heap.cc revision bad0267eaab9d6a522d05469ff90501deefdb88b
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/allocator.h" 27#include "base/histogram-inl.h" 28#include "base/stl_util.h" 29#include "common_throws.h" 30#include "cutils/sched_policy.h" 31#include "debugger.h" 32#include "gc/accounting/atomic_stack.h" 33#include "gc/accounting/card_table-inl.h" 34#include "gc/accounting/heap_bitmap-inl.h" 35#include "gc/accounting/mod_union_table.h" 36#include "gc/accounting/mod_union_table-inl.h" 37#include "gc/accounting/remembered_set.h" 38#include "gc/accounting/space_bitmap-inl.h" 39#include "gc/collector/concurrent_copying.h" 40#include "gc/collector/mark_compact.h" 41#include "gc/collector/mark_sweep-inl.h" 42#include "gc/collector/partial_mark_sweep.h" 43#include "gc/collector/semi_space.h" 44#include "gc/collector/sticky_mark_sweep.h" 45#include "gc/reference_processor.h" 46#include "gc/space/bump_pointer_space.h" 47#include "gc/space/dlmalloc_space-inl.h" 48#include "gc/space/image_space.h" 49#include "gc/space/large_object_space.h" 50#include "gc/space/rosalloc_space-inl.h" 51#include "gc/space/space-inl.h" 52#include "gc/space/zygote_space.h" 53#include "entrypoints/quick/quick_alloc_entrypoints.h" 54#include "heap-inl.h" 55#include "image.h" 56#include "mirror/art_field-inl.h" 57#include "mirror/class-inl.h" 58#include "mirror/object.h" 59#include "mirror/object-inl.h" 60#include "mirror/object_array-inl.h" 61#include "mirror/reference-inl.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; 90// How many reserve entries are at the end of the allocation stack, these are only needed if the 91// allocation stack overflows. 92static constexpr size_t kAllocationStackReserveSize = 1024; 93// Default mark stack size in bytes. 94static const size_t kDefaultMarkStackSize = 64 * KB; 95// Define space name. 96static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 97static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 98static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 99static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 100 101Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 102 double target_utilization, double foreground_heap_growth_multiplier, 103 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 104 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 105 CollectorType background_collector_type, size_t parallel_gc_threads, 106 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 zygote_space_(nullptr), 133 large_object_threshold_(kDefaultLargeObjectThreshold), // 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 verify_missing_card_marks_(false), 151 verify_system_weaks_(false), 152 verify_pre_gc_heap_(verify_pre_gc_heap), 153 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 154 verify_post_gc_heap_(verify_post_gc_heap), 155 verify_mod_union_table_(false), 156 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 157 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 158 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 159 last_gc_time_ns_(NanoTime()), 160 allocation_rate_(0), 161 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 162 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 163 * verification is enabled, we limit the size of allocation stacks to speed up their 164 * searching. 165 */ 166 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 167 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 168 current_allocator_(kAllocatorTypeDlMalloc), 169 current_non_moving_allocator_(kAllocatorTypeNonMoving), 170 bump_pointer_space_(nullptr), 171 temp_space_(nullptr), 172 min_free_(min_free), 173 max_free_(max_free), 174 target_utilization_(target_utilization), 175 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 176 total_wait_time_(0), 177 total_allocation_time_(0), 178 verify_object_mode_(kVerifyObjectModeDisabled), 179 disable_moving_gc_count_(0), 180 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 181 use_tlab_(use_tlab), 182 main_space_backup_(nullptr), 183 min_interval_homogeneous_space_compaction_by_oom_( 184 min_interval_homogeneous_space_compaction_by_oom), 185 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 186 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 187 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 188 LOG(INFO) << "Heap() entering"; 189 } 190 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 191 // entrypoints. 192 const bool is_zygote = Runtime::Current()->IsZygote(); 193 if (!is_zygote) { 194 // Background compaction is currently not supported for command line runs. 195 if (background_collector_type_ != foreground_collector_type_) { 196 VLOG(heap) << "Disabling background compaction for non zygote"; 197 background_collector_type_ = foreground_collector_type_; 198 } 199 } 200 ChangeCollector(desired_collector_type_); 201 live_bitmap_.reset(new accounting::HeapBitmap(this)); 202 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 203 // Requested begin for the alloc space, to follow the mapped image and oat files 204 byte* requested_alloc_space_begin = nullptr; 205 if (!image_file_name.empty()) { 206 std::string error_msg; 207 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 208 image_instruction_set, 209 &error_msg); 210 if (image_space != nullptr) { 211 AddSpace(image_space); 212 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 213 // isn't going to get in the middle 214 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 215 CHECK_GT(oat_file_end_addr, image_space->End()); 216 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 217 } else { 218 LOG(WARNING) << "Could not create image space with image file '" << image_file_name << "'. " 219 << "Attempting to fall back to imageless running. Error was: " << error_msg; 220 } 221 } 222 /* 223 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 224 +- nonmoving space (non_moving_space_capacity)+- 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 226 +-????????????????????????????????????????????+- 227 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 228 +-main alloc space / bump space 1 (capacity_) +- 229 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 230 +-????????????????????????????????????????????+- 231 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 232 +-main alloc space2 / bump space 2 (capacity_)+- 233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 234 */ 235 bool support_homogeneous_space_compaction = 236 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 237 use_homogeneous_space_compaction_for_oom; 238 // We may use the same space the main space for the non moving space if we don't need to compact 239 // from the main space. 240 // This is not the case if we support homogeneous compaction or have a moving background 241 // collector type. 242 bool separate_non_moving_space = is_zygote || 243 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 244 IsMovingGc(background_collector_type_); 245 if (foreground_collector_type == kCollectorTypeGSS) { 246 separate_non_moving_space = false; 247 } 248 std::unique_ptr<MemMap> main_mem_map_1; 249 std::unique_ptr<MemMap> main_mem_map_2; 250 byte* request_begin = requested_alloc_space_begin; 251 if (request_begin != nullptr && separate_non_moving_space) { 252 request_begin += non_moving_space_capacity; 253 } 254 std::string error_str; 255 std::unique_ptr<MemMap> non_moving_space_mem_map; 256 if (separate_non_moving_space) { 257 // Reserve the non moving mem map before the other two since it needs to be at a specific 258 // address. 259 non_moving_space_mem_map.reset( 260 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 261 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str)); 262 CHECK(non_moving_space_mem_map != nullptr) << error_str; 263 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 264 request_begin = reinterpret_cast<byte*>(0x1000000); 265 } 266 // Attempt to create 2 mem maps at or after the requested begin. 267 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 268 PROT_READ | PROT_WRITE, &error_str)); 269 CHECK(main_mem_map_1.get() != nullptr) << error_str; 270 if (support_homogeneous_space_compaction || 271 background_collector_type_ == kCollectorTypeSS || 272 foreground_collector_type_ == kCollectorTypeSS) { 273 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 274 capacity_, PROT_READ | PROT_WRITE, 275 &error_str)); 276 CHECK(main_mem_map_2.get() != nullptr) << error_str; 277 } 278 // Create the non moving space first so that bitmaps don't take up the address range. 279 if (separate_non_moving_space) { 280 // Non moving space is always dlmalloc since we currently don't have support for multiple 281 // active rosalloc spaces. 282 const size_t size = non_moving_space_mem_map->Size(); 283 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 284 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 285 initial_size, size, size, false); 286 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 287 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 288 << requested_alloc_space_begin; 289 AddSpace(non_moving_space_); 290 } 291 // Create other spaces based on whether or not we have a moving GC. 292 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 293 // Create bump pointer spaces. 294 // We only to create the bump pointer if the foreground collector is a compacting GC. 295 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 296 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 297 main_mem_map_1.release()); 298 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 299 AddSpace(bump_pointer_space_); 300 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 301 main_mem_map_2.release()); 302 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 303 AddSpace(temp_space_); 304 CHECK(separate_non_moving_space); 305 } else { 306 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 307 CHECK(main_space_ != nullptr); 308 AddSpace(main_space_); 309 if (!separate_non_moving_space) { 310 non_moving_space_ = main_space_; 311 CHECK(!non_moving_space_->CanMoveObjects()); 312 } 313 if (foreground_collector_type_ == kCollectorTypeGSS) { 314 CHECK_EQ(foreground_collector_type_, background_collector_type_); 315 // Create bump pointer spaces instead of a backup space. 316 main_mem_map_2.release(); 317 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 318 kGSSBumpPointerSpaceCapacity, nullptr); 319 CHECK(bump_pointer_space_ != nullptr); 320 AddSpace(bump_pointer_space_); 321 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 322 kGSSBumpPointerSpaceCapacity, nullptr); 323 CHECK(temp_space_ != nullptr); 324 AddSpace(temp_space_); 325 } else if (main_mem_map_2.get() != nullptr) { 326 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 327 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 328 growth_limit_, capacity_, name, true)); 329 CHECK(main_space_backup_.get() != nullptr); 330 // Add the space so its accounted for in the heap_begin and heap_end. 331 AddSpace(main_space_backup_.get()); 332 } 333 } 334 CHECK(non_moving_space_ != nullptr); 335 CHECK(!non_moving_space_->CanMoveObjects()); 336 // Allocate the large object space. 337 if (kUseFreeListSpaceForLOS) { 338 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 339 } else { 340 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 341 } 342 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 343 AddSpace(large_object_space_); 344 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 345 CHECK(!continuous_spaces_.empty()); 346 // Relies on the spaces being sorted. 347 byte* heap_begin = continuous_spaces_.front()->Begin(); 348 byte* heap_end = continuous_spaces_.back()->Limit(); 349 size_t heap_capacity = heap_end - heap_begin; 350 // Remove the main backup space since it slows down the GC to have unused extra spaces. 351 if (main_space_backup_.get() != nullptr) { 352 RemoveSpace(main_space_backup_.get()); 353 } 354 // Allocate the card table. 355 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 356 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 357 // Card cache for now since it makes it easier for us to update the references to the copying 358 // spaces. 359 accounting::ModUnionTable* mod_union_table = 360 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 361 GetImageSpace()); 362 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 363 AddModUnionTable(mod_union_table); 364 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 365 accounting::RememberedSet* non_moving_space_rem_set = 366 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 367 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 368 AddRememberedSet(non_moving_space_rem_set); 369 } 370 // TODO: Count objects in the image space here? 371 num_bytes_allocated_.StoreRelaxed(0); 372 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 373 kDefaultMarkStackSize)); 374 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 375 allocation_stack_.reset(accounting::ObjectStack::Create( 376 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 377 live_stack_.reset(accounting::ObjectStack::Create( 378 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 379 // It's still too early to take a lock because there are no threads yet, but we can create locks 380 // now. We don't create it earlier to make it clear that you can't use locks during heap 381 // initialization. 382 gc_complete_lock_ = new Mutex("GC complete lock"); 383 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 384 *gc_complete_lock_)); 385 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 386 last_gc_size_ = GetBytesAllocated(); 387 if (ignore_max_footprint_) { 388 SetIdealFootprint(std::numeric_limits<size_t>::max()); 389 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 390 } 391 CHECK_NE(max_allowed_footprint_, 0U); 392 // Create our garbage collectors. 393 for (size_t i = 0; i < 2; ++i) { 394 const bool concurrent = i != 0; 395 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 396 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 397 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 398 } 399 if (kMovingCollector) { 400 // TODO: Clean this up. 401 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 402 semi_space_collector_ = new collector::SemiSpace(this, generational, 403 generational ? "generational" : ""); 404 garbage_collectors_.push_back(semi_space_collector_); 405 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 406 garbage_collectors_.push_back(concurrent_copying_collector_); 407 mark_compact_collector_ = new collector::MarkCompact(this); 408 garbage_collectors_.push_back(mark_compact_collector_); 409 } 410 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 411 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 412 // Check that there's no gap between the image space and the non moving space so that the 413 // immune region won't break (eg. due to a large object allocated in the gap). This is only 414 // required when we're the zygote or using GSS. 415 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 416 non_moving_space_->GetMemMap()); 417 if (!no_gap) { 418 MemMap::DumpMaps(LOG(ERROR)); 419 LOG(FATAL) << "There's a gap between the image space and the main space"; 420 } 421 } 422 if (running_on_valgrind_) { 423 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 424 } 425 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 426 LOG(INFO) << "Heap() exiting"; 427 } 428} 429 430MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 431 int prot_flags, std::string* out_error_str) { 432 while (true) { 433 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 434 PROT_READ | PROT_WRITE, true, out_error_str); 435 if (map != nullptr || request_begin == nullptr) { 436 return map; 437 } 438 // Retry a second time with no specified request begin. 439 request_begin = nullptr; 440 } 441 return nullptr; 442} 443 444space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 445 size_t growth_limit, size_t capacity, 446 const char* name, bool can_move_objects) { 447 space::MallocSpace* malloc_space = nullptr; 448 if (kUseRosAlloc) { 449 // Create rosalloc space. 450 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 451 initial_size, growth_limit, capacity, 452 low_memory_mode_, can_move_objects); 453 } else { 454 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 455 initial_size, growth_limit, capacity, 456 can_move_objects); 457 } 458 if (collector::SemiSpace::kUseRememberedSet) { 459 accounting::RememberedSet* rem_set = 460 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 461 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 462 AddRememberedSet(rem_set); 463 } 464 CHECK(malloc_space != nullptr) << "Failed to create " << name; 465 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 466 return malloc_space; 467} 468 469void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 470 size_t capacity) { 471 // Is background compaction is enabled? 472 bool can_move_objects = IsMovingGc(background_collector_type_) != 473 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 474 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 475 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 476 // from the main space to the zygote space. If background compaction is enabled, always pass in 477 // that we can move objets. 478 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 479 // After the zygote we want this to be false if we don't have background compaction enabled so 480 // that getting primitive array elements is faster. 481 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 482 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 483 } 484 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 485 RemoveRememberedSet(main_space_); 486 } 487 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 488 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 489 can_move_objects); 490 SetSpaceAsDefault(main_space_); 491 VLOG(heap) << "Created main space " << main_space_; 492} 493 494void Heap::ChangeAllocator(AllocatorType allocator) { 495 if (current_allocator_ != allocator) { 496 // These two allocators are only used internally and don't have any entrypoints. 497 CHECK_NE(allocator, kAllocatorTypeLOS); 498 CHECK_NE(allocator, kAllocatorTypeNonMoving); 499 current_allocator_ = allocator; 500 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 501 SetQuickAllocEntryPointsAllocator(current_allocator_); 502 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 503 } 504} 505 506void Heap::DisableMovingGc() { 507 if (IsMovingGc(foreground_collector_type_)) { 508 foreground_collector_type_ = kCollectorTypeCMS; 509 } 510 if (IsMovingGc(background_collector_type_)) { 511 background_collector_type_ = foreground_collector_type_; 512 } 513 TransitionCollector(foreground_collector_type_); 514 ThreadList* tl = Runtime::Current()->GetThreadList(); 515 Thread* self = Thread::Current(); 516 ScopedThreadStateChange tsc(self, kSuspended); 517 tl->SuspendAll(); 518 // Something may have caused the transition to fail. 519 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 520 CHECK(main_space_ != nullptr); 521 // The allocation stack may have non movable objects in it. We need to flush it since the GC 522 // can't only handle marking allocation stack objects of one non moving space and one main 523 // space. 524 { 525 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 526 FlushAllocStack(); 527 } 528 main_space_->DisableMovingObjects(); 529 non_moving_space_ = main_space_; 530 CHECK(!non_moving_space_->CanMoveObjects()); 531 } 532 tl->ResumeAll(); 533} 534 535std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 536 if (!IsValidContinuousSpaceObjectAddress(klass)) { 537 return StringPrintf("<non heap address klass %p>", klass); 538 } 539 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 540 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 541 std::string result("["); 542 result += SafeGetClassDescriptor(component_type); 543 return result; 544 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 545 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 546 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 547 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 548 } else { 549 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 550 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 551 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 552 } 553 const DexFile* dex_file = dex_cache->GetDexFile(); 554 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 555 if (class_def_idx == DexFile::kDexNoIndex16) { 556 return "<class def not found>"; 557 } 558 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 559 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 560 return dex_file->GetTypeDescriptor(type_id); 561 } 562} 563 564std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 565 if (obj == nullptr) { 566 return "null"; 567 } 568 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 569 if (klass == nullptr) { 570 return "(class=null)"; 571 } 572 std::string result(SafeGetClassDescriptor(klass)); 573 if (obj->IsClass()) { 574 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 575 } 576 return result; 577} 578 579void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 580 if (obj == nullptr) { 581 stream << "(obj=null)"; 582 return; 583 } 584 if (IsAligned<kObjectAlignment>(obj)) { 585 space::Space* space = nullptr; 586 // Don't use find space since it only finds spaces which actually contain objects instead of 587 // spaces which may contain objects (e.g. cleared bump pointer spaces). 588 for (const auto& cur_space : continuous_spaces_) { 589 if (cur_space->HasAddress(obj)) { 590 space = cur_space; 591 break; 592 } 593 } 594 // Unprotect all the spaces. 595 for (const auto& space : continuous_spaces_) { 596 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 597 } 598 stream << "Object " << obj; 599 if (space != nullptr) { 600 stream << " in space " << *space; 601 } 602 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 603 stream << "\nclass=" << klass; 604 if (klass != nullptr) { 605 stream << " type= " << SafePrettyTypeOf(obj); 606 } 607 // Re-protect the address we faulted on. 608 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 609 } 610} 611 612bool Heap::IsCompilingBoot() const { 613 if (!Runtime::Current()->IsCompiler()) { 614 return false; 615 } 616 for (const auto& space : continuous_spaces_) { 617 if (space->IsImageSpace() || space->IsZygoteSpace()) { 618 return false; 619 } 620 } 621 return true; 622} 623 624bool Heap::HasImageSpace() const { 625 for (const auto& space : continuous_spaces_) { 626 if (space->IsImageSpace()) { 627 return true; 628 } 629 } 630 return false; 631} 632 633void Heap::IncrementDisableMovingGC(Thread* self) { 634 // Need to do this holding the lock to prevent races where the GC is about to run / running when 635 // we attempt to disable it. 636 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 637 MutexLock mu(self, *gc_complete_lock_); 638 ++disable_moving_gc_count_; 639 if (IsMovingGc(collector_type_running_)) { 640 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 641 } 642} 643 644void Heap::DecrementDisableMovingGC(Thread* self) { 645 MutexLock mu(self, *gc_complete_lock_); 646 CHECK_GE(disable_moving_gc_count_, 0U); 647 --disable_moving_gc_count_; 648} 649 650void Heap::UpdateProcessState(ProcessState process_state) { 651 if (process_state_ != process_state) { 652 process_state_ = process_state; 653 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 654 // Start at index 1 to avoid "is always false" warning. 655 // Have iteration 1 always transition the collector. 656 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 657 ? foreground_collector_type_ : background_collector_type_); 658 usleep(kCollectorTransitionStressWait); 659 } 660 if (process_state_ == kProcessStateJankPerceptible) { 661 // Transition back to foreground right away to prevent jank. 662 RequestCollectorTransition(foreground_collector_type_, 0); 663 } else { 664 // Don't delay for debug builds since we may want to stress test the GC. 665 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 666 // special handling which does a homogenous space compaction once but then doesn't transition 667 // the collector. 668 RequestCollectorTransition(background_collector_type_, 669 kIsDebugBuild ? 0 : kCollectorTransitionWait); 670 } 671 } 672} 673 674void Heap::CreateThreadPool() { 675 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 676 if (num_threads != 0) { 677 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 678 } 679} 680 681void Heap::VisitObjects(ObjectCallback callback, void* arg) { 682 Thread* self = Thread::Current(); 683 // GCs can move objects, so don't allow this. 684 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 685 if (bump_pointer_space_ != nullptr) { 686 // Visit objects in bump pointer space. 687 bump_pointer_space_->Walk(callback, arg); 688 } 689 // TODO: Switch to standard begin and end to use ranged a based loop. 690 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 691 it < end; ++it) { 692 mirror::Object* obj = *it; 693 if (obj != nullptr && obj->GetClass() != nullptr) { 694 // Avoid the race condition caused by the object not yet being written into the allocation 695 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 696 // there can be nulls on the allocation stack. 697 callback(obj, arg); 698 } 699 } 700 GetLiveBitmap()->Walk(callback, arg); 701 self->EndAssertNoThreadSuspension(old_cause); 702} 703 704void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 705 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 706 space::ContinuousSpace* space2 = non_moving_space_; 707 // TODO: Generalize this to n bitmaps? 708 CHECK(space1 != nullptr); 709 CHECK(space2 != nullptr); 710 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 711 large_object_space_->GetLiveBitmap(), stack); 712} 713 714void Heap::DeleteThreadPool() { 715 thread_pool_.reset(nullptr); 716} 717 718void Heap::AddSpace(space::Space* space) { 719 CHECK(space != nullptr); 720 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 721 if (space->IsContinuousSpace()) { 722 DCHECK(!space->IsDiscontinuousSpace()); 723 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 724 // Continuous spaces don't necessarily have bitmaps. 725 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 726 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 727 if (live_bitmap != nullptr) { 728 CHECK(mark_bitmap != nullptr); 729 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 730 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 731 } 732 continuous_spaces_.push_back(continuous_space); 733 // Ensure that spaces remain sorted in increasing order of start address. 734 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 735 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 736 return a->Begin() < b->Begin(); 737 }); 738 } else { 739 CHECK(space->IsDiscontinuousSpace()); 740 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 741 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 742 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 743 discontinuous_spaces_.push_back(discontinuous_space); 744 } 745 if (space->IsAllocSpace()) { 746 alloc_spaces_.push_back(space->AsAllocSpace()); 747 } 748} 749 750void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 751 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 752 if (continuous_space->IsDlMallocSpace()) { 753 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 754 } else if (continuous_space->IsRosAllocSpace()) { 755 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 756 } 757} 758 759void Heap::RemoveSpace(space::Space* space) { 760 DCHECK(space != nullptr); 761 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 762 if (space->IsContinuousSpace()) { 763 DCHECK(!space->IsDiscontinuousSpace()); 764 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 765 // Continuous spaces don't necessarily have bitmaps. 766 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 767 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 768 if (live_bitmap != nullptr) { 769 DCHECK(mark_bitmap != nullptr); 770 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 771 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 772 } 773 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 774 DCHECK(it != continuous_spaces_.end()); 775 continuous_spaces_.erase(it); 776 } else { 777 DCHECK(space->IsDiscontinuousSpace()); 778 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 779 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 780 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 781 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 782 discontinuous_space); 783 DCHECK(it != discontinuous_spaces_.end()); 784 discontinuous_spaces_.erase(it); 785 } 786 if (space->IsAllocSpace()) { 787 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 788 DCHECK(it != alloc_spaces_.end()); 789 alloc_spaces_.erase(it); 790 } 791} 792 793void Heap::DumpGcPerformanceInfo(std::ostream& os) { 794 // Dump cumulative timings. 795 os << "Dumping cumulative Gc timings\n"; 796 uint64_t total_duration = 0; 797 // Dump cumulative loggers for each GC type. 798 uint64_t total_paused_time = 0; 799 for (auto& collector : garbage_collectors_) { 800 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 801 total_paused_time += collector->GetTotalPausedTimeNs(); 802 collector->DumpPerformanceInfo(os); 803 collector->ResetMeasurements(); 804 } 805 uint64_t allocation_time = 806 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 807 if (total_duration != 0) { 808 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 809 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 810 os << "Mean GC size throughput: " 811 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 812 os << "Mean GC object throughput: " 813 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 814 } 815 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 816 os << "Total number of allocations " << total_objects_allocated << "\n"; 817 uint64_t total_bytes_allocated = GetBytesAllocatedEver(); 818 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 819 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 820 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 821 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 822 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 823 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 824 if (kMeasureAllocationTime) { 825 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 826 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 827 << "\n"; 828 } 829 if (HasZygoteSpace()) { 830 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 831 } 832 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 833 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 834 BaseMutex::DumpAll(os); 835} 836 837Heap::~Heap() { 838 VLOG(heap) << "Starting ~Heap()"; 839 STLDeleteElements(&garbage_collectors_); 840 // If we don't reset then the mark stack complains in its destructor. 841 allocation_stack_->Reset(); 842 live_stack_->Reset(); 843 STLDeleteValues(&mod_union_tables_); 844 STLDeleteValues(&remembered_sets_); 845 STLDeleteElements(&continuous_spaces_); 846 STLDeleteElements(&discontinuous_spaces_); 847 delete gc_complete_lock_; 848 delete heap_trim_request_lock_; 849 VLOG(heap) << "Finished ~Heap()"; 850} 851 852space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 853 bool fail_ok) const { 854 for (const auto& space : continuous_spaces_) { 855 if (space->Contains(obj)) { 856 return space; 857 } 858 } 859 if (!fail_ok) { 860 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 861 } 862 return NULL; 863} 864 865space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 866 bool fail_ok) const { 867 for (const auto& space : discontinuous_spaces_) { 868 if (space->Contains(obj)) { 869 return space; 870 } 871 } 872 if (!fail_ok) { 873 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 874 } 875 return NULL; 876} 877 878space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 879 space::Space* result = FindContinuousSpaceFromObject(obj, true); 880 if (result != NULL) { 881 return result; 882 } 883 return FindDiscontinuousSpaceFromObject(obj, true); 884} 885 886space::ImageSpace* Heap::GetImageSpace() const { 887 for (const auto& space : continuous_spaces_) { 888 if (space->IsImageSpace()) { 889 return space->AsImageSpace(); 890 } 891 } 892 return NULL; 893} 894 895void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 896 std::ostringstream oss; 897 size_t total_bytes_free = GetFreeMemory(); 898 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 899 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 900 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 901 if (total_bytes_free >= byte_count) { 902 space::AllocSpace* space = nullptr; 903 if (allocator_type == kAllocatorTypeNonMoving) { 904 space = non_moving_space_; 905 } else if (allocator_type == kAllocatorTypeRosAlloc || 906 allocator_type == kAllocatorTypeDlMalloc) { 907 space = main_space_; 908 } else if (allocator_type == kAllocatorTypeBumpPointer || 909 allocator_type == kAllocatorTypeTLAB) { 910 space = bump_pointer_space_; 911 } 912 if (space != nullptr) { 913 space->LogFragmentationAllocFailure(oss, byte_count); 914 } 915 } 916 self->ThrowOutOfMemoryError(oss.str().c_str()); 917} 918 919void Heap::DoPendingTransitionOrTrim() { 920 Thread* self = Thread::Current(); 921 CollectorType desired_collector_type; 922 // Wait until we reach the desired transition time. 923 while (true) { 924 uint64_t wait_time; 925 { 926 MutexLock mu(self, *heap_trim_request_lock_); 927 desired_collector_type = desired_collector_type_; 928 uint64_t current_time = NanoTime(); 929 if (current_time >= heap_transition_or_trim_target_time_) { 930 break; 931 } 932 wait_time = heap_transition_or_trim_target_time_ - current_time; 933 } 934 ScopedThreadStateChange tsc(self, kSleeping); 935 usleep(wait_time / 1000); // Usleep takes microseconds. 936 } 937 // Launch homogeneous space compaction if it is desired. 938 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 939 if (!CareAboutPauseTimes()) { 940 PerformHomogeneousSpaceCompact(); 941 } 942 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 943 desired_collector_type = collector_type_; 944 return; 945 } 946 // Transition the collector if the desired collector type is not the same as the current 947 // collector type. 948 TransitionCollector(desired_collector_type); 949 if (!CareAboutPauseTimes()) { 950 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 951 // about pauses. 952 Runtime* runtime = Runtime::Current(); 953 runtime->GetThreadList()->SuspendAll(); 954 uint64_t start_time = NanoTime(); 955 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 956 VLOG(heap) << "Deflating " << count << " monitors took " 957 << PrettyDuration(NanoTime() - start_time); 958 runtime->GetThreadList()->ResumeAll(); 959 } 960 // Do a heap trim if it is needed. 961 Trim(); 962} 963 964void Heap::Trim() { 965 Thread* self = Thread::Current(); 966 { 967 MutexLock mu(self, *heap_trim_request_lock_); 968 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 969 return; 970 } 971 last_trim_time_ = NanoTime(); 972 heap_trim_request_pending_ = false; 973 } 974 { 975 // Need to do this before acquiring the locks since we don't want to get suspended while 976 // holding any locks. 977 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 978 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 979 // trimming. 980 MutexLock mu(self, *gc_complete_lock_); 981 // Ensure there is only one GC at a time. 982 WaitForGcToCompleteLocked(kGcCauseTrim, self); 983 collector_type_running_ = kCollectorTypeHeapTrim; 984 } 985 uint64_t start_ns = NanoTime(); 986 // Trim the managed spaces. 987 uint64_t total_alloc_space_allocated = 0; 988 uint64_t total_alloc_space_size = 0; 989 uint64_t managed_reclaimed = 0; 990 for (const auto& space : continuous_spaces_) { 991 if (space->IsMallocSpace()) { 992 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 993 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 994 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 995 // for a long period of time. 996 managed_reclaimed += malloc_space->Trim(); 997 } 998 total_alloc_space_size += malloc_space->Size(); 999 } 1000 } 1001 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 1002 if (bump_pointer_space_ != nullptr) { 1003 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1004 } 1005 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1006 static_cast<float>(total_alloc_space_size); 1007 uint64_t gc_heap_end_ns = NanoTime(); 1008 // We never move things in the native heap, so we can finish the GC at this point. 1009 FinishGC(self, collector::kGcTypeNone); 1010 size_t native_reclaimed = 0; 1011 // Only trim the native heap if we don't care about pauses. 1012 if (!CareAboutPauseTimes()) { 1013#if defined(USE_DLMALLOC) 1014 // Trim the native heap. 1015 dlmalloc_trim(0); 1016 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1017#elif defined(USE_JEMALLOC) 1018 // Jemalloc does it's own internal trimming. 1019#else 1020 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1021#endif 1022 } 1023 uint64_t end_ns = NanoTime(); 1024 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1025 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1026 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1027 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1028 << "%."; 1029} 1030 1031bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1032 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1033 // taking the lock. 1034 if (obj == nullptr) { 1035 return true; 1036 } 1037 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1038} 1039 1040bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1041 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1042} 1043 1044bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1045 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1046 return false; 1047 } 1048 for (const auto& space : continuous_spaces_) { 1049 if (space->HasAddress(obj)) { 1050 return true; 1051 } 1052 } 1053 return false; 1054} 1055 1056bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1057 bool search_live_stack, bool sorted) { 1058 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1059 return false; 1060 } 1061 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1062 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1063 if (obj == klass) { 1064 // This case happens for java.lang.Class. 1065 return true; 1066 } 1067 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1068 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1069 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1070 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1071 return temp_space_->Contains(obj); 1072 } 1073 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1074 space::DiscontinuousSpace* d_space = nullptr; 1075 if (c_space != nullptr) { 1076 if (c_space->GetLiveBitmap()->Test(obj)) { 1077 return true; 1078 } 1079 } else { 1080 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1081 if (d_space != nullptr) { 1082 if (d_space->GetLiveBitmap()->Test(obj)) { 1083 return true; 1084 } 1085 } 1086 } 1087 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1088 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1089 if (i > 0) { 1090 NanoSleep(MsToNs(10)); 1091 } 1092 if (search_allocation_stack) { 1093 if (sorted) { 1094 if (allocation_stack_->ContainsSorted(obj)) { 1095 return true; 1096 } 1097 } else if (allocation_stack_->Contains(obj)) { 1098 return true; 1099 } 1100 } 1101 1102 if (search_live_stack) { 1103 if (sorted) { 1104 if (live_stack_->ContainsSorted(obj)) { 1105 return true; 1106 } 1107 } else if (live_stack_->Contains(obj)) { 1108 return true; 1109 } 1110 } 1111 } 1112 // We need to check the bitmaps again since there is a race where we mark something as live and 1113 // then clear the stack containing it. 1114 if (c_space != nullptr) { 1115 if (c_space->GetLiveBitmap()->Test(obj)) { 1116 return true; 1117 } 1118 } else { 1119 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1120 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1121 return true; 1122 } 1123 } 1124 return false; 1125} 1126 1127std::string Heap::DumpSpaces() const { 1128 std::ostringstream oss; 1129 DumpSpaces(oss); 1130 return oss.str(); 1131} 1132 1133void Heap::DumpSpaces(std::ostream& stream) const { 1134 for (const auto& space : continuous_spaces_) { 1135 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1136 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1137 stream << space << " " << *space << "\n"; 1138 if (live_bitmap != nullptr) { 1139 stream << live_bitmap << " " << *live_bitmap << "\n"; 1140 } 1141 if (mark_bitmap != nullptr) { 1142 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1143 } 1144 } 1145 for (const auto& space : discontinuous_spaces_) { 1146 stream << space << " " << *space << "\n"; 1147 } 1148} 1149 1150void Heap::VerifyObjectBody(mirror::Object* obj) { 1151 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1152 return; 1153 } 1154 1155 // Ignore early dawn of the universe verifications. 1156 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1157 return; 1158 } 1159 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1160 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1161 CHECK(c != nullptr) << "Null class in object " << obj; 1162 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1163 CHECK(VerifyClassClass(c)); 1164 1165 if (verify_object_mode_ > kVerifyObjectModeFast) { 1166 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1167 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1168 } 1169} 1170 1171void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1172 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1173} 1174 1175void Heap::VerifyHeap() { 1176 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1177 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1178} 1179 1180void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1181 // Use signed comparison since freed bytes can be negative when background compaction foreground 1182 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1183 // free list backed space typically increasing memory footprint due to padding and binning. 1184 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1185 // Note: This relies on 2s complement for handling negative freed_bytes. 1186 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1187 if (Runtime::Current()->HasStatsEnabled()) { 1188 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1189 thread_stats->freed_objects += freed_objects; 1190 thread_stats->freed_bytes += freed_bytes; 1191 // TODO: Do this concurrently. 1192 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1193 global_stats->freed_objects += freed_objects; 1194 global_stats->freed_bytes += freed_bytes; 1195 } 1196} 1197 1198space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1199 for (const auto& space : continuous_spaces_) { 1200 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1201 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1202 return space->AsContinuousSpace()->AsRosAllocSpace(); 1203 } 1204 } 1205 } 1206 return nullptr; 1207} 1208 1209mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1210 size_t alloc_size, size_t* bytes_allocated, 1211 size_t* usable_size, 1212 mirror::Class** klass) { 1213 bool was_default_allocator = allocator == GetCurrentAllocator(); 1214 DCHECK(klass != nullptr); 1215 StackHandleScope<1> hs(self); 1216 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1217 klass = nullptr; // Invalidate for safety. 1218 // The allocation failed. If the GC is running, block until it completes, and then retry the 1219 // allocation. 1220 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1221 if (last_gc != collector::kGcTypeNone) { 1222 // If we were the default allocator but the allocator changed while we were suspended, 1223 // abort the allocation. 1224 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1225 return nullptr; 1226 } 1227 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1228 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1229 usable_size); 1230 if (ptr != nullptr) { 1231 return ptr; 1232 } 1233 } 1234 1235 collector::GcType tried_type = next_gc_type_; 1236 const bool gc_ran = 1237 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1238 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1239 return nullptr; 1240 } 1241 if (gc_ran) { 1242 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1243 usable_size); 1244 if (ptr != nullptr) { 1245 return ptr; 1246 } 1247 } 1248 1249 // Loop through our different Gc types and try to Gc until we get enough free memory. 1250 for (collector::GcType gc_type : gc_plan_) { 1251 if (gc_type == tried_type) { 1252 continue; 1253 } 1254 // Attempt to run the collector, if we succeed, re-try the allocation. 1255 const bool gc_ran = 1256 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1257 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1258 return nullptr; 1259 } 1260 if (gc_ran) { 1261 // Did we free sufficient memory for the allocation to succeed? 1262 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1263 usable_size); 1264 if (ptr != nullptr) { 1265 return ptr; 1266 } 1267 } 1268 } 1269 // Allocations have failed after GCs; this is an exceptional state. 1270 // Try harder, growing the heap if necessary. 1271 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1272 usable_size); 1273 if (ptr != nullptr) { 1274 return ptr; 1275 } 1276 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1277 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1278 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1279 // OOME. 1280 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1281 << " allocation"; 1282 // TODO: Run finalization, but this may cause more allocations to occur. 1283 // We don't need a WaitForGcToComplete here either. 1284 DCHECK(!gc_plan_.empty()); 1285 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1286 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1287 return nullptr; 1288 } 1289 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1290 if (ptr == nullptr) { 1291 const uint64_t current_time = NanoTime(); 1292 switch (allocator) { 1293 case kAllocatorTypeRosAlloc: 1294 // Fall-through. 1295 case kAllocatorTypeDlMalloc: { 1296 if (use_homogeneous_space_compaction_for_oom_ && 1297 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1298 min_interval_homogeneous_space_compaction_by_oom_) { 1299 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1300 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1301 switch (result) { 1302 case HomogeneousSpaceCompactResult::kSuccess: 1303 // If the allocation succeeded, we delayed an oom. 1304 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1305 usable_size); 1306 if (ptr != nullptr) { 1307 count_delayed_oom_++; 1308 } 1309 break; 1310 case HomogeneousSpaceCompactResult::kErrorReject: 1311 // Reject due to disabled moving GC. 1312 break; 1313 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1314 // Throw OOM by default. 1315 break; 1316 default: { 1317 LOG(FATAL) << "Unimplemented homogeneous space compaction result " 1318 << static_cast<size_t>(result); 1319 } 1320 } 1321 // Always print that we ran homogeneous space compation since this can cause jank. 1322 VLOG(heap) << "Ran heap homogeneous space compaction, " 1323 << " requested defragmentation " 1324 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1325 << " performed defragmentation " 1326 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1327 << " ignored homogeneous space compaction " 1328 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1329 << " delayed count = " 1330 << count_delayed_oom_.LoadSequentiallyConsistent(); 1331 } 1332 break; 1333 } 1334 case kAllocatorTypeNonMoving: { 1335 // Try to transition the heap if the allocation failure was due to the space being full. 1336 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1337 // If we aren't out of memory then the OOM was probably from the non moving space being 1338 // full. Attempt to disable compaction and turn the main space into a non moving space. 1339 DisableMovingGc(); 1340 // If we are still a moving GC then something must have caused the transition to fail. 1341 if (IsMovingGc(collector_type_)) { 1342 MutexLock mu(self, *gc_complete_lock_); 1343 // If we couldn't disable moving GC, just throw OOME and return null. 1344 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1345 << disable_moving_gc_count_; 1346 } else { 1347 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1348 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1349 usable_size); 1350 } 1351 } 1352 break; 1353 } 1354 default: { 1355 // Do nothing for others allocators. 1356 } 1357 } 1358 } 1359 // If the allocation hasn't succeeded by this point, throw an OOM error. 1360 if (ptr == nullptr) { 1361 ThrowOutOfMemoryError(self, alloc_size, allocator); 1362 } 1363 return ptr; 1364} 1365 1366void Heap::SetTargetHeapUtilization(float target) { 1367 DCHECK_GT(target, 0.0f); // asserted in Java code 1368 DCHECK_LT(target, 1.0f); 1369 target_utilization_ = target; 1370} 1371 1372size_t Heap::GetObjectsAllocated() const { 1373 size_t total = 0; 1374 for (space::AllocSpace* space : alloc_spaces_) { 1375 total += space->GetObjectsAllocated(); 1376 } 1377 return total; 1378} 1379 1380uint64_t Heap::GetObjectsAllocatedEver() const { 1381 return GetObjectsFreedEver() + GetObjectsAllocated(); 1382} 1383 1384uint64_t Heap::GetBytesAllocatedEver() const { 1385 return GetBytesFreedEver() + GetBytesAllocated(); 1386} 1387 1388class InstanceCounter { 1389 public: 1390 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1391 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1392 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1393 } 1394 static void Callback(mirror::Object* obj, void* arg) 1395 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1396 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1397 mirror::Class* instance_class = obj->GetClass(); 1398 CHECK(instance_class != nullptr); 1399 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1400 if (instance_counter->use_is_assignable_from_) { 1401 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1402 ++instance_counter->counts_[i]; 1403 } 1404 } else if (instance_class == instance_counter->classes_[i]) { 1405 ++instance_counter->counts_[i]; 1406 } 1407 } 1408 } 1409 1410 private: 1411 const std::vector<mirror::Class*>& classes_; 1412 bool use_is_assignable_from_; 1413 uint64_t* const counts_; 1414 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1415}; 1416 1417void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1418 uint64_t* counts) { 1419 // Can't do any GC in this function since this may move classes. 1420 Thread* self = Thread::Current(); 1421 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1422 InstanceCounter counter(classes, use_is_assignable_from, counts); 1423 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1424 VisitObjects(InstanceCounter::Callback, &counter); 1425 self->EndAssertNoThreadSuspension(old_cause); 1426} 1427 1428class InstanceCollector { 1429 public: 1430 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1431 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1432 : class_(c), max_count_(max_count), instances_(instances) { 1433 } 1434 static void Callback(mirror::Object* obj, void* arg) 1435 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1436 DCHECK(arg != nullptr); 1437 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1438 mirror::Class* instance_class = obj->GetClass(); 1439 if (instance_class == instance_collector->class_) { 1440 if (instance_collector->max_count_ == 0 || 1441 instance_collector->instances_.size() < instance_collector->max_count_) { 1442 instance_collector->instances_.push_back(obj); 1443 } 1444 } 1445 } 1446 1447 private: 1448 mirror::Class* class_; 1449 uint32_t max_count_; 1450 std::vector<mirror::Object*>& instances_; 1451 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1452}; 1453 1454void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1455 std::vector<mirror::Object*>& instances) { 1456 // Can't do any GC in this function since this may move classes. 1457 Thread* self = Thread::Current(); 1458 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1459 InstanceCollector collector(c, max_count, instances); 1460 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1461 VisitObjects(&InstanceCollector::Callback, &collector); 1462 self->EndAssertNoThreadSuspension(old_cause); 1463} 1464 1465class ReferringObjectsFinder { 1466 public: 1467 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1468 std::vector<mirror::Object*>& referring_objects) 1469 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1470 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1471 } 1472 1473 static void Callback(mirror::Object* obj, void* arg) 1474 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1475 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1476 } 1477 1478 // For bitmap Visit. 1479 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1480 // annotalysis on visitors. 1481 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1482 o->VisitReferences<true>(*this, VoidFunctor()); 1483 } 1484 1485 // For Object::VisitReferences. 1486 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1487 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1488 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1489 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1490 referring_objects_.push_back(obj); 1491 } 1492 } 1493 1494 private: 1495 mirror::Object* object_; 1496 uint32_t max_count_; 1497 std::vector<mirror::Object*>& referring_objects_; 1498 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1499}; 1500 1501void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1502 std::vector<mirror::Object*>& referring_objects) { 1503 // Can't do any GC in this function since this may move the object o. 1504 Thread* self = Thread::Current(); 1505 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1506 ReferringObjectsFinder finder(o, max_count, referring_objects); 1507 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1508 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1509 self->EndAssertNoThreadSuspension(old_cause); 1510} 1511 1512void Heap::CollectGarbage(bool clear_soft_references) { 1513 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1514 // last GC will not have necessarily been cleared. 1515 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1516} 1517 1518HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1519 Thread* self = Thread::Current(); 1520 // Inc requested homogeneous space compaction. 1521 count_requested_homogeneous_space_compaction_++; 1522 // Store performed homogeneous space compaction at a new request arrival. 1523 ThreadList* tl = Runtime::Current()->GetThreadList(); 1524 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1525 Locks::mutator_lock_->AssertNotHeld(self); 1526 { 1527 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1528 MutexLock mu(self, *gc_complete_lock_); 1529 // Ensure there is only one GC at a time. 1530 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1531 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1532 // is non zero. 1533 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1534 // exit. 1535 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1536 !main_space_->CanMoveObjects()) { 1537 return HomogeneousSpaceCompactResult::kErrorReject; 1538 } 1539 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1540 } 1541 if (Runtime::Current()->IsShuttingDown(self)) { 1542 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1543 // cause objects to get finalized. 1544 FinishGC(self, collector::kGcTypeNone); 1545 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1546 } 1547 // Suspend all threads. 1548 tl->SuspendAll(); 1549 uint64_t start_time = NanoTime(); 1550 // Launch compaction. 1551 space::MallocSpace* to_space = main_space_backup_.release(); 1552 space::MallocSpace* from_space = main_space_; 1553 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1554 const uint64_t space_size_before_compaction = from_space->Size(); 1555 AddSpace(to_space); 1556 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1557 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1558 from_space->GetMemMap()->Protect(PROT_READ); 1559 const uint64_t space_size_after_compaction = to_space->Size(); 1560 main_space_ = to_space; 1561 main_space_backup_.reset(from_space); 1562 RemoveSpace(from_space); 1563 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1564 // Update performed homogeneous space compaction count. 1565 count_performed_homogeneous_space_compaction_++; 1566 // Print statics log and resume all threads. 1567 uint64_t duration = NanoTime() - start_time; 1568 VLOG(gc) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1569 << PrettySize(space_size_before_compaction) << " -> " 1570 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1571 << std::fixed << static_cast<double>(space_size_after_compaction) / 1572 static_cast<double>(space_size_before_compaction); 1573 tl->ResumeAll(); 1574 // Finish GC. 1575 reference_processor_.EnqueueClearedReferences(self); 1576 GrowForUtilization(semi_space_collector_); 1577 FinishGC(self, collector::kGcTypeFull); 1578 return HomogeneousSpaceCompactResult::kSuccess; 1579} 1580 1581 1582void Heap::TransitionCollector(CollectorType collector_type) { 1583 if (collector_type == collector_type_) { 1584 return; 1585 } 1586 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1587 << " -> " << static_cast<int>(collector_type); 1588 uint64_t start_time = NanoTime(); 1589 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1590 Runtime* const runtime = Runtime::Current(); 1591 ThreadList* const tl = runtime->GetThreadList(); 1592 Thread* const self = Thread::Current(); 1593 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1594 Locks::mutator_lock_->AssertNotHeld(self); 1595 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1596 // compacting_gc_disable_count_, this should rarely occurs). 1597 for (;;) { 1598 { 1599 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1600 MutexLock mu(self, *gc_complete_lock_); 1601 // Ensure there is only one GC at a time. 1602 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1603 // Currently we only need a heap transition if we switch from a moving collector to a 1604 // non-moving one, or visa versa. 1605 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1606 // If someone else beat us to it and changed the collector before we could, exit. 1607 // This is safe to do before the suspend all since we set the collector_type_running_ before 1608 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1609 // then it would get blocked on WaitForGcToCompleteLocked. 1610 if (collector_type == collector_type_) { 1611 return; 1612 } 1613 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1614 if (!copying_transition || disable_moving_gc_count_ == 0) { 1615 // TODO: Not hard code in semi-space collector? 1616 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1617 break; 1618 } 1619 } 1620 usleep(1000); 1621 } 1622 if (runtime->IsShuttingDown(self)) { 1623 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1624 // cause objects to get finalized. 1625 FinishGC(self, collector::kGcTypeNone); 1626 return; 1627 } 1628 tl->SuspendAll(); 1629 switch (collector_type) { 1630 case kCollectorTypeSS: { 1631 if (!IsMovingGc(collector_type_)) { 1632 // Create the bump pointer space from the backup space. 1633 CHECK(main_space_backup_ != nullptr); 1634 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1635 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1636 // pointer space last transition it will be protected. 1637 CHECK(mem_map != nullptr); 1638 mem_map->Protect(PROT_READ | PROT_WRITE); 1639 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1640 mem_map.release()); 1641 AddSpace(bump_pointer_space_); 1642 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1643 // Use the now empty main space mem map for the bump pointer temp space. 1644 mem_map.reset(main_space_->ReleaseMemMap()); 1645 // Unset the pointers just in case. 1646 if (dlmalloc_space_ == main_space_) { 1647 dlmalloc_space_ = nullptr; 1648 } else if (rosalloc_space_ == main_space_) { 1649 rosalloc_space_ = nullptr; 1650 } 1651 // Remove the main space so that we don't try to trim it, this doens't work for debug 1652 // builds since RosAlloc attempts to read the magic number from a protected page. 1653 RemoveSpace(main_space_); 1654 RemoveRememberedSet(main_space_); 1655 delete main_space_; // Delete the space since it has been removed. 1656 main_space_ = nullptr; 1657 RemoveRememberedSet(main_space_backup_.get()); 1658 main_space_backup_.reset(nullptr); // Deletes the space. 1659 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1660 mem_map.release()); 1661 AddSpace(temp_space_); 1662 } 1663 break; 1664 } 1665 case kCollectorTypeMS: 1666 // Fall through. 1667 case kCollectorTypeCMS: { 1668 if (IsMovingGc(collector_type_)) { 1669 CHECK(temp_space_ != nullptr); 1670 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1671 RemoveSpace(temp_space_); 1672 temp_space_ = nullptr; 1673 mem_map->Protect(PROT_READ | PROT_WRITE); 1674 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1675 mem_map->Size()); 1676 mem_map.release(); 1677 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1678 AddSpace(main_space_); 1679 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1680 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1681 RemoveSpace(bump_pointer_space_); 1682 bump_pointer_space_ = nullptr; 1683 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1684 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1685 if (kIsDebugBuild && kUseRosAlloc) { 1686 mem_map->Protect(PROT_READ | PROT_WRITE); 1687 } 1688 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1689 mem_map->Size(), mem_map->Size(), 1690 name, true)); 1691 if (kIsDebugBuild && kUseRosAlloc) { 1692 mem_map->Protect(PROT_NONE); 1693 } 1694 mem_map.release(); 1695 } 1696 break; 1697 } 1698 default: { 1699 LOG(FATAL) << "Attempted to transition to invalid collector type " 1700 << static_cast<size_t>(collector_type); 1701 break; 1702 } 1703 } 1704 ChangeCollector(collector_type); 1705 tl->ResumeAll(); 1706 // Can't call into java code with all threads suspended. 1707 reference_processor_.EnqueueClearedReferences(self); 1708 uint64_t duration = NanoTime() - start_time; 1709 GrowForUtilization(semi_space_collector_); 1710 FinishGC(self, collector::kGcTypeFull); 1711 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1712 int32_t delta_allocated = before_allocated - after_allocated; 1713 std::string saved_str; 1714 if (delta_allocated >= 0) { 1715 saved_str = " saved at least " + PrettySize(delta_allocated); 1716 } else { 1717 saved_str = " expanded " + PrettySize(-delta_allocated); 1718 } 1719 VLOG(gc) << "Heap transition to " << process_state_ << " took " 1720 << PrettyDuration(duration) << saved_str; 1721} 1722 1723void Heap::ChangeCollector(CollectorType collector_type) { 1724 // TODO: Only do this with all mutators suspended to avoid races. 1725 if (collector_type != collector_type_) { 1726 if (collector_type == kCollectorTypeMC) { 1727 // Don't allow mark compact unless support is compiled in. 1728 CHECK(kMarkCompactSupport); 1729 } 1730 collector_type_ = collector_type; 1731 gc_plan_.clear(); 1732 switch (collector_type_) { 1733 case kCollectorTypeCC: // Fall-through. 1734 case kCollectorTypeMC: // Fall-through. 1735 case kCollectorTypeSS: // Fall-through. 1736 case kCollectorTypeGSS: { 1737 gc_plan_.push_back(collector::kGcTypeFull); 1738 if (use_tlab_) { 1739 ChangeAllocator(kAllocatorTypeTLAB); 1740 } else { 1741 ChangeAllocator(kAllocatorTypeBumpPointer); 1742 } 1743 break; 1744 } 1745 case kCollectorTypeMS: { 1746 gc_plan_.push_back(collector::kGcTypeSticky); 1747 gc_plan_.push_back(collector::kGcTypePartial); 1748 gc_plan_.push_back(collector::kGcTypeFull); 1749 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1750 break; 1751 } 1752 case kCollectorTypeCMS: { 1753 gc_plan_.push_back(collector::kGcTypeSticky); 1754 gc_plan_.push_back(collector::kGcTypePartial); 1755 gc_plan_.push_back(collector::kGcTypeFull); 1756 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1757 break; 1758 } 1759 default: { 1760 LOG(FATAL) << "Unimplemented"; 1761 } 1762 } 1763 if (IsGcConcurrent()) { 1764 concurrent_start_bytes_ = 1765 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1766 } else { 1767 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1768 } 1769 } 1770} 1771 1772// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1773class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1774 public: 1775 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1776 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1777 } 1778 1779 void BuildBins(space::ContinuousSpace* space) { 1780 bin_live_bitmap_ = space->GetLiveBitmap(); 1781 bin_mark_bitmap_ = space->GetMarkBitmap(); 1782 BinContext context; 1783 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1784 context.collector_ = this; 1785 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1786 // Note: This requires traversing the space in increasing order of object addresses. 1787 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1788 // Add the last bin which spans after the last object to the end of the space. 1789 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1790 } 1791 1792 private: 1793 struct BinContext { 1794 uintptr_t prev_; // The end of the previous object. 1795 ZygoteCompactingCollector* collector_; 1796 }; 1797 // Maps from bin sizes to locations. 1798 std::multimap<size_t, uintptr_t> bins_; 1799 // Live bitmap of the space which contains the bins. 1800 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1801 // Mark bitmap of the space which contains the bins. 1802 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1803 1804 static void Callback(mirror::Object* obj, void* arg) 1805 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1806 DCHECK(arg != nullptr); 1807 BinContext* context = reinterpret_cast<BinContext*>(arg); 1808 ZygoteCompactingCollector* collector = context->collector_; 1809 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1810 size_t bin_size = object_addr - context->prev_; 1811 // Add the bin consisting of the end of the previous object to the start of the current object. 1812 collector->AddBin(bin_size, context->prev_); 1813 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1814 } 1815 1816 void AddBin(size_t size, uintptr_t position) { 1817 if (size != 0) { 1818 bins_.insert(std::make_pair(size, position)); 1819 } 1820 } 1821 1822 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1823 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1824 // allocator. 1825 return false; 1826 } 1827 1828 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1829 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1830 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1831 mirror::Object* forward_address; 1832 // Find the smallest bin which we can move obj in. 1833 auto it = bins_.lower_bound(object_size); 1834 if (it == bins_.end()) { 1835 // No available space in the bins, place it in the target space instead (grows the zygote 1836 // space). 1837 size_t bytes_allocated; 1838 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1839 if (to_space_live_bitmap_ != nullptr) { 1840 to_space_live_bitmap_->Set(forward_address); 1841 } else { 1842 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1843 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1844 } 1845 } else { 1846 size_t size = it->first; 1847 uintptr_t pos = it->second; 1848 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1849 forward_address = reinterpret_cast<mirror::Object*>(pos); 1850 // Set the live and mark bits so that sweeping system weaks works properly. 1851 bin_live_bitmap_->Set(forward_address); 1852 bin_mark_bitmap_->Set(forward_address); 1853 DCHECK_GE(size, object_size); 1854 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1855 } 1856 // Copy the object over to its new location. 1857 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1858 if (kUseBakerOrBrooksReadBarrier) { 1859 obj->AssertReadBarrierPointer(); 1860 if (kUseBrooksReadBarrier) { 1861 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1862 forward_address->SetReadBarrierPointer(forward_address); 1863 } 1864 forward_address->AssertReadBarrierPointer(); 1865 } 1866 return forward_address; 1867 } 1868}; 1869 1870void Heap::UnBindBitmaps() { 1871 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1872 for (const auto& space : GetContinuousSpaces()) { 1873 if (space->IsContinuousMemMapAllocSpace()) { 1874 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1875 if (alloc_space->HasBoundBitmaps()) { 1876 alloc_space->UnBindBitmaps(); 1877 } 1878 } 1879 } 1880} 1881 1882void Heap::PreZygoteFork() { 1883 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1884 Thread* self = Thread::Current(); 1885 MutexLock mu(self, zygote_creation_lock_); 1886 // Try to see if we have any Zygote spaces. 1887 if (HasZygoteSpace()) { 1888 LOG(WARNING) << __FUNCTION__ << " called when we already have a zygote space."; 1889 return; 1890 } 1891 VLOG(heap) << "Starting PreZygoteFork"; 1892 // Trim the pages at the end of the non moving space. 1893 non_moving_space_->Trim(); 1894 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1895 // there. 1896 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1897 const bool same_space = non_moving_space_ == main_space_; 1898 if (kCompactZygote) { 1899 // Can't compact if the non moving space is the same as the main space. 1900 DCHECK(semi_space_collector_ != nullptr); 1901 // Temporarily disable rosalloc verification because the zygote 1902 // compaction will mess up the rosalloc internal metadata. 1903 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1904 ZygoteCompactingCollector zygote_collector(this); 1905 zygote_collector.BuildBins(non_moving_space_); 1906 // Create a new bump pointer space which we will compact into. 1907 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1908 non_moving_space_->Limit()); 1909 // Compact the bump pointer space to a new zygote bump pointer space. 1910 bool reset_main_space = false; 1911 if (IsMovingGc(collector_type_)) { 1912 zygote_collector.SetFromSpace(bump_pointer_space_); 1913 } else { 1914 CHECK(main_space_ != nullptr); 1915 // Copy from the main space. 1916 zygote_collector.SetFromSpace(main_space_); 1917 reset_main_space = true; 1918 } 1919 zygote_collector.SetToSpace(&target_space); 1920 zygote_collector.SetSwapSemiSpaces(false); 1921 zygote_collector.Run(kGcCauseCollectorTransition, false); 1922 if (reset_main_space) { 1923 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1924 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1925 MemMap* mem_map = main_space_->ReleaseMemMap(); 1926 RemoveSpace(main_space_); 1927 space::Space* old_main_space = main_space_; 1928 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1929 delete old_main_space; 1930 AddSpace(main_space_); 1931 } else { 1932 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1933 } 1934 if (temp_space_ != nullptr) { 1935 CHECK(temp_space_->IsEmpty()); 1936 } 1937 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1938 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1939 // Update the end and write out image. 1940 non_moving_space_->SetEnd(target_space.End()); 1941 non_moving_space_->SetLimit(target_space.Limit()); 1942 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1943 } 1944 // Change the collector to the post zygote one. 1945 ChangeCollector(foreground_collector_type_); 1946 // Save the old space so that we can remove it after we complete creating the zygote space. 1947 space::MallocSpace* old_alloc_space = non_moving_space_; 1948 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1949 // the remaining available space. 1950 // Remove the old space before creating the zygote space since creating the zygote space sets 1951 // the old alloc space's bitmaps to nullptr. 1952 RemoveSpace(old_alloc_space); 1953 if (collector::SemiSpace::kUseRememberedSet) { 1954 // Sanity bound check. 1955 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1956 // Remove the remembered set for the now zygote space (the old 1957 // non-moving space). Note now that we have compacted objects into 1958 // the zygote space, the data in the remembered set is no longer 1959 // needed. The zygote space will instead have a mod-union table 1960 // from this point on. 1961 RemoveRememberedSet(old_alloc_space); 1962 } 1963 zygote_space_ = old_alloc_space->CreateZygoteSpace("alloc space", low_memory_mode_, 1964 &non_moving_space_); 1965 CHECK(!non_moving_space_->CanMoveObjects()); 1966 if (same_space) { 1967 main_space_ = non_moving_space_; 1968 SetSpaceAsDefault(main_space_); 1969 } 1970 delete old_alloc_space; 1971 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 1972 AddSpace(zygote_space_); 1973 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1974 AddSpace(non_moving_space_); 1975 // Create the zygote space mod union table. 1976 accounting::ModUnionTable* mod_union_table = 1977 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 1978 zygote_space_); 1979 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1980 // Set all the cards in the mod-union table since we don't know which objects contain references 1981 // to large objects. 1982 mod_union_table->SetCards(); 1983 AddModUnionTable(mod_union_table); 1984 if (collector::SemiSpace::kUseRememberedSet) { 1985 // Add a new remembered set for the post-zygote non-moving space. 1986 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1987 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1988 non_moving_space_); 1989 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1990 << "Failed to create post-zygote non-moving space remembered set"; 1991 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1992 } 1993} 1994 1995void Heap::FlushAllocStack() { 1996 MarkAllocStackAsLive(allocation_stack_.get()); 1997 allocation_stack_->Reset(); 1998} 1999 2000void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2001 accounting::ContinuousSpaceBitmap* bitmap2, 2002 accounting::LargeObjectBitmap* large_objects, 2003 accounting::ObjectStack* stack) { 2004 DCHECK(bitmap1 != nullptr); 2005 DCHECK(bitmap2 != nullptr); 2006 mirror::Object** limit = stack->End(); 2007 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 2008 const mirror::Object* obj = *it; 2009 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2010 if (bitmap1->HasAddress(obj)) { 2011 bitmap1->Set(obj); 2012 } else if (bitmap2->HasAddress(obj)) { 2013 bitmap2->Set(obj); 2014 } else { 2015 large_objects->Set(obj); 2016 } 2017 } 2018 } 2019} 2020 2021void Heap::SwapSemiSpaces() { 2022 CHECK(bump_pointer_space_ != nullptr); 2023 CHECK(temp_space_ != nullptr); 2024 std::swap(bump_pointer_space_, temp_space_); 2025} 2026 2027void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2028 space::ContinuousMemMapAllocSpace* source_space, 2029 GcCause gc_cause) { 2030 CHECK(kMovingCollector); 2031 if (target_space != source_space) { 2032 // Don't swap spaces since this isn't a typical semi space collection. 2033 semi_space_collector_->SetSwapSemiSpaces(false); 2034 semi_space_collector_->SetFromSpace(source_space); 2035 semi_space_collector_->SetToSpace(target_space); 2036 semi_space_collector_->Run(gc_cause, false); 2037 } else { 2038 CHECK(target_space->IsBumpPointerSpace()) 2039 << "In-place compaction is only supported for bump pointer spaces"; 2040 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2041 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2042 } 2043} 2044 2045collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2046 bool clear_soft_references) { 2047 Thread* self = Thread::Current(); 2048 Runtime* runtime = Runtime::Current(); 2049 // If the heap can't run the GC, silently fail and return that no GC was run. 2050 switch (gc_type) { 2051 case collector::kGcTypePartial: { 2052 if (!HasZygoteSpace()) { 2053 return collector::kGcTypeNone; 2054 } 2055 break; 2056 } 2057 default: { 2058 // Other GC types don't have any special cases which makes them not runnable. The main case 2059 // here is full GC. 2060 } 2061 } 2062 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2063 Locks::mutator_lock_->AssertNotHeld(self); 2064 if (self->IsHandlingStackOverflow()) { 2065 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2066 } 2067 bool compacting_gc; 2068 { 2069 gc_complete_lock_->AssertNotHeld(self); 2070 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2071 MutexLock mu(self, *gc_complete_lock_); 2072 // Ensure there is only one GC at a time. 2073 WaitForGcToCompleteLocked(gc_cause, self); 2074 compacting_gc = IsMovingGc(collector_type_); 2075 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2076 if (compacting_gc && disable_moving_gc_count_ != 0) { 2077 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2078 return collector::kGcTypeNone; 2079 } 2080 collector_type_running_ = collector_type_; 2081 } 2082 2083 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2084 ++runtime->GetStats()->gc_for_alloc_count; 2085 ++self->GetStats()->gc_for_alloc_count; 2086 } 2087 uint64_t gc_start_time_ns = NanoTime(); 2088 uint64_t gc_start_size = GetBytesAllocated(); 2089 // Approximate allocation rate in bytes / second. 2090 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2091 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2092 if (LIKELY(ms_delta != 0)) { 2093 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2094 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2095 } 2096 2097 DCHECK_LT(gc_type, collector::kGcTypeMax); 2098 DCHECK_NE(gc_type, collector::kGcTypeNone); 2099 2100 collector::GarbageCollector* collector = nullptr; 2101 // TODO: Clean this up. 2102 if (compacting_gc) { 2103 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2104 current_allocator_ == kAllocatorTypeTLAB); 2105 switch (collector_type_) { 2106 case kCollectorTypeSS: 2107 // Fall-through. 2108 case kCollectorTypeGSS: 2109 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2110 semi_space_collector_->SetToSpace(temp_space_); 2111 semi_space_collector_->SetSwapSemiSpaces(true); 2112 collector = semi_space_collector_; 2113 break; 2114 case kCollectorTypeCC: 2115 collector = concurrent_copying_collector_; 2116 break; 2117 case kCollectorTypeMC: 2118 mark_compact_collector_->SetSpace(bump_pointer_space_); 2119 collector = mark_compact_collector_; 2120 break; 2121 default: 2122 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2123 } 2124 if (collector != mark_compact_collector_) { 2125 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2126 CHECK(temp_space_->IsEmpty()); 2127 } 2128 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2129 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2130 current_allocator_ == kAllocatorTypeDlMalloc) { 2131 collector = FindCollectorByGcType(gc_type); 2132 } else { 2133 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2134 } 2135 CHECK(collector != nullptr) 2136 << "Could not find garbage collector with collector_type=" 2137 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2138 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2139 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2140 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2141 RequestHeapTrim(); 2142 // Enqueue cleared references. 2143 reference_processor_.EnqueueClearedReferences(self); 2144 // Grow the heap so that we know when to perform the next GC. 2145 GrowForUtilization(collector); 2146 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2147 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2148 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2149 // (mutator time blocked >= long_pause_log_threshold_). 2150 bool log_gc = gc_cause == kGcCauseExplicit; 2151 if (!log_gc && CareAboutPauseTimes()) { 2152 // GC for alloc pauses the allocating thread, so consider it as a pause. 2153 log_gc = duration > long_gc_log_threshold_ || 2154 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2155 for (uint64_t pause : pause_times) { 2156 log_gc = log_gc || pause >= long_pause_log_threshold_; 2157 } 2158 } 2159 if (log_gc) { 2160 const size_t percent_free = GetPercentFree(); 2161 const size_t current_heap_size = GetBytesAllocated(); 2162 const size_t total_memory = GetTotalMemory(); 2163 std::ostringstream pause_string; 2164 for (size_t i = 0; i < pause_times.size(); ++i) { 2165 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2166 << ((i != pause_times.size() - 1) ? "," : ""); 2167 } 2168 LOG(INFO) << gc_cause << " " << collector->GetName() 2169 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2170 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2171 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2172 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2173 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2174 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2175 << " total " << PrettyDuration((duration / 1000) * 1000); 2176 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2177 } 2178 FinishGC(self, gc_type); 2179 // Inform DDMS that a GC completed. 2180 Dbg::GcDidFinish(); 2181 return gc_type; 2182} 2183 2184void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2185 MutexLock mu(self, *gc_complete_lock_); 2186 collector_type_running_ = kCollectorTypeNone; 2187 if (gc_type != collector::kGcTypeNone) { 2188 last_gc_type_ = gc_type; 2189 } 2190 // Wake anyone who may have been waiting for the GC to complete. 2191 gc_complete_cond_->Broadcast(self); 2192} 2193 2194static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2195 RootType /*root_type*/) { 2196 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2197 if (*root == obj) { 2198 LOG(INFO) << "Object " << obj << " is a root"; 2199 } 2200} 2201 2202class ScanVisitor { 2203 public: 2204 void operator()(const mirror::Object* obj) const { 2205 LOG(ERROR) << "Would have rescanned object " << obj; 2206 } 2207}; 2208 2209// Verify a reference from an object. 2210class VerifyReferenceVisitor { 2211 public: 2212 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2213 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2214 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2215 2216 size_t GetFailureCount() const { 2217 return fail_count_->LoadSequentiallyConsistent(); 2218 } 2219 2220 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2221 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2222 if (verify_referent_) { 2223 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2224 } 2225 } 2226 2227 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2228 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2229 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2230 } 2231 2232 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2233 return heap_->IsLiveObjectLocked(obj, true, false, true); 2234 } 2235 2236 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2237 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2238 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2239 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2240 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2241 << " thread_id= " << thread_id << " root_type= " << root_type; 2242 } 2243 } 2244 2245 private: 2246 // TODO: Fix the no thread safety analysis. 2247 // Returns false on failure. 2248 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2249 NO_THREAD_SAFETY_ANALYSIS { 2250 if (ref == nullptr || IsLive(ref)) { 2251 // Verify that the reference is live. 2252 return true; 2253 } 2254 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2255 // Print message on only on first failure to prevent spam. 2256 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2257 } 2258 if (obj != nullptr) { 2259 // Only do this part for non roots. 2260 accounting::CardTable* card_table = heap_->GetCardTable(); 2261 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2262 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2263 byte* card_addr = card_table->CardFromAddr(obj); 2264 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2265 << offset << "\n card value = " << static_cast<int>(*card_addr); 2266 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2267 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2268 } else { 2269 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2270 } 2271 2272 // Attempt to find the class inside of the recently freed objects. 2273 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2274 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2275 space::MallocSpace* space = ref_space->AsMallocSpace(); 2276 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2277 if (ref_class != nullptr) { 2278 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2279 << PrettyClass(ref_class); 2280 } else { 2281 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2282 } 2283 } 2284 2285 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2286 ref->GetClass()->IsClass()) { 2287 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2288 } else { 2289 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2290 << ") is not a valid heap address"; 2291 } 2292 2293 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2294 void* cover_begin = card_table->AddrFromCard(card_addr); 2295 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2296 accounting::CardTable::kCardSize); 2297 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2298 << "-" << cover_end; 2299 accounting::ContinuousSpaceBitmap* bitmap = 2300 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2301 2302 if (bitmap == nullptr) { 2303 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2304 if (!VerifyClassClass(obj->GetClass())) { 2305 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2306 } 2307 } else { 2308 // Print out how the object is live. 2309 if (bitmap->Test(obj)) { 2310 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2311 } 2312 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2313 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2314 } 2315 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2316 LOG(ERROR) << "Object " << obj << " found in live stack"; 2317 } 2318 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2319 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2320 } 2321 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2322 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2323 } 2324 // Attempt to see if the card table missed the reference. 2325 ScanVisitor scan_visitor; 2326 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2327 card_table->Scan(bitmap, byte_cover_begin, 2328 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2329 } 2330 2331 // Search to see if any of the roots reference our object. 2332 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2333 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2334 2335 // Search to see if any of the roots reference our reference. 2336 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2337 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2338 } 2339 return false; 2340 } 2341 2342 Heap* const heap_; 2343 Atomic<size_t>* const fail_count_; 2344 const bool verify_referent_; 2345}; 2346 2347// Verify all references within an object, for use with HeapBitmap::Visit. 2348class VerifyObjectVisitor { 2349 public: 2350 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2351 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2352 } 2353 2354 void operator()(mirror::Object* obj) const 2355 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2356 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2357 // be live or else how did we find it in the live bitmap? 2358 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2359 // The class doesn't count as a reference but we should verify it anyways. 2360 obj->VisitReferences<true>(visitor, visitor); 2361 } 2362 2363 static void VisitCallback(mirror::Object* obj, void* arg) 2364 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2365 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2366 visitor->operator()(obj); 2367 } 2368 2369 size_t GetFailureCount() const { 2370 return fail_count_->LoadSequentiallyConsistent(); 2371 } 2372 2373 private: 2374 Heap* const heap_; 2375 Atomic<size_t>* const fail_count_; 2376 const bool verify_referent_; 2377}; 2378 2379void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2380 // Slow path, the allocation stack push back must have already failed. 2381 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2382 do { 2383 // TODO: Add handle VerifyObject. 2384 StackHandleScope<1> hs(self); 2385 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2386 // Push our object into the reserve region of the allocaiton stack. This is only required due 2387 // to heap verification requiring that roots are live (either in the live bitmap or in the 2388 // allocation stack). 2389 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2390 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2391 } while (!allocation_stack_->AtomicPushBack(*obj)); 2392} 2393 2394void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2395 // Slow path, the allocation stack push back must have already failed. 2396 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2397 mirror::Object** start_address; 2398 mirror::Object** end_address; 2399 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2400 &end_address)) { 2401 // TODO: Add handle VerifyObject. 2402 StackHandleScope<1> hs(self); 2403 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2404 // Push our object into the reserve region of the allocaiton stack. This is only required due 2405 // to heap verification requiring that roots are live (either in the live bitmap or in the 2406 // allocation stack). 2407 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2408 // Push into the reserve allocation stack. 2409 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2410 } 2411 self->SetThreadLocalAllocationStack(start_address, end_address); 2412 // Retry on the new thread-local allocation stack. 2413 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2414} 2415 2416// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2417size_t Heap::VerifyHeapReferences(bool verify_referents) { 2418 Thread* self = Thread::Current(); 2419 Locks::mutator_lock_->AssertExclusiveHeld(self); 2420 // Lets sort our allocation stacks so that we can efficiently binary search them. 2421 allocation_stack_->Sort(); 2422 live_stack_->Sort(); 2423 // Since we sorted the allocation stack content, need to revoke all 2424 // thread-local allocation stacks. 2425 RevokeAllThreadLocalAllocationStacks(self); 2426 Atomic<size_t> fail_count_(0); 2427 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2428 // Verify objects in the allocation stack since these will be objects which were: 2429 // 1. Allocated prior to the GC (pre GC verification). 2430 // 2. Allocated during the GC (pre sweep GC verification). 2431 // We don't want to verify the objects in the live stack since they themselves may be 2432 // pointing to dead objects if they are not reachable. 2433 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2434 // Verify the roots: 2435 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2436 if (visitor.GetFailureCount() > 0) { 2437 // Dump mod-union tables. 2438 for (const auto& table_pair : mod_union_tables_) { 2439 accounting::ModUnionTable* mod_union_table = table_pair.second; 2440 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2441 } 2442 // Dump remembered sets. 2443 for (const auto& table_pair : remembered_sets_) { 2444 accounting::RememberedSet* remembered_set = table_pair.second; 2445 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2446 } 2447 DumpSpaces(LOG(ERROR)); 2448 } 2449 return visitor.GetFailureCount(); 2450} 2451 2452class VerifyReferenceCardVisitor { 2453 public: 2454 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2455 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2456 Locks::heap_bitmap_lock_) 2457 : heap_(heap), failed_(failed) { 2458 } 2459 2460 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2461 // annotalysis on visitors. 2462 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2463 NO_THREAD_SAFETY_ANALYSIS { 2464 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2465 // Filter out class references since changing an object's class does not mark the card as dirty. 2466 // Also handles large objects, since the only reference they hold is a class reference. 2467 if (ref != nullptr && !ref->IsClass()) { 2468 accounting::CardTable* card_table = heap_->GetCardTable(); 2469 // If the object is not dirty and it is referencing something in the live stack other than 2470 // class, then it must be on a dirty card. 2471 if (!card_table->AddrIsInCardTable(obj)) { 2472 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2473 *failed_ = true; 2474 } else if (!card_table->IsDirty(obj)) { 2475 // TODO: Check mod-union tables. 2476 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2477 // kCardDirty - 1 if it didnt get touched since we aged it. 2478 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2479 if (live_stack->ContainsSorted(ref)) { 2480 if (live_stack->ContainsSorted(obj)) { 2481 LOG(ERROR) << "Object " << obj << " found in live stack"; 2482 } 2483 if (heap_->GetLiveBitmap()->Test(obj)) { 2484 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2485 } 2486 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2487 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2488 2489 // Print which field of the object is dead. 2490 if (!obj->IsObjectArray()) { 2491 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2492 CHECK(klass != NULL); 2493 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2494 : klass->GetIFields(); 2495 CHECK(fields != NULL); 2496 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2497 mirror::ArtField* cur = fields->Get(i); 2498 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2499 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2500 << PrettyField(cur); 2501 break; 2502 } 2503 } 2504 } else { 2505 mirror::ObjectArray<mirror::Object>* object_array = 2506 obj->AsObjectArray<mirror::Object>(); 2507 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2508 if (object_array->Get(i) == ref) { 2509 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2510 } 2511 } 2512 } 2513 2514 *failed_ = true; 2515 } 2516 } 2517 } 2518 } 2519 2520 private: 2521 Heap* const heap_; 2522 bool* const failed_; 2523}; 2524 2525class VerifyLiveStackReferences { 2526 public: 2527 explicit VerifyLiveStackReferences(Heap* heap) 2528 : heap_(heap), 2529 failed_(false) {} 2530 2531 void operator()(mirror::Object* obj) const 2532 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2533 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2534 obj->VisitReferences<true>(visitor, VoidFunctor()); 2535 } 2536 2537 bool Failed() const { 2538 return failed_; 2539 } 2540 2541 private: 2542 Heap* const heap_; 2543 bool failed_; 2544}; 2545 2546bool Heap::VerifyMissingCardMarks() { 2547 Thread* self = Thread::Current(); 2548 Locks::mutator_lock_->AssertExclusiveHeld(self); 2549 // We need to sort the live stack since we binary search it. 2550 live_stack_->Sort(); 2551 // Since we sorted the allocation stack content, need to revoke all 2552 // thread-local allocation stacks. 2553 RevokeAllThreadLocalAllocationStacks(self); 2554 VerifyLiveStackReferences visitor(this); 2555 GetLiveBitmap()->Visit(visitor); 2556 // We can verify objects in the live stack since none of these should reference dead objects. 2557 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2558 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2559 visitor(*it); 2560 } 2561 } 2562 return !visitor.Failed(); 2563} 2564 2565void Heap::SwapStacks(Thread* self) { 2566 if (kUseThreadLocalAllocationStack) { 2567 live_stack_->AssertAllZero(); 2568 } 2569 allocation_stack_.swap(live_stack_); 2570} 2571 2572void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2573 // This must be called only during the pause. 2574 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2575 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2576 MutexLock mu2(self, *Locks::thread_list_lock_); 2577 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2578 for (Thread* t : thread_list) { 2579 t->RevokeThreadLocalAllocationStack(); 2580 } 2581} 2582 2583void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2584 if (kIsDebugBuild) { 2585 if (rosalloc_space_ != nullptr) { 2586 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2587 } 2588 if (bump_pointer_space_ != nullptr) { 2589 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2590 } 2591 } 2592} 2593 2594void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2595 if (kIsDebugBuild) { 2596 if (bump_pointer_space_ != nullptr) { 2597 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2598 } 2599 } 2600} 2601 2602accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2603 auto it = mod_union_tables_.find(space); 2604 if (it == mod_union_tables_.end()) { 2605 return nullptr; 2606 } 2607 return it->second; 2608} 2609 2610accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2611 auto it = remembered_sets_.find(space); 2612 if (it == remembered_sets_.end()) { 2613 return nullptr; 2614 } 2615 return it->second; 2616} 2617 2618void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2619 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2620 // Clear cards and keep track of cards cleared in the mod-union table. 2621 for (const auto& space : continuous_spaces_) { 2622 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2623 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2624 if (table != nullptr) { 2625 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2626 "ImageModUnionClearCards"; 2627 TimingLogger::ScopedTiming t(name, timings); 2628 table->ClearCards(); 2629 } else if (use_rem_sets && rem_set != nullptr) { 2630 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2631 << static_cast<int>(collector_type_); 2632 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2633 rem_set->ClearCards(); 2634 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2635 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2636 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2637 // were dirty before the GC started. 2638 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2639 // -> clean(cleaning thread). 2640 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2641 // roots and then we scan / update mod union tables after. We will always scan either card. 2642 // If we end up with the non aged card, we scan it it in the pause. 2643 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2644 VoidFunctor()); 2645 } 2646 } 2647} 2648 2649static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2650} 2651 2652void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2653 Thread* const self = Thread::Current(); 2654 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2655 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2656 if (verify_pre_gc_heap_) { 2657 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2658 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2659 size_t failures = VerifyHeapReferences(); 2660 if (failures > 0) { 2661 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2662 << " failures"; 2663 } 2664 } 2665 // Check that all objects which reference things in the live stack are on dirty cards. 2666 if (verify_missing_card_marks_) { 2667 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2668 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2669 SwapStacks(self); 2670 // Sort the live stack so that we can quickly binary search it later. 2671 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2672 << " missing card mark verification failed\n" << DumpSpaces(); 2673 SwapStacks(self); 2674 } 2675 if (verify_mod_union_table_) { 2676 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2677 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2678 for (const auto& table_pair : mod_union_tables_) { 2679 accounting::ModUnionTable* mod_union_table = table_pair.second; 2680 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2681 mod_union_table->Verify(); 2682 } 2683 } 2684} 2685 2686void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2687 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2688 collector::GarbageCollector::ScopedPause pause(gc); 2689 PreGcVerificationPaused(gc); 2690 } 2691} 2692 2693void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2694 // TODO: Add a new runtime option for this? 2695 if (verify_pre_gc_rosalloc_) { 2696 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2697 } 2698} 2699 2700void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2701 Thread* const self = Thread::Current(); 2702 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2703 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2704 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2705 // reachable objects. 2706 if (verify_pre_sweeping_heap_) { 2707 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2708 CHECK_NE(self->GetState(), kRunnable); 2709 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2710 // Swapping bound bitmaps does nothing. 2711 gc->SwapBitmaps(); 2712 // Pass in false since concurrent reference processing can mean that the reference referents 2713 // may point to dead objects at the point which PreSweepingGcVerification is called. 2714 size_t failures = VerifyHeapReferences(false); 2715 if (failures > 0) { 2716 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2717 << " failures"; 2718 } 2719 gc->SwapBitmaps(); 2720 } 2721 if (verify_pre_sweeping_rosalloc_) { 2722 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2723 } 2724} 2725 2726void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2727 // Only pause if we have to do some verification. 2728 Thread* const self = Thread::Current(); 2729 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2730 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2731 if (verify_system_weaks_) { 2732 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2733 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2734 mark_sweep->VerifySystemWeaks(); 2735 } 2736 if (verify_post_gc_rosalloc_) { 2737 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2738 } 2739 if (verify_post_gc_heap_) { 2740 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2741 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2742 size_t failures = VerifyHeapReferences(); 2743 if (failures > 0) { 2744 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2745 << " failures"; 2746 } 2747 } 2748} 2749 2750void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2751 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2752 collector::GarbageCollector::ScopedPause pause(gc); 2753 PostGcVerificationPaused(gc); 2754 } 2755} 2756 2757void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2758 TimingLogger::ScopedTiming t(name, timings); 2759 for (const auto& space : continuous_spaces_) { 2760 if (space->IsRosAllocSpace()) { 2761 VLOG(heap) << name << " : " << space->GetName(); 2762 space->AsRosAllocSpace()->Verify(); 2763 } 2764 } 2765} 2766 2767collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2768 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2769 MutexLock mu(self, *gc_complete_lock_); 2770 return WaitForGcToCompleteLocked(cause, self); 2771} 2772 2773collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2774 collector::GcType last_gc_type = collector::kGcTypeNone; 2775 uint64_t wait_start = NanoTime(); 2776 while (collector_type_running_ != kCollectorTypeNone) { 2777 ATRACE_BEGIN("GC: Wait For Completion"); 2778 // We must wait, change thread state then sleep on gc_complete_cond_; 2779 gc_complete_cond_->Wait(self); 2780 last_gc_type = last_gc_type_; 2781 ATRACE_END(); 2782 } 2783 uint64_t wait_time = NanoTime() - wait_start; 2784 total_wait_time_ += wait_time; 2785 if (wait_time > long_pause_log_threshold_) { 2786 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2787 << " for cause " << cause; 2788 } 2789 return last_gc_type; 2790} 2791 2792void Heap::DumpForSigQuit(std::ostream& os) { 2793 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2794 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2795 DumpGcPerformanceInfo(os); 2796} 2797 2798size_t Heap::GetPercentFree() { 2799 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2800} 2801 2802void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2803 if (max_allowed_footprint > GetMaxMemory()) { 2804 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2805 << PrettySize(GetMaxMemory()); 2806 max_allowed_footprint = GetMaxMemory(); 2807 } 2808 max_allowed_footprint_ = max_allowed_footprint; 2809} 2810 2811bool Heap::IsMovableObject(const mirror::Object* obj) const { 2812 if (kMovingCollector) { 2813 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2814 if (space != nullptr) { 2815 // TODO: Check large object? 2816 return space->CanMoveObjects(); 2817 } 2818 } 2819 return false; 2820} 2821 2822void Heap::UpdateMaxNativeFootprint() { 2823 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2824 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2825 size_t target_size = native_size / GetTargetHeapUtilization(); 2826 if (target_size > native_size + max_free_) { 2827 target_size = native_size + max_free_; 2828 } else if (target_size < native_size + min_free_) { 2829 target_size = native_size + min_free_; 2830 } 2831 native_footprint_gc_watermark_ = target_size; 2832 native_footprint_limit_ = 2 * target_size - native_size; 2833} 2834 2835collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2836 for (const auto& collector : garbage_collectors_) { 2837 if (collector->GetCollectorType() == collector_type_ && 2838 collector->GetGcType() == gc_type) { 2839 return collector; 2840 } 2841 } 2842 return nullptr; 2843} 2844 2845double Heap::HeapGrowthMultiplier() const { 2846 // If we don't care about pause times we are background, so return 1.0. 2847 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2848 return 1.0; 2849 } 2850 return foreground_heap_growth_multiplier_; 2851} 2852 2853void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2854 // We know what our utilization is at this moment. 2855 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2856 const uint64_t bytes_allocated = GetBytesAllocated(); 2857 last_gc_size_ = bytes_allocated; 2858 last_gc_time_ns_ = NanoTime(); 2859 uint64_t target_size; 2860 collector::GcType gc_type = collector_ran->GetGcType(); 2861 if (gc_type != collector::kGcTypeSticky) { 2862 // Grow the heap for non sticky GC. 2863 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2864 // foreground. 2865 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2866 CHECK_GE(delta, 0); 2867 target_size = bytes_allocated + delta * multiplier; 2868 target_size = std::min(target_size, 2869 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2870 target_size = std::max(target_size, 2871 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2872 native_need_to_run_finalization_ = true; 2873 next_gc_type_ = collector::kGcTypeSticky; 2874 } else { 2875 collector::GcType non_sticky_gc_type = 2876 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 2877 // Find what the next non sticky collector will be. 2878 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2879 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2880 // do another sticky collection next. 2881 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2882 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2883 // if the sticky GC throughput always remained >= the full/partial throughput. 2884 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2885 non_sticky_collector->GetEstimatedMeanThroughput() && 2886 non_sticky_collector->NumberOfIterations() > 0 && 2887 bytes_allocated <= max_allowed_footprint_) { 2888 next_gc_type_ = collector::kGcTypeSticky; 2889 } else { 2890 next_gc_type_ = non_sticky_gc_type; 2891 } 2892 // If we have freed enough memory, shrink the heap back down. 2893 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2894 target_size = bytes_allocated + max_free_; 2895 } else { 2896 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2897 } 2898 } 2899 if (!ignore_max_footprint_) { 2900 SetIdealFootprint(target_size); 2901 if (IsGcConcurrent()) { 2902 // Calculate when to perform the next ConcurrentGC. 2903 // Calculate the estimated GC duration. 2904 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2905 // Estimate how many remaining bytes we will have when we need to start the next GC. 2906 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2907 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2908 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2909 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2910 // A never going to happen situation that from the estimated allocation rate we will exceed 2911 // the applications entire footprint with the given estimated allocation rate. Schedule 2912 // another GC nearly straight away. 2913 remaining_bytes = kMinConcurrentRemainingBytes; 2914 } 2915 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2916 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 2917 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2918 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2919 // right away. 2920 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2921 static_cast<size_t>(bytes_allocated)); 2922 } 2923 } 2924} 2925 2926void Heap::ClearGrowthLimit() { 2927 growth_limit_ = capacity_; 2928 non_moving_space_->ClearGrowthLimit(); 2929} 2930 2931void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2932 ScopedObjectAccess soa(self); 2933 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2934 jvalue args[1]; 2935 args[0].l = arg.get(); 2936 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2937 // Restore object in case it gets moved. 2938 *object = soa.Decode<mirror::Object*>(arg.get()); 2939} 2940 2941void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2942 StackHandleScope<1> hs(self); 2943 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2944 RequestConcurrentGC(self); 2945} 2946 2947void Heap::RequestConcurrentGC(Thread* self) { 2948 // Make sure that we can do a concurrent GC. 2949 Runtime* runtime = Runtime::Current(); 2950 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2951 self->IsHandlingStackOverflow()) { 2952 return; 2953 } 2954 // We already have a request pending, no reason to start more until we update 2955 // concurrent_start_bytes_. 2956 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2957 JNIEnv* env = self->GetJniEnv(); 2958 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2959 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2960 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2961 WellKnownClasses::java_lang_Daemons_requestGC); 2962 CHECK(!env->ExceptionCheck()); 2963} 2964 2965void Heap::ConcurrentGC(Thread* self) { 2966 if (Runtime::Current()->IsShuttingDown(self)) { 2967 return; 2968 } 2969 // Wait for any GCs currently running to finish. 2970 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2971 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2972 // instead. E.g. can't do partial, so do full instead. 2973 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2974 collector::kGcTypeNone) { 2975 for (collector::GcType gc_type : gc_plan_) { 2976 // Attempt to run the collector, if we succeed, we are done. 2977 if (gc_type > next_gc_type_ && 2978 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2979 break; 2980 } 2981 } 2982 } 2983 } 2984} 2985 2986void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2987 Thread* self = Thread::Current(); 2988 { 2989 MutexLock mu(self, *heap_trim_request_lock_); 2990 if (desired_collector_type_ == desired_collector_type) { 2991 return; 2992 } 2993 heap_transition_or_trim_target_time_ = 2994 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2995 desired_collector_type_ = desired_collector_type; 2996 } 2997 SignalHeapTrimDaemon(self); 2998} 2999 3000void Heap::RequestHeapTrim() { 3001 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3002 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3003 // a space it will hold its lock and can become a cause of jank. 3004 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3005 // forking. 3006 3007 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3008 // because that only marks object heads, so a large array looks like lots of empty space. We 3009 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3010 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3011 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3012 // not how much use we're making of those pages. 3013 3014 Thread* self = Thread::Current(); 3015 Runtime* runtime = Runtime::Current(); 3016 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 3017 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 3018 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 3019 // as we don't hold the lock while requesting the trim). 3020 return; 3021 } 3022 { 3023 MutexLock mu(self, *heap_trim_request_lock_); 3024 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 3025 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 3026 // just yet. 3027 return; 3028 } 3029 heap_trim_request_pending_ = true; 3030 uint64_t current_time = NanoTime(); 3031 if (heap_transition_or_trim_target_time_ < current_time) { 3032 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 3033 } 3034 } 3035 // Notify the daemon thread which will actually do the heap trim. 3036 SignalHeapTrimDaemon(self); 3037} 3038 3039void Heap::SignalHeapTrimDaemon(Thread* self) { 3040 JNIEnv* env = self->GetJniEnv(); 3041 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 3042 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 3043 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 3044 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 3045 CHECK(!env->ExceptionCheck()); 3046} 3047 3048void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3049 if (rosalloc_space_ != nullptr) { 3050 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3051 } 3052 if (bump_pointer_space_ != nullptr) { 3053 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 3054 } 3055} 3056 3057void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3058 if (rosalloc_space_ != nullptr) { 3059 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3060 } 3061} 3062 3063void Heap::RevokeAllThreadLocalBuffers() { 3064 if (rosalloc_space_ != nullptr) { 3065 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3066 } 3067 if (bump_pointer_space_ != nullptr) { 3068 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3069 } 3070} 3071 3072bool Heap::IsGCRequestPending() const { 3073 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3074} 3075 3076void Heap::RunFinalization(JNIEnv* env) { 3077 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3078 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3079 CHECK(WellKnownClasses::java_lang_System != nullptr); 3080 WellKnownClasses::java_lang_System_runFinalization = 3081 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3082 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3083 } 3084 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3085 WellKnownClasses::java_lang_System_runFinalization); 3086} 3087 3088void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3089 Thread* self = ThreadForEnv(env); 3090 if (native_need_to_run_finalization_) { 3091 RunFinalization(env); 3092 UpdateMaxNativeFootprint(); 3093 native_need_to_run_finalization_ = false; 3094 } 3095 // Total number of native bytes allocated. 3096 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3097 new_native_bytes_allocated += bytes; 3098 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3099 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3100 collector::kGcTypeFull; 3101 3102 // The second watermark is higher than the gc watermark. If you hit this it means you are 3103 // allocating native objects faster than the GC can keep up with. 3104 if (new_native_bytes_allocated > native_footprint_limit_) { 3105 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3106 // Just finished a GC, attempt to run finalizers. 3107 RunFinalization(env); 3108 CHECK(!env->ExceptionCheck()); 3109 } 3110 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3111 if (new_native_bytes_allocated > native_footprint_limit_) { 3112 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3113 RunFinalization(env); 3114 native_need_to_run_finalization_ = false; 3115 CHECK(!env->ExceptionCheck()); 3116 } 3117 // We have just run finalizers, update the native watermark since it is very likely that 3118 // finalizers released native managed allocations. 3119 UpdateMaxNativeFootprint(); 3120 } else if (!IsGCRequestPending()) { 3121 if (IsGcConcurrent()) { 3122 RequestConcurrentGC(self); 3123 } else { 3124 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3125 } 3126 } 3127 } 3128} 3129 3130void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3131 int expected_size, new_size; 3132 do { 3133 expected_size = native_bytes_allocated_.LoadRelaxed(); 3134 new_size = expected_size - bytes; 3135 if (UNLIKELY(new_size < 0)) { 3136 ScopedObjectAccess soa(env); 3137 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3138 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3139 "registered as allocated", bytes, expected_size).c_str()); 3140 break; 3141 } 3142 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3143} 3144 3145size_t Heap::GetTotalMemory() const { 3146 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3147} 3148 3149void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3150 DCHECK(mod_union_table != nullptr); 3151 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3152} 3153 3154void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3155 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3156 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3157 CHECK_GE(byte_count, sizeof(mirror::Object)); 3158} 3159 3160void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3161 CHECK(remembered_set != nullptr); 3162 space::Space* space = remembered_set->GetSpace(); 3163 CHECK(space != nullptr); 3164 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3165 remembered_sets_.Put(space, remembered_set); 3166 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3167} 3168 3169void Heap::RemoveRememberedSet(space::Space* space) { 3170 CHECK(space != nullptr); 3171 auto it = remembered_sets_.find(space); 3172 CHECK(it != remembered_sets_.end()); 3173 delete it->second; 3174 remembered_sets_.erase(it); 3175 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3176} 3177 3178void Heap::ClearMarkedObjects() { 3179 // Clear all of the spaces' mark bitmaps. 3180 for (const auto& space : GetContinuousSpaces()) { 3181 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3182 if (space->GetLiveBitmap() != mark_bitmap) { 3183 mark_bitmap->Clear(); 3184 } 3185 } 3186 // Clear the marked objects in the discontinous space object sets. 3187 for (const auto& space : GetDiscontinuousSpaces()) { 3188 space->GetMarkBitmap()->Clear(); 3189 } 3190} 3191 3192} // namespace gc 3193} // namespace art 3194