heap.cc revision 1c46a24c1ddaac587b8baa38626cbc9e502872d1
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 CHECK(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 CHECK(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 // Unset the pointers just in case. 1603 if (dlmalloc_space_ == main_space_) { 1604 dlmalloc_space_ = nullptr; 1605 } else if (rosalloc_space_ == main_space_) { 1606 rosalloc_space_ = nullptr; 1607 } 1608 // Remove the main space so that we don't try to trim it, this doens't work for debug 1609 // builds since RosAlloc attempts to read the magic number from a protected page. 1610 RemoveSpace(main_space_); 1611 RemoveRememberedSet(main_space_); 1612 delete main_space_; // Delete the space since it has been removed. 1613 main_space_ = nullptr; 1614 RemoveRememberedSet(main_space_backup_.get()); 1615 main_space_backup_.reset(nullptr); // Deletes the space. 1616 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1617 mem_map.release()); 1618 AddSpace(temp_space_); 1619 } 1620 break; 1621 } 1622 case kCollectorTypeMS: 1623 // Fall through. 1624 case kCollectorTypeCMS: { 1625 if (IsMovingGc(collector_type_)) { 1626 CHECK(temp_space_ != nullptr); 1627 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1628 RemoveSpace(temp_space_); 1629 temp_space_ = nullptr; 1630 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1631 mem_map->Size()); 1632 mem_map.release(); 1633 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1634 AddSpace(main_space_); 1635 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1636 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1637 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1638 RemoveSpace(bump_pointer_space_); 1639 bump_pointer_space_ = nullptr; 1640 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1641 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1642 mem_map->Size(), mem_map->Size(), 1643 name, true)); 1644 mem_map.release(); 1645 } 1646 break; 1647 } 1648 default: { 1649 LOG(FATAL) << "Attempted to transition to invalid collector type " 1650 << static_cast<size_t>(collector_type); 1651 break; 1652 } 1653 } 1654 ChangeCollector(collector_type); 1655 tl->ResumeAll(); 1656 // Can't call into java code with all threads suspended. 1657 reference_processor_.EnqueueClearedReferences(self); 1658 uint64_t duration = NanoTime() - start_time; 1659 GrowForUtilization(semi_space_collector_); 1660 FinishGC(self, collector::kGcTypeFull); 1661 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1662 int32_t delta_allocated = before_allocated - after_allocated; 1663 std::string saved_str; 1664 if (delta_allocated >= 0) { 1665 saved_str = " saved at least " + PrettySize(delta_allocated); 1666 } else { 1667 saved_str = " expanded " + PrettySize(-delta_allocated); 1668 } 1669 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1670 << PrettyDuration(duration) << saved_str; 1671} 1672 1673void Heap::ChangeCollector(CollectorType collector_type) { 1674 // TODO: Only do this with all mutators suspended to avoid races. 1675 if (collector_type != collector_type_) { 1676 if (collector_type == kCollectorTypeMC) { 1677 // Don't allow mark compact unless support is compiled in. 1678 CHECK(kMarkCompactSupport); 1679 } 1680 collector_type_ = collector_type; 1681 gc_plan_.clear(); 1682 switch (collector_type_) { 1683 case kCollectorTypeCC: // Fall-through. 1684 case kCollectorTypeMC: // Fall-through. 1685 case kCollectorTypeSS: // Fall-through. 1686 case kCollectorTypeGSS: { 1687 gc_plan_.push_back(collector::kGcTypeFull); 1688 if (use_tlab_) { 1689 ChangeAllocator(kAllocatorTypeTLAB); 1690 } else { 1691 ChangeAllocator(kAllocatorTypeBumpPointer); 1692 } 1693 break; 1694 } 1695 case kCollectorTypeMS: { 1696 gc_plan_.push_back(collector::kGcTypeSticky); 1697 gc_plan_.push_back(collector::kGcTypePartial); 1698 gc_plan_.push_back(collector::kGcTypeFull); 1699 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1700 break; 1701 } 1702 case kCollectorTypeCMS: { 1703 gc_plan_.push_back(collector::kGcTypeSticky); 1704 gc_plan_.push_back(collector::kGcTypePartial); 1705 gc_plan_.push_back(collector::kGcTypeFull); 1706 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1707 break; 1708 } 1709 default: { 1710 LOG(FATAL) << "Unimplemented"; 1711 } 1712 } 1713 if (IsGcConcurrent()) { 1714 concurrent_start_bytes_ = 1715 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1716 } else { 1717 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1718 } 1719 } 1720} 1721 1722// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1723class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1724 public: 1725 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1726 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1727 } 1728 1729 void BuildBins(space::ContinuousSpace* space) { 1730 bin_live_bitmap_ = space->GetLiveBitmap(); 1731 bin_mark_bitmap_ = space->GetMarkBitmap(); 1732 BinContext context; 1733 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1734 context.collector_ = this; 1735 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1736 // Note: This requires traversing the space in increasing order of object addresses. 1737 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1738 // Add the last bin which spans after the last object to the end of the space. 1739 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1740 } 1741 1742 private: 1743 struct BinContext { 1744 uintptr_t prev_; // The end of the previous object. 1745 ZygoteCompactingCollector* collector_; 1746 }; 1747 // Maps from bin sizes to locations. 1748 std::multimap<size_t, uintptr_t> bins_; 1749 // Live bitmap of the space which contains the bins. 1750 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1751 // Mark bitmap of the space which contains the bins. 1752 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1753 1754 static void Callback(mirror::Object* obj, void* arg) 1755 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1756 DCHECK(arg != nullptr); 1757 BinContext* context = reinterpret_cast<BinContext*>(arg); 1758 ZygoteCompactingCollector* collector = context->collector_; 1759 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1760 size_t bin_size = object_addr - context->prev_; 1761 // Add the bin consisting of the end of the previous object to the start of the current object. 1762 collector->AddBin(bin_size, context->prev_); 1763 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1764 } 1765 1766 void AddBin(size_t size, uintptr_t position) { 1767 if (size != 0) { 1768 bins_.insert(std::make_pair(size, position)); 1769 } 1770 } 1771 1772 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1773 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1774 // allocator. 1775 return false; 1776 } 1777 1778 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1779 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1780 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1781 mirror::Object* forward_address; 1782 // Find the smallest bin which we can move obj in. 1783 auto it = bins_.lower_bound(object_size); 1784 if (it == bins_.end()) { 1785 // No available space in the bins, place it in the target space instead (grows the zygote 1786 // space). 1787 size_t bytes_allocated; 1788 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1789 if (to_space_live_bitmap_ != nullptr) { 1790 to_space_live_bitmap_->Set(forward_address); 1791 } else { 1792 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1793 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1794 } 1795 } else { 1796 size_t size = it->first; 1797 uintptr_t pos = it->second; 1798 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1799 forward_address = reinterpret_cast<mirror::Object*>(pos); 1800 // Set the live and mark bits so that sweeping system weaks works properly. 1801 bin_live_bitmap_->Set(forward_address); 1802 bin_mark_bitmap_->Set(forward_address); 1803 DCHECK_GE(size, object_size); 1804 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1805 } 1806 // Copy the object over to its new location. 1807 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1808 if (kUseBakerOrBrooksReadBarrier) { 1809 obj->AssertReadBarrierPointer(); 1810 if (kUseBrooksReadBarrier) { 1811 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1812 forward_address->SetReadBarrierPointer(forward_address); 1813 } 1814 forward_address->AssertReadBarrierPointer(); 1815 } 1816 return forward_address; 1817 } 1818}; 1819 1820void Heap::UnBindBitmaps() { 1821 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1822 for (const auto& space : GetContinuousSpaces()) { 1823 if (space->IsContinuousMemMapAllocSpace()) { 1824 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1825 if (alloc_space->HasBoundBitmaps()) { 1826 alloc_space->UnBindBitmaps(); 1827 } 1828 } 1829 } 1830} 1831 1832void Heap::PreZygoteFork() { 1833 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1834 Thread* self = Thread::Current(); 1835 MutexLock mu(self, zygote_creation_lock_); 1836 // Try to see if we have any Zygote spaces. 1837 if (have_zygote_space_) { 1838 return; 1839 } 1840 VLOG(heap) << "Starting PreZygoteFork"; 1841 // Trim the pages at the end of the non moving space. 1842 non_moving_space_->Trim(); 1843 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1844 // there. 1845 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1846 // Change the collector to the post zygote one. 1847 bool same_space = non_moving_space_ == main_space_; 1848 if (kCompactZygote) { 1849 DCHECK(semi_space_collector_ != nullptr); 1850 // Temporarily disable rosalloc verification because the zygote 1851 // compaction will mess up the rosalloc internal metadata. 1852 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1853 ZygoteCompactingCollector zygote_collector(this); 1854 zygote_collector.BuildBins(non_moving_space_); 1855 // Create a new bump pointer space which we will compact into. 1856 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1857 non_moving_space_->Limit()); 1858 // Compact the bump pointer space to a new zygote bump pointer space. 1859 bool reset_main_space = false; 1860 if (IsMovingGc(collector_type_)) { 1861 zygote_collector.SetFromSpace(bump_pointer_space_); 1862 } else { 1863 CHECK(main_space_ != nullptr); 1864 // Copy from the main space. 1865 zygote_collector.SetFromSpace(main_space_); 1866 reset_main_space = true; 1867 } 1868 zygote_collector.SetToSpace(&target_space); 1869 zygote_collector.SetSwapSemiSpaces(false); 1870 zygote_collector.Run(kGcCauseCollectorTransition, false); 1871 if (reset_main_space) { 1872 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1873 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1874 MemMap* mem_map = main_space_->ReleaseMemMap(); 1875 RemoveSpace(main_space_); 1876 space::Space* old_main_space = main_space_; 1877 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1878 delete old_main_space; 1879 AddSpace(main_space_); 1880 } else { 1881 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1882 } 1883 if (temp_space_ != nullptr) { 1884 CHECK(temp_space_->IsEmpty()); 1885 } 1886 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1887 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1888 // Update the end and write out image. 1889 non_moving_space_->SetEnd(target_space.End()); 1890 non_moving_space_->SetLimit(target_space.Limit()); 1891 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1892 } 1893 ChangeCollector(foreground_collector_type_); 1894 // Save the old space so that we can remove it after we complete creating the zygote space. 1895 space::MallocSpace* old_alloc_space = non_moving_space_; 1896 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1897 // the remaining available space. 1898 // Remove the old space before creating the zygote space since creating the zygote space sets 1899 // the old alloc space's bitmaps to nullptr. 1900 RemoveSpace(old_alloc_space); 1901 if (collector::SemiSpace::kUseRememberedSet) { 1902 // Sanity bound check. 1903 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1904 // Remove the remembered set for the now zygote space (the old 1905 // non-moving space). Note now that we have compacted objects into 1906 // the zygote space, the data in the remembered set is no longer 1907 // needed. The zygote space will instead have a mod-union table 1908 // from this point on. 1909 RemoveRememberedSet(old_alloc_space); 1910 } 1911 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1912 low_memory_mode_, 1913 &non_moving_space_); 1914 CHECK(!non_moving_space_->CanMoveObjects()); 1915 if (same_space) { 1916 main_space_ = non_moving_space_; 1917 SetSpaceAsDefault(main_space_); 1918 } 1919 delete old_alloc_space; 1920 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1921 AddSpace(zygote_space); 1922 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1923 AddSpace(non_moving_space_); 1924 have_zygote_space_ = true; 1925 // Enable large object space allocations. 1926 large_object_threshold_ = kDefaultLargeObjectThreshold; 1927 // Create the zygote space mod union table. 1928 accounting::ModUnionTable* mod_union_table = 1929 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1930 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1931 AddModUnionTable(mod_union_table); 1932 if (collector::SemiSpace::kUseRememberedSet) { 1933 // Add a new remembered set for the post-zygote non-moving space. 1934 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1935 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1936 non_moving_space_); 1937 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1938 << "Failed to create post-zygote non-moving space remembered set"; 1939 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1940 } 1941} 1942 1943void Heap::FlushAllocStack() { 1944 MarkAllocStackAsLive(allocation_stack_.get()); 1945 allocation_stack_->Reset(); 1946} 1947 1948void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1949 accounting::ContinuousSpaceBitmap* bitmap2, 1950 accounting::LargeObjectBitmap* large_objects, 1951 accounting::ObjectStack* stack) { 1952 DCHECK(bitmap1 != nullptr); 1953 DCHECK(bitmap2 != nullptr); 1954 mirror::Object** limit = stack->End(); 1955 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1956 const mirror::Object* obj = *it; 1957 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1958 if (bitmap1->HasAddress(obj)) { 1959 bitmap1->Set(obj); 1960 } else if (bitmap2->HasAddress(obj)) { 1961 bitmap2->Set(obj); 1962 } else { 1963 large_objects->Set(obj); 1964 } 1965 } 1966 } 1967} 1968 1969void Heap::SwapSemiSpaces() { 1970 CHECK(bump_pointer_space_ != nullptr); 1971 CHECK(temp_space_ != nullptr); 1972 std::swap(bump_pointer_space_, temp_space_); 1973} 1974 1975void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1976 space::ContinuousMemMapAllocSpace* source_space, 1977 GcCause gc_cause) { 1978 CHECK(kMovingCollector); 1979 if (target_space != source_space) { 1980 // Don't swap spaces since this isn't a typical semi space collection. 1981 semi_space_collector_->SetSwapSemiSpaces(false); 1982 semi_space_collector_->SetFromSpace(source_space); 1983 semi_space_collector_->SetToSpace(target_space); 1984 semi_space_collector_->Run(gc_cause, false); 1985 } else { 1986 CHECK(target_space->IsBumpPointerSpace()) 1987 << "In-place compaction is only supported for bump pointer spaces"; 1988 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1989 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1990 } 1991} 1992 1993collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1994 bool clear_soft_references) { 1995 Thread* self = Thread::Current(); 1996 Runtime* runtime = Runtime::Current(); 1997 // If the heap can't run the GC, silently fail and return that no GC was run. 1998 switch (gc_type) { 1999 case collector::kGcTypePartial: { 2000 if (!have_zygote_space_) { 2001 return collector::kGcTypeNone; 2002 } 2003 break; 2004 } 2005 default: { 2006 // Other GC types don't have any special cases which makes them not runnable. The main case 2007 // here is full GC. 2008 } 2009 } 2010 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2011 Locks::mutator_lock_->AssertNotHeld(self); 2012 if (self->IsHandlingStackOverflow()) { 2013 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2014 } 2015 bool compacting_gc; 2016 { 2017 gc_complete_lock_->AssertNotHeld(self); 2018 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2019 MutexLock mu(self, *gc_complete_lock_); 2020 // Ensure there is only one GC at a time. 2021 WaitForGcToCompleteLocked(gc_cause, self); 2022 compacting_gc = IsMovingGc(collector_type_); 2023 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2024 if (compacting_gc && disable_moving_gc_count_ != 0) { 2025 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2026 return collector::kGcTypeNone; 2027 } 2028 collector_type_running_ = collector_type_; 2029 } 2030 2031 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2032 ++runtime->GetStats()->gc_for_alloc_count; 2033 ++self->GetStats()->gc_for_alloc_count; 2034 } 2035 uint64_t gc_start_time_ns = NanoTime(); 2036 uint64_t gc_start_size = GetBytesAllocated(); 2037 // Approximate allocation rate in bytes / second. 2038 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2039 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2040 if (LIKELY(ms_delta != 0)) { 2041 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2042 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2043 } 2044 2045 DCHECK_LT(gc_type, collector::kGcTypeMax); 2046 DCHECK_NE(gc_type, collector::kGcTypeNone); 2047 2048 collector::GarbageCollector* collector = nullptr; 2049 // TODO: Clean this up. 2050 if (compacting_gc) { 2051 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2052 current_allocator_ == kAllocatorTypeTLAB); 2053 switch (collector_type_) { 2054 case kCollectorTypeSS: 2055 // Fall-through. 2056 case kCollectorTypeGSS: 2057 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2058 semi_space_collector_->SetToSpace(temp_space_); 2059 semi_space_collector_->SetSwapSemiSpaces(true); 2060 collector = semi_space_collector_; 2061 break; 2062 case kCollectorTypeCC: 2063 collector = concurrent_copying_collector_; 2064 break; 2065 case kCollectorTypeMC: 2066 mark_compact_collector_->SetSpace(bump_pointer_space_); 2067 collector = mark_compact_collector_; 2068 break; 2069 default: 2070 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2071 } 2072 if (collector != mark_compact_collector_) { 2073 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2074 CHECK(temp_space_->IsEmpty()); 2075 } 2076 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2077 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2078 current_allocator_ == kAllocatorTypeDlMalloc) { 2079 collector = FindCollectorByGcType(gc_type); 2080 } else { 2081 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2082 } 2083 CHECK(collector != nullptr) 2084 << "Could not find garbage collector with collector_type=" 2085 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2086 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2087 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2088 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2089 RequestHeapTrim(); 2090 // Enqueue cleared references. 2091 reference_processor_.EnqueueClearedReferences(self); 2092 // Grow the heap so that we know when to perform the next GC. 2093 GrowForUtilization(collector); 2094 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2095 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2096 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2097 // (mutator time blocked >= long_pause_log_threshold_). 2098 bool log_gc = gc_cause == kGcCauseExplicit; 2099 if (!log_gc && CareAboutPauseTimes()) { 2100 // GC for alloc pauses the allocating thread, so consider it as a pause. 2101 log_gc = duration > long_gc_log_threshold_ || 2102 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2103 for (uint64_t pause : pause_times) { 2104 log_gc = log_gc || pause >= long_pause_log_threshold_; 2105 } 2106 } 2107 if (log_gc) { 2108 const size_t percent_free = GetPercentFree(); 2109 const size_t current_heap_size = GetBytesAllocated(); 2110 const size_t total_memory = GetTotalMemory(); 2111 std::ostringstream pause_string; 2112 for (size_t i = 0; i < pause_times.size(); ++i) { 2113 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2114 << ((i != pause_times.size() - 1) ? "," : ""); 2115 } 2116 LOG(INFO) << gc_cause << " " << collector->GetName() 2117 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2118 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2119 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2120 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2121 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2122 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2123 << " total " << PrettyDuration((duration / 1000) * 1000); 2124 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2125 } 2126 FinishGC(self, gc_type); 2127 // Inform DDMS that a GC completed. 2128 Dbg::GcDidFinish(); 2129 return gc_type; 2130} 2131 2132void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2133 MutexLock mu(self, *gc_complete_lock_); 2134 collector_type_running_ = kCollectorTypeNone; 2135 if (gc_type != collector::kGcTypeNone) { 2136 last_gc_type_ = gc_type; 2137 } 2138 // Wake anyone who may have been waiting for the GC to complete. 2139 gc_complete_cond_->Broadcast(self); 2140} 2141 2142static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2143 RootType /*root_type*/) { 2144 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2145 if (*root == obj) { 2146 LOG(INFO) << "Object " << obj << " is a root"; 2147 } 2148} 2149 2150class ScanVisitor { 2151 public: 2152 void operator()(const mirror::Object* obj) const { 2153 LOG(ERROR) << "Would have rescanned object " << obj; 2154 } 2155}; 2156 2157// Verify a reference from an object. 2158class VerifyReferenceVisitor { 2159 public: 2160 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2161 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2162 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2163 2164 size_t GetFailureCount() const { 2165 return fail_count_->LoadSequentiallyConsistent(); 2166 } 2167 2168 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2169 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2170 if (verify_referent_) { 2171 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2172 } 2173 } 2174 2175 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2176 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2177 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2178 } 2179 2180 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2181 return heap_->IsLiveObjectLocked(obj, true, false, true); 2182 } 2183 2184 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2185 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2186 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2187 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2188 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2189 << " thread_id= " << thread_id << " root_type= " << root_type; 2190 } 2191 } 2192 2193 private: 2194 // TODO: Fix the no thread safety analysis. 2195 // Returns false on failure. 2196 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2197 NO_THREAD_SAFETY_ANALYSIS { 2198 if (ref == nullptr || IsLive(ref)) { 2199 // Verify that the reference is live. 2200 return true; 2201 } 2202 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2203 // Print message on only on first failure to prevent spam. 2204 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2205 } 2206 if (obj != nullptr) { 2207 // Only do this part for non roots. 2208 accounting::CardTable* card_table = heap_->GetCardTable(); 2209 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2210 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2211 byte* card_addr = card_table->CardFromAddr(obj); 2212 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2213 << offset << "\n card value = " << static_cast<int>(*card_addr); 2214 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2215 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2216 } else { 2217 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2218 } 2219 2220 // Attempt to find the class inside of the recently freed objects. 2221 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2222 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2223 space::MallocSpace* space = ref_space->AsMallocSpace(); 2224 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2225 if (ref_class != nullptr) { 2226 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2227 << PrettyClass(ref_class); 2228 } else { 2229 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2230 } 2231 } 2232 2233 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2234 ref->GetClass()->IsClass()) { 2235 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2236 } else { 2237 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2238 << ") is not a valid heap address"; 2239 } 2240 2241 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2242 void* cover_begin = card_table->AddrFromCard(card_addr); 2243 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2244 accounting::CardTable::kCardSize); 2245 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2246 << "-" << cover_end; 2247 accounting::ContinuousSpaceBitmap* bitmap = 2248 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2249 2250 if (bitmap == nullptr) { 2251 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2252 if (!VerifyClassClass(obj->GetClass())) { 2253 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2254 } 2255 } else { 2256 // Print out how the object is live. 2257 if (bitmap->Test(obj)) { 2258 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2259 } 2260 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2261 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2262 } 2263 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2264 LOG(ERROR) << "Object " << obj << " found in live stack"; 2265 } 2266 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2267 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2268 } 2269 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2270 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2271 } 2272 // Attempt to see if the card table missed the reference. 2273 ScanVisitor scan_visitor; 2274 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2275 card_table->Scan(bitmap, byte_cover_begin, 2276 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2277 } 2278 2279 // Search to see if any of the roots reference our object. 2280 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2281 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2282 2283 // Search to see if any of the roots reference our reference. 2284 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2285 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2286 } 2287 return false; 2288 } 2289 2290 Heap* const heap_; 2291 Atomic<size_t>* const fail_count_; 2292 const bool verify_referent_; 2293}; 2294 2295// Verify all references within an object, for use with HeapBitmap::Visit. 2296class VerifyObjectVisitor { 2297 public: 2298 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2299 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2300 } 2301 2302 void operator()(mirror::Object* obj) const 2303 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2304 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2305 // be live or else how did we find it in the live bitmap? 2306 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2307 // The class doesn't count as a reference but we should verify it anyways. 2308 obj->VisitReferences<true>(visitor, visitor); 2309 } 2310 2311 static void VisitCallback(mirror::Object* obj, void* arg) 2312 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2313 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2314 visitor->operator()(obj); 2315 } 2316 2317 size_t GetFailureCount() const { 2318 return fail_count_->LoadSequentiallyConsistent(); 2319 } 2320 2321 private: 2322 Heap* const heap_; 2323 Atomic<size_t>* const fail_count_; 2324 const bool verify_referent_; 2325}; 2326 2327void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2328 // Slow path, the allocation stack push back must have already failed. 2329 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2330 do { 2331 // TODO: Add handle VerifyObject. 2332 StackHandleScope<1> hs(self); 2333 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2334 // Push our object into the reserve region of the allocaiton stack. This is only required due 2335 // to heap verification requiring that roots are live (either in the live bitmap or in the 2336 // allocation stack). 2337 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2338 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2339 } while (!allocation_stack_->AtomicPushBack(*obj)); 2340} 2341 2342void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2343 // Slow path, the allocation stack push back must have already failed. 2344 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2345 mirror::Object** start_address; 2346 mirror::Object** end_address; 2347 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2348 &end_address)) { 2349 // TODO: Add handle VerifyObject. 2350 StackHandleScope<1> hs(self); 2351 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2352 // Push our object into the reserve region of the allocaiton stack. This is only required due 2353 // to heap verification requiring that roots are live (either in the live bitmap or in the 2354 // allocation stack). 2355 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2356 // Push into the reserve allocation stack. 2357 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2358 } 2359 self->SetThreadLocalAllocationStack(start_address, end_address); 2360 // Retry on the new thread-local allocation stack. 2361 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2362} 2363 2364// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2365size_t Heap::VerifyHeapReferences(bool verify_referents) { 2366 Thread* self = Thread::Current(); 2367 Locks::mutator_lock_->AssertExclusiveHeld(self); 2368 // Lets sort our allocation stacks so that we can efficiently binary search them. 2369 allocation_stack_->Sort(); 2370 live_stack_->Sort(); 2371 // Since we sorted the allocation stack content, need to revoke all 2372 // thread-local allocation stacks. 2373 RevokeAllThreadLocalAllocationStacks(self); 2374 Atomic<size_t> fail_count_(0); 2375 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2376 // Verify objects in the allocation stack since these will be objects which were: 2377 // 1. Allocated prior to the GC (pre GC verification). 2378 // 2. Allocated during the GC (pre sweep GC verification). 2379 // We don't want to verify the objects in the live stack since they themselves may be 2380 // pointing to dead objects if they are not reachable. 2381 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2382 // Verify the roots: 2383 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2384 if (visitor.GetFailureCount() > 0) { 2385 // Dump mod-union tables. 2386 for (const auto& table_pair : mod_union_tables_) { 2387 accounting::ModUnionTable* mod_union_table = table_pair.second; 2388 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2389 } 2390 // Dump remembered sets. 2391 for (const auto& table_pair : remembered_sets_) { 2392 accounting::RememberedSet* remembered_set = table_pair.second; 2393 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2394 } 2395 DumpSpaces(LOG(ERROR)); 2396 } 2397 return visitor.GetFailureCount(); 2398} 2399 2400class VerifyReferenceCardVisitor { 2401 public: 2402 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2403 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2404 Locks::heap_bitmap_lock_) 2405 : heap_(heap), failed_(failed) { 2406 } 2407 2408 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2409 // annotalysis on visitors. 2410 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2411 NO_THREAD_SAFETY_ANALYSIS { 2412 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2413 // Filter out class references since changing an object's class does not mark the card as dirty. 2414 // Also handles large objects, since the only reference they hold is a class reference. 2415 if (ref != nullptr && !ref->IsClass()) { 2416 accounting::CardTable* card_table = heap_->GetCardTable(); 2417 // If the object is not dirty and it is referencing something in the live stack other than 2418 // class, then it must be on a dirty card. 2419 if (!card_table->AddrIsInCardTable(obj)) { 2420 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2421 *failed_ = true; 2422 } else if (!card_table->IsDirty(obj)) { 2423 // TODO: Check mod-union tables. 2424 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2425 // kCardDirty - 1 if it didnt get touched since we aged it. 2426 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2427 if (live_stack->ContainsSorted(ref)) { 2428 if (live_stack->ContainsSorted(obj)) { 2429 LOG(ERROR) << "Object " << obj << " found in live stack"; 2430 } 2431 if (heap_->GetLiveBitmap()->Test(obj)) { 2432 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2433 } 2434 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2435 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2436 2437 // Print which field of the object is dead. 2438 if (!obj->IsObjectArray()) { 2439 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2440 CHECK(klass != NULL); 2441 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2442 : klass->GetIFields(); 2443 CHECK(fields != NULL); 2444 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2445 mirror::ArtField* cur = fields->Get(i); 2446 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2447 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2448 << PrettyField(cur); 2449 break; 2450 } 2451 } 2452 } else { 2453 mirror::ObjectArray<mirror::Object>* object_array = 2454 obj->AsObjectArray<mirror::Object>(); 2455 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2456 if (object_array->Get(i) == ref) { 2457 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2458 } 2459 } 2460 } 2461 2462 *failed_ = true; 2463 } 2464 } 2465 } 2466 } 2467 2468 private: 2469 Heap* const heap_; 2470 bool* const failed_; 2471}; 2472 2473class VerifyLiveStackReferences { 2474 public: 2475 explicit VerifyLiveStackReferences(Heap* heap) 2476 : heap_(heap), 2477 failed_(false) {} 2478 2479 void operator()(mirror::Object* obj) const 2480 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2481 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2482 obj->VisitReferences<true>(visitor, VoidFunctor()); 2483 } 2484 2485 bool Failed() const { 2486 return failed_; 2487 } 2488 2489 private: 2490 Heap* const heap_; 2491 bool failed_; 2492}; 2493 2494bool Heap::VerifyMissingCardMarks() { 2495 Thread* self = Thread::Current(); 2496 Locks::mutator_lock_->AssertExclusiveHeld(self); 2497 2498 // We need to sort the live stack since we binary search it. 2499 live_stack_->Sort(); 2500 // Since we sorted the allocation stack content, need to revoke all 2501 // thread-local allocation stacks. 2502 RevokeAllThreadLocalAllocationStacks(self); 2503 VerifyLiveStackReferences visitor(this); 2504 GetLiveBitmap()->Visit(visitor); 2505 2506 // We can verify objects in the live stack since none of these should reference dead objects. 2507 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2508 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2509 visitor(*it); 2510 } 2511 } 2512 return !visitor.Failed(); 2513} 2514 2515void Heap::SwapStacks(Thread* self) { 2516 if (kUseThreadLocalAllocationStack) { 2517 live_stack_->AssertAllZero(); 2518 } 2519 allocation_stack_.swap(live_stack_); 2520} 2521 2522void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2523 // This must be called only during the pause. 2524 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2525 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2526 MutexLock mu2(self, *Locks::thread_list_lock_); 2527 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2528 for (Thread* t : thread_list) { 2529 t->RevokeThreadLocalAllocationStack(); 2530 } 2531} 2532 2533void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2534 if (kIsDebugBuild) { 2535 if (bump_pointer_space_ != nullptr) { 2536 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2537 } 2538 } 2539} 2540 2541accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2542 auto it = mod_union_tables_.find(space); 2543 if (it == mod_union_tables_.end()) { 2544 return nullptr; 2545 } 2546 return it->second; 2547} 2548 2549accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2550 auto it = remembered_sets_.find(space); 2551 if (it == remembered_sets_.end()) { 2552 return nullptr; 2553 } 2554 return it->second; 2555} 2556 2557void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2558 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2559 // Clear cards and keep track of cards cleared in the mod-union table. 2560 for (const auto& space : continuous_spaces_) { 2561 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2562 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2563 if (table != nullptr) { 2564 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2565 "ImageModUnionClearCards"; 2566 TimingLogger::ScopedTiming t(name, timings); 2567 table->ClearCards(); 2568 } else if (use_rem_sets && rem_set != nullptr) { 2569 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2570 << static_cast<int>(collector_type_); 2571 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2572 rem_set->ClearCards(); 2573 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2574 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2575 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2576 // were dirty before the GC started. 2577 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2578 // -> clean(cleaning thread). 2579 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2580 // roots and then we scan / update mod union tables after. We will always scan either card. 2581 // If we end up with the non aged card, we scan it it in the pause. 2582 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2583 VoidFunctor()); 2584 } 2585 } 2586} 2587 2588static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2589} 2590 2591void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2592 Thread* const self = Thread::Current(); 2593 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2594 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2595 if (verify_pre_gc_heap_) { 2596 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2597 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2598 size_t failures = VerifyHeapReferences(); 2599 if (failures > 0) { 2600 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2601 << " failures"; 2602 } 2603 } 2604 // Check that all objects which reference things in the live stack are on dirty cards. 2605 if (verify_missing_card_marks_) { 2606 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2607 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2608 SwapStacks(self); 2609 // Sort the live stack so that we can quickly binary search it later. 2610 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2611 << " missing card mark verification failed\n" << DumpSpaces(); 2612 SwapStacks(self); 2613 } 2614 if (verify_mod_union_table_) { 2615 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2616 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2617 for (const auto& table_pair : mod_union_tables_) { 2618 accounting::ModUnionTable* mod_union_table = table_pair.second; 2619 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2620 mod_union_table->Verify(); 2621 } 2622 } 2623} 2624 2625void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2626 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2627 collector::GarbageCollector::ScopedPause pause(gc); 2628 PreGcVerificationPaused(gc); 2629 } 2630} 2631 2632void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2633 // TODO: Add a new runtime option for this? 2634 if (verify_pre_gc_rosalloc_) { 2635 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2636 } 2637} 2638 2639void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2640 Thread* const self = Thread::Current(); 2641 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2642 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2643 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2644 // reachable objects. 2645 if (verify_pre_sweeping_heap_) { 2646 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2647 CHECK_NE(self->GetState(), kRunnable); 2648 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2649 // Swapping bound bitmaps does nothing. 2650 gc->SwapBitmaps(); 2651 // Pass in false since concurrent reference processing can mean that the reference referents 2652 // may point to dead objects at the point which PreSweepingGcVerification is called. 2653 size_t failures = VerifyHeapReferences(false); 2654 if (failures > 0) { 2655 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2656 << " failures"; 2657 } 2658 gc->SwapBitmaps(); 2659 } 2660 if (verify_pre_sweeping_rosalloc_) { 2661 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2662 } 2663} 2664 2665void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2666 // Only pause if we have to do some verification. 2667 Thread* const self = Thread::Current(); 2668 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2669 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2670 if (verify_system_weaks_) { 2671 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2672 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2673 mark_sweep->VerifySystemWeaks(); 2674 } 2675 if (verify_post_gc_rosalloc_) { 2676 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2677 } 2678 if (verify_post_gc_heap_) { 2679 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2680 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2681 size_t failures = VerifyHeapReferences(); 2682 if (failures > 0) { 2683 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2684 << " failures"; 2685 } 2686 } 2687} 2688 2689void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2690 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2691 collector::GarbageCollector::ScopedPause pause(gc); 2692 PreGcVerificationPaused(gc); 2693 } 2694} 2695 2696void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2697 TimingLogger::ScopedTiming t(name, timings); 2698 for (const auto& space : continuous_spaces_) { 2699 if (space->IsRosAllocSpace()) { 2700 VLOG(heap) << name << " : " << space->GetName(); 2701 space->AsRosAllocSpace()->Verify(); 2702 } 2703 } 2704} 2705 2706collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2707 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2708 MutexLock mu(self, *gc_complete_lock_); 2709 return WaitForGcToCompleteLocked(cause, self); 2710} 2711 2712collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2713 collector::GcType last_gc_type = collector::kGcTypeNone; 2714 uint64_t wait_start = NanoTime(); 2715 while (collector_type_running_ != kCollectorTypeNone) { 2716 ATRACE_BEGIN("GC: Wait For Completion"); 2717 // We must wait, change thread state then sleep on gc_complete_cond_; 2718 gc_complete_cond_->Wait(self); 2719 last_gc_type = last_gc_type_; 2720 ATRACE_END(); 2721 } 2722 uint64_t wait_time = NanoTime() - wait_start; 2723 total_wait_time_ += wait_time; 2724 if (wait_time > long_pause_log_threshold_) { 2725 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2726 << " for cause " << cause; 2727 } 2728 return last_gc_type; 2729} 2730 2731void Heap::DumpForSigQuit(std::ostream& os) { 2732 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2733 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2734 DumpGcPerformanceInfo(os); 2735} 2736 2737size_t Heap::GetPercentFree() { 2738 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2739} 2740 2741void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2742 if (max_allowed_footprint > GetMaxMemory()) { 2743 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2744 << PrettySize(GetMaxMemory()); 2745 max_allowed_footprint = GetMaxMemory(); 2746 } 2747 max_allowed_footprint_ = max_allowed_footprint; 2748} 2749 2750bool Heap::IsMovableObject(const mirror::Object* obj) const { 2751 if (kMovingCollector) { 2752 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2753 if (space != nullptr) { 2754 // TODO: Check large object? 2755 return space->CanMoveObjects(); 2756 } 2757 } 2758 return false; 2759} 2760 2761void Heap::UpdateMaxNativeFootprint() { 2762 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2763 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2764 size_t target_size = native_size / GetTargetHeapUtilization(); 2765 if (target_size > native_size + max_free_) { 2766 target_size = native_size + max_free_; 2767 } else if (target_size < native_size + min_free_) { 2768 target_size = native_size + min_free_; 2769 } 2770 native_footprint_gc_watermark_ = target_size; 2771 native_footprint_limit_ = 2 * target_size - native_size; 2772} 2773 2774collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2775 for (const auto& collector : garbage_collectors_) { 2776 if (collector->GetCollectorType() == collector_type_ && 2777 collector->GetGcType() == gc_type) { 2778 return collector; 2779 } 2780 } 2781 return nullptr; 2782} 2783 2784double Heap::HeapGrowthMultiplier() const { 2785 // If we don't care about pause times we are background, so return 1.0. 2786 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2787 return 1.0; 2788 } 2789 return foreground_heap_growth_multiplier_; 2790} 2791 2792void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2793 // We know what our utilization is at this moment. 2794 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2795 const uint64_t bytes_allocated = GetBytesAllocated(); 2796 last_gc_size_ = bytes_allocated; 2797 last_gc_time_ns_ = NanoTime(); 2798 uint64_t target_size; 2799 collector::GcType gc_type = collector_ran->GetGcType(); 2800 if (gc_type != collector::kGcTypeSticky) { 2801 // Grow the heap for non sticky GC. 2802 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2803 // foreground. 2804 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2805 CHECK_GE(delta, 0); 2806 target_size = bytes_allocated + delta * multiplier; 2807 target_size = std::min(target_size, 2808 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2809 target_size = std::max(target_size, 2810 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2811 native_need_to_run_finalization_ = true; 2812 next_gc_type_ = collector::kGcTypeSticky; 2813 } else { 2814 collector::GcType non_sticky_gc_type = 2815 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2816 // Find what the next non sticky collector will be. 2817 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2818 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2819 // do another sticky collection next. 2820 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2821 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2822 // if the sticky GC throughput always remained >= the full/partial throughput. 2823 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2824 non_sticky_collector->GetEstimatedMeanThroughput() && 2825 non_sticky_collector->NumberOfIterations() > 0 && 2826 bytes_allocated <= max_allowed_footprint_) { 2827 next_gc_type_ = collector::kGcTypeSticky; 2828 } else { 2829 next_gc_type_ = non_sticky_gc_type; 2830 } 2831 // If we have freed enough memory, shrink the heap back down. 2832 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2833 target_size = bytes_allocated + max_free_; 2834 } else { 2835 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2836 } 2837 } 2838 if (!ignore_max_footprint_) { 2839 SetIdealFootprint(target_size); 2840 if (IsGcConcurrent()) { 2841 // Calculate when to perform the next ConcurrentGC. 2842 // Calculate the estimated GC duration. 2843 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2844 // Estimate how many remaining bytes we will have when we need to start the next GC. 2845 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2846 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2847 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2848 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2849 // A never going to happen situation that from the estimated allocation rate we will exceed 2850 // the applications entire footprint with the given estimated allocation rate. Schedule 2851 // another GC nearly straight away. 2852 remaining_bytes = kMinConcurrentRemainingBytes; 2853 } 2854 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2855 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2856 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2857 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2858 // right away. 2859 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2860 static_cast<size_t>(bytes_allocated)); 2861 } 2862 } 2863} 2864 2865void Heap::ClearGrowthLimit() { 2866 growth_limit_ = capacity_; 2867 non_moving_space_->ClearGrowthLimit(); 2868} 2869 2870void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2871 ScopedObjectAccess soa(self); 2872 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2873 jvalue args[1]; 2874 args[0].l = arg.get(); 2875 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2876 // Restore object in case it gets moved. 2877 *object = soa.Decode<mirror::Object*>(arg.get()); 2878} 2879 2880void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2881 StackHandleScope<1> hs(self); 2882 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2883 RequestConcurrentGC(self); 2884} 2885 2886void Heap::RequestConcurrentGC(Thread* self) { 2887 // Make sure that we can do a concurrent GC. 2888 Runtime* runtime = Runtime::Current(); 2889 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2890 self->IsHandlingStackOverflow()) { 2891 return; 2892 } 2893 // We already have a request pending, no reason to start more until we update 2894 // concurrent_start_bytes_. 2895 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2896 JNIEnv* env = self->GetJniEnv(); 2897 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2898 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2899 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2900 WellKnownClasses::java_lang_Daemons_requestGC); 2901 CHECK(!env->ExceptionCheck()); 2902} 2903 2904void Heap::ConcurrentGC(Thread* self) { 2905 if (Runtime::Current()->IsShuttingDown(self)) { 2906 return; 2907 } 2908 // Wait for any GCs currently running to finish. 2909 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2910 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2911 // instead. E.g. can't do partial, so do full instead. 2912 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2913 collector::kGcTypeNone) { 2914 for (collector::GcType gc_type : gc_plan_) { 2915 // Attempt to run the collector, if we succeed, we are done. 2916 if (gc_type > next_gc_type_ && 2917 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2918 break; 2919 } 2920 } 2921 } 2922 } 2923} 2924 2925void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2926 Thread* self = Thread::Current(); 2927 { 2928 MutexLock mu(self, *heap_trim_request_lock_); 2929 if (desired_collector_type_ == desired_collector_type) { 2930 return; 2931 } 2932 heap_transition_or_trim_target_time_ = 2933 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2934 desired_collector_type_ = desired_collector_type; 2935 } 2936 SignalHeapTrimDaemon(self); 2937} 2938 2939void Heap::RequestHeapTrim() { 2940 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2941 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2942 // a space it will hold its lock and can become a cause of jank. 2943 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2944 // forking. 2945 2946 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2947 // because that only marks object heads, so a large array looks like lots of empty space. We 2948 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2949 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2950 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2951 // not how much use we're making of those pages. 2952 2953 Thread* self = Thread::Current(); 2954 Runtime* runtime = Runtime::Current(); 2955 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2956 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2957 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2958 // as we don't hold the lock while requesting the trim). 2959 return; 2960 } 2961 { 2962 MutexLock mu(self, *heap_trim_request_lock_); 2963 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2964 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2965 // just yet. 2966 return; 2967 } 2968 heap_trim_request_pending_ = true; 2969 uint64_t current_time = NanoTime(); 2970 if (heap_transition_or_trim_target_time_ < current_time) { 2971 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2972 } 2973 } 2974 // Notify the daemon thread which will actually do the heap trim. 2975 SignalHeapTrimDaemon(self); 2976} 2977 2978void Heap::SignalHeapTrimDaemon(Thread* self) { 2979 JNIEnv* env = self->GetJniEnv(); 2980 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2981 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2982 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2983 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2984 CHECK(!env->ExceptionCheck()); 2985} 2986 2987void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2988 if (rosalloc_space_ != nullptr) { 2989 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2990 } 2991 if (bump_pointer_space_ != nullptr) { 2992 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2993 } 2994} 2995 2996void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2997 if (rosalloc_space_ != nullptr) { 2998 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2999 } 3000} 3001 3002void Heap::RevokeAllThreadLocalBuffers() { 3003 if (rosalloc_space_ != nullptr) { 3004 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3005 } 3006 if (bump_pointer_space_ != nullptr) { 3007 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3008 } 3009} 3010 3011bool Heap::IsGCRequestPending() const { 3012 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3013} 3014 3015void Heap::RunFinalization(JNIEnv* env) { 3016 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3017 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3018 CHECK(WellKnownClasses::java_lang_System != nullptr); 3019 WellKnownClasses::java_lang_System_runFinalization = 3020 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3021 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3022 } 3023 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3024 WellKnownClasses::java_lang_System_runFinalization); 3025} 3026 3027void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3028 Thread* self = ThreadForEnv(env); 3029 if (native_need_to_run_finalization_) { 3030 RunFinalization(env); 3031 UpdateMaxNativeFootprint(); 3032 native_need_to_run_finalization_ = false; 3033 } 3034 // Total number of native bytes allocated. 3035 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3036 new_native_bytes_allocated += bytes; 3037 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3038 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3039 collector::kGcTypeFull; 3040 3041 // The second watermark is higher than the gc watermark. If you hit this it means you are 3042 // allocating native objects faster than the GC can keep up with. 3043 if (new_native_bytes_allocated > native_footprint_limit_) { 3044 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3045 // Just finished a GC, attempt to run finalizers. 3046 RunFinalization(env); 3047 CHECK(!env->ExceptionCheck()); 3048 } 3049 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3050 if (new_native_bytes_allocated > native_footprint_limit_) { 3051 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3052 RunFinalization(env); 3053 native_need_to_run_finalization_ = false; 3054 CHECK(!env->ExceptionCheck()); 3055 } 3056 // We have just run finalizers, update the native watermark since it is very likely that 3057 // finalizers released native managed allocations. 3058 UpdateMaxNativeFootprint(); 3059 } else if (!IsGCRequestPending()) { 3060 if (IsGcConcurrent()) { 3061 RequestConcurrentGC(self); 3062 } else { 3063 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3064 } 3065 } 3066 } 3067} 3068 3069void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3070 int expected_size, new_size; 3071 do { 3072 expected_size = native_bytes_allocated_.LoadRelaxed(); 3073 new_size = expected_size - bytes; 3074 if (UNLIKELY(new_size < 0)) { 3075 ScopedObjectAccess soa(env); 3076 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3077 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3078 "registered as allocated", bytes, expected_size).c_str()); 3079 break; 3080 } 3081 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3082} 3083 3084size_t Heap::GetTotalMemory() const { 3085 size_t ret = 0; 3086 for (const auto& space : continuous_spaces_) { 3087 // Currently don't include the image space. 3088 if (!space->IsImageSpace()) { 3089 ret += space->Size(); 3090 } 3091 } 3092 for (const auto& space : discontinuous_spaces_) { 3093 if (space->IsLargeObjectSpace()) { 3094 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3095 } 3096 } 3097 return ret; 3098} 3099 3100void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3101 DCHECK(mod_union_table != nullptr); 3102 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3103} 3104 3105void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3106 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3107 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3108 c->GetDescriptor().empty()); 3109 CHECK_GE(byte_count, sizeof(mirror::Object)); 3110} 3111 3112void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3113 CHECK(remembered_set != nullptr); 3114 space::Space* space = remembered_set->GetSpace(); 3115 CHECK(space != nullptr); 3116 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3117 remembered_sets_.Put(space, remembered_set); 3118 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3119} 3120 3121void Heap::RemoveRememberedSet(space::Space* space) { 3122 CHECK(space != nullptr); 3123 auto it = remembered_sets_.find(space); 3124 CHECK(it != remembered_sets_.end()); 3125 remembered_sets_.erase(it); 3126 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3127} 3128 3129void Heap::ClearMarkedObjects() { 3130 // Clear all of the spaces' mark bitmaps. 3131 for (const auto& space : GetContinuousSpaces()) { 3132 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3133 if (space->GetLiveBitmap() != mark_bitmap) { 3134 mark_bitmap->Clear(); 3135 } 3136 } 3137 // Clear the marked objects in the discontinous space object sets. 3138 for (const auto& space : GetDiscontinuousSpaces()) { 3139 space->GetMarkBitmap()->Clear(); 3140 } 3141} 3142 3143} // namespace gc 3144} // namespace art 3145