bitmap2->HasAddress(obj)) { 1960 bitmap2->Set(obj); 1961 } else { 1962 large_objects->Set(obj); 1963 } 1964 } 1965 } 1966} 1967 1968void Heap::SwapSemiSpaces() { 1969 CHECK(bump_pointer_space_ != nullptr); 1970 CHECK(temp_space_ != nullptr); 1971 std::swap(bump_pointer_space_, temp_space_); 1972} 1973 1974void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1975 space::ContinuousMemMapAllocSpace* source_space, 1976 GcCause gc_cause) { 1977 CHECK(kMovingCollector); 1978 if (target_space != source_space) { 1979 // Don't swap spaces since this isn't a typical semi space collection. 1980 semi_space_collector_->SetSwapSemiSpaces(false); 1981 semi_space_collector_->SetFromSpace(source_space); 1982 semi_space_collector_->SetToSpace(target_space); 1983 semi_space_collector_->Run(gc_cause, false); 1984 } else { 1985 CHECK(target_space->IsBumpPointerSpace()) 1986 << "In-place compaction is only supported for bump pointer spaces"; 1987 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1988 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1989 } 1990} 1991 1992collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1993 bool clear_soft_references) { 1994 Thread* self = Thread::Current(); 1995 Runtime* runtime = Runtime::Current(); 1996 // If the heap can't run the GC, silently fail and return that no GC was run. 1997 switch (gc_type) { 1998 case collector::kGcTypePartial: { 1999 if (!have_zygote_space_) { 2000 return collector::kGcTypeNone; 2001 } 2002 break; 2003 } 2004 default: { 2005 // Other GC types don't have any special cases which makes them not runnable. The main case 2006 // here is full GC. 2007 } 2008 } 2009 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2010 Locks::mutator_lock_->AssertNotHeld(self); 2011 if (self->IsHandlingStackOverflow()) { 2012 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2013 } 2014 bool compacting_gc; 2015 { 2016 gc_complete_lock_->AssertNotHeld(self); 2017 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2018 MutexLock mu(self, *gc_complete_lock_); 2019 // Ensure there is only one GC at a time. 2020 WaitForGcToCompleteLocked(gc_cause, self); 2021 compacting_gc = IsMovingGc(collector_type_); 2022 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2023 if (compacting_gc && disable_moving_gc_count_ != 0) { 2024 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2025 return collector::kGcTypeNone; 2026 } 2027 collector_type_running_ = collector_type_; 2028 } 2029 2030 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2031 ++runtime->GetStats()->gc_for_alloc_count; 2032 ++self->GetStats()->gc_for_alloc_count; 2033 } 2034 uint64_t gc_start_time_ns = NanoTime(); 2035 uint64_t gc_start_size = GetBytesAllocated(); 2036 // Approximate allocation rate in bytes / second. 2037 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2038 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2039 if (LIKELY(ms_delta != 0)) { 2040 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2041 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2042 } 2043 2044 DCHECK_LT(gc_type, collector::kGcTypeMax); 2045 DCHECK_NE(gc_type, collector::kGcTypeNone); 2046 2047 collector::GarbageCollector* collector = nullptr; 2048 // TODO: Clean this up. 2049 if (compacting_gc) { 2050 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2051 current_allocator_ == kAllocatorTypeTLAB); 2052 switch (collector_type_) { 2053 case kCollectorTypeSS: 2054 // Fall-through. 2055 case kCollectorTypeGSS: 2056 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2057 semi_space_collector_->SetToSpace(temp_space_); 2058 semi_space_collector_->SetSwapSemiSpaces(true); 2059 collector = semi_space_collector_; 2060 break; 2061 case kCollectorTypeCC: 2062 collector = concurrent_copying_collector_; 2063 break; 2064 case kCollectorTypeMC: 2065 mark_compact_collector_->SetSpace(bump_pointer_space_); 2066 collector = mark_compact_collector_; 2067 break; 2068 default: 2069 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2070 } 2071 if (collector != mark_compact_collector_) { 2072 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2073 CHECK(temp_space_->IsEmpty()); 2074 } 2075 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2076 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2077 current_allocator_ == kAllocatorTypeDlMalloc) { 2078 collector = FindCollectorByGcType(gc_type); 2079 } else { 2080 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2081 } 2082 CHECK(collector != nullptr) 2083 << "Could not find garbage collector with collector_type=" 2084 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2085 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2086 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2087 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2088 RequestHeapTrim(); 2089 // Enqueue cleared references. 2090 reference_processor_.EnqueueClearedReferences(self); 2091 // Grow the heap so that we know when to perform the next GC. 2092 GrowForUtilization(collector); 2093 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2094 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2095 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2096 // (mutator time blocked >= long_pause_log_threshold_). 2097 bool log_gc = gc_cause == kGcCauseExplicit; 2098 if (!log_gc && CareAboutPauseTimes()) { 2099 // GC for alloc pauses the allocating thread, so consider it as a pause. 2100 log_gc = duration > long_gc_log_threshold_ || 2101 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2102 for (uint64_t pause : pause_times) { 2103 log_gc = log_gc || pause >= long_pause_log_threshold_; 2104 } 2105 } 2106 if (log_gc) { 2107 const size_t percent_free = GetPercentFree(); 2108 const size_t current_heap_size = GetBytesAllocated(); 2109 const size_t total_memory = GetTotalMemory(); 2110 std::ostringstream pause_string; 2111 for (size_t i = 0; i < pause_times.size(); ++i) { 2112 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2113 << ((i != pause_times.size() - 1) ? "," : ""); 2114 } 2115 LOG(INFO) << gc_cause << " " << collector->GetName() 2116 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2117 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2118 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2119 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2120 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2121 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2122 << " total " << PrettyDuration((duration / 1000) * 1000); 2123 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2124 } 2125 FinishGC(self, gc_type); 2126 // Inform DDMS that a GC completed. 2127 Dbg::GcDidFinish(); 2128 return gc_type; 2129} 2130 2131void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2132 MutexLock mu(self, *gc_complete_lock_); 2133 collector_type_running_ = kCollectorTypeNone; 2134 if (gc_type != collector::kGcTypeNone) { 2135 last_gc_type_ = gc_type; 2136 } 2137 // Wake anyone who may have been waiting for the GC to complete. 2138 gc_complete_cond_->Broadcast(self); 2139} 2140 2141static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2142 RootType /*root_type*/) { 2143 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2144 if (*root == obj) { 2145 LOG(INFO) << "Object " << obj << " is a root"; 2146 } 2147} 2148 2149class ScanVisitor { 2150 public: 2151 void operator()(const mirror::Object* obj) const { 2152 LOG(ERROR) << "Would have rescanned object " << obj; 2153 } 2154}; 2155 2156// Verify a reference from an object. 2157class VerifyReferenceVisitor { 2158 public: 2159 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2160 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2161 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2162 2163 size_t GetFailureCount() const { 2164 return fail_count_->LoadSequentiallyConsistent(); 2165 } 2166 2167 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2168 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2169 if (verify_referent_) { 2170 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2171 } 2172 } 2173 2174 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2175 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2176 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2177 } 2178 2179 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2180 return heap_->IsLiveObjectLocked(obj, true, false, true); 2181 } 2182 2183 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2184 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2185 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2186 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2187 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2188 << " thread_id= " << thread_id << " root_type= " << root_type; 2189 } 2190 } 2191 2192 private: 2193 // TODO: Fix the no thread safety analysis. 2194 // Returns false on failure. 2195 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2196 NO_THREAD_SAFETY_ANALYSIS { 2197 if (ref == nullptr || IsLive(ref)) { 2198 // Verify that the reference is live. 2199 return true; 2200 } 2201 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2202 // Print message on only on first failure to prevent spam. 2203 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2204 } 2205 if (obj != nullptr) { 2206 // Only do this part for non roots. 2207 accounting::CardTable* card_table = heap_->GetCardTable(); 2208 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2209 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2210 byte* card_addr = card_table->CardFromAddr(obj); 2211 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2212 << offset << "\n card value = " << static_cast<int>(*card_addr); 2213 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2214 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2215 } else { 2216 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2217 } 2218 2219 // Attempt to find the class inside of the recently freed objects. 2220 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2221 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2222 space::MallocSpace* space = ref_space->AsMallocSpace(); 2223 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2224 if (ref_class != nullptr) { 2225 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2226 << PrettyClass(ref_class); 2227 } else { 2228 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2229 } 2230 } 2231 2232 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2233 ref->GetClass()->IsClass()) { 2234 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2235 } else { 2236 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2237 << ") is not a valid heap address"; 2238 } 2239 2240 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2241 void* cover_begin = card_table->AddrFromCard(card_addr); 2242 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2243 accounting::CardTable::kCardSize); 2244 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2245 << "-" << cover_end; 2246 accounting::ContinuousSpaceBitmap* bitmap = 2247 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2248 2249 if (bitmap == nullptr) { 2250 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2251 if (!VerifyClassClass(obj->GetClass())) { 2252 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2253 } 2254 } else { 2255 // Print out how the object is live. 2256 if (bitmap->Test(obj)) { 2257 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2258 } 2259 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2260 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2261 } 2262 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2263 LOG(ERROR) << "Object " << obj << " found in live stack"; 2264 } 2265 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2266 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2267 } 2268 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2269 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2270 } 2271 // Attempt to see if the card table missed the reference. 2272 ScanVisitor scan_visitor; 2273 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2274 card_table->Scan(bitmap, byte_cover_begin, 2275 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2276 } 2277 2278 // Search to see if any of the roots reference our object. 2279 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2280 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2281 2282 // Search to see if any of the roots reference our reference. 2283 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2284 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2285 } 2286 return false; 2287 } 2288 2289 Heap* const heap_; 2290 Atomic<size_t>* const fail_count_; 2291 const bool verify_referent_; 2292}; 2293 2294// Verify all references within an object, for use with HeapBitmap::Visit. 2295class VerifyObjectVisitor { 2296 public: 2297 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2298 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2299 } 2300 2301 void operator()(mirror::Object* obj) const 2302 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2303 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2304 // be live or else how did we find it in the live bitmap? 2305 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2306 // The class doesn't count as a reference but we should verify it anyways. 2307 obj->VisitReferences<true>(visitor, visitor); 2308 } 2309 2310 static void VisitCallback(mirror::Object* obj, void* arg) 2311 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2312 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2313 visitor->operator()(obj); 2314 } 2315 2316 size_t GetFailureCount() const { 2317 return fail_count_->LoadSequentiallyConsistent(); 2318 } 2319 2320 private: 2321 Heap* const heap_; 2322 Atomic<size_t>* const fail_count_; 2323 const bool verify_referent_; 2324}; 2325 2326void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2327 // Slow path, the allocation stack push back must have already failed. 2328 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2329 do { 2330 // TODO: Add handle VerifyObject. 2331 StackHandleScope<1> hs(self); 2332 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2333 // Push our object into the reserve region of the allocaiton stack. This is only required due 2334 // to heap verification requiring that roots are live (either in the live bitmap or in the 2335 // allocation stack). 2336 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2337 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2338 } while (!allocation_stack_->AtomicPushBack(*obj)); 2339} 2340 2341void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2342 // Slow path, the allocation stack push back must have already failed. 2343 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2344 mirror::Object** start_address; 2345 mirror::Object** end_address; 2346 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2347 &end_address)) { 2348 // TODO: Add handle VerifyObject. 2349 StackHandleScope<1> hs(self); 2350 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2351 // Push our object into the reserve region of the allocaiton stack. This is only required due 2352 // to heap verification requiring that roots are live (either in the live bitmap or in the 2353 // allocation stack). 2354 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2355 // Push into the reserve allocation stack. 2356 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2357 } 2358 self->SetThreadLocalAllocationStack(start_address, end_address); 2359 // Retry on the new thread-local allocation stack. 2360 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2361} 2362 2363// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2364size_t Heap::VerifyHeapReferences(bool verify_referents) { 2365 Thread* self = Thread::Current(); 2366 Locks::mutator_lock_->AssertExclusiveHeld(self); 2367 // Lets sort our allocation stacks so that we can efficiently binary search them. 2368 allocation_stack_->Sort(); 2369 live_stack_->Sort(); 2370 // Since we sorted the allocation stack content, need to revoke all 2371 // thread-local allocation stacks. 2372 RevokeAllThreadLocalAllocationStacks(self); 2373 Atomic<size_t> fail_count_(0); 2374 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2375 // Verify objects in the allocation stack since these will be objects which were: 2376 // 1. Allocated prior to the GC (pre GC verification). 2377 // 2. Allocated during the GC (pre sweep GC verification). 2378 // We don't want to verify the objects in the live stack since they themselves may be 2379 // pointing to dead objects if they are not reachable. 2380 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2381 // Verify the roots: 2382 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2383 if (visitor.GetFailureCount() > 0) { 2384 // Dump mod-union tables. 2385 for (const auto& table_pair : mod_union_tables_) { 2386 accounting::ModUnionTable* mod_union_table = table_pair.second; 2387 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2388 } 2389 // Dump remembered sets. 2390 for (const auto& table_pair : remembered_sets_) { 2391 accounting::RememberedSet* remembered_set = table_pair.second; 2392 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2393 } 2394 DumpSpaces(LOG(ERROR)); 2395 } 2396 return visitor.GetFailureCount(); 2397} 2398 2399class VerifyReferenceCardVisitor { 2400 public: 2401 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2402 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2403 Locks::heap_bitmap_lock_) 2404 : heap_(heap), failed_(failed) { 2405 } 2406 2407 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2408 // annotalysis on visitors. 2409 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2410 NO_THREAD_SAFETY_ANALYSIS { 2411 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2412 // Filter out class references since changing an object's class does not mark the card as dirty. 2413 // Also handles large objects, since the only reference they hold is a class reference. 2414 if (ref != nullptr && !ref->IsClass()) { 2415 accounting::CardTable* card_table = heap_->GetCardTable(); 2416 // If the object is not dirty and it is referencing something in the live stack other than 2417 // class, then it must be on a dirty card. 2418 if (!card_table->AddrIsInCardTable(obj)) { 2419 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2420 *failed_ = true; 2421 } else if (!card_table->IsDirty(obj)) { 2422 // TODO: Check mod-union tables. 2423 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2424 // kCardDirty - 1 if it didnt get touched since we aged it. 2425 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2426 if (live_stack->ContainsSorted(ref)) { 2427 if (live_stack->ContainsSorted(obj)) { 2428 LOG(ERROR) << "Object " << obj << " found in live stack"; 2429 } 2430 if (heap_->GetLiveBitmap()->Test(obj)) { 2431 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2432 } 2433 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2434 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2435 2436 // Print which field of the object is dead. 2437 if (!obj->IsObjectArray()) { 2438 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2439 CHECK(klass != NULL); 2440 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2441 : klass->GetIFields(); 2442 CHECK(fields != NULL); 2443 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2444 mirror::ArtField* cur = fields->Get(i); 2445 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2446 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2447 << PrettyField(cur); 2448 break; 2449 } 2450 } 2451 } else { 2452 mirror::ObjectArray<mirror::Object>* object_array = 2453 obj->AsObjectArray<mirror::Object>(); 2454 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2455 if (object_array->Get(i) == ref) { 2456 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2457 } 2458 } 2459 } 2460 2461 *failed_ = true; 2462 } 2463 } 2464 } 2465 } 2466 2467 private: 2468 Heap* const heap_; 2469 bool* const failed_; 2470}; 2471 2472class VerifyLiveStackReferences { 2473 public: 2474 explicit VerifyLiveStackReferences(Heap* heap) 2475 : heap_(heap), 2476 failed_(false) {} 2477 2478 void operator()(mirror::Object* obj) const 2479 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2480 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2481 obj->VisitReferences<true>(visitor, VoidFunctor()); 2482 } 2483 2484 bool Failed() const { 2485 return failed_; 2486 } 2487 2488 private: 2489 Heap* const heap_; 2490 bool failed_; 2491}; 2492 2493bool Heap::VerifyMissingCardMarks() { 2494 Thread* self = Thread::Current(); 2495 Locks::mutator_lock_->AssertExclusiveHeld(self); 2496 2497 // We need to sort the live stack since we binary search it. 2498 live_stack_->Sort(); 2499 // Since we sorted the allocation stack content, need to revoke all 2500 // thread-local allocation stacks. 2501 RevokeAllThreadLocalAllocationStacks(self); 2502 VerifyLiveStackReferences visitor(this); 2503 GetLiveBitmap()->Visit(visitor); 2504 2505 // We can verify objects in the live stack since none of these should reference dead objects. 2506 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2507 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2508 visitor(*it); 2509 } 2510 } 2511 return !visitor.Failed(); 2512} 2513 2514void Heap::SwapStacks(Thread* self) { 2515 if (kUseThreadLocalAllocationStack) { 2516 live_stack_->AssertAllZero(); 2517 } 2518 allocation_stack_.swap(live_stack_); 2519} 2520 2521void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2522 // This must be called only during the pause. 2523 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2524 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2525 MutexLock mu2(self, *Locks::thread_list_lock_); 2526 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2527 for (Thread* t : thread_list) { 2528 t->RevokeThreadLocalAllocationStack(); 2529 } 2530} 2531 2532void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2533 if (kIsDebugBuild) { 2534 if (bump_pointer_space_ != nullptr) { 2535 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2536 } 2537 } 2538} 2539 2540accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2541 auto it = mod_union_tables_.find(space); 2542 if (it == mod_union_tables_.end()) { 2543 return nullptr; 2544 } 2545 return it->second; 2546} 2547 2548accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2549 auto it = remembered_sets_.find(space); 2550 if (it == remembered_sets_.end()) { 2551 return nullptr; 2552 } 2553 return it->second; 2554} 2555 2556void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2557 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2558 // Clear cards and keep track of cards cleared in the mod-union table. 2559 for (const auto& space : continuous_spaces_) { 2560 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2561 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2562 if (table != nullptr) { 2563 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2564 "ImageModUnionClearCards"; 2565 TimingLogger::ScopedTiming t(name, timings); 2566 table->ClearCards(); 2567 } else if (use_rem_sets && rem_set != nullptr) { 2568 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2569 << static_cast<int>(collector_type_); 2570 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2571 rem_set->ClearCards(); 2572 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2573 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2574 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2575 // were dirty before the GC started. 2576 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2577 // -> clean(cleaning thread). 2578 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2579 // roots and then we scan / update mod union tables after. We will always scan either card. 2580 // If we end up with the non aged card, we scan it it in the pause. 2581 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2582 VoidFunctor()); 2583 } 2584 } 2585} 2586 2587static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2588} 2589 2590void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2591 Thread* const self = Thread::Current(); 2592 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2593 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2594 if (verify_pre_gc_heap_) { 2595 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2596 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2597 size_t failures = VerifyHeapReferences(); 2598 if (failures > 0) { 2599 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2600 << " failures"; 2601 } 2602 } 2603 // Check that all objects which reference things in the live stack are on dirty cards. 2604 if (verify_missing_card_marks_) { 2605 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2606 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2607 SwapStacks(self); 2608 // Sort the live stack so that we can quickly binary search it later. 2609 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2610 << " missing card mark verification failed\n" << DumpSpaces(); 2611 SwapStacks(self); 2612 } 2613 if (verify_mod_union_table_) { 2614 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2615 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2616 for (const auto& table_pair : mod_union_tables_) { 2617 accounting::ModUnionTable* mod_union_table = table_pair.second; 2618 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2619 mod_union_table->Verify(); 2620 } 2621 } 2622} 2623 2624void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2625 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2626 collector::GarbageCollector::ScopedPause pause(gc); 2627 PreGcVerificationPaused(gc); 2628 } 2629} 2630 2631void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2632 // TODO: Add a new runtime option for this? 2633 if (verify_pre_gc_rosalloc_) { 2634 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2635 } 2636} 2637 2638void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2639 Thread* const self = Thread::Current(); 2640 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2641 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2642 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2643 // reachable objects. 2644 if (verify_pre_sweeping_heap_) { 2645 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2646 CHECK_NE(self->GetState(), kRunnable); 2647 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2648 // Swapping bound bitmaps does nothing. 2649 gc->SwapBitmaps(); 2650 // Pass in false since concurrent reference processing can mean that the reference referents 2651 // may point to dead objects at the point which PreSweepingGcVerification is called. 2652 size_t failures = VerifyHeapReferences(false); 2653 if (failures > 0) { 2654 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2655 << " failures"; 2656 } 2657 gc->SwapBitmaps(); 2658 } 2659 if (verify_pre_sweeping_rosalloc_) { 2660 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2661 } 2662} 2663 2664void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2665 // Only pause if we have to do some verification. 2666 Thread* const self = Thread::Current(); 2667 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2668 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2669 if (verify_system_weaks_) { 2670 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2671 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2672 mark_sweep->VerifySystemWeaks(); 2673 } 2674 if (verify_post_gc_rosalloc_) { 2675 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2676 } 2677 if (verify_post_gc_heap_) { 2678 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2679 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2680 size_t failures = VerifyHeapReferences(); 2681 if (failures > 0) { 2682 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2683 << " failures"; 2684 } 2685 } 2686} 2687 2688void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2689 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2690 collector::GarbageCollector::ScopedPause pause(gc); 2691 PreGcVerificationPaused(gc); 2692 } 2693} 2694 2695void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2696 TimingLogger::ScopedTiming t(name, timings); 2697 for (const auto& space : continuous_spaces_) { 2698 if (space->IsRosAllocSpace()) { 2699 VLOG(heap) << name << " : " << space->GetName(); 2700 space->AsRosAllocSpace()->Verify(); 2701 } 2702 } 2703} 2704 2705collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2706 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2707 MutexLock mu(self, *gc_complete_lock_); 2708 return WaitForGcToCompleteLocked(cause, self); 2709} 2710 2711collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2712 collector::GcType last_gc_type = collector::kGcTypeNone; 2713 uint64_t wait_start = NanoTime(); 2714 while (collector_type_running_ != kCollectorTypeNone) { 2715 ATRACE_BEGIN("GC: Wait For Completion"); 2716 // We must wait, change thread state then sleep on gc_complete_cond_; 2717 gc_complete_cond_->Wait(self); 2718 last_gc_type = last_gc_type_; 2719 ATRACE_END(); 2720 } 2721 uint64_t wait_time = NanoTime() - wait_start; 2722 total_wait_time_ += wait_time; 2723 if (wait_time > long_pause_log_threshold_) { 2724 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2725 << " for cause " << cause; 2726 } 2727 return last_gc_type; 2728} 2729 2730void Heap::DumpForSigQuit(std::ostream& os) { 2731 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2732 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2733 DumpGcPerformanceInfo(os); 2734} 2735 2736size_t Heap::GetPercentFree() { 2737 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2738} 2739 2740void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2741 if (max_allowed_footprint > GetMaxMemory()) { 2742 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2743 << PrettySize(GetMaxMemory()); 2744 max_allowed_footprint = GetMaxMemory(); 2745 } 2746 max_allowed_footprint_ = max_allowed_footprint; 2747} 2748 2749bool Heap::IsMovableObject(const mirror::Object* obj) const { 2750 if (kMovingCollector) { 2751 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2752 if (space != nullptr) { 2753 // TODO: Check large object? 2754 return space->CanMoveObjects(); 2755 } 2756 } 2757 return false; 2758} 2759 2760void Heap::UpdateMaxNativeFootprint() { 2761 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2762 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2763 size_t target_size = native_size / GetTargetHeapUtilization(); 2764 if (target_size > native_size + max_free_) { 2765 target_size = native_size + max_free_; 2766 } else if (target_size < native_size + min_free_) { 2767 target_size = native_size + min_free_; 2768 } 2769 native_footprint_gc_watermark_ = target_size; 2770 native_footprint_limit_ = 2 * target_size - native_size; 2771} 2772 2773collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2774 for (const auto& collector : garbage_collectors_) { 2775 if (collector->GetCollectorType() == collector_type_ && 2776 collector->GetGcType() == gc_type) { 2777 return collector; 2778 } 2779 } 2780 return nullptr; 2781} 2782 2783double Heap::HeapGrowthMultiplier() const { 2784 // If we don't care about pause times we are background, so return 1.0. 2785 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2786 return 1.0; 2787 } 2788 return foreground_heap_growth_multiplier_; 2789} 2790 2791void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2792 // We know what our utilization is at this moment. 2793 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2794 const uint64_t bytes_allocated = GetBytesAllocated(); 2795 last_gc_size_ = bytes_allocated; 2796 last_gc_time_ns_ = NanoTime(); 2797 uint64_t target_size; 2798 collector::GcType gc_type = collector_ran->GetGcType(); 2799 if (gc_type != collector::kGcTypeSticky) { 2800 // Grow the heap for non sticky GC. 2801 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2802 // foreground. 2803 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2804 CHECK_GE(delta, 0); 2805 target_size = bytes_allocated + delta * multiplier; 2806 target_size = std::min(target_size, 2807 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2808 target_size = std::max(target_size, 2809 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2810 native_need_to_run_finalization_ = true; 2811 next_gc_type_ = collector::kGcTypeSticky; 2812 } else { 2813 collector::GcType non_sticky_gc_type = 2814 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2815 // Find what the next non sticky collector will be. 2816 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2817 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2818 // do another sticky collection next. 2819 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2820 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2821 // if the sticky GC throughput always remained >= the full/partial throughput. 2822 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2823 non_sticky_collector->GetEstimatedMeanThroughput() && 2824 non_sticky_collector->NumberOfIterations() > 0 && 2825 bytes_allocated <= max_allowed_footprint_) { 2826 next_gc_type_ = collector::kGcTypeSticky; 2827 } else { 2828 next_gc_type_ = non_sticky_gc_type; 2829 } 2830 // If we have freed enough memory, shrink the heap back down. 2831 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2832 target_size = bytes_allocated + max_free_; 2833 } else { 2834 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2835 } 2836 } 2837 if (!ignore_max_footprint_) { 2838 SetIdealFootprint(target_size); 2839 if (IsGcConcurrent()) { 2840 // Calculate when to perform the next ConcurrentGC. 2841 // Calculate the estimated GC duration. 2842 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2843 // Estimate how many remaining bytes we will have when we need to start the next GC. 2844 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2845 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2846 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2847 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2848 // A never going to happen situation that from the estimated allocation rate we will exceed 2849 // the applications entire footprint with the given estimated allocation rate. Schedule 2850 // another GC nearly straight away. 2851 remaining_bytes = kMinConcurrentRemainingBytes; 2852 } 2853 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2854 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2855 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2856 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2857 // right away. 2858 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2859 static_cast<size_t>(bytes_allocated)); 2860 } 2861 } 2862} 2863 2864void Heap::ClearGrowthLimit() { 2865 growth_limit_ = capacity_; 2866 non_moving_space_->ClearGrowthLimit(); 2867} 2868 2869void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2870 ScopedObjectAccess soa(self); 2871 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2872 jvalue args[1]; 2873 args[0].l = arg.get(); 2874 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2875 // Restore object in case it gets moved. 2876 *object = soa.Decode<mirror::Object*>(arg.get()); 2877} 2878 2879void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2880 StackHandleScope<1> hs(self); 2881 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2882 RequestConcurrentGC(self); 2883} 2884 2885void Heap::RequestConcurrentGC(Thread* self) { 2886 // Make sure that we can do a concurrent GC. 2887 Runtime* runtime = Runtime::Current(); 2888 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2889 self->IsHandlingStackOverflow()) { 2890 return; 2891 } 2892 // We already have a request pending, no reason to start more until we update 2893 // concurrent_start_bytes_. 2894 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2895 JNIEnv* env = self->GetJniEnv(); 2896 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2897 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2898 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2899 WellKnownClasses::java_lang_Daemons_requestGC); 2900 CHECK(!env->ExceptionCheck()); 2901} 2902 2903void Heap::ConcurrentGC(Thread* self) { 2904 if (Runtime::Current()->IsShuttingDown(self)) { 2905 return; 2906 } 2907 // Wait for any GCs currently running to finish. 2908 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2909 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2910 // instead. E.g. can't do partial, so do full instead. 2911 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2912 collector::kGcTypeNone) { 2913 for (collector::GcType gc_type : gc_plan_) { 2914 // Attempt to run the collector, if we succeed, we are done. 2915 if (gc_type > next_gc_type_ && 2916 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2917 break; 2918 } 2919 } 2920 } 2921 } 2922} 2923 2924void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2925 Thread* self = Thread::Current(); 2926 { 2927 MutexLock mu(self, *heap_trim_request_lock_); 2928 if (desired_collector_type_ == desired_collector_type) { 2929 return; 2930 } 2931 heap_transition_or_trim_target_time_ = 2932 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2933 desired_collector_type_ = desired_collector_type; 2934 } 2935 SignalHeapTrimDaemon(self); 2936} 2937 2938void Heap::RequestHeapTrim() { 2939 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2940 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2941 // a space it will hold its lock and can become a cause of jank. 2942 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2943 // forking. 2944 2945 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2946 // because that only marks object heads, so a large array looks like lots of empty space. We 2947 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2948 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2949 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2950 // not how much use we're making of those pages. 2951 2952 Thread* self = Thread::Current(); 2953 Runtime* runtime = Runtime::Current(); 2954 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2955 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2956 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2957 // as we don't hold the lock while requesting the trim). 2958 return; 2959 } 2960 { 2961 MutexLock mu(self, *heap_trim_request_lock_); 2962 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2963 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2964 // just yet. 2965 return; 2966 } 2967 heap_trim_request_pending_ = true; 2968 uint64_t current_time = NanoTime(); 2969 if (heap_transition_or_trim_target_time_ < current_time) { 2970 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2971 } 2972 } 2973 // Notify the daemon thread which will actually do the heap trim. 2974 SignalHeapTrimDaemon(self); 2975} 2976 2977void Heap::SignalHeapTrimDaemon(Thread* self) { 2978 JNIEnv* env = self->GetJniEnv(); 2979 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2980 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2981 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2982 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2983 CHECK(!env->ExceptionCheck()); 2984} 2985 2986void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2987 if (rosalloc_space_ != nullptr) { 2988 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2989 } 2990 if (bump_pointer_space_ != nullptr) { 2991 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2992 } 2993} 2994 2995void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2996 if (rosalloc_space_ != nullptr) { 2997 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2998 } 2999} 3000 3001void Heap::RevokeAllThreadLocalBuffers() { 3002 if (rosalloc_space_ != nullptr) { 3003 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3004 } 3005 if (bump_pointer_space_ != nullptr) { 3006 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3007 } 3008} 3009 3010bool Heap::IsGCRequestPending() const { 3011 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3012} 3013 3014void Heap::RunFinalization(JNIEnv* env) { 3015 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3016 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3017 CHECK(WellKnownClasses::java_lang_System != nullptr); 3018 WellKnownClasses::java_lang_System_runFinalization = 3019 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3020 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3021 } 3022 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3023 WellKnownClasses::java_lang_System_runFinalization); 3024} 3025 3026void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3027 Thread* self = ThreadForEnv(env); 3028 if (native_need_to_run_finalization_) { 3029 RunFinalization(env); 3030 UpdateMaxNativeFootprint(); 3031 native_need_to_run_finalization_ = false; 3032 } 3033 // Total number of native bytes allocated. 3034 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3035 new_native_bytes_allocated += bytes; 3036 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3037 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3038 collector::kGcTypeFull; 3039 3040 // The second watermark is higher than the gc watermark. If you hit this it means you are 3041 // allocating native objects faster than the GC can keep up with. 3042 if (new_native_bytes_allocated > native_footprint_limit_) { 3043 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3044 // Just finished a GC, attempt to run finalizers. 3045 RunFinalization(env); 3046 CHECK(!env->ExceptionCheck()); 3047 } 3048 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3049 if (new_native_bytes_allocated > native_footprint_limit_) { 3050 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3051 RunFinalization(env); 3052 native_need_to_run_finalization_ = false; 3053 CHECK(!env->ExceptionCheck()); 3054 } 3055 // We have just run finalizers, update the native watermark since it is very likely that 3056 // finalizers released native managed allocations. 3057 UpdateMaxNativeFootprint(); 3058 } else if (!IsGCRequestPending()) { 3059 if (IsGcConcurrent()) { 3060 RequestConcurrentGC(self); 3061 } else { 3062 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3063 } 3064 } 3065 } 3066} 3067 3068void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3069 int expected_size, new_size; 3070 do { 3071 expected_size = native_bytes_allocated_.LoadRelaxed(); 3072 new_size = expected_size - bytes; 3073 if (UNLIKELY(new_size < 0)) { 3074 ScopedObjectAccess soa(env); 3075 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3076 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3077 "registered as allocated", bytes, expected_size).c_str()); 3078 break; 3079 } 3080 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3081} 3082 3083size_t Heap::GetTotalMemory() const { 3084 size_t ret = 0; 3085 for (const auto& space : continuous_spaces_) { 3086 // Currently don't include the image space. 3087 if (!space->IsImageSpace()) { 3088 ret += space->Size(); 3089 } 3090 } 3091 for (const auto& space : discontinuous_spaces_) { 3092 if (space->IsLargeObjectSpace()) { 3093 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3094 } 3095 } 3096 return ret; 3097} 3098 3099void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3100 DCHECK(mod_union_table != nullptr); 3101 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3102} 3103 3104void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3105 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3106 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3107 c->GetDescriptor().empty()); 3108 CHECK_GE(byte_count, sizeof(mirror::Object)); 3109} 3110 3111void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3112 CHECK(remembered_set != nullptr); 3113 space::Space* space = remembered_set->GetSpace(); 3114 CHECK(space != nullptr); 3115 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3116 remembered_sets_.Put(space, remembered_set); 3117 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3118} 3119 3120void Heap::RemoveRememberedSet(space::Space* space) { 3121 CHECK(space != nullptr); 3122 auto it = remembered_sets_.find(space); 3123 CHECK(it != remembered_sets_.end()); 3124 remembered_sets_.erase(it); 3125 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3126} 3127 3128void Heap::ClearMarkedObjects() { 3129 // Clear all of the spaces' mark bitmaps. 3130 for (const auto& space : GetContinuousSpaces()) { 3131 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3132 if (space->GetLiveBitmap() != mark_bitmap) { 3133 mark_bitmap->Clear(); 3134 } 3135 } 3136 // Clear the marked objects in the discontinous space object sets. 3137 for (const auto& space : GetDiscontinuousSpaces()) { 3138 space->GetMarkBitmap()->Clear(); 3139 } 3140} 3141 3142} // namespace gc 3143} // namespace art 3144