heap.cc revision b363f666883860d40823d5528df3c98c897f74f4
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/concurrent_copying.h" 39#include "gc/collector/mark_compact.h" 40#include "gc/collector/mark_sweep-inl.h" 41#include "gc/collector/partial_mark_sweep.h" 42#include "gc/collector/semi_space.h" 43#include "gc/collector/sticky_mark_sweep.h" 44#include "gc/reference_processor.h" 45#include "gc/space/bump_pointer_space.h" 46#include "gc/space/dlmalloc_space-inl.h" 47#include "gc/space/image_space.h" 48#include "gc/space/large_object_space.h" 49#include "gc/space/rosalloc_space-inl.h" 50#include "gc/space/space-inl.h" 51#include "gc/space/zygote_space.h" 52#include "entrypoints/quick/quick_alloc_entrypoints.h" 53#include "heap-inl.h" 54#include "image.h" 55#include "mirror/art_field-inl.h" 56#include "mirror/class-inl.h" 57#include "mirror/object.h" 58#include "mirror/object-inl.h" 59#include "mirror/object_array-inl.h" 60#include "mirror/reference-inl.h" 61#include "os.h" 62#include "reflection.h" 63#include "runtime.h" 64#include "ScopedLocalRef.h" 65#include "scoped_thread_state_change.h" 66#include "handle_scope-inl.h" 67#include "thread_list.h" 68#include "well_known_classes.h" 69 70namespace art { 71 72namespace gc { 73 74static constexpr size_t kCollectorTransitionStressIterations = 0; 75static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 76static constexpr bool kGCALotMode = false; 77static constexpr size_t kGcAlotInterval = KB; 78// Minimum amount of remaining bytes before a concurrent GC is triggered. 79static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 80static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 81// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 82// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 83// threads (lower pauses, use less memory bandwidth). 84static constexpr double kStickyGcThroughputAdjustment = 1.0; 85// Whether or not we use the free list large object space. 86static constexpr bool kUseFreeListSpaceForLOS = false; 87// Whether or not we compact the zygote in PreZygoteFork. 88static constexpr bool kCompactZygote = kMovingCollector; 89static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 90// How many reserve entries are at the end of the allocation stack, these are only needed if the 91// allocation stack overflows. 92static constexpr size_t kAllocationStackReserveSize = 1024; 93// Default mark stack size in bytes. 94static const size_t kDefaultMarkStackSize = 64 * KB; 95// Define space name. 96static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 97static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 98static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 99static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 100 101Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 102 double target_utilization, double foreground_heap_growth_multiplier, size_t capacity, 103 const std::string& image_file_name, const InstructionSet image_instruction_set, 104 CollectorType foreground_collector_type, CollectorType background_collector_type, 105 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 106 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 107 bool ignore_max_footprint, bool use_tlab, 108 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 109 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 110 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 111 uint64_t min_interval_homogeneous_space_compaction_by_oom) 112 : non_moving_space_(nullptr), 113 rosalloc_space_(nullptr), 114 dlmalloc_space_(nullptr), 115 main_space_(nullptr), 116 collector_type_(kCollectorTypeNone), 117 foreground_collector_type_(foreground_collector_type), 118 background_collector_type_(background_collector_type), 119 desired_collector_type_(foreground_collector_type_), 120 heap_trim_request_lock_(nullptr), 121 last_trim_time_(0), 122 heap_transition_or_trim_target_time_(0), 123 heap_trim_request_pending_(false), 124 parallel_gc_threads_(parallel_gc_threads), 125 conc_gc_threads_(conc_gc_threads), 126 low_memory_mode_(low_memory_mode), 127 long_pause_log_threshold_(long_pause_log_threshold), 128 long_gc_log_threshold_(long_gc_log_threshold), 129 ignore_max_footprint_(ignore_max_footprint), 130 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 131 have_zygote_space_(false), 132 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 133 collector_type_running_(kCollectorTypeNone), 134 last_gc_type_(collector::kGcTypeNone), 135 next_gc_type_(collector::kGcTypePartial), 136 capacity_(capacity), 137 growth_limit_(growth_limit), 138 max_allowed_footprint_(initial_size), 139 native_footprint_gc_watermark_(initial_size), 140 native_footprint_limit_(2 * initial_size), 141 native_need_to_run_finalization_(false), 142 // Initially assume we perceive jank in case the process state is never updated. 143 process_state_(kProcessStateJankPerceptible), 144 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 145 total_bytes_freed_ever_(0), 146 total_objects_freed_ever_(0), 147 num_bytes_allocated_(0), 148 native_bytes_allocated_(0), 149 gc_memory_overhead_(0), 150 verify_missing_card_marks_(false), 151 verify_system_weaks_(false), 152 verify_pre_gc_heap_(verify_pre_gc_heap), 153 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 154 verify_post_gc_heap_(verify_post_gc_heap), 155 verify_mod_union_table_(false), 156 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 157 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 158 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 159 last_gc_time_ns_(NanoTime()), 160 allocation_rate_(0), 161 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 162 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 163 * verification is enabled, we limit the size of allocation stacks to speed up their 164 * searching. 165 */ 166 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 167 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 168 current_allocator_(kAllocatorTypeDlMalloc), 169 current_non_moving_allocator_(kAllocatorTypeNonMoving), 170 bump_pointer_space_(nullptr), 171 temp_space_(nullptr), 172 min_free_(min_free), 173 max_free_(max_free), 174 target_utilization_(target_utilization), 175 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 176 total_wait_time_(0), 177 total_allocation_time_(0), 178 verify_object_mode_(kVerifyObjectModeDisabled), 179 disable_moving_gc_count_(0), 180 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 181 use_tlab_(use_tlab), 182 main_space_backup_(nullptr), 183 min_interval_homogeneous_space_compaction_by_oom_( 184 min_interval_homogeneous_space_compaction_by_oom), 185 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 186 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 187 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 188 LOG(INFO) << "Heap() entering"; 189 } 190 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 191 // entrypoints. 192 if (!Runtime::Current()->IsZygote()) { 193 large_object_threshold_ = kDefaultLargeObjectThreshold; 194 // Background compaction is currently not supported for command line runs. 195 if (background_collector_type_ != foreground_collector_type_) { 196 VLOG(heap) << "Disabling background compaction for non zygote"; 197 background_collector_type_ = foreground_collector_type_; 198 } 199 } 200 ChangeCollector(desired_collector_type_); 201 live_bitmap_.reset(new accounting::HeapBitmap(this)); 202 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 203 // Requested begin for the alloc space, to follow the mapped image and oat files 204 byte* requested_alloc_space_begin = nullptr; 205 if (!image_file_name.empty()) { 206 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 207 image_instruction_set); 208 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 209 AddSpace(image_space); 210 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 211 // isn't going to get in the middle 212 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 213 CHECK_GT(oat_file_end_addr, image_space->End()); 214 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 215 } 216 /* 217 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 218 +- nonmoving space (kNonMovingSpaceCapacity) +- 219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 220 +-main alloc space / bump space 1 (capacity_) +- 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 222 +-????????????????????????????????????????????+- 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 224 +-main alloc space2 / bump space 2 (capacity_)+- 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 226 */ 227 bool support_homogeneous_space_compaction = 228 background_collector_type == gc::kCollectorTypeHomogeneousSpaceCompact || 229 use_homogeneous_space_compaction_for_oom; 230 // We may use the same space the main space for the non moving space if we don't need to compact 231 // from the main space. 232 // This is not the case if we support homogeneous compaction or have a moving background 233 // collector type. 234 const bool is_zygote = Runtime::Current()->IsZygote(); 235 bool separate_non_moving_space = is_zygote || 236 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 237 IsMovingGc(background_collector_type_); 238 if (foreground_collector_type == kCollectorTypeGSS) { 239 separate_non_moving_space = false; 240 } 241 std::unique_ptr<MemMap> main_mem_map_1; 242 std::unique_ptr<MemMap> main_mem_map_2; 243 byte* request_begin = requested_alloc_space_begin; 244 if (request_begin != nullptr && separate_non_moving_space) { 245 request_begin += kNonMovingSpaceCapacity; 246 } 247 std::string error_str; 248 std::unique_ptr<MemMap> non_moving_space_mem_map; 249 if (separate_non_moving_space) { 250 // Reserve the non moving mem map before the other two since it needs to be at a specific 251 // address. 252 non_moving_space_mem_map.reset( 253 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 254 kNonMovingSpaceCapacity, PROT_READ | PROT_WRITE, true, &error_str)); 255 CHECK(non_moving_space_mem_map != nullptr) << error_str; 256 } 257 // Attempt to create 2 mem maps at or after the requested begin. 258 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 259 PROT_READ | PROT_WRITE, &error_str)); 260 CHECK(main_mem_map_1.get() != nullptr) << error_str; 261 if (support_homogeneous_space_compaction || 262 background_collector_type_ == kCollectorTypeSS || 263 foreground_collector_type_ == kCollectorTypeSS) { 264 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 265 capacity_, PROT_READ | PROT_WRITE, 266 &error_str)); 267 CHECK(main_mem_map_2.get() != nullptr) << error_str; 268 } 269 // Create the non moving space first so that bitmaps don't take up the address range. 270 if (separate_non_moving_space) { 271 // Non moving space is always dlmalloc since we currently don't have support for multiple 272 // active rosalloc spaces. 273 const size_t size = non_moving_space_mem_map->Size(); 274 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 275 non_moving_space_mem_map.release(), "zygote / non moving space", initial_size, 276 initial_size, size, size, false); 277 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 278 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 279 << requested_alloc_space_begin; 280 AddSpace(non_moving_space_); 281 } 282 // Create other spaces based on whether or not we have a moving GC. 283 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 284 // Create bump pointer spaces. 285 // We only to create the bump pointer if the foreground collector is a compacting GC. 286 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 287 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 288 main_mem_map_1.release()); 289 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 290 AddSpace(bump_pointer_space_); 291 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 292 main_mem_map_2.release()); 293 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 294 AddSpace(temp_space_); 295 CHECK(separate_non_moving_space); 296 } else { 297 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 298 CHECK(main_space_ != nullptr); 299 AddSpace(main_space_); 300 if (!separate_non_moving_space) { 301 non_moving_space_ = main_space_; 302 CHECK(!non_moving_space_->CanMoveObjects()); 303 } 304 if (foreground_collector_type_ == kCollectorTypeGSS) { 305 CHECK_EQ(foreground_collector_type_, background_collector_type_); 306 // Create bump pointer spaces instead of a backup space. 307 main_mem_map_2.release(); 308 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 309 kGSSBumpPointerSpaceCapacity, nullptr); 310 CHECK(bump_pointer_space_ != nullptr); 311 AddSpace(bump_pointer_space_); 312 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 313 kGSSBumpPointerSpaceCapacity, nullptr); 314 CHECK(temp_space_ != nullptr); 315 AddSpace(temp_space_); 316 } else if (main_mem_map_2.get() != nullptr) { 317 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 318 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 319 growth_limit_, capacity_, name, true)); 320 CHECK(main_space_backup_.get() != nullptr); 321 // Add the space so its accounted for in the heap_begin and heap_end. 322 AddSpace(main_space_backup_.get()); 323 } 324 } 325 CHECK(non_moving_space_ != nullptr); 326 CHECK(!non_moving_space_->CanMoveObjects()); 327 // Allocate the large object space. 328 if (kUseFreeListSpaceForLOS) { 329 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 330 } else { 331 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 332 } 333 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 334 AddSpace(large_object_space_); 335 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 336 CHECK(!continuous_spaces_.empty()); 337 // Relies on the spaces being sorted. 338 byte* heap_begin = continuous_spaces_.front()->Begin(); 339 byte* heap_end = continuous_spaces_.back()->Limit(); 340 size_t heap_capacity = heap_end - heap_begin; 341 // Remove the main backup space since it slows down the GC to have unused extra spaces. 342 if (main_space_backup_.get() != nullptr) { 343 RemoveSpace(main_space_backup_.get()); 344 } 345 // Allocate the card table. 346 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 347 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 348 // Card cache for now since it makes it easier for us to update the references to the copying 349 // spaces. 350 accounting::ModUnionTable* mod_union_table = 351 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 352 GetImageSpace()); 353 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 354 AddModUnionTable(mod_union_table); 355 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 356 accounting::RememberedSet* non_moving_space_rem_set = 357 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 358 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 359 AddRememberedSet(non_moving_space_rem_set); 360 } 361 // TODO: Count objects in the image space here? 362 num_bytes_allocated_.StoreRelaxed(0); 363 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 364 kDefaultMarkStackSize)); 365 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 366 allocation_stack_.reset(accounting::ObjectStack::Create( 367 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 368 live_stack_.reset(accounting::ObjectStack::Create( 369 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 370 // It's still too early to take a lock because there are no threads yet, but we can create locks 371 // now. We don't create it earlier to make it clear that you can't use locks during heap 372 // initialization. 373 gc_complete_lock_ = new Mutex("GC complete lock"); 374 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 375 *gc_complete_lock_)); 376 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 377 last_gc_size_ = GetBytesAllocated(); 378 if (ignore_max_footprint_) { 379 SetIdealFootprint(std::numeric_limits<size_t>::max()); 380 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 381 } 382 CHECK_NE(max_allowed_footprint_, 0U); 383 // Create our garbage collectors. 384 for (size_t i = 0; i < 2; ++i) { 385 const bool concurrent = i != 0; 386 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 387 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 388 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 389 } 390 if (kMovingCollector) { 391 // TODO: Clean this up. 392 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 393 semi_space_collector_ = new collector::SemiSpace(this, generational, 394 generational ? "generational" : ""); 395 garbage_collectors_.push_back(semi_space_collector_); 396 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 397 garbage_collectors_.push_back(concurrent_copying_collector_); 398 mark_compact_collector_ = new collector::MarkCompact(this); 399 garbage_collectors_.push_back(mark_compact_collector_); 400 } 401 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr) { 402 // Check that there's no gap between the image space and the non moving space so that the 403 // immune region won't break (eg. due to a large object allocated in the gap). 404 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 405 non_moving_space_->GetMemMap()); 406 if (!no_gap) { 407 MemMap::DumpMaps(LOG(ERROR)); 408 LOG(FATAL) << "There's a gap between the image space and the main space"; 409 } 410 } 411 if (running_on_valgrind_) { 412 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 413 } 414 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 415 LOG(INFO) << "Heap() exiting"; 416 } 417} 418 419MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 420 int prot_flags, std::string* out_error_str) { 421 while (true) { 422 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 423 PROT_READ | PROT_WRITE, true, out_error_str); 424 if (map != nullptr || request_begin == nullptr) { 425 return map; 426 } 427 // Retry a second time with no specified request begin. 428 request_begin = nullptr; 429 } 430 return nullptr; 431} 432 433space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 434 size_t growth_limit, size_t capacity, 435 const char* name, bool can_move_objects) { 436 space::MallocSpace* malloc_space = nullptr; 437 if (kUseRosAlloc) { 438 // Create rosalloc space. 439 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 440 initial_size, growth_limit, capacity, 441 low_memory_mode_, can_move_objects); 442 } else { 443 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 444 initial_size, growth_limit, capacity, 445 can_move_objects); 446 } 447 if (collector::SemiSpace::kUseRememberedSet) { 448 accounting::RememberedSet* rem_set = 449 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 450 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 451 AddRememberedSet(rem_set); 452 } 453 CHECK(malloc_space != nullptr) << "Failed to create " << name; 454 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 455 return malloc_space; 456} 457 458void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 459 size_t capacity) { 460 // Is background compaction is enabled? 461 bool can_move_objects = IsMovingGc(background_collector_type_) != 462 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 463 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 464 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 465 // from the main space to the zygote space. If background compaction is enabled, always pass in 466 // that we can move objets. 467 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 468 // After the zygote we want this to be false if we don't have background compaction enabled so 469 // that getting primitive array elements is faster. 470 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 471 can_move_objects = !have_zygote_space_ && foreground_collector_type_ != kCollectorTypeGSS; 472 } 473 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 474 RemoveRememberedSet(main_space_); 475 } 476 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 477 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 478 can_move_objects); 479 SetSpaceAsDefault(main_space_); 480 VLOG(heap) << "Created main space " << main_space_; 481} 482 483void Heap::ChangeAllocator(AllocatorType allocator) { 484 if (current_allocator_ != allocator) { 485 // These two allocators are only used internally and don't have any entrypoints. 486 CHECK_NE(allocator, kAllocatorTypeLOS); 487 CHECK_NE(allocator, kAllocatorTypeNonMoving); 488 current_allocator_ = allocator; 489 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 490 SetQuickAllocEntryPointsAllocator(current_allocator_); 491 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 492 } 493} 494 495void Heap::DisableCompaction() { 496 if (IsMovingGc(foreground_collector_type_)) { 497 foreground_collector_type_ = kCollectorTypeCMS; 498 } 499 if (IsMovingGc(background_collector_type_)) { 500 background_collector_type_ = foreground_collector_type_; 501 } 502 TransitionCollector(foreground_collector_type_); 503} 504 505std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 506 if (!IsValidContinuousSpaceObjectAddress(klass)) { 507 return StringPrintf("<non heap address klass %p>", klass); 508 } 509 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 510 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 511 std::string result("["); 512 result += SafeGetClassDescriptor(component_type); 513 return result; 514 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 515 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 516 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 517 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 518 } else { 519 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 520 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 521 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 522 } 523 const DexFile* dex_file = dex_cache->GetDexFile(); 524 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 525 if (class_def_idx == DexFile::kDexNoIndex16) { 526 return "<class def not found>"; 527 } 528 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 529 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 530 return dex_file->GetTypeDescriptor(type_id); 531 } 532} 533 534std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 535 if (obj == nullptr) { 536 return "null"; 537 } 538 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 539 if (klass == nullptr) { 540 return "(class=null)"; 541 } 542 std::string result(SafeGetClassDescriptor(klass)); 543 if (obj->IsClass()) { 544 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 545 } 546 return result; 547} 548 549void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 550 if (obj == nullptr) { 551 stream << "(obj=null)"; 552 return; 553 } 554 if (IsAligned<kObjectAlignment>(obj)) { 555 space::Space* space = nullptr; 556 // Don't use find space since it only finds spaces which actually contain objects instead of 557 // spaces which may contain objects (e.g. cleared bump pointer spaces). 558 for (const auto& cur_space : continuous_spaces_) { 559 if (cur_space->HasAddress(obj)) { 560 space = cur_space; 561 break; 562 } 563 } 564 // Unprotect all the spaces. 565 for (const auto& space : continuous_spaces_) { 566 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 567 } 568 stream << "Object " << obj; 569 if (space != nullptr) { 570 stream << " in space " << *space; 571 } 572 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 573 stream << "\nclass=" << klass; 574 if (klass != nullptr) { 575 stream << " type= " << SafePrettyTypeOf(obj); 576 } 577 // Re-protect the address we faulted on. 578 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 579 } 580} 581 582bool Heap::IsCompilingBoot() const { 583 for (const auto& space : continuous_spaces_) { 584 if (space->IsImageSpace() || space->IsZygoteSpace()) { 585 return false; 586 } 587 } 588 return true; 589} 590 591bool Heap::HasImageSpace() const { 592 for (const auto& space : continuous_spaces_) { 593 if (space->IsImageSpace()) { 594 return true; 595 } 596 } 597 return false; 598} 599 600void Heap::IncrementDisableMovingGC(Thread* self) { 601 // Need to do this holding the lock to prevent races where the GC is about to run / running when 602 // we attempt to disable it. 603 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 604 MutexLock mu(self, *gc_complete_lock_); 605 ++disable_moving_gc_count_; 606 if (IsMovingGc(collector_type_running_)) { 607 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 608 } 609} 610 611void Heap::DecrementDisableMovingGC(Thread* self) { 612 MutexLock mu(self, *gc_complete_lock_); 613 CHECK_GE(disable_moving_gc_count_, 0U); 614 --disable_moving_gc_count_; 615} 616 617void Heap::UpdateProcessState(ProcessState process_state) { 618 if (process_state_ != process_state) { 619 process_state_ = process_state; 620 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 621 // Start at index 1 to avoid "is always false" warning. 622 // Have iteration 1 always transition the collector. 623 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 624 ? foreground_collector_type_ : background_collector_type_); 625 usleep(kCollectorTransitionStressWait); 626 } 627 if (process_state_ == kProcessStateJankPerceptible) { 628 // Transition back to foreground right away to prevent jank. 629 RequestCollectorTransition(foreground_collector_type_, 0); 630 } else { 631 // Don't delay for debug builds since we may want to stress test the GC. 632 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 633 // special handling which does a homogenous space compaction once but then doesn't transition 634 // the collector. 635 RequestCollectorTransition(background_collector_type_, 636 kIsDebugBuild ? 0 : kCollectorTransitionWait); 637 } 638 } 639} 640 641void Heap::CreateThreadPool() { 642 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 643 if (num_threads != 0) { 644 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 645 } 646} 647 648void Heap::VisitObjects(ObjectCallback callback, void* arg) { 649 Thread* self = Thread::Current(); 650 // GCs can move objects, so don't allow this. 651 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 652 if (bump_pointer_space_ != nullptr) { 653 // Visit objects in bump pointer space. 654 bump_pointer_space_->Walk(callback, arg); 655 } 656 // TODO: Switch to standard begin and end to use ranged a based loop. 657 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 658 it < end; ++it) { 659 mirror::Object* obj = *it; 660 if (obj != nullptr && obj->GetClass() != nullptr) { 661 // Avoid the race condition caused by the object not yet being written into the allocation 662 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 663 // there can be nulls on the allocation stack. 664 callback(obj, arg); 665 } 666 } 667 GetLiveBitmap()->Walk(callback, arg); 668 self->EndAssertNoThreadSuspension(old_cause); 669} 670 671void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 672 space::ContinuousSpace* space1 = rosalloc_space_ != nullptr ? rosalloc_space_ : non_moving_space_; 673 space::ContinuousSpace* space2 = dlmalloc_space_ != nullptr ? dlmalloc_space_ : non_moving_space_; 674 // This is just logic to handle a case of either not having a rosalloc or dlmalloc space. 675 // TODO: Generalize this to n bitmaps? 676 if (space1 == nullptr) { 677 DCHECK(space2 != nullptr); 678 space1 = space2; 679 } 680 if (space2 == nullptr) { 681 DCHECK(space1 != nullptr); 682 space2 = space1; 683 } 684 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 685 large_object_space_->GetLiveBitmap(), stack); 686} 687 688void Heap::DeleteThreadPool() { 689 thread_pool_.reset(nullptr); 690} 691 692void Heap::AddSpace(space::Space* space) { 693 CHECK(space != nullptr); 694 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 695 if (space->IsContinuousSpace()) { 696 DCHECK(!space->IsDiscontinuousSpace()); 697 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 698 // Continuous spaces don't necessarily have bitmaps. 699 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 700 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 701 if (live_bitmap != nullptr) { 702 DCHECK(mark_bitmap != nullptr); 703 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 704 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 705 } 706 continuous_spaces_.push_back(continuous_space); 707 // Ensure that spaces remain sorted in increasing order of start address. 708 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 709 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 710 return a->Begin() < b->Begin(); 711 }); 712 } else { 713 DCHECK(space->IsDiscontinuousSpace()); 714 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 715 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 716 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 717 discontinuous_spaces_.push_back(discontinuous_space); 718 } 719 if (space->IsAllocSpace()) { 720 alloc_spaces_.push_back(space->AsAllocSpace()); 721 } 722} 723 724void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 725 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 726 if (continuous_space->IsDlMallocSpace()) { 727 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 728 } else if (continuous_space->IsRosAllocSpace()) { 729 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 730 } 731} 732 733void Heap::RemoveSpace(space::Space* space) { 734 DCHECK(space != nullptr); 735 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 736 if (space->IsContinuousSpace()) { 737 DCHECK(!space->IsDiscontinuousSpace()); 738 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 739 // Continuous spaces don't necessarily have bitmaps. 740 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 741 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 742 if (live_bitmap != nullptr) { 743 DCHECK(mark_bitmap != nullptr); 744 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 745 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 746 } 747 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 748 DCHECK(it != continuous_spaces_.end()); 749 continuous_spaces_.erase(it); 750 } else { 751 DCHECK(space->IsDiscontinuousSpace()); 752 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 753 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 754 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 755 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 756 discontinuous_space); 757 DCHECK(it != discontinuous_spaces_.end()); 758 discontinuous_spaces_.erase(it); 759 } 760 if (space->IsAllocSpace()) { 761 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 762 DCHECK(it != alloc_spaces_.end()); 763 alloc_spaces_.erase(it); 764 } 765} 766 767void Heap::RegisterGCAllocation(size_t bytes) { 768 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 769} 770 771void Heap::RegisterGCDeAllocation(size_t bytes) { 772 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 773} 774 775void Heap::DumpGcPerformanceInfo(std::ostream& os) { 776 // Dump cumulative timings. 777 os << "Dumping cumulative Gc timings\n"; 778 uint64_t total_duration = 0; 779 // Dump cumulative loggers for each GC type. 780 uint64_t total_paused_time = 0; 781 for (auto& collector : garbage_collectors_) { 782 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 783 const size_t iterations = logger.GetIterations(); 784 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 785 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 786 os << ConstDumpable<CumulativeLogger>(logger); 787 const uint64_t total_ns = logger.GetTotalNs(); 788 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 789 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 790 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 791 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 792 Histogram<uint64_t>::CumulativeData cumulative_data; 793 pause_histogram.CreateHistogram(&cumulative_data); 794 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 795 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 796 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 797 << collector->GetName() << " freed: " << freed_objects 798 << " objects with total size " << PrettySize(freed_bytes) << "\n" 799 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 800 << PrettySize(freed_bytes / seconds) << "/s\n"; 801 total_duration += total_ns; 802 total_paused_time += total_pause_ns; 803 } 804 collector->ResetMeasurements(); 805 } 806 uint64_t allocation_time = 807 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 808 if (total_duration != 0) { 809 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 810 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 811 os << "Mean GC size throughput: " 812 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 813 os << "Mean GC object throughput: " 814 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 815 } 816 size_t total_objects_allocated = GetObjectsAllocatedEver(); 817 os << "Total number of allocations: " << total_objects_allocated << "\n"; 818 size_t total_bytes_allocated = GetBytesAllocatedEver(); 819 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 820 if (kMeasureAllocationTime) { 821 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 822 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 823 << "\n"; 824 } 825 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 826 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 827 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 828 BaseMutex::DumpAll(os); 829} 830 831Heap::~Heap() { 832 VLOG(heap) << "Starting ~Heap()"; 833 STLDeleteElements(&garbage_collectors_); 834 // If we don't reset then the mark stack complains in its destructor. 835 allocation_stack_->Reset(); 836 live_stack_->Reset(); 837 STLDeleteValues(&mod_union_tables_); 838 STLDeleteValues(&remembered_sets_); 839 STLDeleteElements(&continuous_spaces_); 840 STLDeleteElements(&discontinuous_spaces_); 841 delete gc_complete_lock_; 842 delete heap_trim_request_lock_; 843 VLOG(heap) << "Finished ~Heap()"; 844} 845 846space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 847 bool fail_ok) const { 848 for (const auto& space : continuous_spaces_) { 849 if (space->Contains(obj)) { 850 return space; 851 } 852 } 853 if (!fail_ok) { 854 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 855 } 856 return NULL; 857} 858 859space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 860 bool fail_ok) const { 861 for (const auto& space : discontinuous_spaces_) { 862 if (space->Contains(obj)) { 863 return space; 864 } 865 } 866 if (!fail_ok) { 867 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 868 } 869 return NULL; 870} 871 872space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 873 space::Space* result = FindContinuousSpaceFromObject(obj, true); 874 if (result != NULL) { 875 return result; 876 } 877 return FindDiscontinuousSpaceFromObject(obj, true); 878} 879 880space::ImageSpace* Heap::GetImageSpace() const { 881 for (const auto& space : continuous_spaces_) { 882 if (space->IsImageSpace()) { 883 return space->AsImageSpace(); 884 } 885 } 886 return NULL; 887} 888 889void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 890 std::ostringstream oss; 891 size_t total_bytes_free = GetFreeMemory(); 892 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 893 << " free bytes"; 894 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 895 if (total_bytes_free >= byte_count) { 896 space::AllocSpace* space = nullptr; 897 if (allocator_type == kAllocatorTypeNonMoving) { 898 space = non_moving_space_; 899 } else if (allocator_type == kAllocatorTypeRosAlloc || 900 allocator_type == kAllocatorTypeDlMalloc) { 901 space = main_space_; 902 } else if (allocator_type == kAllocatorTypeBumpPointer || 903 allocator_type == kAllocatorTypeTLAB) { 904 space = bump_pointer_space_; 905 } 906 if (space != nullptr) { 907 space->LogFragmentationAllocFailure(oss, byte_count); 908 } 909 } 910 self->ThrowOutOfMemoryError(oss.str().c_str()); 911} 912 913void Heap::DoPendingTransitionOrTrim() { 914 Thread* self = Thread::Current(); 915 CollectorType desired_collector_type; 916 // Wait until we reach the desired transition time. 917 while (true) { 918 uint64_t wait_time; 919 { 920 MutexLock mu(self, *heap_trim_request_lock_); 921 desired_collector_type = desired_collector_type_; 922 uint64_t current_time = NanoTime(); 923 if (current_time >= heap_transition_or_trim_target_time_) { 924 break; 925 } 926 wait_time = heap_transition_or_trim_target_time_ - current_time; 927 } 928 ScopedThreadStateChange tsc(self, kSleeping); 929 usleep(wait_time / 1000); // Usleep takes microseconds. 930 } 931 // Launch homogeneous space compaction if it is desired. 932 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 933 if (!CareAboutPauseTimes()) { 934 PerformHomogeneousSpaceCompact(); 935 } 936 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 937 desired_collector_type = collector_type_; 938 return; 939 } 940 // Transition the collector if the desired collector type is not the same as the current 941 // collector type. 942 TransitionCollector(desired_collector_type); 943 if (!CareAboutPauseTimes()) { 944 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 945 // about pauses. 946 Runtime* runtime = Runtime::Current(); 947 runtime->GetThreadList()->SuspendAll(); 948 uint64_t start_time = NanoTime(); 949 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 950 VLOG(heap) << "Deflating " << count << " monitors took " 951 << PrettyDuration(NanoTime() - start_time); 952 runtime->GetThreadList()->ResumeAll(); 953 } 954 // Do a heap trim if it is needed. 955 Trim(); 956} 957 958void Heap::Trim() { 959 Thread* self = Thread::Current(); 960 { 961 MutexLock mu(self, *heap_trim_request_lock_); 962 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 963 return; 964 } 965 last_trim_time_ = NanoTime(); 966 heap_trim_request_pending_ = false; 967 } 968 { 969 // Need to do this before acquiring the locks since we don't want to get suspended while 970 // holding any locks. 971 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 972 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 973 // trimming. 974 MutexLock mu(self, *gc_complete_lock_); 975 // Ensure there is only one GC at a time. 976 WaitForGcToCompleteLocked(kGcCauseTrim, self); 977 collector_type_running_ = kCollectorTypeHeapTrim; 978 } 979 uint64_t start_ns = NanoTime(); 980 // Trim the managed spaces. 981 uint64_t total_alloc_space_allocated = 0; 982 uint64_t total_alloc_space_size = 0; 983 uint64_t managed_reclaimed = 0; 984 for (const auto& space : continuous_spaces_) { 985 if (space->IsMallocSpace()) { 986 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 987 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 988 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 989 // for a long period of time. 990 managed_reclaimed += malloc_space->Trim(); 991 } 992 total_alloc_space_size += malloc_space->Size(); 993 } 994 } 995 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 996 if (bump_pointer_space_ != nullptr) { 997 total_alloc_space_allocated -= bump_pointer_space_->Size(); 998 } 999 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1000 static_cast<float>(total_alloc_space_size); 1001 uint64_t gc_heap_end_ns = NanoTime(); 1002 // We never move things in the native heap, so we can finish the GC at this point. 1003 FinishGC(self, collector::kGcTypeNone); 1004 size_t native_reclaimed = 0; 1005 // Only trim the native heap if we don't care about pauses. 1006 if (!CareAboutPauseTimes()) { 1007#if defined(USE_DLMALLOC) 1008 // Trim the native heap. 1009 dlmalloc_trim(0); 1010 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1011#elif defined(USE_JEMALLOC) 1012 // Jemalloc does it's own internal trimming. 1013#else 1014 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1015#endif 1016 } 1017 uint64_t end_ns = NanoTime(); 1018 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1019 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1020 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1021 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1022 << "%."; 1023} 1024 1025bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1026 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1027 // taking the lock. 1028 if (obj == nullptr) { 1029 return true; 1030 } 1031 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1032} 1033 1034bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1035 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1036} 1037 1038bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1039 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1040 return false; 1041 } 1042 for (const auto& space : continuous_spaces_) { 1043 if (space->HasAddress(obj)) { 1044 return true; 1045 } 1046 } 1047 return false; 1048} 1049 1050bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1051 bool search_live_stack, bool sorted) { 1052 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1053 return false; 1054 } 1055 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1056 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1057 if (obj == klass) { 1058 // This case happens for java.lang.Class. 1059 return true; 1060 } 1061 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1062 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1063 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1064 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1065 return temp_space_->Contains(obj); 1066 } 1067 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1068 space::DiscontinuousSpace* d_space = nullptr; 1069 if (c_space != nullptr) { 1070 if (c_space->GetLiveBitmap()->Test(obj)) { 1071 return true; 1072 } 1073 } else { 1074 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1075 if (d_space != nullptr) { 1076 if (d_space->GetLiveBitmap()->Test(obj)) { 1077 return true; 1078 } 1079 } 1080 } 1081 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1082 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1083 if (i > 0) { 1084 NanoSleep(MsToNs(10)); 1085 } 1086 if (search_allocation_stack) { 1087 if (sorted) { 1088 if (allocation_stack_->ContainsSorted(obj)) { 1089 return true; 1090 } 1091 } else if (allocation_stack_->Contains(obj)) { 1092 return true; 1093 } 1094 } 1095 1096 if (search_live_stack) { 1097 if (sorted) { 1098 if (live_stack_->ContainsSorted(obj)) { 1099 return true; 1100 } 1101 } else if (live_stack_->Contains(obj)) { 1102 return true; 1103 } 1104 } 1105 } 1106 // We need to check the bitmaps again since there is a race where we mark something as live and 1107 // then clear the stack containing it. 1108 if (c_space != nullptr) { 1109 if (c_space->GetLiveBitmap()->Test(obj)) { 1110 return true; 1111 } 1112 } else { 1113 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1114 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1115 return true; 1116 } 1117 } 1118 return false; 1119} 1120 1121std::string Heap::DumpSpaces() const { 1122 std::ostringstream oss; 1123 DumpSpaces(oss); 1124 return oss.str(); 1125} 1126 1127void Heap::DumpSpaces(std::ostream& stream) const { 1128 for (const auto& space : continuous_spaces_) { 1129 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1130 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1131 stream << space << " " << *space << "\n"; 1132 if (live_bitmap != nullptr) { 1133 stream << live_bitmap << " " << *live_bitmap << "\n"; 1134 } 1135 if (mark_bitmap != nullptr) { 1136 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1137 } 1138 } 1139 for (const auto& space : discontinuous_spaces_) { 1140 stream << space << " " << *space << "\n"; 1141 } 1142} 1143 1144void Heap::VerifyObjectBody(mirror::Object* obj) { 1145 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1146 return; 1147 } 1148 1149 // Ignore early dawn of the universe verifications. 1150 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1151 return; 1152 } 1153 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1154 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1155 CHECK(c != nullptr) << "Null class in object " << obj; 1156 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1157 CHECK(VerifyClassClass(c)); 1158 1159 if (verify_object_mode_ > kVerifyObjectModeFast) { 1160 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1161 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1162 } 1163} 1164 1165void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1166 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1167} 1168 1169void Heap::VerifyHeap() { 1170 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1171 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1172} 1173 1174void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1175 // Use signed comparison since freed bytes can be negative when background compaction foreground 1176 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1177 // free list backed space typically increasing memory footprint due to padding and binning. 1178 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1179 // Note: This relies on 2s complement for handling negative freed_bytes. 1180 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1181 if (Runtime::Current()->HasStatsEnabled()) { 1182 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1183 thread_stats->freed_objects += freed_objects; 1184 thread_stats->freed_bytes += freed_bytes; 1185 // TODO: Do this concurrently. 1186 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1187 global_stats->freed_objects += freed_objects; 1188 global_stats->freed_bytes += freed_bytes; 1189 } 1190} 1191 1192space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1193 for (const auto& space : continuous_spaces_) { 1194 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1195 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1196 return space->AsContinuousSpace()->AsRosAllocSpace(); 1197 } 1198 } 1199 } 1200 return nullptr; 1201} 1202 1203mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1204 size_t alloc_size, size_t* bytes_allocated, 1205 size_t* usable_size, 1206 mirror::Class** klass) { 1207 bool was_default_allocator = allocator == GetCurrentAllocator(); 1208 DCHECK(klass != nullptr); 1209 StackHandleScope<1> hs(self); 1210 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1211 klass = nullptr; // Invalidate for safety. 1212 // The allocation failed. If the GC is running, block until it completes, and then retry the 1213 // allocation. 1214 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1215 if (last_gc != collector::kGcTypeNone) { 1216 // If we were the default allocator but the allocator changed while we were suspended, 1217 // abort the allocation. 1218 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1219 return nullptr; 1220 } 1221 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1222 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1223 usable_size); 1224 if (ptr != nullptr) { 1225 return ptr; 1226 } 1227 } 1228 1229 collector::GcType tried_type = next_gc_type_; 1230 const bool gc_ran = 1231 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1232 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1233 return nullptr; 1234 } 1235 if (gc_ran) { 1236 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1237 usable_size); 1238 if (ptr != nullptr) { 1239 return ptr; 1240 } 1241 } 1242 1243 // Loop through our different Gc types and try to Gc until we get enough free memory. 1244 for (collector::GcType gc_type : gc_plan_) { 1245 if (gc_type == tried_type) { 1246 continue; 1247 } 1248 // Attempt to run the collector, if we succeed, re-try the allocation. 1249 const bool gc_ran = 1250 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1251 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1252 return nullptr; 1253 } 1254 if (gc_ran) { 1255 // Did we free sufficient memory for the allocation to succeed? 1256 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1257 usable_size); 1258 if (ptr != nullptr) { 1259 return ptr; 1260 } 1261 } 1262 } 1263 // Allocations have failed after GCs; this is an exceptional state. 1264 // Try harder, growing the heap if necessary. 1265 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1266 usable_size); 1267 if (ptr != nullptr) { 1268 return ptr; 1269 } 1270 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1271 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1272 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1273 // OOME. 1274 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1275 << " allocation"; 1276 // TODO: Run finalization, but this may cause more allocations to occur. 1277 // We don't need a WaitForGcToComplete here either. 1278 DCHECK(!gc_plan_.empty()); 1279 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1280 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1281 return nullptr; 1282 } 1283 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1284 if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) { 1285 const uint64_t current_time = NanoTime(); 1286 if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) && 1287 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1288 min_interval_homogeneous_space_compaction_by_oom_) { 1289 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1290 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1291 switch (result) { 1292 case HomogeneousSpaceCompactResult::kSuccess: 1293 // If the allocation succeeded, we delayed an oom. 1294 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1295 if (ptr != nullptr) { 1296 count_delayed_oom_++; 1297 } 1298 break; 1299 case HomogeneousSpaceCompactResult::kErrorReject: 1300 // Reject due to disabled moving GC. 1301 break; 1302 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1303 // Throw OOM by default. 1304 break; 1305 default: { 1306 LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result); 1307 } 1308 } 1309 // Always print that we ran homogeneous space compation since this can cause jank. 1310 VLOG(heap) << "Ran heap homogeneous space compaction, " 1311 << " requested defragmentation " 1312 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1313 << " performed defragmentation " 1314 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1315 << " ignored homogeneous space compaction " 1316 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1317 << " delayed count = " 1318 << count_delayed_oom_.LoadSequentiallyConsistent(); 1319 } 1320 } 1321 // If the allocation hasn't succeeded by this point, throw an OOM error. 1322 if (ptr == nullptr) { 1323 ThrowOutOfMemoryError(self, alloc_size, allocator); 1324 } 1325 return ptr; 1326} 1327 1328void Heap::SetTargetHeapUtilization(float target) { 1329 DCHECK_GT(target, 0.0f); // asserted in Java code 1330 DCHECK_LT(target, 1.0f); 1331 target_utilization_ = target; 1332} 1333 1334size_t Heap::GetObjectsAllocated() const { 1335 size_t total = 0; 1336 for (space::AllocSpace* space : alloc_spaces_) { 1337 total += space->GetObjectsAllocated(); 1338 } 1339 return total; 1340} 1341 1342size_t Heap::GetObjectsAllocatedEver() const { 1343 return GetObjectsFreedEver() + GetObjectsAllocated(); 1344} 1345 1346size_t Heap::GetBytesAllocatedEver() const { 1347 return GetBytesFreedEver() + GetBytesAllocated(); 1348} 1349 1350class InstanceCounter { 1351 public: 1352 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1353 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1354 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1355 } 1356 static void Callback(mirror::Object* obj, void* arg) 1357 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1358 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1359 mirror::Class* instance_class = obj->GetClass(); 1360 CHECK(instance_class != nullptr); 1361 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1362 if (instance_counter->use_is_assignable_from_) { 1363 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1364 ++instance_counter->counts_[i]; 1365 } 1366 } else if (instance_class == instance_counter->classes_[i]) { 1367 ++instance_counter->counts_[i]; 1368 } 1369 } 1370 } 1371 1372 private: 1373 const std::vector<mirror::Class*>& classes_; 1374 bool use_is_assignable_from_; 1375 uint64_t* const counts_; 1376 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1377}; 1378 1379void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1380 uint64_t* counts) { 1381 // Can't do any GC in this function since this may move classes. 1382 Thread* self = Thread::Current(); 1383 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1384 InstanceCounter counter(classes, use_is_assignable_from, counts); 1385 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1386 VisitObjects(InstanceCounter::Callback, &counter); 1387 self->EndAssertNoThreadSuspension(old_cause); 1388} 1389 1390class InstanceCollector { 1391 public: 1392 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1393 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1394 : class_(c), max_count_(max_count), instances_(instances) { 1395 } 1396 static void Callback(mirror::Object* obj, void* arg) 1397 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1398 DCHECK(arg != nullptr); 1399 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1400 mirror::Class* instance_class = obj->GetClass(); 1401 if (instance_class == instance_collector->class_) { 1402 if (instance_collector->max_count_ == 0 || 1403 instance_collector->instances_.size() < instance_collector->max_count_) { 1404 instance_collector->instances_.push_back(obj); 1405 } 1406 } 1407 } 1408 1409 private: 1410 mirror::Class* class_; 1411 uint32_t max_count_; 1412 std::vector<mirror::Object*>& instances_; 1413 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1414}; 1415 1416void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1417 std::vector<mirror::Object*>& instances) { 1418 // Can't do any GC in this function since this may move classes. 1419 Thread* self = Thread::Current(); 1420 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1421 InstanceCollector collector(c, max_count, instances); 1422 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1423 VisitObjects(&InstanceCollector::Callback, &collector); 1424 self->EndAssertNoThreadSuspension(old_cause); 1425} 1426 1427class ReferringObjectsFinder { 1428 public: 1429 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1430 std::vector<mirror::Object*>& referring_objects) 1431 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1432 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1433 } 1434 1435 static void Callback(mirror::Object* obj, void* arg) 1436 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1437 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1438 } 1439 1440 // For bitmap Visit. 1441 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1442 // annotalysis on visitors. 1443 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1444 o->VisitReferences<true>(*this, VoidFunctor()); 1445 } 1446 1447 // For Object::VisitReferences. 1448 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1449 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1450 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1451 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1452 referring_objects_.push_back(obj); 1453 } 1454 } 1455 1456 private: 1457 mirror::Object* object_; 1458 uint32_t max_count_; 1459 std::vector<mirror::Object*>& referring_objects_; 1460 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1461}; 1462 1463void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1464 std::vector<mirror::Object*>& referring_objects) { 1465 // Can't do any GC in this function since this may move the object o. 1466 Thread* self = Thread::Current(); 1467 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1468 ReferringObjectsFinder finder(o, max_count, referring_objects); 1469 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1470 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1471 self->EndAssertNoThreadSuspension(old_cause); 1472} 1473 1474void Heap::CollectGarbage(bool clear_soft_references) { 1475 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1476 // last GC will not have necessarily been cleared. 1477 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1478} 1479 1480HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1481 Thread* self = Thread::Current(); 1482 // Inc requested homogeneous space compaction. 1483 count_requested_homogeneous_space_compaction_++; 1484 // Store performed homogeneous space compaction at a new request arrival. 1485 ThreadList* tl = Runtime::Current()->GetThreadList(); 1486 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1487 Locks::mutator_lock_->AssertNotHeld(self); 1488 { 1489 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1490 MutexLock mu(self, *gc_complete_lock_); 1491 // Ensure there is only one GC at a time. 1492 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1493 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1494 // is non zero. 1495 // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction, 1496 // exit. 1497 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) { 1498 return HomogeneousSpaceCompactResult::kErrorReject; 1499 } 1500 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1501 } 1502 if (Runtime::Current()->IsShuttingDown(self)) { 1503 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1504 // cause objects to get finalized. 1505 FinishGC(self, collector::kGcTypeNone); 1506 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1507 } 1508 // Suspend all threads. 1509 tl->SuspendAll(); 1510 uint64_t start_time = NanoTime(); 1511 // Launch compaction. 1512 space::MallocSpace* to_space = main_space_backup_.release(); 1513 space::MallocSpace* from_space = main_space_; 1514 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1515 const uint64_t space_size_before_compaction = from_space->Size(); 1516 AddSpace(to_space); 1517 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1518 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1519 from_space->GetMemMap()->Protect(PROT_READ); 1520 const uint64_t space_size_after_compaction = to_space->Size(); 1521 main_space_ = to_space; 1522 main_space_backup_.reset(from_space); 1523 RemoveSpace(from_space); 1524 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1525 // Update performed homogeneous space compaction count. 1526 count_performed_homogeneous_space_compaction_++; 1527 // Print statics log and resume all threads. 1528 uint64_t duration = NanoTime() - start_time; 1529 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1530 << PrettySize(space_size_before_compaction) << " -> " 1531 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1532 << std::fixed << static_cast<double>(space_size_after_compaction) / 1533 static_cast<double>(space_size_before_compaction); 1534 tl->ResumeAll(); 1535 // Finish GC. 1536 reference_processor_.EnqueueClearedReferences(self); 1537 GrowForUtilization(semi_space_collector_); 1538 FinishGC(self, collector::kGcTypeFull); 1539 return HomogeneousSpaceCompactResult::kSuccess; 1540} 1541 1542 1543void Heap::TransitionCollector(CollectorType collector_type) { 1544 if (collector_type == collector_type_) { 1545 return; 1546 } 1547 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1548 << " -> " << static_cast<int>(collector_type); 1549 uint64_t start_time = NanoTime(); 1550 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1551 Runtime* const runtime = Runtime::Current(); 1552 ThreadList* const tl = runtime->GetThreadList(); 1553 Thread* const self = Thread::Current(); 1554 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1555 Locks::mutator_lock_->AssertNotHeld(self); 1556 const bool copying_transition = 1557 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1558 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1559 // compacting_gc_disable_count_, this should rarely occurs). 1560 for (;;) { 1561 { 1562 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1563 MutexLock mu(self, *gc_complete_lock_); 1564 // Ensure there is only one GC at a time. 1565 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1566 // If someone else beat us to it and changed the collector before we could, exit. 1567 // This is safe to do before the suspend all since we set the collector_type_running_ before 1568 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1569 // then it would get blocked on WaitForGcToCompleteLocked. 1570 if (collector_type == collector_type_) { 1571 return; 1572 } 1573 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1574 if (!copying_transition || disable_moving_gc_count_ == 0) { 1575 // TODO: Not hard code in semi-space collector? 1576 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1577 break; 1578 } 1579 } 1580 usleep(1000); 1581 } 1582 if (runtime->IsShuttingDown(self)) { 1583 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1584 // cause objects to get finalized. 1585 FinishGC(self, collector::kGcTypeNone); 1586 return; 1587 } 1588 tl->SuspendAll(); 1589 switch (collector_type) { 1590 case kCollectorTypeSS: { 1591 if (!IsMovingGc(collector_type_)) { 1592 // Create the bump pointer space from the backup space. 1593 CHECK(main_space_backup_ != nullptr); 1594 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1595 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1596 // pointer space last transition it will be protected. 1597 CHECK(mem_map != nullptr); 1598 mem_map->Protect(PROT_READ | PROT_WRITE); 1599 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1600 mem_map.release()); 1601 AddSpace(bump_pointer_space_); 1602 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1603 // Use the now empty main space mem map for the bump pointer temp space. 1604 mem_map.reset(main_space_->ReleaseMemMap()); 1605 // Remove the main space so that we don't try to trim it, this doens't work for debug 1606 // builds since RosAlloc attempts to read the magic number from a protected page. 1607 RemoveSpace(main_space_); 1608 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1609 mem_map.release()); 1610 AddSpace(temp_space_); 1611 } 1612 break; 1613 } 1614 case kCollectorTypeMS: 1615 // Fall through. 1616 case kCollectorTypeCMS: { 1617 if (IsMovingGc(collector_type_)) { 1618 CHECK(temp_space_ != nullptr); 1619 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1620 RemoveSpace(temp_space_); 1621 temp_space_ = nullptr; 1622 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1623 mem_map->Size()); 1624 mem_map.release(); 1625 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1626 AddSpace(main_space_); 1627 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1628 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1629 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1630 RemoveSpace(bump_pointer_space_); 1631 bump_pointer_space_ = nullptr; 1632 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1633 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1634 mem_map->Size(), mem_map->Size(), 1635 name, true)); 1636 mem_map.release(); 1637 } 1638 break; 1639 } 1640 default: { 1641 LOG(FATAL) << "Attempted to transition to invalid collector type " 1642 << static_cast<size_t>(collector_type); 1643 break; 1644 } 1645 } 1646 ChangeCollector(collector_type); 1647 tl->ResumeAll(); 1648 // Can't call into java code with all threads suspended. 1649 reference_processor_.EnqueueClearedReferences(self); 1650 uint64_t duration = NanoTime() - start_time; 1651 GrowForUtilization(semi_space_collector_); 1652 FinishGC(self, collector::kGcTypeFull); 1653 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1654 int32_t delta_allocated = before_allocated - after_allocated; 1655 std::string saved_str; 1656 if (delta_allocated >= 0) { 1657 saved_str = " saved at least " + PrettySize(delta_allocated); 1658 } else { 1659 saved_str = " expanded " + PrettySize(-delta_allocated); 1660 } 1661 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1662 << PrettyDuration(duration) << saved_str; 1663} 1664 1665void Heap::ChangeCollector(CollectorType collector_type) { 1666 // TODO: Only do this with all mutators suspended to avoid races. 1667 if (collector_type != collector_type_) { 1668 if (collector_type == kCollectorTypeMC) { 1669 // Don't allow mark compact unless support is compiled in. 1670 CHECK(kMarkCompactSupport); 1671 } 1672 collector_type_ = collector_type; 1673 gc_plan_.clear(); 1674 switch (collector_type_) { 1675 case kCollectorTypeCC: // Fall-through. 1676 case kCollectorTypeMC: // Fall-through. 1677 case kCollectorTypeSS: // Fall-through. 1678 case kCollectorTypeGSS: { 1679 gc_plan_.push_back(collector::kGcTypeFull); 1680 if (use_tlab_) { 1681 ChangeAllocator(kAllocatorTypeTLAB); 1682 } else { 1683 ChangeAllocator(kAllocatorTypeBumpPointer); 1684 } 1685 break; 1686 } 1687 case kCollectorTypeMS: { 1688 gc_plan_.push_back(collector::kGcTypeSticky); 1689 gc_plan_.push_back(collector::kGcTypePartial); 1690 gc_plan_.push_back(collector::kGcTypeFull); 1691 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1692 break; 1693 } 1694 case kCollectorTypeCMS: { 1695 gc_plan_.push_back(collector::kGcTypeSticky); 1696 gc_plan_.push_back(collector::kGcTypePartial); 1697 gc_plan_.push_back(collector::kGcTypeFull); 1698 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1699 break; 1700 } 1701 default: { 1702 LOG(FATAL) << "Unimplemented"; 1703 } 1704 } 1705 if (IsGcConcurrent()) { 1706 concurrent_start_bytes_ = 1707 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1708 } else { 1709 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1710 } 1711 } 1712} 1713 1714// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1715class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1716 public: 1717 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1718 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1719 } 1720 1721 void BuildBins(space::ContinuousSpace* space) { 1722 bin_live_bitmap_ = space->GetLiveBitmap(); 1723 bin_mark_bitmap_ = space->GetMarkBitmap(); 1724 BinContext context; 1725 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1726 context.collector_ = this; 1727 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1728 // Note: This requires traversing the space in increasing order of object addresses. 1729 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1730 // Add the last bin which spans after the last object to the end of the space. 1731 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1732 } 1733 1734 private: 1735 struct BinContext { 1736 uintptr_t prev_; // The end of the previous object. 1737 ZygoteCompactingCollector* collector_; 1738 }; 1739 // Maps from bin sizes to locations. 1740 std::multimap<size_t, uintptr_t> bins_; 1741 // Live bitmap of the space which contains the bins. 1742 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1743 // Mark bitmap of the space which contains the bins. 1744 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1745 1746 static void Callback(mirror::Object* obj, void* arg) 1747 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1748 DCHECK(arg != nullptr); 1749 BinContext* context = reinterpret_cast<BinContext*>(arg); 1750 ZygoteCompactingCollector* collector = context->collector_; 1751 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1752 size_t bin_size = object_addr - context->prev_; 1753 // Add the bin consisting of the end of the previous object to the start of the current object. 1754 collector->AddBin(bin_size, context->prev_); 1755 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1756 } 1757 1758 void AddBin(size_t size, uintptr_t position) { 1759 if (size != 0) { 1760 bins_.insert(std::make_pair(size, position)); 1761 } 1762 } 1763 1764 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1765 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1766 // allocator. 1767 return false; 1768 } 1769 1770 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1771 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1772 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1773 mirror::Object* forward_address; 1774 // Find the smallest bin which we can move obj in. 1775 auto it = bins_.lower_bound(object_size); 1776 if (it == bins_.end()) { 1777 // No available space in the bins, place it in the target space instead (grows the zygote 1778 // space). 1779 size_t bytes_allocated; 1780 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1781 if (to_space_live_bitmap_ != nullptr) { 1782 to_space_live_bitmap_->Set(forward_address); 1783 } else { 1784 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1785 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1786 } 1787 } else { 1788 size_t size = it->first; 1789 uintptr_t pos = it->second; 1790 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1791 forward_address = reinterpret_cast<mirror::Object*>(pos); 1792 // Set the live and mark bits so that sweeping system weaks works properly. 1793 bin_live_bitmap_->Set(forward_address); 1794 bin_mark_bitmap_->Set(forward_address); 1795 DCHECK_GE(size, object_size); 1796 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1797 } 1798 // Copy the object over to its new location. 1799 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1800 if (kUseBakerOrBrooksReadBarrier) { 1801 obj->AssertReadBarrierPointer(); 1802 if (kUseBrooksReadBarrier) { 1803 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1804 forward_address->SetReadBarrierPointer(forward_address); 1805 } 1806 forward_address->AssertReadBarrierPointer(); 1807 } 1808 return forward_address; 1809 } 1810}; 1811 1812void Heap::UnBindBitmaps() { 1813 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1814 for (const auto& space : GetContinuousSpaces()) { 1815 if (space->IsContinuousMemMapAllocSpace()) { 1816 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1817 if (alloc_space->HasBoundBitmaps()) { 1818 alloc_space->UnBindBitmaps(); 1819 } 1820 } 1821 } 1822} 1823 1824void Heap::PreZygoteFork() { 1825 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1826 Thread* self = Thread::Current(); 1827 MutexLock mu(self, zygote_creation_lock_); 1828 // Try to see if we have any Zygote spaces. 1829 if (have_zygote_space_) { 1830 return; 1831 } 1832 VLOG(heap) << "Starting PreZygoteFork"; 1833 // Trim the pages at the end of the non moving space. 1834 non_moving_space_->Trim(); 1835 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1836 // there. 1837 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1838 // Change the collector to the post zygote one. 1839 bool same_space = non_moving_space_ == main_space_; 1840 if (kCompactZygote) { 1841 DCHECK(semi_space_collector_ != nullptr); 1842 // Temporarily disable rosalloc verification because the zygote 1843 // compaction will mess up the rosalloc internal metadata. 1844 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1845 ZygoteCompactingCollector zygote_collector(this); 1846 zygote_collector.BuildBins(non_moving_space_); 1847 // Create a new bump pointer space which we will compact into. 1848 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1849 non_moving_space_->Limit()); 1850 // Compact the bump pointer space to a new zygote bump pointer space. 1851 bool reset_main_space = false; 1852 if (IsMovingGc(collector_type_)) { 1853 zygote_collector.SetFromSpace(bump_pointer_space_); 1854 } else { 1855 CHECK(main_space_ != nullptr); 1856 // Copy from the main space. 1857 zygote_collector.SetFromSpace(main_space_); 1858 reset_main_space = true; 1859 } 1860 zygote_collector.SetToSpace(&target_space); 1861 zygote_collector.SetSwapSemiSpaces(false); 1862 zygote_collector.Run(kGcCauseCollectorTransition, false); 1863 if (reset_main_space) { 1864 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1865 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1866 MemMap* mem_map = main_space_->ReleaseMemMap(); 1867 RemoveSpace(main_space_); 1868 space::Space* old_main_space = main_space_; 1869 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1870 delete old_main_space; 1871 AddSpace(main_space_); 1872 } else { 1873 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1874 } 1875 if (temp_space_ != nullptr) { 1876 CHECK(temp_space_->IsEmpty()); 1877 } 1878 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1879 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1880 // Update the end and write out image. 1881 non_moving_space_->SetEnd(target_space.End()); 1882 non_moving_space_->SetLimit(target_space.Limit()); 1883 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1884 } 1885 ChangeCollector(foreground_collector_type_); 1886 // Save the old space so that we can remove it after we complete creating the zygote space. 1887 space::MallocSpace* old_alloc_space = non_moving_space_; 1888 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1889 // the remaining available space. 1890 // Remove the old space before creating the zygote space since creating the zygote space sets 1891 // the old alloc space's bitmaps to nullptr. 1892 RemoveSpace(old_alloc_space); 1893 if (collector::SemiSpace::kUseRememberedSet) { 1894 // Sanity bound check. 1895 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1896 // Remove the remembered set for the now zygote space (the old 1897 // non-moving space). Note now that we have compacted objects into 1898 // the zygote space, the data in the remembered set is no longer 1899 // needed. The zygote space will instead have a mod-union table 1900 // from this point on. 1901 RemoveRememberedSet(old_alloc_space); 1902 } 1903 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1904 low_memory_mode_, 1905 &non_moving_space_); 1906 CHECK(!non_moving_space_->CanMoveObjects()); 1907 if (same_space) { 1908 main_space_ = non_moving_space_; 1909 SetSpaceAsDefault(main_space_); 1910 } 1911 delete old_alloc_space; 1912 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1913 AddSpace(zygote_space); 1914 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1915 AddSpace(non_moving_space_); 1916 have_zygote_space_ = true; 1917 // Enable large object space allocations. 1918 large_object_threshold_ = kDefaultLargeObjectThreshold; 1919 // Create the zygote space mod union table. 1920 accounting::ModUnionTable* mod_union_table = 1921 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1922 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1923 AddModUnionTable(mod_union_table); 1924 if (collector::SemiSpace::kUseRememberedSet) { 1925 // Add a new remembered set for the post-zygote non-moving space. 1926 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1927 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1928 non_moving_space_); 1929 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1930 << "Failed to create post-zygote non-moving space remembered set"; 1931 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1932 } 1933} 1934 1935void Heap::FlushAllocStack() { 1936 MarkAllocStackAsLive(allocation_stack_.get()); 1937 allocation_stack_->Reset(); 1938} 1939 1940void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1941 accounting::ContinuousSpaceBitmap* bitmap2, 1942 accounting::LargeObjectBitmap* large_objects, 1943 accounting::ObjectStack* stack) { 1944 DCHECK(bitmap1 != nullptr); 1945 DCHECK(bitmap2 != nullptr); 1946 mirror::Object** limit = stack->End(); 1947 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1948 const mirror::Object* obj = *it; 1949 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1950 if (bitmap1->HasAddress(obj)) { 1951 bitmap1->Set(obj); 1952 } else if (bitmap2->HasAddress(obj)) { 1953 bitmap2->Set(obj); 1954 } else { 1955 large_objects->Set(obj); 1956 } 1957 } 1958 } 1959} 1960 1961void Heap::SwapSemiSpaces() { 1962 CHECK(bump_pointer_space_ != nullptr); 1963 CHECK(temp_space_ != nullptr); 1964 std::swap(bump_pointer_space_, temp_space_); 1965} 1966 1967void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1968 space::ContinuousMemMapAllocSpace* source_space, 1969 GcCause gc_cause) { 1970 CHECK(kMovingCollector); 1971 if (target_space != source_space) { 1972 // Don't swap spaces since this isn't a typical semi space collection. 1973 semi_space_collector_->SetSwapSemiSpaces(false); 1974 semi_space_collector_->SetFromSpace(source_space); 1975 semi_space_collector_->SetToSpace(target_space); 1976 semi_space_collector_->Run(gc_cause, false); 1977 } else { 1978 CHECK(target_space->IsBumpPointerSpace()) 1979 << "In-place compaction is only supported for bump pointer spaces"; 1980 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1981 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1982 } 1983} 1984 1985collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1986 bool clear_soft_references) { 1987 Thread* self = Thread::Current(); 1988 Runtime* runtime = Runtime::Current(); 1989 // If the heap can't run the GC, silently fail and return that no GC was run. 1990 switch (gc_type) { 1991 case collector::kGcTypePartial: { 1992 if (!have_zygote_space_) { 1993 return collector::kGcTypeNone; 1994 } 1995 break; 1996 } 1997 default: { 1998 // Other GC types don't have any special cases which makes them not runnable. The main case 1999 // here is full GC. 2000 } 2001 } 2002 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2003 Locks::mutator_lock_->AssertNotHeld(self); 2004 if (self->IsHandlingStackOverflow()) { 2005 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2006 } 2007 bool compacting_gc; 2008 { 2009 gc_complete_lock_->AssertNotHeld(self); 2010 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2011 MutexLock mu(self, *gc_complete_lock_); 2012 // Ensure there is only one GC at a time. 2013 WaitForGcToCompleteLocked(gc_cause, self); 2014 compacting_gc = IsMovingGc(collector_type_); 2015 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2016 if (compacting_gc && disable_moving_gc_count_ != 0) { 2017 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2018 return collector::kGcTypeNone; 2019 } 2020 collector_type_running_ = collector_type_; 2021 } 2022 2023 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2024 ++runtime->GetStats()->gc_for_alloc_count; 2025 ++self->GetStats()->gc_for_alloc_count; 2026 } 2027 uint64_t gc_start_time_ns = NanoTime(); 2028 uint64_t gc_start_size = GetBytesAllocated(); 2029 // Approximate allocation rate in bytes / second. 2030 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2031 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2032 if (LIKELY(ms_delta != 0)) { 2033 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2034 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2035 } 2036 2037 DCHECK_LT(gc_type, collector::kGcTypeMax); 2038 DCHECK_NE(gc_type, collector::kGcTypeNone); 2039 2040 collector::GarbageCollector* collector = nullptr; 2041 // TODO: Clean this up. 2042 if (compacting_gc) { 2043 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2044 current_allocator_ == kAllocatorTypeTLAB); 2045 switch (collector_type_) { 2046 case kCollectorTypeSS: 2047 // Fall-through. 2048 case kCollectorTypeGSS: 2049 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2050 semi_space_collector_->SetToSpace(temp_space_); 2051 semi_space_collector_->SetSwapSemiSpaces(true); 2052 collector = semi_space_collector_; 2053 break; 2054 case kCollectorTypeCC: 2055 collector = concurrent_copying_collector_; 2056 break; 2057 case kCollectorTypeMC: 2058 mark_compact_collector_->SetSpace(bump_pointer_space_); 2059 collector = mark_compact_collector_; 2060 break; 2061 default: 2062 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2063 } 2064 if (collector != mark_compact_collector_) { 2065 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2066 CHECK(temp_space_->IsEmpty()); 2067 } 2068 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2069 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2070 current_allocator_ == kAllocatorTypeDlMalloc) { 2071 collector = FindCollectorByGcType(gc_type); 2072 } else { 2073 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2074 } 2075 CHECK(collector != nullptr) 2076 << "Could not find garbage collector with collector_type=" 2077 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2078 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2079 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2080 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2081 RequestHeapTrim(); 2082 // Enqueue cleared references. 2083 reference_processor_.EnqueueClearedReferences(self); 2084 // Grow the heap so that we know when to perform the next GC. 2085 GrowForUtilization(collector); 2086 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2087 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2088 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2089 // (mutator time blocked >= long_pause_log_threshold_). 2090 bool log_gc = gc_cause == kGcCauseExplicit; 2091 if (!log_gc && CareAboutPauseTimes()) { 2092 // GC for alloc pauses the allocating thread, so consider it as a pause. 2093 log_gc = duration > long_gc_log_threshold_ || 2094 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2095 for (uint64_t pause : pause_times) { 2096 log_gc = log_gc || pause >= long_pause_log_threshold_; 2097 } 2098 } 2099 if (log_gc) { 2100 const size_t percent_free = GetPercentFree(); 2101 const size_t current_heap_size = GetBytesAllocated(); 2102 const size_t total_memory = GetTotalMemory(); 2103 std::ostringstream pause_string; 2104 for (size_t i = 0; i < pause_times.size(); ++i) { 2105 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2106 << ((i != pause_times.size() - 1) ? "," : ""); 2107 } 2108 LOG(INFO) << gc_cause << " " << collector->GetName() 2109 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2110 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2111 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2112 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2113 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2114 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2115 << " total " << PrettyDuration((duration / 1000) * 1000); 2116 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2117 } 2118 FinishGC(self, gc_type); 2119 // Inform DDMS that a GC completed. 2120 Dbg::GcDidFinish(); 2121 return gc_type; 2122} 2123 2124void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2125 MutexLock mu(self, *gc_complete_lock_); 2126 collector_type_running_ = kCollectorTypeNone; 2127 if (gc_type != collector::kGcTypeNone) { 2128 last_gc_type_ = gc_type; 2129 } 2130 // Wake anyone who may have been waiting for the GC to complete. 2131 gc_complete_cond_->Broadcast(self); 2132} 2133 2134static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2135 RootType /*root_type*/) { 2136 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2137 if (*root == obj) { 2138 LOG(INFO) << "Object " << obj << " is a root"; 2139 } 2140} 2141 2142class ScanVisitor { 2143 public: 2144 void operator()(const mirror::Object* obj) const { 2145 LOG(ERROR) << "Would have rescanned object " << obj; 2146 } 2147}; 2148 2149// Verify a reference from an object. 2150class VerifyReferenceVisitor { 2151 public: 2152 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2153 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2154 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2155 2156 size_t GetFailureCount() const { 2157 return fail_count_->LoadSequentiallyConsistent(); 2158 } 2159 2160 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2161 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2162 if (verify_referent_) { 2163 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2164 } 2165 } 2166 2167 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2168 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2169 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2170 } 2171 2172 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2173 return heap_->IsLiveObjectLocked(obj, true, false, true); 2174 } 2175 2176 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2177 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2178 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2179 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2180 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2181 << " thread_id= " << thread_id << " root_type= " << root_type; 2182 } 2183 } 2184 2185 private: 2186 // TODO: Fix the no thread safety analysis. 2187 // Returns false on failure. 2188 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2189 NO_THREAD_SAFETY_ANALYSIS { 2190 if (ref == nullptr || IsLive(ref)) { 2191 // Verify that the reference is live. 2192 return true; 2193 } 2194 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2195 // Print message on only on first failure to prevent spam. 2196 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2197 } 2198 if (obj != nullptr) { 2199 // Only do this part for non roots. 2200 accounting::CardTable* card_table = heap_->GetCardTable(); 2201 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2202 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2203 byte* card_addr = card_table->CardFromAddr(obj); 2204 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2205 << offset << "\n card value = " << static_cast<int>(*card_addr); 2206 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2207 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2208 } else { 2209 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2210 } 2211 2212 // Attempt to find the class inside of the recently freed objects. 2213 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2214 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2215 space::MallocSpace* space = ref_space->AsMallocSpace(); 2216 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2217 if (ref_class != nullptr) { 2218 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2219 << PrettyClass(ref_class); 2220 } else { 2221 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2222 } 2223 } 2224 2225 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2226 ref->GetClass()->IsClass()) { 2227 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2228 } else { 2229 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2230 << ") is not a valid heap address"; 2231 } 2232 2233 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2234 void* cover_begin = card_table->AddrFromCard(card_addr); 2235 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2236 accounting::CardTable::kCardSize); 2237 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2238 << "-" << cover_end; 2239 accounting::ContinuousSpaceBitmap* bitmap = 2240 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2241 2242 if (bitmap == nullptr) { 2243 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2244 if (!VerifyClassClass(obj->GetClass())) { 2245 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2246 } 2247 } else { 2248 // Print out how the object is live. 2249 if (bitmap->Test(obj)) { 2250 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2251 } 2252 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2253 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2254 } 2255 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2256 LOG(ERROR) << "Object " << obj << " found in live stack"; 2257 } 2258 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2259 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2260 } 2261 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2262 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2263 } 2264 // Attempt to see if the card table missed the reference. 2265 ScanVisitor scan_visitor; 2266 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2267 card_table->Scan(bitmap, byte_cover_begin, 2268 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2269 } 2270 2271 // Search to see if any of the roots reference our object. 2272 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2273 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2274 2275 // Search to see if any of the roots reference our reference. 2276 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2277 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2278 } 2279 return false; 2280 } 2281 2282 Heap* const heap_; 2283 Atomic<size_t>* const fail_count_; 2284 const bool verify_referent_; 2285}; 2286 2287// Verify all references within an object, for use with HeapBitmap::Visit. 2288class VerifyObjectVisitor { 2289 public: 2290 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2291 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2292 } 2293 2294 void operator()(mirror::Object* obj) const 2295 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2296 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2297 // be live or else how did we find it in the live bitmap? 2298 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2299 // The class doesn't count as a reference but we should verify it anyways. 2300 obj->VisitReferences<true>(visitor, visitor); 2301 } 2302 2303 static void VisitCallback(mirror::Object* obj, void* arg) 2304 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2305 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2306 visitor->operator()(obj); 2307 } 2308 2309 size_t GetFailureCount() const { 2310 return fail_count_->LoadSequentiallyConsistent(); 2311 } 2312 2313 private: 2314 Heap* const heap_; 2315 Atomic<size_t>* const fail_count_; 2316 const bool verify_referent_; 2317}; 2318 2319void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2320 // Slow path, the allocation stack push back must have already failed. 2321 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2322 do { 2323 // TODO: Add handle VerifyObject. 2324 StackHandleScope<1> hs(self); 2325 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2326 // Push our object into the reserve region of the allocaiton stack. This is only required due 2327 // to heap verification requiring that roots are live (either in the live bitmap or in the 2328 // allocation stack). 2329 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2330 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2331 } while (!allocation_stack_->AtomicPushBack(*obj)); 2332} 2333 2334void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2335 // Slow path, the allocation stack push back must have already failed. 2336 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2337 mirror::Object** start_address; 2338 mirror::Object** end_address; 2339 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2340 &end_address)) { 2341 // TODO: Add handle VerifyObject. 2342 StackHandleScope<1> hs(self); 2343 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2344 // Push our object into the reserve region of the allocaiton stack. This is only required due 2345 // to heap verification requiring that roots are live (either in the live bitmap or in the 2346 // allocation stack). 2347 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2348 // Push into the reserve allocation stack. 2349 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2350 } 2351 self->SetThreadLocalAllocationStack(start_address, end_address); 2352 // Retry on the new thread-local allocation stack. 2353 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2354} 2355 2356// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2357size_t Heap::VerifyHeapReferences(bool verify_referents) { 2358 Thread* self = Thread::Current(); 2359 Locks::mutator_lock_->AssertExclusiveHeld(self); 2360 // Lets sort our allocation stacks so that we can efficiently binary search them. 2361 allocation_stack_->Sort(); 2362 live_stack_->Sort(); 2363 // Since we sorted the allocation stack content, need to revoke all 2364 // thread-local allocation stacks. 2365 RevokeAllThreadLocalAllocationStacks(self); 2366 Atomic<size_t> fail_count_(0); 2367 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2368 // Verify objects in the allocation stack since these will be objects which were: 2369 // 1. Allocated prior to the GC (pre GC verification). 2370 // 2. Allocated during the GC (pre sweep GC verification). 2371 // We don't want to verify the objects in the live stack since they themselves may be 2372 // pointing to dead objects if they are not reachable. 2373 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2374 // Verify the roots: 2375 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2376 if (visitor.GetFailureCount() > 0) { 2377 // Dump mod-union tables. 2378 for (const auto& table_pair : mod_union_tables_) { 2379 accounting::ModUnionTable* mod_union_table = table_pair.second; 2380 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2381 } 2382 // Dump remembered sets. 2383 for (const auto& table_pair : remembered_sets_) { 2384 accounting::RememberedSet* remembered_set = table_pair.second; 2385 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2386 } 2387 DumpSpaces(LOG(ERROR)); 2388 } 2389 return visitor.GetFailureCount(); 2390} 2391 2392class VerifyReferenceCardVisitor { 2393 public: 2394 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2395 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2396 Locks::heap_bitmap_lock_) 2397 : heap_(heap), failed_(failed) { 2398 } 2399 2400 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2401 // annotalysis on visitors. 2402 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2403 NO_THREAD_SAFETY_ANALYSIS { 2404 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2405 // Filter out class references since changing an object's class does not mark the card as dirty. 2406 // Also handles large objects, since the only reference they hold is a class reference. 2407 if (ref != nullptr && !ref->IsClass()) { 2408 accounting::CardTable* card_table = heap_->GetCardTable(); 2409 // If the object is not dirty and it is referencing something in the live stack other than 2410 // class, then it must be on a dirty card. 2411 if (!card_table->AddrIsInCardTable(obj)) { 2412 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2413 *failed_ = true; 2414 } else if (!card_table->IsDirty(obj)) { 2415 // TODO: Check mod-union tables. 2416 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2417 // kCardDirty - 1 if it didnt get touched since we aged it. 2418 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2419 if (live_stack->ContainsSorted(ref)) { 2420 if (live_stack->ContainsSorted(obj)) { 2421 LOG(ERROR) << "Object " << obj << " found in live stack"; 2422 } 2423 if (heap_->GetLiveBitmap()->Test(obj)) { 2424 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2425 } 2426 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2427 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2428 2429 // Print which field of the object is dead. 2430 if (!obj->IsObjectArray()) { 2431 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2432 CHECK(klass != NULL); 2433 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2434 : klass->GetIFields(); 2435 CHECK(fields != NULL); 2436 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2437 mirror::ArtField* cur = fields->Get(i); 2438 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2439 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2440 << PrettyField(cur); 2441 break; 2442 } 2443 } 2444 } else { 2445 mirror::ObjectArray<mirror::Object>* object_array = 2446 obj->AsObjectArray<mirror::Object>(); 2447 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2448 if (object_array->Get(i) == ref) { 2449 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2450 } 2451 } 2452 } 2453 2454 *failed_ = true; 2455 } 2456 } 2457 } 2458 } 2459 2460 private: 2461 Heap* const heap_; 2462 bool* const failed_; 2463}; 2464 2465class VerifyLiveStackReferences { 2466 public: 2467 explicit VerifyLiveStackReferences(Heap* heap) 2468 : heap_(heap), 2469 failed_(false) {} 2470 2471 void operator()(mirror::Object* obj) const 2472 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2473 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2474 obj->VisitReferences<true>(visitor, VoidFunctor()); 2475 } 2476 2477 bool Failed() const { 2478 return failed_; 2479 } 2480 2481 private: 2482 Heap* const heap_; 2483 bool failed_; 2484}; 2485 2486bool Heap::VerifyMissingCardMarks() { 2487 Thread* self = Thread::Current(); 2488 Locks::mutator_lock_->AssertExclusiveHeld(self); 2489 2490 // We need to sort the live stack since we binary search it. 2491 live_stack_->Sort(); 2492 // Since we sorted the allocation stack content, need to revoke all 2493 // thread-local allocation stacks. 2494 RevokeAllThreadLocalAllocationStacks(self); 2495 VerifyLiveStackReferences visitor(this); 2496 GetLiveBitmap()->Visit(visitor); 2497 2498 // We can verify objects in the live stack since none of these should reference dead objects. 2499 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2500 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2501 visitor(*it); 2502 } 2503 } 2504 return !visitor.Failed(); 2505} 2506 2507void Heap::SwapStacks(Thread* self) { 2508 if (kUseThreadLocalAllocationStack) { 2509 live_stack_->AssertAllZero(); 2510 } 2511 allocation_stack_.swap(live_stack_); 2512} 2513 2514void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2515 // This must be called only during the pause. 2516 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2517 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2518 MutexLock mu2(self, *Locks::thread_list_lock_); 2519 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2520 for (Thread* t : thread_list) { 2521 t->RevokeThreadLocalAllocationStack(); 2522 } 2523} 2524 2525void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2526 if (kIsDebugBuild) { 2527 if (bump_pointer_space_ != nullptr) { 2528 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2529 } 2530 } 2531} 2532 2533accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2534 auto it = mod_union_tables_.find(space); 2535 if (it == mod_union_tables_.end()) { 2536 return nullptr; 2537 } 2538 return it->second; 2539} 2540 2541accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2542 auto it = remembered_sets_.find(space); 2543 if (it == remembered_sets_.end()) { 2544 return nullptr; 2545 } 2546 return it->second; 2547} 2548 2549void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2550 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2551 // Clear cards and keep track of cards cleared in the mod-union table. 2552 for (const auto& space : continuous_spaces_) { 2553 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2554 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2555 if (table != nullptr) { 2556 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2557 "ImageModUnionClearCards"; 2558 TimingLogger::ScopedTiming t(name, timings); 2559 table->ClearCards(); 2560 } else if (use_rem_sets && rem_set != nullptr) { 2561 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2562 << static_cast<int>(collector_type_); 2563 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2564 rem_set->ClearCards(); 2565 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2566 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2567 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2568 // were dirty before the GC started. 2569 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2570 // -> clean(cleaning thread). 2571 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2572 // roots and then we scan / update mod union tables after. We will always scan either card. 2573 // If we end up with the non aged card, we scan it it in the pause. 2574 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2575 VoidFunctor()); 2576 } 2577 } 2578} 2579 2580static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2581} 2582 2583void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2584 Thread* const self = Thread::Current(); 2585 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2586 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2587 if (verify_pre_gc_heap_) { 2588 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2589 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2590 size_t failures = VerifyHeapReferences(); 2591 if (failures > 0) { 2592 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2593 << " failures"; 2594 } 2595 } 2596 // Check that all objects which reference things in the live stack are on dirty cards. 2597 if (verify_missing_card_marks_) { 2598 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2599 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2600 SwapStacks(self); 2601 // Sort the live stack so that we can quickly binary search it later. 2602 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2603 << " missing card mark verification failed\n" << DumpSpaces(); 2604 SwapStacks(self); 2605 } 2606 if (verify_mod_union_table_) { 2607 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2608 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2609 for (const auto& table_pair : mod_union_tables_) { 2610 accounting::ModUnionTable* mod_union_table = table_pair.second; 2611 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2612 mod_union_table->Verify(); 2613 } 2614 } 2615} 2616 2617void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2618 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2619 collector::GarbageCollector::ScopedPause pause(gc); 2620 PreGcVerificationPaused(gc); 2621 } 2622} 2623 2624void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2625 // TODO: Add a new runtime option for this? 2626 if (verify_pre_gc_rosalloc_) { 2627 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2628 } 2629} 2630 2631void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2632 Thread* const self = Thread::Current(); 2633 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2634 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2635 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2636 // reachable objects. 2637 if (verify_pre_sweeping_heap_) { 2638 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2639 CHECK_NE(self->GetState(), kRunnable); 2640 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2641 // Swapping bound bitmaps does nothing. 2642 gc->SwapBitmaps(); 2643 // Pass in false since concurrent reference processing can mean that the reference referents 2644 // may point to dead objects at the point which PreSweepingGcVerification is called. 2645 size_t failures = VerifyHeapReferences(false); 2646 if (failures > 0) { 2647 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2648 << " failures"; 2649 } 2650 gc->SwapBitmaps(); 2651 } 2652 if (verify_pre_sweeping_rosalloc_) { 2653 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2654 } 2655} 2656 2657void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2658 // Only pause if we have to do some verification. 2659 Thread* const self = Thread::Current(); 2660 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2661 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2662 if (verify_system_weaks_) { 2663 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2664 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2665 mark_sweep->VerifySystemWeaks(); 2666 } 2667 if (verify_post_gc_rosalloc_) { 2668 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2669 } 2670 if (verify_post_gc_heap_) { 2671 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2672 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2673 size_t failures = VerifyHeapReferences(); 2674 if (failures > 0) { 2675 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2676 << " failures"; 2677 } 2678 } 2679} 2680 2681void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2682 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2683 collector::GarbageCollector::ScopedPause pause(gc); 2684 PreGcVerificationPaused(gc); 2685 } 2686} 2687 2688void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2689 TimingLogger::ScopedTiming t(name, timings); 2690 for (const auto& space : continuous_spaces_) { 2691 if (space->IsRosAllocSpace()) { 2692 VLOG(heap) << name << " : " << space->GetName(); 2693 space->AsRosAllocSpace()->Verify(); 2694 } 2695 } 2696} 2697 2698collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2699 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2700 MutexLock mu(self, *gc_complete_lock_); 2701 return WaitForGcToCompleteLocked(cause, self); 2702} 2703 2704collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2705 collector::GcType last_gc_type = collector::kGcTypeNone; 2706 uint64_t wait_start = NanoTime(); 2707 while (collector_type_running_ != kCollectorTypeNone) { 2708 ATRACE_BEGIN("GC: Wait For Completion"); 2709 // We must wait, change thread state then sleep on gc_complete_cond_; 2710 gc_complete_cond_->Wait(self); 2711 last_gc_type = last_gc_type_; 2712 ATRACE_END(); 2713 } 2714 uint64_t wait_time = NanoTime() - wait_start; 2715 total_wait_time_ += wait_time; 2716 if (wait_time > long_pause_log_threshold_) { 2717 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2718 << " for cause " << cause; 2719 } 2720 return last_gc_type; 2721} 2722 2723void Heap::DumpForSigQuit(std::ostream& os) { 2724 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2725 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2726 DumpGcPerformanceInfo(os); 2727} 2728 2729size_t Heap::GetPercentFree() { 2730 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2731} 2732 2733void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2734 if (max_allowed_footprint > GetMaxMemory()) { 2735 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2736 << PrettySize(GetMaxMemory()); 2737 max_allowed_footprint = GetMaxMemory(); 2738 } 2739 max_allowed_footprint_ = max_allowed_footprint; 2740} 2741 2742bool Heap::IsMovableObject(const mirror::Object* obj) const { 2743 if (kMovingCollector) { 2744 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2745 if (space != nullptr) { 2746 // TODO: Check large object? 2747 return space->CanMoveObjects(); 2748 } 2749 } 2750 return false; 2751} 2752 2753void Heap::UpdateMaxNativeFootprint() { 2754 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2755 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2756 size_t target_size = native_size / GetTargetHeapUtilization(); 2757 if (target_size > native_size + max_free_) { 2758 target_size = native_size + max_free_; 2759 } else if (target_size < native_size + min_free_) { 2760 target_size = native_size + min_free_; 2761 } 2762 native_footprint_gc_watermark_ = target_size; 2763 native_footprint_limit_ = 2 * target_size - native_size; 2764} 2765 2766collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2767 for (const auto& collector : garbage_collectors_) { 2768 if (collector->GetCollectorType() == collector_type_ && 2769 collector->GetGcType() == gc_type) { 2770 return collector; 2771 } 2772 } 2773 return nullptr; 2774} 2775 2776double Heap::HeapGrowthMultiplier() const { 2777 // If we don't care about pause times we are background, so return 1.0. 2778 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2779 return 1.0; 2780 } 2781 return foreground_heap_growth_multiplier_; 2782} 2783 2784void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2785 // We know what our utilization is at this moment. 2786 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2787 const uint64_t bytes_allocated = GetBytesAllocated(); 2788 last_gc_size_ = bytes_allocated; 2789 last_gc_time_ns_ = NanoTime(); 2790 uint64_t target_size; 2791 collector::GcType gc_type = collector_ran->GetGcType(); 2792 if (gc_type != collector::kGcTypeSticky) { 2793 // Grow the heap for non sticky GC. 2794 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2795 // foreground. 2796 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2797 CHECK_GE(delta, 0); 2798 target_size = bytes_allocated + delta * multiplier; 2799 target_size = std::min(target_size, 2800 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2801 target_size = std::max(target_size, 2802 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2803 native_need_to_run_finalization_ = true; 2804 next_gc_type_ = collector::kGcTypeSticky; 2805 } else { 2806 collector::GcType non_sticky_gc_type = 2807 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2808 // Find what the next non sticky collector will be. 2809 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2810 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2811 // do another sticky collection next. 2812 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2813 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2814 // if the sticky GC throughput always remained >= the full/partial throughput. 2815 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2816 non_sticky_collector->GetEstimatedMeanThroughput() && 2817 non_sticky_collector->NumberOfIterations() > 0 && 2818 bytes_allocated <= max_allowed_footprint_) { 2819 next_gc_type_ = collector::kGcTypeSticky; 2820 } else { 2821 next_gc_type_ = non_sticky_gc_type; 2822 } 2823 // If we have freed enough memory, shrink the heap back down. 2824 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2825 target_size = bytes_allocated + max_free_; 2826 } else { 2827 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2828 } 2829 } 2830 if (!ignore_max_footprint_) { 2831 SetIdealFootprint(target_size); 2832 if (IsGcConcurrent()) { 2833 // Calculate when to perform the next ConcurrentGC. 2834 // Calculate the estimated GC duration. 2835 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2836 // Estimate how many remaining bytes we will have when we need to start the next GC. 2837 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2838 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2839 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2840 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2841 // A never going to happen situation that from the estimated allocation rate we will exceed 2842 // the applications entire footprint with the given estimated allocation rate. Schedule 2843 // another GC nearly straight away. 2844 remaining_bytes = kMinConcurrentRemainingBytes; 2845 } 2846 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2847 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2848 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2849 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2850 // right away. 2851 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2852 static_cast<size_t>(bytes_allocated)); 2853 } 2854 } 2855} 2856 2857void Heap::ClearGrowthLimit() { 2858 growth_limit_ = capacity_; 2859 non_moving_space_->ClearGrowthLimit(); 2860} 2861 2862void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2863 ScopedObjectAccess soa(self); 2864 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2865 jvalue args[1]; 2866 args[0].l = arg.get(); 2867 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2868 // Restore object in case it gets moved. 2869 *object = soa.Decode<mirror::Object*>(arg.get()); 2870} 2871 2872void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2873 StackHandleScope<1> hs(self); 2874 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2875 RequestConcurrentGC(self); 2876} 2877 2878void Heap::RequestConcurrentGC(Thread* self) { 2879 // Make sure that we can do a concurrent GC. 2880 Runtime* runtime = Runtime::Current(); 2881 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2882 self->IsHandlingStackOverflow()) { 2883 return; 2884 } 2885 // We already have a request pending, no reason to start more until we update 2886 // concurrent_start_bytes_. 2887 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2888 JNIEnv* env = self->GetJniEnv(); 2889 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2890 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2891 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2892 WellKnownClasses::java_lang_Daemons_requestGC); 2893 CHECK(!env->ExceptionCheck()); 2894} 2895 2896void Heap::ConcurrentGC(Thread* self) { 2897 if (Runtime::Current()->IsShuttingDown(self)) { 2898 return; 2899 } 2900 // Wait for any GCs currently running to finish. 2901 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2902 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2903 // instead. E.g. can't do partial, so do full instead. 2904 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2905 collector::kGcTypeNone) { 2906 for (collector::GcType gc_type : gc_plan_) { 2907 // Attempt to run the collector, if we succeed, we are done. 2908 if (gc_type > next_gc_type_ && 2909 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2910 break; 2911 } 2912 } 2913 } 2914 } 2915} 2916 2917void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2918 Thread* self = Thread::Current(); 2919 { 2920 MutexLock mu(self, *heap_trim_request_lock_); 2921 if (desired_collector_type_ == desired_collector_type) { 2922 return; 2923 } 2924 heap_transition_or_trim_target_time_ = 2925 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2926 desired_collector_type_ = desired_collector_type; 2927 } 2928 SignalHeapTrimDaemon(self); 2929} 2930 2931void Heap::RequestHeapTrim() { 2932 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2933 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2934 // a space it will hold its lock and can become a cause of jank. 2935 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2936 // forking. 2937 2938 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2939 // because that only marks object heads, so a large array looks like lots of empty space. We 2940 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2941 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2942 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2943 // not how much use we're making of those pages. 2944 2945 Thread* self = Thread::Current(); 2946 Runtime* runtime = Runtime::Current(); 2947 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2948 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2949 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2950 // as we don't hold the lock while requesting the trim). 2951 return; 2952 } 2953 { 2954 MutexLock mu(self, *heap_trim_request_lock_); 2955 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2956 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2957 // just yet. 2958 return; 2959 } 2960 heap_trim_request_pending_ = true; 2961 uint64_t current_time = NanoTime(); 2962 if (heap_transition_or_trim_target_time_ < current_time) { 2963 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2964 } 2965 } 2966 // Notify the daemon thread which will actually do the heap trim. 2967 SignalHeapTrimDaemon(self); 2968} 2969 2970void Heap::SignalHeapTrimDaemon(Thread* self) { 2971 JNIEnv* env = self->GetJniEnv(); 2972 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2973 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2974 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2975 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2976 CHECK(!env->ExceptionCheck()); 2977} 2978 2979void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2980 if (rosalloc_space_ != nullptr) { 2981 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2982 } 2983 if (bump_pointer_space_ != nullptr) { 2984 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2985 } 2986} 2987 2988void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2989 if (rosalloc_space_ != nullptr) { 2990 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2991 } 2992} 2993 2994void Heap::RevokeAllThreadLocalBuffers() { 2995 if (rosalloc_space_ != nullptr) { 2996 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2997 } 2998 if (bump_pointer_space_ != nullptr) { 2999 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3000 } 3001} 3002 3003bool Heap::IsGCRequestPending() const { 3004 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3005} 3006 3007void Heap::RunFinalization(JNIEnv* env) { 3008 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3009 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3010 CHECK(WellKnownClasses::java_lang_System != nullptr); 3011 WellKnownClasses::java_lang_System_runFinalization = 3012 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3013 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3014 } 3015 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3016 WellKnownClasses::java_lang_System_runFinalization); 3017} 3018 3019void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3020 Thread* self = ThreadForEnv(env); 3021 if (native_need_to_run_finalization_) { 3022 RunFinalization(env); 3023 UpdateMaxNativeFootprint(); 3024 native_need_to_run_finalization_ = false; 3025 } 3026 // Total number of native bytes allocated. 3027 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3028 new_native_bytes_allocated += bytes; 3029 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3030 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3031 collector::kGcTypeFull; 3032 3033 // The second watermark is higher than the gc watermark. If you hit this it means you are 3034 // allocating native objects faster than the GC can keep up with. 3035 if (new_native_bytes_allocated > native_footprint_limit_) { 3036 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3037 // Just finished a GC, attempt to run finalizers. 3038 RunFinalization(env); 3039 CHECK(!env->ExceptionCheck()); 3040 } 3041 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3042 if (new_native_bytes_allocated > native_footprint_limit_) { 3043 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3044 RunFinalization(env); 3045 native_need_to_run_finalization_ = false; 3046 CHECK(!env->ExceptionCheck()); 3047 } 3048 // We have just run finalizers, update the native watermark since it is very likely that 3049 // finalizers released native managed allocations. 3050 UpdateMaxNativeFootprint(); 3051 } else if (!IsGCRequestPending()) { 3052 if (IsGcConcurrent()) { 3053 RequestConcurrentGC(self); 3054 } else { 3055 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3056 } 3057 } 3058 } 3059} 3060 3061void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3062 int expected_size, new_size; 3063 do { 3064 expected_size = native_bytes_allocated_.LoadRelaxed(); 3065 new_size = expected_size - bytes; 3066 if (UNLIKELY(new_size < 0)) { 3067 ScopedObjectAccess soa(env); 3068 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3069 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3070 "registered as allocated", bytes, expected_size).c_str()); 3071 break; 3072 } 3073 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3074} 3075 3076size_t Heap::GetTotalMemory() const { 3077 size_t ret = 0; 3078 for (const auto& space : continuous_spaces_) { 3079 // Currently don't include the image space. 3080 if (!space->IsImageSpace()) { 3081 ret += space->Size(); 3082 } 3083 } 3084 for (const auto& space : discontinuous_spaces_) { 3085 if (space->IsLargeObjectSpace()) { 3086 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3087 } 3088 } 3089 return ret; 3090} 3091 3092void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3093 DCHECK(mod_union_table != nullptr); 3094 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3095} 3096 3097void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3098 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3099 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3100 c->GetDescriptor().empty()); 3101 CHECK_GE(byte_count, sizeof(mirror::Object)); 3102} 3103 3104void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3105 CHECK(remembered_set != nullptr); 3106 space::Space* space = remembered_set->GetSpace(); 3107 CHECK(space != nullptr); 3108 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3109 remembered_sets_.Put(space, remembered_set); 3110 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3111} 3112 3113void Heap::RemoveRememberedSet(space::Space* space) { 3114 CHECK(space != nullptr); 3115 auto it = remembered_sets_.find(space); 3116 CHECK(it != remembered_sets_.end()); 3117 remembered_sets_.erase(it); 3118 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3119} 3120 3121void Heap::ClearMarkedObjects() { 3122 // Clear all of the spaces' mark bitmaps. 3123 for (const auto& space : GetContinuousSpaces()) { 3124 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3125 if (space->GetLiveBitmap() != mark_bitmap) { 3126 mark_bitmap->Clear(); 3127 } 3128 } 3129 // Clear the marked objects in the discontinous space object sets. 3130 for (const auto& space : GetDiscontinuousSpaces()) { 3131 space->GetMarkBitmap()->Clear(); 3132 } 3133} 3134 3135} // namespace gc 3136} // namespace art 3137