heap.cc revision b2ac1ab47f84bd989fb2c94a532f5dc7d177ebe4
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/concurrent_copying.h" 39#include "gc/collector/mark_compact.h" 40#include "gc/collector/mark_sweep-inl.h" 41#include "gc/collector/partial_mark_sweep.h" 42#include "gc/collector/semi_space.h" 43#include "gc/collector/sticky_mark_sweep.h" 44#include "gc/reference_processor.h" 45#include "gc/space/bump_pointer_space.h" 46#include "gc/space/dlmalloc_space-inl.h" 47#include "gc/space/image_space.h" 48#include "gc/space/large_object_space.h" 49#include "gc/space/rosalloc_space-inl.h" 50#include "gc/space/space-inl.h" 51#include "gc/space/zygote_space.h" 52#include "entrypoints/quick/quick_alloc_entrypoints.h" 53#include "heap-inl.h" 54#include "image.h" 55#include "mirror/art_field-inl.h" 56#include "mirror/class-inl.h" 57#include "mirror/object.h" 58#include "mirror/object-inl.h" 59#include "mirror/object_array-inl.h" 60#include "mirror/reference-inl.h" 61#include "object_utils.h" 62#include "os.h" 63#include "reflection.h" 64#include "runtime.h" 65#include "ScopedLocalRef.h" 66#include "scoped_thread_state_change.h" 67#include "handle_scope-inl.h" 68#include "thread_list.h" 69#include "well_known_classes.h" 70 71namespace art { 72 73namespace gc { 74 75static constexpr size_t kCollectorTransitionStressIterations = 0; 76static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 77static constexpr bool kGCALotMode = false; 78static constexpr size_t kGcAlotInterval = KB; 79// Minimum amount of remaining bytes before a concurrent GC is triggered. 80static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 81static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 82// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 83// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 84// threads (lower pauses, use less memory bandwidth). 85static constexpr double kStickyGcThroughputAdjustment = 1.0; 86// Whether or not we use the free list large object space. 87static constexpr bool kUseFreeListSpaceForLOS = false; 88// Whether or not we compact the zygote in PreZygoteFork. 89static constexpr bool kCompactZygote = kMovingCollector; 90static constexpr size_t kNonMovingSpaceCapacity = 64 * MB; 91// How many reserve entries are at the end of the allocation stack, these are only needed if the 92// allocation stack overflows. 93static constexpr size_t kAllocationStackReserveSize = 1024; 94// Default mark stack size in bytes. 95static const size_t kDefaultMarkStackSize = 64 * KB; 96// Define space name. 97static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 98static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 99static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 100static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 101 102Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 103 double target_utilization, double foreground_heap_growth_multiplier, size_t capacity, 104 const std::string& image_file_name, const InstructionSet image_instruction_set, 105 CollectorType foreground_collector_type, CollectorType background_collector_type, 106 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 107 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 108 bool ignore_max_footprint, bool use_tlab, 109 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 110 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 111 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 112 uint64_t min_interval_homogeneous_space_compaction_by_oom) 113 : non_moving_space_(nullptr), 114 rosalloc_space_(nullptr), 115 dlmalloc_space_(nullptr), 116 main_space_(nullptr), 117 collector_type_(kCollectorTypeNone), 118 foreground_collector_type_(foreground_collector_type), 119 background_collector_type_(background_collector_type), 120 desired_collector_type_(foreground_collector_type_), 121 heap_trim_request_lock_(nullptr), 122 last_trim_time_(0), 123 heap_transition_or_trim_target_time_(0), 124 heap_trim_request_pending_(false), 125 parallel_gc_threads_(parallel_gc_threads), 126 conc_gc_threads_(conc_gc_threads), 127 low_memory_mode_(low_memory_mode), 128 long_pause_log_threshold_(long_pause_log_threshold), 129 long_gc_log_threshold_(long_gc_log_threshold), 130 ignore_max_footprint_(ignore_max_footprint), 131 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 132 have_zygote_space_(false), 133 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 134 collector_type_running_(kCollectorTypeNone), 135 last_gc_type_(collector::kGcTypeNone), 136 next_gc_type_(collector::kGcTypePartial), 137 capacity_(capacity), 138 growth_limit_(growth_limit), 139 max_allowed_footprint_(initial_size), 140 native_footprint_gc_watermark_(initial_size), 141 native_footprint_limit_(2 * initial_size), 142 native_need_to_run_finalization_(false), 143 // Initially assume we perceive jank in case the process state is never updated. 144 process_state_(kProcessStateJankPerceptible), 145 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 146 total_bytes_freed_ever_(0), 147 total_objects_freed_ever_(0), 148 num_bytes_allocated_(0), 149 native_bytes_allocated_(0), 150 gc_memory_overhead_(0), 151 verify_missing_card_marks_(false), 152 verify_system_weaks_(false), 153 verify_pre_gc_heap_(verify_pre_gc_heap), 154 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 155 verify_post_gc_heap_(verify_post_gc_heap), 156 verify_mod_union_table_(false), 157 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 158 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 159 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 160 last_gc_time_ns_(NanoTime()), 161 allocation_rate_(0), 162 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 163 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 164 * verification is enabled, we limit the size of allocation stacks to speed up their 165 * searching. 166 */ 167 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 168 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 169 current_allocator_(kAllocatorTypeDlMalloc), 170 current_non_moving_allocator_(kAllocatorTypeNonMoving), 171 bump_pointer_space_(nullptr), 172 temp_space_(nullptr), 173 min_free_(min_free), 174 max_free_(max_free), 175 target_utilization_(target_utilization), 176 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 177 total_wait_time_(0), 178 total_allocation_time_(0), 179 verify_object_mode_(kVerifyObjectModeDisabled), 180 disable_moving_gc_count_(0), 181 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 182 use_tlab_(use_tlab), 183 main_space_backup_(nullptr), 184 min_interval_homogeneous_space_compaction_by_oom_( 185 min_interval_homogeneous_space_compaction_by_oom), 186 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 187 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 188 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 189 LOG(INFO) << "Heap() entering"; 190 } 191 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 192 // entrypoints. 193 if (!Runtime::Current()->IsZygote()) { 194 large_object_threshold_ = kDefaultLargeObjectThreshold; 195 // Background compaction is currently not supported for command line runs. 196 if (background_collector_type_ != foreground_collector_type_) { 197 VLOG(heap) << "Disabling background compaction for non zygote"; 198 background_collector_type_ = foreground_collector_type_; 199 } 200 } 201 ChangeCollector(desired_collector_type_); 202 live_bitmap_.reset(new accounting::HeapBitmap(this)); 203 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 204 // Requested begin for the alloc space, to follow the mapped image and oat files 205 byte* requested_alloc_space_begin = nullptr; 206 if (!image_file_name.empty()) { 207 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 208 image_instruction_set); 209 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 210 AddSpace(image_space); 211 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 212 // isn't going to get in the middle 213 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 214 CHECK_GT(oat_file_end_addr, image_space->End()); 215 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 216 } 217 /* 218 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 219 +- nonmoving space (kNonMovingSpaceCapacity) +- 220 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 221 +-main alloc space / bump space 1 (capacity_) +- 222 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 223 +-????????????????????????????????????????????+- 224 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 225 +-main alloc space2 / bump space 2 (capacity_)+- 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 227 */ 228 bool support_homogeneous_space_compaction = 229 background_collector_type == gc::kCollectorTypeHomogeneousSpaceCompact || 230 use_homogeneous_space_compaction_for_oom; 231 // We may use the same space the main space for the non moving space if we don't need to compact 232 // from the main space. 233 // This is not the case if we support homogeneous compaction or have a moving background 234 // collector type. 235 const bool is_zygote = Runtime::Current()->IsZygote(); 236 bool separate_non_moving_space = is_zygote || 237 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 238 IsMovingGc(background_collector_type_); 239 if (foreground_collector_type == kCollectorTypeGSS) { 240 separate_non_moving_space = false; 241 } 242 std::unique_ptr<MemMap> main_mem_map_1; 243 std::unique_ptr<MemMap> main_mem_map_2; 244 byte* request_begin = requested_alloc_space_begin; 245 if (request_begin != nullptr && separate_non_moving_space) { 246 request_begin += kNonMovingSpaceCapacity; 247 } 248 std::string error_str; 249 std::unique_ptr<MemMap> non_moving_space_mem_map; 250 if (separate_non_moving_space) { 251 // Reserve the non moving mem map before the other two since it needs to be at a specific 252 // address. 253 non_moving_space_mem_map.reset( 254 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 255 kNonMovingSpaceCapacity, PROT_READ | PROT_WRITE, true, &error_str)); 256 CHECK(non_moving_space_mem_map != nullptr) << error_str; 257 } 258 // Attempt to create 2 mem maps at or after the requested begin. 259 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 260 PROT_READ | PROT_WRITE, &error_str)); 261 CHECK(main_mem_map_1.get() != nullptr) << error_str; 262 if (support_homogeneous_space_compaction || 263 background_collector_type_ == kCollectorTypeSS || 264 foreground_collector_type_ == kCollectorTypeSS) { 265 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 266 capacity_, PROT_READ | PROT_WRITE, 267 &error_str)); 268 CHECK(main_mem_map_2.get() != nullptr) << error_str; 269 } 270 // Create the non moving space first so that bitmaps don't take up the address range. 271 if (separate_non_moving_space) { 272 // Non moving space is always dlmalloc since we currently don't have support for multiple 273 // active rosalloc spaces. 274 const size_t size = non_moving_space_mem_map->Size(); 275 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 276 non_moving_space_mem_map.release(), "zygote / non moving space", initial_size, 277 initial_size, size, size, false); 278 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 279 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 280 << requested_alloc_space_begin; 281 AddSpace(non_moving_space_); 282 } 283 // Create other spaces based on whether or not we have a moving GC. 284 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 285 // Create bump pointer spaces. 286 // We only to create the bump pointer if the foreground collector is a compacting GC. 287 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 288 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 289 main_mem_map_1.release()); 290 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 291 AddSpace(bump_pointer_space_); 292 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 293 main_mem_map_2.release()); 294 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 295 AddSpace(temp_space_); 296 CHECK(separate_non_moving_space); 297 } else { 298 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 299 CHECK(main_space_ != nullptr); 300 AddSpace(main_space_); 301 if (!separate_non_moving_space) { 302 non_moving_space_ = main_space_; 303 CHECK(!non_moving_space_->CanMoveObjects()); 304 } 305 if (foreground_collector_type_ == kCollectorTypeGSS) { 306 CHECK_EQ(foreground_collector_type_, background_collector_type_); 307 // Create bump pointer spaces instead of a backup space. 308 main_mem_map_2.release(); 309 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 310 kGSSBumpPointerSpaceCapacity, nullptr); 311 CHECK(bump_pointer_space_ != nullptr); 312 AddSpace(bump_pointer_space_); 313 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 314 kGSSBumpPointerSpaceCapacity, nullptr); 315 CHECK(temp_space_ != nullptr); 316 AddSpace(temp_space_); 317 } else if (main_mem_map_2.get() != nullptr) { 318 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 319 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 320 growth_limit_, capacity_, name, true)); 321 CHECK(main_space_backup_.get() != nullptr); 322 // Add the space so its accounted for in the heap_begin and heap_end. 323 AddSpace(main_space_backup_.get()); 324 } 325 } 326 CHECK(non_moving_space_ != nullptr); 327 CHECK(!non_moving_space_->CanMoveObjects()); 328 // Allocate the large object space. 329 if (kUseFreeListSpaceForLOS) { 330 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 331 } else { 332 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 333 } 334 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 335 AddSpace(large_object_space_); 336 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 337 CHECK(!continuous_spaces_.empty()); 338 // Relies on the spaces being sorted. 339 byte* heap_begin = continuous_spaces_.front()->Begin(); 340 byte* heap_end = continuous_spaces_.back()->Limit(); 341 size_t heap_capacity = heap_end - heap_begin; 342 // Remove the main backup space since it slows down the GC to have unused extra spaces. 343 if (main_space_backup_.get() != nullptr) { 344 RemoveSpace(main_space_backup_.get()); 345 } 346 // Allocate the card table. 347 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 348 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 349 // Card cache for now since it makes it easier for us to update the references to the copying 350 // spaces. 351 accounting::ModUnionTable* mod_union_table = 352 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 353 GetImageSpace()); 354 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 355 AddModUnionTable(mod_union_table); 356 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 357 accounting::RememberedSet* non_moving_space_rem_set = 358 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 359 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 360 AddRememberedSet(non_moving_space_rem_set); 361 } 362 // TODO: Count objects in the image space here? 363 num_bytes_allocated_.StoreRelaxed(0); 364 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 365 kDefaultMarkStackSize)); 366 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 367 allocation_stack_.reset(accounting::ObjectStack::Create( 368 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 369 live_stack_.reset(accounting::ObjectStack::Create( 370 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 371 // It's still too early to take a lock because there are no threads yet, but we can create locks 372 // now. We don't create it earlier to make it clear that you can't use locks during heap 373 // initialization. 374 gc_complete_lock_ = new Mutex("GC complete lock"); 375 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 376 *gc_complete_lock_)); 377 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 378 last_gc_size_ = GetBytesAllocated(); 379 if (ignore_max_footprint_) { 380 SetIdealFootprint(std::numeric_limits<size_t>::max()); 381 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 382 } 383 CHECK_NE(max_allowed_footprint_, 0U); 384 // Create our garbage collectors. 385 for (size_t i = 0; i < 2; ++i) { 386 const bool concurrent = i != 0; 387 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 388 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 389 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 390 } 391 if (kMovingCollector) { 392 // TODO: Clean this up. 393 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 394 semi_space_collector_ = new collector::SemiSpace(this, generational, 395 generational ? "generational" : ""); 396 garbage_collectors_.push_back(semi_space_collector_); 397 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 398 garbage_collectors_.push_back(concurrent_copying_collector_); 399 mark_compact_collector_ = new collector::MarkCompact(this); 400 garbage_collectors_.push_back(mark_compact_collector_); 401 } 402 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr) { 403 // Check that there's no gap between the image space and the non moving space so that the 404 // immune region won't break (eg. due to a large object allocated in the gap). 405 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 406 non_moving_space_->GetMemMap()); 407 if (!no_gap) { 408 MemMap::DumpMaps(LOG(ERROR)); 409 LOG(FATAL) << "There's a gap between the image space and the main space"; 410 } 411 } 412 if (running_on_valgrind_) { 413 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 414 } 415 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 416 LOG(INFO) << "Heap() exiting"; 417 } 418} 419 420MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 421 int prot_flags, std::string* out_error_str) { 422 while (true) { 423 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 424 PROT_READ | PROT_WRITE, true, out_error_str); 425 if (map != nullptr || request_begin == nullptr) { 426 return map; 427 } 428 // Retry a second time with no specified request begin. 429 request_begin = nullptr; 430 } 431 return nullptr; 432} 433 434space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 435 size_t growth_limit, size_t capacity, 436 const char* name, bool can_move_objects) { 437 space::MallocSpace* malloc_space = nullptr; 438 if (kUseRosAlloc) { 439 // Create rosalloc space. 440 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 441 initial_size, growth_limit, capacity, 442 low_memory_mode_, can_move_objects); 443 } else { 444 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 445 initial_size, growth_limit, capacity, 446 can_move_objects); 447 } 448 if (collector::SemiSpace::kUseRememberedSet) { 449 accounting::RememberedSet* rem_set = 450 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 451 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 452 AddRememberedSet(rem_set); 453 } 454 CHECK(malloc_space != nullptr) << "Failed to create " << name; 455 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 456 return malloc_space; 457} 458 459void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 460 size_t capacity) { 461 // Is background compaction is enabled? 462 bool can_move_objects = IsMovingGc(background_collector_type_) != 463 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 464 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 465 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 466 // from the main space to the zygote space. If background compaction is enabled, always pass in 467 // that we can move objets. 468 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 469 // After the zygote we want this to be false if we don't have background compaction enabled so 470 // that getting primitive array elements is faster. 471 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 472 can_move_objects = !have_zygote_space_ && foreground_collector_type_ != kCollectorTypeGSS; 473 } 474 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 475 RemoveRememberedSet(main_space_); 476 } 477 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 478 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 479 can_move_objects); 480 SetSpaceAsDefault(main_space_); 481 VLOG(heap) << "Created main space " << main_space_; 482} 483 484void Heap::ChangeAllocator(AllocatorType allocator) { 485 if (current_allocator_ != allocator) { 486 // These two allocators are only used internally and don't have any entrypoints. 487 CHECK_NE(allocator, kAllocatorTypeLOS); 488 CHECK_NE(allocator, kAllocatorTypeNonMoving); 489 current_allocator_ = allocator; 490 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 491 SetQuickAllocEntryPointsAllocator(current_allocator_); 492 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 493 } 494} 495 496void Heap::DisableCompaction() { 497 if (IsMovingGc(foreground_collector_type_)) { 498 foreground_collector_type_ = kCollectorTypeCMS; 499 } 500 if (IsMovingGc(background_collector_type_)) { 501 background_collector_type_ = foreground_collector_type_; 502 } 503 TransitionCollector(foreground_collector_type_); 504} 505 506std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 507 if (!IsValidContinuousSpaceObjectAddress(klass)) { 508 return StringPrintf("<non heap address klass %p>", klass); 509 } 510 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 511 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 512 std::string result("["); 513 result += SafeGetClassDescriptor(component_type); 514 return result; 515 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 516 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 517 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 518 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 519 } else { 520 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 521 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 522 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 523 } 524 const DexFile* dex_file = dex_cache->GetDexFile(); 525 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 526 if (class_def_idx == DexFile::kDexNoIndex16) { 527 return "<class def not found>"; 528 } 529 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 530 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 531 return dex_file->GetTypeDescriptor(type_id); 532 } 533} 534 535std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 536 if (obj == nullptr) { 537 return "null"; 538 } 539 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 540 if (klass == nullptr) { 541 return "(class=null)"; 542 } 543 std::string result(SafeGetClassDescriptor(klass)); 544 if (obj->IsClass()) { 545 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 546 } 547 return result; 548} 549 550void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 551 if (obj == nullptr) { 552 stream << "(obj=null)"; 553 return; 554 } 555 if (IsAligned<kObjectAlignment>(obj)) { 556 space::Space* space = nullptr; 557 // Don't use find space since it only finds spaces which actually contain objects instead of 558 // spaces which may contain objects (e.g. cleared bump pointer spaces). 559 for (const auto& cur_space : continuous_spaces_) { 560 if (cur_space->HasAddress(obj)) { 561 space = cur_space; 562 break; 563 } 564 } 565 // Unprotect all the spaces. 566 for (const auto& space : continuous_spaces_) { 567 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 568 } 569 stream << "Object " << obj; 570 if (space != nullptr) { 571 stream << " in space " << *space; 572 } 573 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 574 stream << "\nclass=" << klass; 575 if (klass != nullptr) { 576 stream << " type= " << SafePrettyTypeOf(obj); 577 } 578 // Re-protect the address we faulted on. 579 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 580 } 581} 582 583bool Heap::IsCompilingBoot() const { 584 for (const auto& space : continuous_spaces_) { 585 if (space->IsImageSpace() || space->IsZygoteSpace()) { 586 return false; 587 } 588 } 589 return true; 590} 591 592bool Heap::HasImageSpace() const { 593 for (const auto& space : continuous_spaces_) { 594 if (space->IsImageSpace()) { 595 return true; 596 } 597 } 598 return false; 599} 600 601void Heap::IncrementDisableMovingGC(Thread* self) { 602 // Need to do this holding the lock to prevent races where the GC is about to run / running when 603 // we attempt to disable it. 604 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 605 MutexLock mu(self, *gc_complete_lock_); 606 ++disable_moving_gc_count_; 607 if (IsMovingGc(collector_type_running_)) { 608 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 609 } 610} 611 612void Heap::DecrementDisableMovingGC(Thread* self) { 613 MutexLock mu(self, *gc_complete_lock_); 614 CHECK_GE(disable_moving_gc_count_, 0U); 615 --disable_moving_gc_count_; 616} 617 618void Heap::UpdateProcessState(ProcessState process_state) { 619 if (process_state_ != process_state) { 620 process_state_ = process_state; 621 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 622 // Start at index 1 to avoid "is always false" warning. 623 // Have iteration 1 always transition the collector. 624 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 625 ? foreground_collector_type_ : background_collector_type_); 626 usleep(kCollectorTransitionStressWait); 627 } 628 if (process_state_ == kProcessStateJankPerceptible) { 629 // Transition back to foreground right away to prevent jank. 630 RequestCollectorTransition(foreground_collector_type_, 0); 631 } else { 632 // Don't delay for debug builds since we may want to stress test the GC. 633 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 634 // special handling which does a homogenous space compaction once but then doesn't transition 635 // the collector. 636 RequestCollectorTransition(background_collector_type_, 637 kIsDebugBuild ? 0 : kCollectorTransitionWait); 638 } 639 } 640} 641 642void Heap::CreateThreadPool() { 643 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 644 if (num_threads != 0) { 645 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 646 } 647} 648 649void Heap::VisitObjects(ObjectCallback callback, void* arg) { 650 Thread* self = Thread::Current(); 651 // GCs can move objects, so don't allow this. 652 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 653 if (bump_pointer_space_ != nullptr) { 654 // Visit objects in bump pointer space. 655 bump_pointer_space_->Walk(callback, arg); 656 } 657 // TODO: Switch to standard begin and end to use ranged a based loop. 658 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 659 it < end; ++it) { 660 mirror::Object* obj = *it; 661 if (obj != nullptr && obj->GetClass() != nullptr) { 662 // Avoid the race condition caused by the object not yet being written into the allocation 663 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 664 // there can be nulls on the allocation stack. 665 callback(obj, arg); 666 } 667 } 668 GetLiveBitmap()->Walk(callback, arg); 669 self->EndAssertNoThreadSuspension(old_cause); 670} 671 672void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 673 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 674 space::ContinuousSpace* space2 = non_moving_space_; 675 // TODO: Generalize this to n bitmaps? 676 CHECK(space1 != nullptr); 677 CHECK(space2 != nullptr); 678 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 679 large_object_space_->GetLiveBitmap(), stack); 680} 681 682void Heap::DeleteThreadPool() { 683 thread_pool_.reset(nullptr); 684} 685 686void Heap::AddSpace(space::Space* space) { 687 CHECK(space != nullptr); 688 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 689 if (space->IsContinuousSpace()) { 690 DCHECK(!space->IsDiscontinuousSpace()); 691 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 692 // Continuous spaces don't necessarily have bitmaps. 693 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 694 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 695 if (live_bitmap != nullptr) { 696 CHECK(mark_bitmap != nullptr); 697 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 698 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 699 } 700 continuous_spaces_.push_back(continuous_space); 701 // Ensure that spaces remain sorted in increasing order of start address. 702 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 703 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 704 return a->Begin() < b->Begin(); 705 }); 706 } else { 707 CHECK(space->IsDiscontinuousSpace()); 708 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 709 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 710 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 711 discontinuous_spaces_.push_back(discontinuous_space); 712 } 713 if (space->IsAllocSpace()) { 714 alloc_spaces_.push_back(space->AsAllocSpace()); 715 } 716} 717 718void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 719 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 720 if (continuous_space->IsDlMallocSpace()) { 721 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 722 } else if (continuous_space->IsRosAllocSpace()) { 723 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 724 } 725} 726 727void Heap::RemoveSpace(space::Space* space) { 728 DCHECK(space != nullptr); 729 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 730 if (space->IsContinuousSpace()) { 731 DCHECK(!space->IsDiscontinuousSpace()); 732 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 733 // Continuous spaces don't necessarily have bitmaps. 734 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 735 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 736 if (live_bitmap != nullptr) { 737 DCHECK(mark_bitmap != nullptr); 738 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 739 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 740 } 741 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 742 DCHECK(it != continuous_spaces_.end()); 743 continuous_spaces_.erase(it); 744 } else { 745 DCHECK(space->IsDiscontinuousSpace()); 746 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 747 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 748 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 749 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 750 discontinuous_space); 751 DCHECK(it != discontinuous_spaces_.end()); 752 discontinuous_spaces_.erase(it); 753 } 754 if (space->IsAllocSpace()) { 755 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 756 DCHECK(it != alloc_spaces_.end()); 757 alloc_spaces_.erase(it); 758 } 759} 760 761void Heap::RegisterGCAllocation(size_t bytes) { 762 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 763} 764 765void Heap::RegisterGCDeAllocation(size_t bytes) { 766 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 767} 768 769void Heap::DumpGcPerformanceInfo(std::ostream& os) { 770 // Dump cumulative timings. 771 os << "Dumping cumulative Gc timings\n"; 772 uint64_t total_duration = 0; 773 // Dump cumulative loggers for each GC type. 774 uint64_t total_paused_time = 0; 775 for (auto& collector : garbage_collectors_) { 776 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 777 const size_t iterations = logger.GetIterations(); 778 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 779 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 780 os << ConstDumpable<CumulativeLogger>(logger); 781 const uint64_t total_ns = logger.GetTotalNs(); 782 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 783 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 784 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 785 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 786 Histogram<uint64_t>::CumulativeData cumulative_data; 787 pause_histogram.CreateHistogram(&cumulative_data); 788 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 789 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 790 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 791 << collector->GetName() << " freed: " << freed_objects 792 << " objects with total size " << PrettySize(freed_bytes) << "\n" 793 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 794 << PrettySize(freed_bytes / seconds) << "/s\n"; 795 total_duration += total_ns; 796 total_paused_time += total_pause_ns; 797 } 798 collector->ResetMeasurements(); 799 } 800 uint64_t allocation_time = 801 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 802 if (total_duration != 0) { 803 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 804 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 805 os << "Mean GC size throughput: " 806 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 807 os << "Mean GC object throughput: " 808 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 809 } 810 size_t total_objects_allocated = GetObjectsAllocatedEver(); 811 os << "Total number of allocations: " << total_objects_allocated << "\n"; 812 size_t total_bytes_allocated = GetBytesAllocatedEver(); 813 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 814 if (kMeasureAllocationTime) { 815 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 816 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 817 << "\n"; 818 } 819 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 820 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 821 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 822 BaseMutex::DumpAll(os); 823} 824 825Heap::~Heap() { 826 VLOG(heap) << "Starting ~Heap()"; 827 STLDeleteElements(&garbage_collectors_); 828 // If we don't reset then the mark stack complains in its destructor. 829 allocation_stack_->Reset(); 830 live_stack_->Reset(); 831 STLDeleteValues(&mod_union_tables_); 832 STLDeleteValues(&remembered_sets_); 833 STLDeleteElements(&continuous_spaces_); 834 STLDeleteElements(&discontinuous_spaces_); 835 delete gc_complete_lock_; 836 delete heap_trim_request_lock_; 837 VLOG(heap) << "Finished ~Heap()"; 838} 839 840space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 841 bool fail_ok) const { 842 for (const auto& space : continuous_spaces_) { 843 if (space->Contains(obj)) { 844 return space; 845 } 846 } 847 if (!fail_ok) { 848 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 849 } 850 return NULL; 851} 852 853space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 854 bool fail_ok) const { 855 for (const auto& space : discontinuous_spaces_) { 856 if (space->Contains(obj)) { 857 return space; 858 } 859 } 860 if (!fail_ok) { 861 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 862 } 863 return NULL; 864} 865 866space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 867 space::Space* result = FindContinuousSpaceFromObject(obj, true); 868 if (result != NULL) { 869 return result; 870 } 871 return FindDiscontinuousSpaceFromObject(obj, true); 872} 873 874space::ImageSpace* Heap::GetImageSpace() const { 875 for (const auto& space : continuous_spaces_) { 876 if (space->IsImageSpace()) { 877 return space->AsImageSpace(); 878 } 879 } 880 return NULL; 881} 882 883void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 884 std::ostringstream oss; 885 size_t total_bytes_free = GetFreeMemory(); 886 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 887 << " free bytes"; 888 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 889 if (total_bytes_free >= byte_count) { 890 space::AllocSpace* space = nullptr; 891 if (allocator_type == kAllocatorTypeNonMoving) { 892 space = non_moving_space_; 893 } else if (allocator_type == kAllocatorTypeRosAlloc || 894 allocator_type == kAllocatorTypeDlMalloc) { 895 space = main_space_; 896 } else if (allocator_type == kAllocatorTypeBumpPointer || 897 allocator_type == kAllocatorTypeTLAB) { 898 space = bump_pointer_space_; 899 } 900 if (space != nullptr) { 901 space->LogFragmentationAllocFailure(oss, byte_count); 902 } 903 } 904 self->ThrowOutOfMemoryError(oss.str().c_str()); 905} 906 907void Heap::DoPendingTransitionOrTrim() { 908 Thread* self = Thread::Current(); 909 CollectorType desired_collector_type; 910 // Wait until we reach the desired transition time. 911 while (true) { 912 uint64_t wait_time; 913 { 914 MutexLock mu(self, *heap_trim_request_lock_); 915 desired_collector_type = desired_collector_type_; 916 uint64_t current_time = NanoTime(); 917 if (current_time >= heap_transition_or_trim_target_time_) { 918 break; 919 } 920 wait_time = heap_transition_or_trim_target_time_ - current_time; 921 } 922 ScopedThreadStateChange tsc(self, kSleeping); 923 usleep(wait_time / 1000); // Usleep takes microseconds. 924 } 925 // Launch homogeneous space compaction if it is desired. 926 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 927 if (!CareAboutPauseTimes()) { 928 PerformHomogeneousSpaceCompact(); 929 } 930 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 931 desired_collector_type = collector_type_; 932 return; 933 } 934 // Transition the collector if the desired collector type is not the same as the current 935 // collector type. 936 TransitionCollector(desired_collector_type); 937 if (!CareAboutPauseTimes()) { 938 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 939 // about pauses. 940 Runtime* runtime = Runtime::Current(); 941 runtime->GetThreadList()->SuspendAll(); 942 uint64_t start_time = NanoTime(); 943 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 944 VLOG(heap) << "Deflating " << count << " monitors took " 945 << PrettyDuration(NanoTime() - start_time); 946 runtime->GetThreadList()->ResumeAll(); 947 } 948 // Do a heap trim if it is needed. 949 Trim(); 950} 951 952void Heap::Trim() { 953 Thread* self = Thread::Current(); 954 { 955 MutexLock mu(self, *heap_trim_request_lock_); 956 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 957 return; 958 } 959 last_trim_time_ = NanoTime(); 960 heap_trim_request_pending_ = false; 961 } 962 { 963 // Need to do this before acquiring the locks since we don't want to get suspended while 964 // holding any locks. 965 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 966 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 967 // trimming. 968 MutexLock mu(self, *gc_complete_lock_); 969 // Ensure there is only one GC at a time. 970 WaitForGcToCompleteLocked(kGcCauseTrim, self); 971 collector_type_running_ = kCollectorTypeHeapTrim; 972 } 973 uint64_t start_ns = NanoTime(); 974 // Trim the managed spaces. 975 uint64_t total_alloc_space_allocated = 0; 976 uint64_t total_alloc_space_size = 0; 977 uint64_t managed_reclaimed = 0; 978 for (const auto& space : continuous_spaces_) { 979 if (space->IsMallocSpace()) { 980 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 981 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 982 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 983 // for a long period of time. 984 managed_reclaimed += malloc_space->Trim(); 985 } 986 total_alloc_space_size += malloc_space->Size(); 987 } 988 } 989 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 990 if (bump_pointer_space_ != nullptr) { 991 total_alloc_space_allocated -= bump_pointer_space_->Size(); 992 } 993 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 994 static_cast<float>(total_alloc_space_size); 995 uint64_t gc_heap_end_ns = NanoTime(); 996 // We never move things in the native heap, so we can finish the GC at this point. 997 FinishGC(self, collector::kGcTypeNone); 998 size_t native_reclaimed = 0; 999 // Only trim the native heap if we don't care about pauses. 1000 if (!CareAboutPauseTimes()) { 1001#if defined(USE_DLMALLOC) 1002 // Trim the native heap. 1003 dlmalloc_trim(0); 1004 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1005#elif defined(USE_JEMALLOC) 1006 // Jemalloc does it's own internal trimming. 1007#else 1008 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1009#endif 1010 } 1011 uint64_t end_ns = NanoTime(); 1012 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1013 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1014 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1015 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1016 << "%."; 1017} 1018 1019bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1020 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1021 // taking the lock. 1022 if (obj == nullptr) { 1023 return true; 1024 } 1025 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1026} 1027 1028bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1029 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1030} 1031 1032bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1033 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1034 return false; 1035 } 1036 for (const auto& space : continuous_spaces_) { 1037 if (space->HasAddress(obj)) { 1038 return true; 1039 } 1040 } 1041 return false; 1042} 1043 1044bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1045 bool search_live_stack, bool sorted) { 1046 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1047 return false; 1048 } 1049 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1050 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1051 if (obj == klass) { 1052 // This case happens for java.lang.Class. 1053 return true; 1054 } 1055 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1056 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1057 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1058 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1059 return temp_space_->Contains(obj); 1060 } 1061 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1062 space::DiscontinuousSpace* d_space = nullptr; 1063 if (c_space != nullptr) { 1064 if (c_space->GetLiveBitmap()->Test(obj)) { 1065 return true; 1066 } 1067 } else { 1068 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1069 if (d_space != nullptr) { 1070 if (d_space->GetLiveBitmap()->Test(obj)) { 1071 return true; 1072 } 1073 } 1074 } 1075 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1076 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1077 if (i > 0) { 1078 NanoSleep(MsToNs(10)); 1079 } 1080 if (search_allocation_stack) { 1081 if (sorted) { 1082 if (allocation_stack_->ContainsSorted(obj)) { 1083 return true; 1084 } 1085 } else if (allocation_stack_->Contains(obj)) { 1086 return true; 1087 } 1088 } 1089 1090 if (search_live_stack) { 1091 if (sorted) { 1092 if (live_stack_->ContainsSorted(obj)) { 1093 return true; 1094 } 1095 } else if (live_stack_->Contains(obj)) { 1096 return true; 1097 } 1098 } 1099 } 1100 // We need to check the bitmaps again since there is a race where we mark something as live and 1101 // then clear the stack containing it. 1102 if (c_space != nullptr) { 1103 if (c_space->GetLiveBitmap()->Test(obj)) { 1104 return true; 1105 } 1106 } else { 1107 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1108 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1109 return true; 1110 } 1111 } 1112 return false; 1113} 1114 1115std::string Heap::DumpSpaces() const { 1116 std::ostringstream oss; 1117 DumpSpaces(oss); 1118 return oss.str(); 1119} 1120 1121void Heap::DumpSpaces(std::ostream& stream) const { 1122 for (const auto& space : continuous_spaces_) { 1123 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1124 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1125 stream << space << " " << *space << "\n"; 1126 if (live_bitmap != nullptr) { 1127 stream << live_bitmap << " " << *live_bitmap << "\n"; 1128 } 1129 if (mark_bitmap != nullptr) { 1130 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1131 } 1132 } 1133 for (const auto& space : discontinuous_spaces_) { 1134 stream << space << " " << *space << "\n"; 1135 } 1136} 1137 1138void Heap::VerifyObjectBody(mirror::Object* obj) { 1139 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1140 return; 1141 } 1142 1143 // Ignore early dawn of the universe verifications. 1144 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1145 return; 1146 } 1147 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1148 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1149 CHECK(c != nullptr) << "Null class in object " << obj; 1150 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1151 CHECK(VerifyClassClass(c)); 1152 1153 if (verify_object_mode_ > kVerifyObjectModeFast) { 1154 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1155 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1156 } 1157} 1158 1159void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1160 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1161} 1162 1163void Heap::VerifyHeap() { 1164 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1165 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1166} 1167 1168void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1169 // Use signed comparison since freed bytes can be negative when background compaction foreground 1170 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1171 // free list backed space typically increasing memory footprint due to padding and binning. 1172 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1173 // Note: This relies on 2s complement for handling negative freed_bytes. 1174 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1175 if (Runtime::Current()->HasStatsEnabled()) { 1176 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1177 thread_stats->freed_objects += freed_objects; 1178 thread_stats->freed_bytes += freed_bytes; 1179 // TODO: Do this concurrently. 1180 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1181 global_stats->freed_objects += freed_objects; 1182 global_stats->freed_bytes += freed_bytes; 1183 } 1184} 1185 1186space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1187 for (const auto& space : continuous_spaces_) { 1188 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1189 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1190 return space->AsContinuousSpace()->AsRosAllocSpace(); 1191 } 1192 } 1193 } 1194 return nullptr; 1195} 1196 1197mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1198 size_t alloc_size, size_t* bytes_allocated, 1199 size_t* usable_size, 1200 mirror::Class** klass) { 1201 bool was_default_allocator = allocator == GetCurrentAllocator(); 1202 DCHECK(klass != nullptr); 1203 StackHandleScope<1> hs(self); 1204 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1205 klass = nullptr; // Invalidate for safety. 1206 // The allocation failed. If the GC is running, block until it completes, and then retry the 1207 // allocation. 1208 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1209 if (last_gc != collector::kGcTypeNone) { 1210 // If we were the default allocator but the allocator changed while we were suspended, 1211 // abort the allocation. 1212 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1213 return nullptr; 1214 } 1215 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1216 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1217 usable_size); 1218 if (ptr != nullptr) { 1219 return ptr; 1220 } 1221 } 1222 1223 collector::GcType tried_type = next_gc_type_; 1224 const bool gc_ran = 1225 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1226 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1227 return nullptr; 1228 } 1229 if (gc_ran) { 1230 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1231 usable_size); 1232 if (ptr != nullptr) { 1233 return ptr; 1234 } 1235 } 1236 1237 // Loop through our different Gc types and try to Gc until we get enough free memory. 1238 for (collector::GcType gc_type : gc_plan_) { 1239 if (gc_type == tried_type) { 1240 continue; 1241 } 1242 // Attempt to run the collector, if we succeed, re-try the allocation. 1243 const bool gc_ran = 1244 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1245 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1246 return nullptr; 1247 } 1248 if (gc_ran) { 1249 // Did we free sufficient memory for the allocation to succeed? 1250 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1251 usable_size); 1252 if (ptr != nullptr) { 1253 return ptr; 1254 } 1255 } 1256 } 1257 // Allocations have failed after GCs; this is an exceptional state. 1258 // Try harder, growing the heap if necessary. 1259 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1260 usable_size); 1261 if (ptr != nullptr) { 1262 return ptr; 1263 } 1264 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1265 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1266 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1267 // OOME. 1268 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1269 << " allocation"; 1270 // TODO: Run finalization, but this may cause more allocations to occur. 1271 // We don't need a WaitForGcToComplete here either. 1272 DCHECK(!gc_plan_.empty()); 1273 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1274 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1275 return nullptr; 1276 } 1277 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1278 if (ptr == nullptr && use_homogeneous_space_compaction_for_oom_) { 1279 const uint64_t current_time = NanoTime(); 1280 if ((allocator == kAllocatorTypeRosAlloc || allocator == kAllocatorTypeDlMalloc) && 1281 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1282 min_interval_homogeneous_space_compaction_by_oom_) { 1283 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1284 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1285 switch (result) { 1286 case HomogeneousSpaceCompactResult::kSuccess: 1287 // If the allocation succeeded, we delayed an oom. 1288 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1289 if (ptr != nullptr) { 1290 count_delayed_oom_++; 1291 } 1292 break; 1293 case HomogeneousSpaceCompactResult::kErrorReject: 1294 // Reject due to disabled moving GC. 1295 break; 1296 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1297 // Throw OOM by default. 1298 break; 1299 default: { 1300 LOG(FATAL) << "Unimplemented homogeneous space compaction result " << static_cast<size_t>(result); 1301 } 1302 } 1303 // Always print that we ran homogeneous space compation since this can cause jank. 1304 VLOG(heap) << "Ran heap homogeneous space compaction, " 1305 << " requested defragmentation " 1306 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1307 << " performed defragmentation " 1308 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1309 << " ignored homogeneous space compaction " 1310 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1311 << " delayed count = " 1312 << count_delayed_oom_.LoadSequentiallyConsistent(); 1313 } 1314 } 1315 // If the allocation hasn't succeeded by this point, throw an OOM error. 1316 if (ptr == nullptr) { 1317 ThrowOutOfMemoryError(self, alloc_size, allocator); 1318 } 1319 return ptr; 1320} 1321 1322void Heap::SetTargetHeapUtilization(float target) { 1323 DCHECK_GT(target, 0.0f); // asserted in Java code 1324 DCHECK_LT(target, 1.0f); 1325 target_utilization_ = target; 1326} 1327 1328size_t Heap::GetObjectsAllocated() const { 1329 size_t total = 0; 1330 for (space::AllocSpace* space : alloc_spaces_) { 1331 total += space->GetObjectsAllocated(); 1332 } 1333 return total; 1334} 1335 1336size_t Heap::GetObjectsAllocatedEver() const { 1337 return GetObjectsFreedEver() + GetObjectsAllocated(); 1338} 1339 1340size_t Heap::GetBytesAllocatedEver() const { 1341 return GetBytesFreedEver() + GetBytesAllocated(); 1342} 1343 1344class InstanceCounter { 1345 public: 1346 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1347 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1348 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1349 } 1350 static void Callback(mirror::Object* obj, void* arg) 1351 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1352 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1353 mirror::Class* instance_class = obj->GetClass(); 1354 CHECK(instance_class != nullptr); 1355 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1356 if (instance_counter->use_is_assignable_from_) { 1357 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1358 ++instance_counter->counts_[i]; 1359 } 1360 } else if (instance_class == instance_counter->classes_[i]) { 1361 ++instance_counter->counts_[i]; 1362 } 1363 } 1364 } 1365 1366 private: 1367 const std::vector<mirror::Class*>& classes_; 1368 bool use_is_assignable_from_; 1369 uint64_t* const counts_; 1370 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1371}; 1372 1373void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1374 uint64_t* counts) { 1375 // Can't do any GC in this function since this may move classes. 1376 Thread* self = Thread::Current(); 1377 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1378 InstanceCounter counter(classes, use_is_assignable_from, counts); 1379 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1380 VisitObjects(InstanceCounter::Callback, &counter); 1381 self->EndAssertNoThreadSuspension(old_cause); 1382} 1383 1384class InstanceCollector { 1385 public: 1386 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1387 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1388 : class_(c), max_count_(max_count), instances_(instances) { 1389 } 1390 static void Callback(mirror::Object* obj, void* arg) 1391 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1392 DCHECK(arg != nullptr); 1393 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1394 mirror::Class* instance_class = obj->GetClass(); 1395 if (instance_class == instance_collector->class_) { 1396 if (instance_collector->max_count_ == 0 || 1397 instance_collector->instances_.size() < instance_collector->max_count_) { 1398 instance_collector->instances_.push_back(obj); 1399 } 1400 } 1401 } 1402 1403 private: 1404 mirror::Class* class_; 1405 uint32_t max_count_; 1406 std::vector<mirror::Object*>& instances_; 1407 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1408}; 1409 1410void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1411 std::vector<mirror::Object*>& instances) { 1412 // Can't do any GC in this function since this may move classes. 1413 Thread* self = Thread::Current(); 1414 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1415 InstanceCollector collector(c, max_count, instances); 1416 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1417 VisitObjects(&InstanceCollector::Callback, &collector); 1418 self->EndAssertNoThreadSuspension(old_cause); 1419} 1420 1421class ReferringObjectsFinder { 1422 public: 1423 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1424 std::vector<mirror::Object*>& referring_objects) 1425 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1426 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1427 } 1428 1429 static void Callback(mirror::Object* obj, void* arg) 1430 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1431 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1432 } 1433 1434 // For bitmap Visit. 1435 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1436 // annotalysis on visitors. 1437 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1438 o->VisitReferences<true>(*this, VoidFunctor()); 1439 } 1440 1441 // For Object::VisitReferences. 1442 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1443 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1444 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1445 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1446 referring_objects_.push_back(obj); 1447 } 1448 } 1449 1450 private: 1451 mirror::Object* object_; 1452 uint32_t max_count_; 1453 std::vector<mirror::Object*>& referring_objects_; 1454 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1455}; 1456 1457void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1458 std::vector<mirror::Object*>& referring_objects) { 1459 // Can't do any GC in this function since this may move the object o. 1460 Thread* self = Thread::Current(); 1461 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1462 ReferringObjectsFinder finder(o, max_count, referring_objects); 1463 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1464 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1465 self->EndAssertNoThreadSuspension(old_cause); 1466} 1467 1468void Heap::CollectGarbage(bool clear_soft_references) { 1469 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1470 // last GC will not have necessarily been cleared. 1471 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1472} 1473 1474HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1475 Thread* self = Thread::Current(); 1476 // Inc requested homogeneous space compaction. 1477 count_requested_homogeneous_space_compaction_++; 1478 // Store performed homogeneous space compaction at a new request arrival. 1479 ThreadList* tl = Runtime::Current()->GetThreadList(); 1480 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1481 Locks::mutator_lock_->AssertNotHeld(self); 1482 { 1483 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1484 MutexLock mu(self, *gc_complete_lock_); 1485 // Ensure there is only one GC at a time. 1486 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1487 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1488 // is non zero. 1489 // If the collecotr type changed to something which doesn't benefit from homogeneous space compaction, 1490 // exit. 1491 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_)) { 1492 return HomogeneousSpaceCompactResult::kErrorReject; 1493 } 1494 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1495 } 1496 if (Runtime::Current()->IsShuttingDown(self)) { 1497 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1498 // cause objects to get finalized. 1499 FinishGC(self, collector::kGcTypeNone); 1500 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1501 } 1502 // Suspend all threads. 1503 tl->SuspendAll(); 1504 uint64_t start_time = NanoTime(); 1505 // Launch compaction. 1506 space::MallocSpace* to_space = main_space_backup_.release(); 1507 space::MallocSpace* from_space = main_space_; 1508 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1509 const uint64_t space_size_before_compaction = from_space->Size(); 1510 AddSpace(to_space); 1511 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1512 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1513 from_space->GetMemMap()->Protect(PROT_READ); 1514 const uint64_t space_size_after_compaction = to_space->Size(); 1515 main_space_ = to_space; 1516 main_space_backup_.reset(from_space); 1517 RemoveSpace(from_space); 1518 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1519 // Update performed homogeneous space compaction count. 1520 count_performed_homogeneous_space_compaction_++; 1521 // Print statics log and resume all threads. 1522 uint64_t duration = NanoTime() - start_time; 1523 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1524 << PrettySize(space_size_before_compaction) << " -> " 1525 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1526 << std::fixed << static_cast<double>(space_size_after_compaction) / 1527 static_cast<double>(space_size_before_compaction); 1528 tl->ResumeAll(); 1529 // Finish GC. 1530 reference_processor_.EnqueueClearedReferences(self); 1531 GrowForUtilization(semi_space_collector_); 1532 FinishGC(self, collector::kGcTypeFull); 1533 return HomogeneousSpaceCompactResult::kSuccess; 1534} 1535 1536 1537void Heap::TransitionCollector(CollectorType collector_type) { 1538 if (collector_type == collector_type_) { 1539 return; 1540 } 1541 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1542 << " -> " << static_cast<int>(collector_type); 1543 uint64_t start_time = NanoTime(); 1544 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1545 Runtime* const runtime = Runtime::Current(); 1546 ThreadList* const tl = runtime->GetThreadList(); 1547 Thread* const self = Thread::Current(); 1548 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1549 Locks::mutator_lock_->AssertNotHeld(self); 1550 const bool copying_transition = 1551 IsMovingGc(background_collector_type_) || IsMovingGc(foreground_collector_type_); 1552 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1553 // compacting_gc_disable_count_, this should rarely occurs). 1554 for (;;) { 1555 { 1556 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1557 MutexLock mu(self, *gc_complete_lock_); 1558 // Ensure there is only one GC at a time. 1559 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1560 // If someone else beat us to it and changed the collector before we could, exit. 1561 // This is safe to do before the suspend all since we set the collector_type_running_ before 1562 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1563 // then it would get blocked on WaitForGcToCompleteLocked. 1564 if (collector_type == collector_type_) { 1565 return; 1566 } 1567 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1568 if (!copying_transition || disable_moving_gc_count_ == 0) { 1569 // TODO: Not hard code in semi-space collector? 1570 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1571 break; 1572 } 1573 } 1574 usleep(1000); 1575 } 1576 if (runtime->IsShuttingDown(self)) { 1577 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1578 // cause objects to get finalized. 1579 FinishGC(self, collector::kGcTypeNone); 1580 return; 1581 } 1582 tl->SuspendAll(); 1583 switch (collector_type) { 1584 case kCollectorTypeSS: { 1585 if (!IsMovingGc(collector_type_)) { 1586 // Create the bump pointer space from the backup space. 1587 CHECK(main_space_backup_ != nullptr); 1588 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1589 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1590 // pointer space last transition it will be protected. 1591 CHECK(mem_map != nullptr); 1592 mem_map->Protect(PROT_READ | PROT_WRITE); 1593 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1594 mem_map.release()); 1595 AddSpace(bump_pointer_space_); 1596 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1597 // Use the now empty main space mem map for the bump pointer temp space. 1598 mem_map.reset(main_space_->ReleaseMemMap()); 1599 // Unset the pointers just in case. 1600 if (dlmalloc_space_ == main_space_) { 1601 dlmalloc_space_ = nullptr; 1602 } else if (rosalloc_space_ == main_space_) { 1603 rosalloc_space_ = nullptr; 1604 } 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 RemoveRememberedSet(main_space_); 1609 delete main_space_; // Delete the space since it has been removed. 1610 main_space_ = nullptr; 1611 RemoveRememberedSet(main_space_backup_.get()); 1612 main_space_backup_.reset(nullptr); // Deletes the space. 1613 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1614 mem_map.release()); 1615 AddSpace(temp_space_); 1616 } 1617 break; 1618 } 1619 case kCollectorTypeMS: 1620 // Fall through. 1621 case kCollectorTypeCMS: { 1622 if (IsMovingGc(collector_type_)) { 1623 CHECK(temp_space_ != nullptr); 1624 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1625 RemoveSpace(temp_space_); 1626 temp_space_ = nullptr; 1627 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1628 mem_map->Size()); 1629 mem_map.release(); 1630 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1631 AddSpace(main_space_); 1632 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1633 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1634 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1635 RemoveSpace(bump_pointer_space_); 1636 bump_pointer_space_ = nullptr; 1637 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1638 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1639 mem_map->Size(), mem_map->Size(), 1640 name, true)); 1641 mem_map.release(); 1642 } 1643 break; 1644 } 1645 default: { 1646 LOG(FATAL) << "Attempted to transition to invalid collector type " 1647 << static_cast<size_t>(collector_type); 1648 break; 1649 } 1650 } 1651 ChangeCollector(collector_type); 1652 tl->ResumeAll(); 1653 // Can't call into java code with all threads suspended. 1654 reference_processor_.EnqueueClearedReferences(self); 1655 uint64_t duration = NanoTime() - start_time; 1656 GrowForUtilization(semi_space_collector_); 1657 FinishGC(self, collector::kGcTypeFull); 1658 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1659 int32_t delta_allocated = before_allocated - after_allocated; 1660 std::string saved_str; 1661 if (delta_allocated >= 0) { 1662 saved_str = " saved at least " + PrettySize(delta_allocated); 1663 } else { 1664 saved_str = " expanded " + PrettySize(-delta_allocated); 1665 } 1666 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1667 << PrettyDuration(duration) << saved_str; 1668} 1669 1670void Heap::ChangeCollector(CollectorType collector_type) { 1671 // TODO: Only do this with all mutators suspended to avoid races. 1672 if (collector_type != collector_type_) { 1673 if (collector_type == kCollectorTypeMC) { 1674 // Don't allow mark compact unless support is compiled in. 1675 CHECK(kMarkCompactSupport); 1676 } 1677 collector_type_ = collector_type; 1678 gc_plan_.clear(); 1679 switch (collector_type_) { 1680 case kCollectorTypeCC: // Fall-through. 1681 case kCollectorTypeMC: // Fall-through. 1682 case kCollectorTypeSS: // Fall-through. 1683 case kCollectorTypeGSS: { 1684 gc_plan_.push_back(collector::kGcTypeFull); 1685 if (use_tlab_) { 1686 ChangeAllocator(kAllocatorTypeTLAB); 1687 } else { 1688 ChangeAllocator(kAllocatorTypeBumpPointer); 1689 } 1690 break; 1691 } 1692 case kCollectorTypeMS: { 1693 gc_plan_.push_back(collector::kGcTypeSticky); 1694 gc_plan_.push_back(collector::kGcTypePartial); 1695 gc_plan_.push_back(collector::kGcTypeFull); 1696 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1697 break; 1698 } 1699 case kCollectorTypeCMS: { 1700 gc_plan_.push_back(collector::kGcTypeSticky); 1701 gc_plan_.push_back(collector::kGcTypePartial); 1702 gc_plan_.push_back(collector::kGcTypeFull); 1703 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1704 break; 1705 } 1706 default: { 1707 LOG(FATAL) << "Unimplemented"; 1708 } 1709 } 1710 if (IsGcConcurrent()) { 1711 concurrent_start_bytes_ = 1712 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1713 } else { 1714 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1715 } 1716 } 1717} 1718 1719// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1720class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1721 public: 1722 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1723 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1724 } 1725 1726 void BuildBins(space::ContinuousSpace* space) { 1727 bin_live_bitmap_ = space->GetLiveBitmap(); 1728 bin_mark_bitmap_ = space->GetMarkBitmap(); 1729 BinContext context; 1730 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1731 context.collector_ = this; 1732 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1733 // Note: This requires traversing the space in increasing order of object addresses. 1734 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1735 // Add the last bin which spans after the last object to the end of the space. 1736 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1737 } 1738 1739 private: 1740 struct BinContext { 1741 uintptr_t prev_; // The end of the previous object. 1742 ZygoteCompactingCollector* collector_; 1743 }; 1744 // Maps from bin sizes to locations. 1745 std::multimap<size_t, uintptr_t> bins_; 1746 // Live bitmap of the space which contains the bins. 1747 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1748 // Mark bitmap of the space which contains the bins. 1749 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1750 1751 static void Callback(mirror::Object* obj, void* arg) 1752 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1753 DCHECK(arg != nullptr); 1754 BinContext* context = reinterpret_cast<BinContext*>(arg); 1755 ZygoteCompactingCollector* collector = context->collector_; 1756 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1757 size_t bin_size = object_addr - context->prev_; 1758 // Add the bin consisting of the end of the previous object to the start of the current object. 1759 collector->AddBin(bin_size, context->prev_); 1760 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1761 } 1762 1763 void AddBin(size_t size, uintptr_t position) { 1764 if (size != 0) { 1765 bins_.insert(std::make_pair(size, position)); 1766 } 1767 } 1768 1769 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1770 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1771 // allocator. 1772 return false; 1773 } 1774 1775 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1776 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1777 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1778 mirror::Object* forward_address; 1779 // Find the smallest bin which we can move obj in. 1780 auto it = bins_.lower_bound(object_size); 1781 if (it == bins_.end()) { 1782 // No available space in the bins, place it in the target space instead (grows the zygote 1783 // space). 1784 size_t bytes_allocated; 1785 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1786 if (to_space_live_bitmap_ != nullptr) { 1787 to_space_live_bitmap_->Set(forward_address); 1788 } else { 1789 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1790 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1791 } 1792 } else { 1793 size_t size = it->first; 1794 uintptr_t pos = it->second; 1795 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1796 forward_address = reinterpret_cast<mirror::Object*>(pos); 1797 // Set the live and mark bits so that sweeping system weaks works properly. 1798 bin_live_bitmap_->Set(forward_address); 1799 bin_mark_bitmap_->Set(forward_address); 1800 DCHECK_GE(size, object_size); 1801 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1802 } 1803 // Copy the object over to its new location. 1804 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1805 if (kUseBakerOrBrooksReadBarrier) { 1806 obj->AssertReadBarrierPointer(); 1807 if (kUseBrooksReadBarrier) { 1808 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1809 forward_address->SetReadBarrierPointer(forward_address); 1810 } 1811 forward_address->AssertReadBarrierPointer(); 1812 } 1813 return forward_address; 1814 } 1815}; 1816 1817void Heap::UnBindBitmaps() { 1818 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1819 for (const auto& space : GetContinuousSpaces()) { 1820 if (space->IsContinuousMemMapAllocSpace()) { 1821 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1822 if (alloc_space->HasBoundBitmaps()) { 1823 alloc_space->UnBindBitmaps(); 1824 } 1825 } 1826 } 1827} 1828 1829void Heap::PreZygoteFork() { 1830 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1831 Thread* self = Thread::Current(); 1832 MutexLock mu(self, zygote_creation_lock_); 1833 // Try to see if we have any Zygote spaces. 1834 if (have_zygote_space_) { 1835 return; 1836 } 1837 VLOG(heap) << "Starting PreZygoteFork"; 1838 // Trim the pages at the end of the non moving space. 1839 non_moving_space_->Trim(); 1840 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1841 // there. 1842 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1843 // Change the collector to the post zygote one. 1844 bool same_space = non_moving_space_ == main_space_; 1845 if (kCompactZygote) { 1846 DCHECK(semi_space_collector_ != nullptr); 1847 // Temporarily disable rosalloc verification because the zygote 1848 // compaction will mess up the rosalloc internal metadata. 1849 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1850 ZygoteCompactingCollector zygote_collector(this); 1851 zygote_collector.BuildBins(non_moving_space_); 1852 // Create a new bump pointer space which we will compact into. 1853 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1854 non_moving_space_->Limit()); 1855 // Compact the bump pointer space to a new zygote bump pointer space. 1856 bool reset_main_space = false; 1857 if (IsMovingGc(collector_type_)) { 1858 zygote_collector.SetFromSpace(bump_pointer_space_); 1859 } else { 1860 CHECK(main_space_ != nullptr); 1861 // Copy from the main space. 1862 zygote_collector.SetFromSpace(main_space_); 1863 reset_main_space = true; 1864 } 1865 zygote_collector.SetToSpace(&target_space); 1866 zygote_collector.SetSwapSemiSpaces(false); 1867 zygote_collector.Run(kGcCauseCollectorTransition, false); 1868 if (reset_main_space) { 1869 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1870 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1871 MemMap* mem_map = main_space_->ReleaseMemMap(); 1872 RemoveSpace(main_space_); 1873 space::Space* old_main_space = main_space_; 1874 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1875 delete old_main_space; 1876 AddSpace(main_space_); 1877 } else { 1878 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1879 } 1880 if (temp_space_ != nullptr) { 1881 CHECK(temp_space_->IsEmpty()); 1882 } 1883 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1884 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1885 // Update the end and write out image. 1886 non_moving_space_->SetEnd(target_space.End()); 1887 non_moving_space_->SetLimit(target_space.Limit()); 1888 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1889 } 1890 ChangeCollector(foreground_collector_type_); 1891 // Save the old space so that we can remove it after we complete creating the zygote space. 1892 space::MallocSpace* old_alloc_space = non_moving_space_; 1893 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1894 // the remaining available space. 1895 // Remove the old space before creating the zygote space since creating the zygote space sets 1896 // the old alloc space's bitmaps to nullptr. 1897 RemoveSpace(old_alloc_space); 1898 if (collector::SemiSpace::kUseRememberedSet) { 1899 // Sanity bound check. 1900 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1901 // Remove the remembered set for the now zygote space (the old 1902 // non-moving space). Note now that we have compacted objects into 1903 // the zygote space, the data in the remembered set is no longer 1904 // needed. The zygote space will instead have a mod-union table 1905 // from this point on. 1906 RemoveRememberedSet(old_alloc_space); 1907 } 1908 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1909 low_memory_mode_, 1910 &non_moving_space_); 1911 CHECK(!non_moving_space_->CanMoveObjects()); 1912 if (same_space) { 1913 main_space_ = non_moving_space_; 1914 SetSpaceAsDefault(main_space_); 1915 } 1916 delete old_alloc_space; 1917 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1918 AddSpace(zygote_space); 1919 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1920 AddSpace(non_moving_space_); 1921 have_zygote_space_ = true; 1922 // Enable large object space allocations. 1923 large_object_threshold_ = kDefaultLargeObjectThreshold; 1924 // Create the zygote space mod union table. 1925 accounting::ModUnionTable* mod_union_table = 1926 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1927 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1928 AddModUnionTable(mod_union_table); 1929 if (collector::SemiSpace::kUseRememberedSet) { 1930 // Add a new remembered set for the post-zygote non-moving space. 1931 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1932 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1933 non_moving_space_); 1934 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1935 << "Failed to create post-zygote non-moving space remembered set"; 1936 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1937 } 1938} 1939 1940void Heap::FlushAllocStack() { 1941 MarkAllocStackAsLive(allocation_stack_.get()); 1942 allocation_stack_->Reset(); 1943} 1944 1945void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 1946 accounting::ContinuousSpaceBitmap* bitmap2, 1947 accounting::LargeObjectBitmap* large_objects, 1948 accounting::ObjectStack* stack) { 1949 DCHECK(bitmap1 != nullptr); 1950 DCHECK(bitmap2 != nullptr); 1951 mirror::Object** limit = stack->End(); 1952 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1953 const mirror::Object* obj = *it; 1954 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1955 if (bitmap1->HasAddress(obj)) { 1956 bitmap1->Set(obj); 1957 } else if (bitmap2->HasAddress(obj)) { 1958 bitmap2->Set(obj); 1959 } else { 1960 large_objects->Set(obj); 1961 } 1962 } 1963 } 1964} 1965 1966void Heap::SwapSemiSpaces() { 1967 CHECK(bump_pointer_space_ != nullptr); 1968 CHECK(temp_space_ != nullptr); 1969 std::swap(bump_pointer_space_, temp_space_); 1970} 1971 1972void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1973 space::ContinuousMemMapAllocSpace* source_space, 1974 GcCause gc_cause) { 1975 CHECK(kMovingCollector); 1976 if (target_space != source_space) { 1977 // Don't swap spaces since this isn't a typical semi space collection. 1978 semi_space_collector_->SetSwapSemiSpaces(false); 1979 semi_space_collector_->SetFromSpace(source_space); 1980 semi_space_collector_->SetToSpace(target_space); 1981 semi_space_collector_->Run(gc_cause, false); 1982 } else { 1983 CHECK(target_space->IsBumpPointerSpace()) 1984 << "In-place compaction is only supported for bump pointer spaces"; 1985 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 1986 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 1987 } 1988} 1989 1990collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1991 bool clear_soft_references) { 1992 Thread* self = Thread::Current(); 1993 Runtime* runtime = Runtime::Current(); 1994 // If the heap can't run the GC, silently fail and return that no GC was run. 1995 switch (gc_type) { 1996 case collector::kGcTypePartial: { 1997 if (!have_zygote_space_) { 1998 return collector::kGcTypeNone; 1999 } 2000 break; 2001 } 2002 default: { 2003 // Other GC types don't have any special cases which makes them not runnable. The main case 2004 // here is full GC. 2005 } 2006 } 2007 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2008 Locks::mutator_lock_->AssertNotHeld(self); 2009 if (self->IsHandlingStackOverflow()) { 2010 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2011 } 2012 bool compacting_gc; 2013 { 2014 gc_complete_lock_->AssertNotHeld(self); 2015 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2016 MutexLock mu(self, *gc_complete_lock_); 2017 // Ensure there is only one GC at a time. 2018 WaitForGcToCompleteLocked(gc_cause, self); 2019 compacting_gc = IsMovingGc(collector_type_); 2020 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2021 if (compacting_gc && disable_moving_gc_count_ != 0) { 2022 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2023 return collector::kGcTypeNone; 2024 } 2025 collector_type_running_ = collector_type_; 2026 } 2027 2028 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2029 ++runtime->GetStats()->gc_for_alloc_count; 2030 ++self->GetStats()->gc_for_alloc_count; 2031 } 2032 uint64_t gc_start_time_ns = NanoTime(); 2033 uint64_t gc_start_size = GetBytesAllocated(); 2034 // Approximate allocation rate in bytes / second. 2035 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2036 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2037 if (LIKELY(ms_delta != 0)) { 2038 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2039 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2040 } 2041 2042 DCHECK_LT(gc_type, collector::kGcTypeMax); 2043 DCHECK_NE(gc_type, collector::kGcTypeNone); 2044 2045 collector::GarbageCollector* collector = nullptr; 2046 // TODO: Clean this up. 2047 if (compacting_gc) { 2048 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2049 current_allocator_ == kAllocatorTypeTLAB); 2050 switch (collector_type_) { 2051 case kCollectorTypeSS: 2052 // Fall-through. 2053 case kCollectorTypeGSS: 2054 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2055 semi_space_collector_->SetToSpace(temp_space_); 2056 semi_space_collector_->SetSwapSemiSpaces(true); 2057 collector = semi_space_collector_; 2058 break; 2059 case kCollectorTypeCC: 2060 collector = concurrent_copying_collector_; 2061 break; 2062 case kCollectorTypeMC: 2063 mark_compact_collector_->SetSpace(bump_pointer_space_); 2064 collector = mark_compact_collector_; 2065 break; 2066 default: 2067 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2068 } 2069 if (collector != mark_compact_collector_) { 2070 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2071 CHECK(temp_space_->IsEmpty()); 2072 } 2073 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2074 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2075 current_allocator_ == kAllocatorTypeDlMalloc) { 2076 collector = FindCollectorByGcType(gc_type); 2077 } else { 2078 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2079 } 2080 CHECK(collector != nullptr) 2081 << "Could not find garbage collector with collector_type=" 2082 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2083 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2084 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2085 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2086 RequestHeapTrim(); 2087 // Enqueue cleared references. 2088 reference_processor_.EnqueueClearedReferences(self); 2089 // Grow the heap so that we know when to perform the next GC. 2090 GrowForUtilization(collector); 2091 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2092 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2093 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2094 // (mutator time blocked >= long_pause_log_threshold_). 2095 bool log_gc = gc_cause == kGcCauseExplicit; 2096 if (!log_gc && CareAboutPauseTimes()) { 2097 // GC for alloc pauses the allocating thread, so consider it as a pause. 2098 log_gc = duration > long_gc_log_threshold_ || 2099 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2100 for (uint64_t pause : pause_times) { 2101 log_gc = log_gc || pause >= long_pause_log_threshold_; 2102 } 2103 } 2104 if (log_gc) { 2105 const size_t percent_free = GetPercentFree(); 2106 const size_t current_heap_size = GetBytesAllocated(); 2107 const size_t total_memory = GetTotalMemory(); 2108 std::ostringstream pause_string; 2109 for (size_t i = 0; i < pause_times.size(); ++i) { 2110 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2111 << ((i != pause_times.size() - 1) ? "," : ""); 2112 } 2113 LOG(INFO) << gc_cause << " " << collector->GetName() 2114 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2115 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2116 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2117 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2118 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2119 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2120 << " total " << PrettyDuration((duration / 1000) * 1000); 2121 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2122 } 2123 FinishGC(self, gc_type); 2124 // Inform DDMS that a GC completed. 2125 Dbg::GcDidFinish(); 2126 return gc_type; 2127} 2128 2129void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2130 MutexLock mu(self, *gc_complete_lock_); 2131 collector_type_running_ = kCollectorTypeNone; 2132 if (gc_type != collector::kGcTypeNone) { 2133 last_gc_type_ = gc_type; 2134 } 2135 // Wake anyone who may have been waiting for the GC to complete. 2136 gc_complete_cond_->Broadcast(self); 2137} 2138 2139static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2140 RootType /*root_type*/) { 2141 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2142 if (*root == obj) { 2143 LOG(INFO) << "Object " << obj << " is a root"; 2144 } 2145} 2146 2147class ScanVisitor { 2148 public: 2149 void operator()(const mirror::Object* obj) const { 2150 LOG(ERROR) << "Would have rescanned object " << obj; 2151 } 2152}; 2153 2154// Verify a reference from an object. 2155class VerifyReferenceVisitor { 2156 public: 2157 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2158 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2159 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2160 2161 size_t GetFailureCount() const { 2162 return fail_count_->LoadSequentiallyConsistent(); 2163 } 2164 2165 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2166 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2167 if (verify_referent_) { 2168 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2169 } 2170 } 2171 2172 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2173 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2174 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2175 } 2176 2177 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2178 return heap_->IsLiveObjectLocked(obj, true, false, true); 2179 } 2180 2181 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2182 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2183 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2184 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2185 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2186 << " thread_id= " << thread_id << " root_type= " << root_type; 2187 } 2188 } 2189 2190 private: 2191 // TODO: Fix the no thread safety analysis. 2192 // Returns false on failure. 2193 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2194 NO_THREAD_SAFETY_ANALYSIS { 2195 if (ref == nullptr || IsLive(ref)) { 2196 // Verify that the reference is live. 2197 return true; 2198 } 2199 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2200 // Print message on only on first failure to prevent spam. 2201 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2202 } 2203 if (obj != nullptr) { 2204 // Only do this part for non roots. 2205 accounting::CardTable* card_table = heap_->GetCardTable(); 2206 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2207 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2208 byte* card_addr = card_table->CardFromAddr(obj); 2209 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2210 << offset << "\n card value = " << static_cast<int>(*card_addr); 2211 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2212 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2213 } else { 2214 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2215 } 2216 2217 // Attempt to find the class inside of the recently freed objects. 2218 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2219 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2220 space::MallocSpace* space = ref_space->AsMallocSpace(); 2221 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2222 if (ref_class != nullptr) { 2223 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2224 << PrettyClass(ref_class); 2225 } else { 2226 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2227 } 2228 } 2229 2230 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2231 ref->GetClass()->IsClass()) { 2232 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2233 } else { 2234 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2235 << ") is not a valid heap address"; 2236 } 2237 2238 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2239 void* cover_begin = card_table->AddrFromCard(card_addr); 2240 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2241 accounting::CardTable::kCardSize); 2242 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2243 << "-" << cover_end; 2244 accounting::ContinuousSpaceBitmap* bitmap = 2245 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2246 2247 if (bitmap == nullptr) { 2248 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2249 if (!VerifyClassClass(obj->GetClass())) { 2250 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2251 } 2252 } else { 2253 // Print out how the object is live. 2254 if (bitmap->Test(obj)) { 2255 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2256 } 2257 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2258 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2259 } 2260 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2261 LOG(ERROR) << "Object " << obj << " found in live stack"; 2262 } 2263 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2264 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2265 } 2266 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2267 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2268 } 2269 // Attempt to see if the card table missed the reference. 2270 ScanVisitor scan_visitor; 2271 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2272 card_table->Scan(bitmap, byte_cover_begin, 2273 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2274 } 2275 2276 // Search to see if any of the roots reference our object. 2277 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2278 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2279 2280 // Search to see if any of the roots reference our reference. 2281 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2282 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2283 } 2284 return false; 2285 } 2286 2287 Heap* const heap_; 2288 Atomic<size_t>* const fail_count_; 2289 const bool verify_referent_; 2290}; 2291 2292// Verify all references within an object, for use with HeapBitmap::Visit. 2293class VerifyObjectVisitor { 2294 public: 2295 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2296 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2297 } 2298 2299 void operator()(mirror::Object* obj) const 2300 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2301 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2302 // be live or else how did we find it in the live bitmap? 2303 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2304 // The class doesn't count as a reference but we should verify it anyways. 2305 obj->VisitReferences<true>(visitor, visitor); 2306 } 2307 2308 static void VisitCallback(mirror::Object* obj, void* arg) 2309 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2310 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2311 visitor->operator()(obj); 2312 } 2313 2314 size_t GetFailureCount() const { 2315 return fail_count_->LoadSequentiallyConsistent(); 2316 } 2317 2318 private: 2319 Heap* const heap_; 2320 Atomic<size_t>* const fail_count_; 2321 const bool verify_referent_; 2322}; 2323 2324void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2325 // Slow path, the allocation stack push back must have already failed. 2326 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2327 do { 2328 // TODO: Add handle VerifyObject. 2329 StackHandleScope<1> hs(self); 2330 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2331 // Push our object into the reserve region of the allocaiton stack. This is only required due 2332 // to heap verification requiring that roots are live (either in the live bitmap or in the 2333 // allocation stack). 2334 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2335 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2336 } while (!allocation_stack_->AtomicPushBack(*obj)); 2337} 2338 2339void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2340 // Slow path, the allocation stack push back must have already failed. 2341 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2342 mirror::Object** start_address; 2343 mirror::Object** end_address; 2344 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2345 &end_address)) { 2346 // TODO: Add handle VerifyObject. 2347 StackHandleScope<1> hs(self); 2348 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2349 // Push our object into the reserve region of the allocaiton stack. This is only required due 2350 // to heap verification requiring that roots are live (either in the live bitmap or in the 2351 // allocation stack). 2352 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2353 // Push into the reserve allocation stack. 2354 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2355 } 2356 self->SetThreadLocalAllocationStack(start_address, end_address); 2357 // Retry on the new thread-local allocation stack. 2358 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2359} 2360 2361// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2362size_t Heap::VerifyHeapReferences(bool verify_referents) { 2363 Thread* self = Thread::Current(); 2364 Locks::mutator_lock_->AssertExclusiveHeld(self); 2365 // Lets sort our allocation stacks so that we can efficiently binary search them. 2366 allocation_stack_->Sort(); 2367 live_stack_->Sort(); 2368 // Since we sorted the allocation stack content, need to revoke all 2369 // thread-local allocation stacks. 2370 RevokeAllThreadLocalAllocationStacks(self); 2371 Atomic<size_t> fail_count_(0); 2372 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2373 // Verify objects in the allocation stack since these will be objects which were: 2374 // 1. Allocated prior to the GC (pre GC verification). 2375 // 2. Allocated during the GC (pre sweep GC verification). 2376 // We don't want to verify the objects in the live stack since they themselves may be 2377 // pointing to dead objects if they are not reachable. 2378 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2379 // Verify the roots: 2380 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2381 if (visitor.GetFailureCount() > 0) { 2382 // Dump mod-union tables. 2383 for (const auto& table_pair : mod_union_tables_) { 2384 accounting::ModUnionTable* mod_union_table = table_pair.second; 2385 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2386 } 2387 // Dump remembered sets. 2388 for (const auto& table_pair : remembered_sets_) { 2389 accounting::RememberedSet* remembered_set = table_pair.second; 2390 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2391 } 2392 DumpSpaces(LOG(ERROR)); 2393 } 2394 return visitor.GetFailureCount(); 2395} 2396 2397class VerifyReferenceCardVisitor { 2398 public: 2399 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2400 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2401 Locks::heap_bitmap_lock_) 2402 : heap_(heap), failed_(failed) { 2403 } 2404 2405 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2406 // annotalysis on visitors. 2407 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2408 NO_THREAD_SAFETY_ANALYSIS { 2409 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2410 // Filter out class references since changing an object's class does not mark the card as dirty. 2411 // Also handles large objects, since the only reference they hold is a class reference. 2412 if (ref != nullptr && !ref->IsClass()) { 2413 accounting::CardTable* card_table = heap_->GetCardTable(); 2414 // If the object is not dirty and it is referencing something in the live stack other than 2415 // class, then it must be on a dirty card. 2416 if (!card_table->AddrIsInCardTable(obj)) { 2417 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2418 *failed_ = true; 2419 } else if (!card_table->IsDirty(obj)) { 2420 // TODO: Check mod-union tables. 2421 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2422 // kCardDirty - 1 if it didnt get touched since we aged it. 2423 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2424 if (live_stack->ContainsSorted(ref)) { 2425 if (live_stack->ContainsSorted(obj)) { 2426 LOG(ERROR) << "Object " << obj << " found in live stack"; 2427 } 2428 if (heap_->GetLiveBitmap()->Test(obj)) { 2429 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2430 } 2431 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2432 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2433 2434 // Print which field of the object is dead. 2435 if (!obj->IsObjectArray()) { 2436 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2437 CHECK(klass != NULL); 2438 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2439 : klass->GetIFields(); 2440 CHECK(fields != NULL); 2441 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2442 mirror::ArtField* cur = fields->Get(i); 2443 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2444 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2445 << PrettyField(cur); 2446 break; 2447 } 2448 } 2449 } else { 2450 mirror::ObjectArray<mirror::Object>* object_array = 2451 obj->AsObjectArray<mirror::Object>(); 2452 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2453 if (object_array->Get(i) == ref) { 2454 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2455 } 2456 } 2457 } 2458 2459 *failed_ = true; 2460 } 2461 } 2462 } 2463 } 2464 2465 private: 2466 Heap* const heap_; 2467 bool* const failed_; 2468}; 2469 2470class VerifyLiveStackReferences { 2471 public: 2472 explicit VerifyLiveStackReferences(Heap* heap) 2473 : heap_(heap), 2474 failed_(false) {} 2475 2476 void operator()(mirror::Object* obj) const 2477 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2478 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2479 obj->VisitReferences<true>(visitor, VoidFunctor()); 2480 } 2481 2482 bool Failed() const { 2483 return failed_; 2484 } 2485 2486 private: 2487 Heap* const heap_; 2488 bool failed_; 2489}; 2490 2491bool Heap::VerifyMissingCardMarks() { 2492 Thread* self = Thread::Current(); 2493 Locks::mutator_lock_->AssertExclusiveHeld(self); 2494 2495 // We need to sort the live stack since we binary search it. 2496 live_stack_->Sort(); 2497 // Since we sorted the allocation stack content, need to revoke all 2498 // thread-local allocation stacks. 2499 RevokeAllThreadLocalAllocationStacks(self); 2500 VerifyLiveStackReferences visitor(this); 2501 GetLiveBitmap()->Visit(visitor); 2502 2503 // We can verify objects in the live stack since none of these should reference dead objects. 2504 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2505 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2506 visitor(*it); 2507 } 2508 } 2509 return !visitor.Failed(); 2510} 2511 2512void Heap::SwapStacks(Thread* self) { 2513 if (kUseThreadLocalAllocationStack) { 2514 live_stack_->AssertAllZero(); 2515 } 2516 allocation_stack_.swap(live_stack_); 2517} 2518 2519void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2520 // This must be called only during the pause. 2521 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2522 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2523 MutexLock mu2(self, *Locks::thread_list_lock_); 2524 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2525 for (Thread* t : thread_list) { 2526 t->RevokeThreadLocalAllocationStack(); 2527 } 2528} 2529 2530void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2531 if (kIsDebugBuild) { 2532 if (bump_pointer_space_ != nullptr) { 2533 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2534 } 2535 } 2536} 2537 2538accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2539 auto it = mod_union_tables_.find(space); 2540 if (it == mod_union_tables_.end()) { 2541 return nullptr; 2542 } 2543 return it->second; 2544} 2545 2546accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2547 auto it = remembered_sets_.find(space); 2548 if (it == remembered_sets_.end()) { 2549 return nullptr; 2550 } 2551 return it->second; 2552} 2553 2554void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2555 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2556 // Clear cards and keep track of cards cleared in the mod-union table. 2557 for (const auto& space : continuous_spaces_) { 2558 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2559 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2560 if (table != nullptr) { 2561 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2562 "ImageModUnionClearCards"; 2563 TimingLogger::ScopedTiming t(name, timings); 2564 table->ClearCards(); 2565 } else if (use_rem_sets && rem_set != nullptr) { 2566 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2567 << static_cast<int>(collector_type_); 2568 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2569 rem_set->ClearCards(); 2570 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2571 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2572 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2573 // were dirty before the GC started. 2574 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2575 // -> clean(cleaning thread). 2576 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2577 // roots and then we scan / update mod union tables after. We will always scan either card. 2578 // If we end up with the non aged card, we scan it it in the pause. 2579 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2580 VoidFunctor()); 2581 } 2582 } 2583} 2584 2585static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2586} 2587 2588void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2589 Thread* const self = Thread::Current(); 2590 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2591 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2592 if (verify_pre_gc_heap_) { 2593 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2594 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2595 size_t failures = VerifyHeapReferences(); 2596 if (failures > 0) { 2597 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2598 << " failures"; 2599 } 2600 } 2601 // Check that all objects which reference things in the live stack are on dirty cards. 2602 if (verify_missing_card_marks_) { 2603 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2604 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2605 SwapStacks(self); 2606 // Sort the live stack so that we can quickly binary search it later. 2607 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2608 << " missing card mark verification failed\n" << DumpSpaces(); 2609 SwapStacks(self); 2610 } 2611 if (verify_mod_union_table_) { 2612 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2613 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2614 for (const auto& table_pair : mod_union_tables_) { 2615 accounting::ModUnionTable* mod_union_table = table_pair.second; 2616 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2617 mod_union_table->Verify(); 2618 } 2619 } 2620} 2621 2622void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2623 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2624 collector::GarbageCollector::ScopedPause pause(gc); 2625 PreGcVerificationPaused(gc); 2626 } 2627} 2628 2629void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2630 // TODO: Add a new runtime option for this? 2631 if (verify_pre_gc_rosalloc_) { 2632 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2633 } 2634} 2635 2636void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2637 Thread* const self = Thread::Current(); 2638 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2639 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2640 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2641 // reachable objects. 2642 if (verify_pre_sweeping_heap_) { 2643 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2644 CHECK_NE(self->GetState(), kRunnable); 2645 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2646 // Swapping bound bitmaps does nothing. 2647 gc->SwapBitmaps(); 2648 // Pass in false since concurrent reference processing can mean that the reference referents 2649 // may point to dead objects at the point which PreSweepingGcVerification is called. 2650 size_t failures = VerifyHeapReferences(false); 2651 if (failures > 0) { 2652 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2653 << " failures"; 2654 } 2655 gc->SwapBitmaps(); 2656 } 2657 if (verify_pre_sweeping_rosalloc_) { 2658 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2659 } 2660} 2661 2662void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2663 // Only pause if we have to do some verification. 2664 Thread* const self = Thread::Current(); 2665 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2666 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2667 if (verify_system_weaks_) { 2668 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2669 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2670 mark_sweep->VerifySystemWeaks(); 2671 } 2672 if (verify_post_gc_rosalloc_) { 2673 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2674 } 2675 if (verify_post_gc_heap_) { 2676 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2677 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2678 size_t failures = VerifyHeapReferences(); 2679 if (failures > 0) { 2680 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2681 << " failures"; 2682 } 2683 } 2684} 2685 2686void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2687 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2688 collector::GarbageCollector::ScopedPause pause(gc); 2689 PreGcVerificationPaused(gc); 2690 } 2691} 2692 2693void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2694 TimingLogger::ScopedTiming t(name, timings); 2695 for (const auto& space : continuous_spaces_) { 2696 if (space->IsRosAllocSpace()) { 2697 VLOG(heap) << name << " : " << space->GetName(); 2698 space->AsRosAllocSpace()->Verify(); 2699 } 2700 } 2701} 2702 2703collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2704 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2705 MutexLock mu(self, *gc_complete_lock_); 2706 return WaitForGcToCompleteLocked(cause, self); 2707} 2708 2709collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2710 collector::GcType last_gc_type = collector::kGcTypeNone; 2711 uint64_t wait_start = NanoTime(); 2712 while (collector_type_running_ != kCollectorTypeNone) { 2713 ATRACE_BEGIN("GC: Wait For Completion"); 2714 // We must wait, change thread state then sleep on gc_complete_cond_; 2715 gc_complete_cond_->Wait(self); 2716 last_gc_type = last_gc_type_; 2717 ATRACE_END(); 2718 } 2719 uint64_t wait_time = NanoTime() - wait_start; 2720 total_wait_time_ += wait_time; 2721 if (wait_time > long_pause_log_threshold_) { 2722 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2723 << " for cause " << cause; 2724 } 2725 return last_gc_type; 2726} 2727 2728void Heap::DumpForSigQuit(std::ostream& os) { 2729 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2730 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2731 DumpGcPerformanceInfo(os); 2732} 2733 2734size_t Heap::GetPercentFree() { 2735 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2736} 2737 2738void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2739 if (max_allowed_footprint > GetMaxMemory()) { 2740 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2741 << PrettySize(GetMaxMemory()); 2742 max_allowed_footprint = GetMaxMemory(); 2743 } 2744 max_allowed_footprint_ = max_allowed_footprint; 2745} 2746 2747bool Heap::IsMovableObject(const mirror::Object* obj) const { 2748 if (kMovingCollector) { 2749 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2750 if (space != nullptr) { 2751 // TODO: Check large object? 2752 return space->CanMoveObjects(); 2753 } 2754 } 2755 return false; 2756} 2757 2758void Heap::UpdateMaxNativeFootprint() { 2759 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2760 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2761 size_t target_size = native_size / GetTargetHeapUtilization(); 2762 if (target_size > native_size + max_free_) { 2763 target_size = native_size + max_free_; 2764 } else if (target_size < native_size + min_free_) { 2765 target_size = native_size + min_free_; 2766 } 2767 native_footprint_gc_watermark_ = target_size; 2768 native_footprint_limit_ = 2 * target_size - native_size; 2769} 2770 2771collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2772 for (const auto& collector : garbage_collectors_) { 2773 if (collector->GetCollectorType() == collector_type_ && 2774 collector->GetGcType() == gc_type) { 2775 return collector; 2776 } 2777 } 2778 return nullptr; 2779} 2780 2781double Heap::HeapGrowthMultiplier() const { 2782 // If we don't care about pause times we are background, so return 1.0. 2783 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2784 return 1.0; 2785 } 2786 return foreground_heap_growth_multiplier_; 2787} 2788 2789void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2790 // We know what our utilization is at this moment. 2791 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2792 const uint64_t bytes_allocated = GetBytesAllocated(); 2793 last_gc_size_ = bytes_allocated; 2794 last_gc_time_ns_ = NanoTime(); 2795 uint64_t target_size; 2796 collector::GcType gc_type = collector_ran->GetGcType(); 2797 if (gc_type != collector::kGcTypeSticky) { 2798 // Grow the heap for non sticky GC. 2799 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2800 // foreground. 2801 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2802 CHECK_GE(delta, 0); 2803 target_size = bytes_allocated + delta * multiplier; 2804 target_size = std::min(target_size, 2805 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2806 target_size = std::max(target_size, 2807 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2808 native_need_to_run_finalization_ = true; 2809 next_gc_type_ = collector::kGcTypeSticky; 2810 } else { 2811 collector::GcType non_sticky_gc_type = 2812 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2813 // Find what the next non sticky collector will be. 2814 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2815 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2816 // do another sticky collection next. 2817 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2818 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2819 // if the sticky GC throughput always remained >= the full/partial throughput. 2820 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2821 non_sticky_collector->GetEstimatedMeanThroughput() && 2822 non_sticky_collector->NumberOfIterations() > 0 && 2823 bytes_allocated <= max_allowed_footprint_) { 2824 next_gc_type_ = collector::kGcTypeSticky; 2825 } else { 2826 next_gc_type_ = non_sticky_gc_type; 2827 } 2828 // If we have freed enough memory, shrink the heap back down. 2829 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2830 target_size = bytes_allocated + max_free_; 2831 } else { 2832 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2833 } 2834 } 2835 if (!ignore_max_footprint_) { 2836 SetIdealFootprint(target_size); 2837 if (IsGcConcurrent()) { 2838 // Calculate when to perform the next ConcurrentGC. 2839 // Calculate the estimated GC duration. 2840 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2841 // Estimate how many remaining bytes we will have when we need to start the next GC. 2842 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2843 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2844 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2845 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2846 // A never going to happen situation that from the estimated allocation rate we will exceed 2847 // the applications entire footprint with the given estimated allocation rate. Schedule 2848 // another GC nearly straight away. 2849 remaining_bytes = kMinConcurrentRemainingBytes; 2850 } 2851 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2852 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2853 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2854 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2855 // right away. 2856 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2857 static_cast<size_t>(bytes_allocated)); 2858 } 2859 } 2860} 2861 2862void Heap::ClearGrowthLimit() { 2863 growth_limit_ = capacity_; 2864 non_moving_space_->ClearGrowthLimit(); 2865} 2866 2867void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2868 ScopedObjectAccess soa(self); 2869 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2870 jvalue args[1]; 2871 args[0].l = arg.get(); 2872 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2873 // Restore object in case it gets moved. 2874 *object = soa.Decode<mirror::Object*>(arg.get()); 2875} 2876 2877void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2878 StackHandleScope<1> hs(self); 2879 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2880 RequestConcurrentGC(self); 2881} 2882 2883void Heap::RequestConcurrentGC(Thread* self) { 2884 // Make sure that we can do a concurrent GC. 2885 Runtime* runtime = Runtime::Current(); 2886 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2887 self->IsHandlingStackOverflow()) { 2888 return; 2889 } 2890 // We already have a request pending, no reason to start more until we update 2891 // concurrent_start_bytes_. 2892 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2893 JNIEnv* env = self->GetJniEnv(); 2894 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2895 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2896 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2897 WellKnownClasses::java_lang_Daemons_requestGC); 2898 CHECK(!env->ExceptionCheck()); 2899} 2900 2901void Heap::ConcurrentGC(Thread* self) { 2902 if (Runtime::Current()->IsShuttingDown(self)) { 2903 return; 2904 } 2905 // Wait for any GCs currently running to finish. 2906 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2907 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2908 // instead. E.g. can't do partial, so do full instead. 2909 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2910 collector::kGcTypeNone) { 2911 for (collector::GcType gc_type : gc_plan_) { 2912 // Attempt to run the collector, if we succeed, we are done. 2913 if (gc_type > next_gc_type_ && 2914 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2915 break; 2916 } 2917 } 2918 } 2919 } 2920} 2921 2922void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2923 Thread* self = Thread::Current(); 2924 { 2925 MutexLock mu(self, *heap_trim_request_lock_); 2926 if (desired_collector_type_ == desired_collector_type) { 2927 return; 2928 } 2929 heap_transition_or_trim_target_time_ = 2930 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2931 desired_collector_type_ = desired_collector_type; 2932 } 2933 SignalHeapTrimDaemon(self); 2934} 2935 2936void Heap::RequestHeapTrim() { 2937 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2938 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2939 // a space it will hold its lock and can become a cause of jank. 2940 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2941 // forking. 2942 2943 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2944 // because that only marks object heads, so a large array looks like lots of empty space. We 2945 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2946 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2947 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2948 // not how much use we're making of those pages. 2949 2950 Thread* self = Thread::Current(); 2951 Runtime* runtime = Runtime::Current(); 2952 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2953 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2954 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2955 // as we don't hold the lock while requesting the trim). 2956 return; 2957 } 2958 { 2959 MutexLock mu(self, *heap_trim_request_lock_); 2960 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2961 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2962 // just yet. 2963 return; 2964 } 2965 heap_trim_request_pending_ = true; 2966 uint64_t current_time = NanoTime(); 2967 if (heap_transition_or_trim_target_time_ < current_time) { 2968 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 2969 } 2970 } 2971 // Notify the daemon thread which will actually do the heap trim. 2972 SignalHeapTrimDaemon(self); 2973} 2974 2975void Heap::SignalHeapTrimDaemon(Thread* self) { 2976 JNIEnv* env = self->GetJniEnv(); 2977 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2978 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2979 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2980 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2981 CHECK(!env->ExceptionCheck()); 2982} 2983 2984void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2985 if (rosalloc_space_ != nullptr) { 2986 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2987 } 2988 if (bump_pointer_space_ != nullptr) { 2989 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2990 } 2991} 2992 2993void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2994 if (rosalloc_space_ != nullptr) { 2995 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2996 } 2997} 2998 2999void Heap::RevokeAllThreadLocalBuffers() { 3000 if (rosalloc_space_ != nullptr) { 3001 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3002 } 3003 if (bump_pointer_space_ != nullptr) { 3004 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3005 } 3006} 3007 3008bool Heap::IsGCRequestPending() const { 3009 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3010} 3011 3012void Heap::RunFinalization(JNIEnv* env) { 3013 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3014 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3015 CHECK(WellKnownClasses::java_lang_System != nullptr); 3016 WellKnownClasses::java_lang_System_runFinalization = 3017 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3018 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3019 } 3020 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3021 WellKnownClasses::java_lang_System_runFinalization); 3022} 3023 3024void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3025 Thread* self = ThreadForEnv(env); 3026 if (native_need_to_run_finalization_) { 3027 RunFinalization(env); 3028 UpdateMaxNativeFootprint(); 3029 native_need_to_run_finalization_ = false; 3030 } 3031 // Total number of native bytes allocated. 3032 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3033 new_native_bytes_allocated += bytes; 3034 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3035 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3036 collector::kGcTypeFull; 3037 3038 // The second watermark is higher than the gc watermark. If you hit this it means you are 3039 // allocating native objects faster than the GC can keep up with. 3040 if (new_native_bytes_allocated > native_footprint_limit_) { 3041 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3042 // Just finished a GC, attempt to run finalizers. 3043 RunFinalization(env); 3044 CHECK(!env->ExceptionCheck()); 3045 } 3046 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3047 if (new_native_bytes_allocated > native_footprint_limit_) { 3048 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3049 RunFinalization(env); 3050 native_need_to_run_finalization_ = false; 3051 CHECK(!env->ExceptionCheck()); 3052 } 3053 // We have just run finalizers, update the native watermark since it is very likely that 3054 // finalizers released native managed allocations. 3055 UpdateMaxNativeFootprint(); 3056 } else if (!IsGCRequestPending()) { 3057 if (IsGcConcurrent()) { 3058 RequestConcurrentGC(self); 3059 } else { 3060 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3061 } 3062 } 3063 } 3064} 3065 3066void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3067 int expected_size, new_size; 3068 do { 3069 expected_size = native_bytes_allocated_.LoadRelaxed(); 3070 new_size = expected_size - bytes; 3071 if (UNLIKELY(new_size < 0)) { 3072 ScopedObjectAccess soa(env); 3073 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3074 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3075 "registered as allocated", bytes, expected_size).c_str()); 3076 break; 3077 } 3078 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3079} 3080 3081size_t Heap::GetTotalMemory() const { 3082 size_t ret = 0; 3083 for (const auto& space : continuous_spaces_) { 3084 // Currently don't include the image space. 3085 if (!space->IsImageSpace()) { 3086 ret += space->Size(); 3087 } 3088 } 3089 for (const auto& space : discontinuous_spaces_) { 3090 if (space->IsLargeObjectSpace()) { 3091 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 3092 } 3093 } 3094 return ret; 3095} 3096 3097void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3098 DCHECK(mod_union_table != nullptr); 3099 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3100} 3101 3102void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3103 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3104 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 3105 c->GetDescriptor().empty()); 3106 CHECK_GE(byte_count, sizeof(mirror::Object)); 3107} 3108 3109void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3110 CHECK(remembered_set != nullptr); 3111 space::Space* space = remembered_set->GetSpace(); 3112 CHECK(space != nullptr); 3113 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3114 remembered_sets_.Put(space, remembered_set); 3115 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3116} 3117 3118void Heap::RemoveRememberedSet(space::Space* space) { 3119 CHECK(space != nullptr); 3120 auto it = remembered_sets_.find(space); 3121 CHECK(it != remembered_sets_.end()); 3122 remembered_sets_.erase(it); 3123 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3124} 3125 3126void Heap::ClearMarkedObjects() { 3127 // Clear all of the spaces' mark bitmaps. 3128 for (const auto& space : GetContinuousSpaces()) { 3129 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3130 if (space->GetLiveBitmap() != mark_bitmap) { 3131 mark_bitmap->Clear(); 3132 } 3133 } 3134 // Clear the marked objects in the discontinous space object sets. 3135 for (const auto& space : GetDiscontinuousSpaces()) { 3136 space->GetMarkBitmap()->Clear(); 3137 } 3138} 3139 3140} // namespace gc 3141} // namespace art 3142