heap.cc revision 18bacb60e09fa8aa20ae0a1d7a4a8968d4913fb0
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/concurrent_copying.h" 39#include "gc/collector/mark_compact.h" 40#include "gc/collector/mark_sweep-inl.h" 41#include "gc/collector/partial_mark_sweep.h" 42#include "gc/collector/semi_space.h" 43#include "gc/collector/sticky_mark_sweep.h" 44#include "gc/reference_processor.h" 45#include "gc/space/bump_pointer_space.h" 46#include "gc/space/dlmalloc_space-inl.h" 47#include "gc/space/image_space.h" 48#include "gc/space/large_object_space.h" 49#include "gc/space/rosalloc_space-inl.h" 50#include "gc/space/space-inl.h" 51#include "gc/space/zygote_space.h" 52#include "entrypoints/quick/quick_alloc_entrypoints.h" 53#include "heap-inl.h" 54#include "image.h" 55#include "mirror/art_field-inl.h" 56#include "mirror/class-inl.h" 57#include "mirror/object.h" 58#include "mirror/object-inl.h" 59#include "mirror/object_array-inl.h" 60#include "mirror/reference-inl.h" 61#include "os.h" 62#include "reflection.h" 63#include "runtime.h" 64#include "ScopedLocalRef.h" 65#include "scoped_thread_state_change.h" 66#include "handle_scope-inl.h" 67#include "thread_list.h" 68#include "well_known_classes.h" 69 70namespace art { 71 72namespace gc { 73 74static constexpr size_t kCollectorTransitionStressIterations = 0; 75static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 76static constexpr bool kGCALotMode = false; 77static constexpr size_t kGcAlotInterval = KB; 78// Minimum amount of remaining bytes before a concurrent GC is triggered. 79static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 80static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 81// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 82// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 83// threads (lower pauses, use less memory bandwidth). 84static constexpr double kStickyGcThroughputAdjustment = 1.0; 85// Whether or not we use the free list large object space. 86static constexpr bool kUseFreeListSpaceForLOS = false; 87// Whether or not we compact the zygote in PreZygoteFork. 88static constexpr bool kCompactZygote = kMovingCollector; 89// How many reserve entries are at the end of the allocation stack, these are only needed if the 90// allocation stack overflows. 91static constexpr size_t kAllocationStackReserveSize = 1024; 92// Default mark stack size in bytes. 93static const size_t kDefaultMarkStackSize = 64 * KB; 94// Define space name. 95static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 96static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 97static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 98static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 99 100Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 101 double target_utilization, double foreground_heap_growth_multiplier, 102 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 103 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 104 CollectorType background_collector_type, size_t parallel_gc_threads, 105 size_t conc_gc_threads, bool low_memory_mode, 106 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 107 bool ignore_max_footprint, bool use_tlab, 108 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 109 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 110 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 111 uint64_t min_interval_homogeneous_space_compaction_by_oom) 112 : non_moving_space_(nullptr), 113 rosalloc_space_(nullptr), 114 dlmalloc_space_(nullptr), 115 main_space_(nullptr), 116 collector_type_(kCollectorTypeNone), 117 foreground_collector_type_(foreground_collector_type), 118 background_collector_type_(background_collector_type), 119 desired_collector_type_(foreground_collector_type_), 120 heap_trim_request_lock_(nullptr), 121 last_trim_time_(0), 122 heap_transition_or_trim_target_time_(0), 123 heap_trim_request_pending_(false), 124 parallel_gc_threads_(parallel_gc_threads), 125 conc_gc_threads_(conc_gc_threads), 126 low_memory_mode_(low_memory_mode), 127 long_pause_log_threshold_(long_pause_log_threshold), 128 long_gc_log_threshold_(long_gc_log_threshold), 129 ignore_max_footprint_(ignore_max_footprint), 130 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 131 have_zygote_space_(false), 132 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 133 collector_type_running_(kCollectorTypeNone), 134 last_gc_type_(collector::kGcTypeNone), 135 next_gc_type_(collector::kGcTypePartial), 136 capacity_(capacity), 137 growth_limit_(growth_limit), 138 max_allowed_footprint_(initial_size), 139 native_footprint_gc_watermark_(initial_size), 140 native_footprint_limit_(2 * initial_size), 141 native_need_to_run_finalization_(false), 142 // Initially assume we perceive jank in case the process state is never updated. 143 process_state_(kProcessStateJankPerceptible), 144 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 145 total_bytes_freed_ever_(0), 146 total_objects_freed_ever_(0), 147 num_bytes_allocated_(0), 148 native_bytes_allocated_(0), 149 gc_memory_overhead_(0), 150 verify_missing_card_marks_(false), 151 verify_system_weaks_(false), 152 verify_pre_gc_heap_(verify_pre_gc_heap), 153 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 154 verify_post_gc_heap_(verify_post_gc_heap), 155 verify_mod_union_table_(false), 156 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 157 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 158 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 159 last_gc_time_ns_(NanoTime()), 160 allocation_rate_(0), 161 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 162 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 163 * verification is enabled, we limit the size of allocation stacks to speed up their 164 * searching. 165 */ 166 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 167 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 168 current_allocator_(kAllocatorTypeDlMalloc), 169 current_non_moving_allocator_(kAllocatorTypeNonMoving), 170 bump_pointer_space_(nullptr), 171 temp_space_(nullptr), 172 min_free_(min_free), 173 max_free_(max_free), 174 target_utilization_(target_utilization), 175 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 176 total_wait_time_(0), 177 total_allocation_time_(0), 178 verify_object_mode_(kVerifyObjectModeDisabled), 179 disable_moving_gc_count_(0), 180 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 181 use_tlab_(use_tlab), 182 main_space_backup_(nullptr), 183 min_interval_homogeneous_space_compaction_by_oom_( 184 min_interval_homogeneous_space_compaction_by_oom), 185 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 186 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 187 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 188 LOG(INFO) << "Heap() entering"; 189 } 190 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 191 // entrypoints. 192 if (!Runtime::Current()->IsZygote()) { 193 large_object_threshold_ = kDefaultLargeObjectThreshold; 194 // Background compaction is currently not supported for command line runs. 195 if (background_collector_type_ != foreground_collector_type_) { 196 VLOG(heap) << "Disabling background compaction for non zygote"; 197 background_collector_type_ = foreground_collector_type_; 198 } 199 } 200 ChangeCollector(desired_collector_type_); 201 live_bitmap_.reset(new accounting::HeapBitmap(this)); 202 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 203 // Requested begin for the alloc space, to follow the mapped image and oat files 204 byte* requested_alloc_space_begin = nullptr; 205 if (!image_file_name.empty()) { 206 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 207 image_instruction_set); 208 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 209 AddSpace(image_space); 210 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 211 // isn't going to get in the middle 212 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 213 CHECK_GT(oat_file_end_addr, image_space->End()); 214 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 215 } 216 /* 217 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 218 +- nonmoving space (non_moving_space_capacity)+- 219 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 220 +-main alloc space / bump space 1 (capacity_) +- 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 222 +-????????????????????????????????????????????+- 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 224 +-main alloc space2 / bump space 2 (capacity_)+- 225 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 226 */ 227 bool support_homogeneous_space_compaction = 228 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 229 use_homogeneous_space_compaction_for_oom; 230 // We may use the same space the main space for the non moving space if we don't need to compact 231 // from the main space. 232 // This is not the case if we support homogeneous compaction or have a moving background 233 // collector type. 234 const bool is_zygote = Runtime::Current()->IsZygote(); 235 bool separate_non_moving_space = is_zygote || 236 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 237 IsMovingGc(background_collector_type_); 238 if (foreground_collector_type == kCollectorTypeGSS) { 239 separate_non_moving_space = false; 240 } 241 std::unique_ptr<MemMap> main_mem_map_1; 242 std::unique_ptr<MemMap> main_mem_map_2; 243 byte* request_begin = requested_alloc_space_begin; 244 if (request_begin != nullptr && separate_non_moving_space) { 245 request_begin += non_moving_space_capacity; 246 } 247 std::string error_str; 248 std::unique_ptr<MemMap> non_moving_space_mem_map; 249 if (separate_non_moving_space) { 250 // Reserve the non moving mem map before the other two since it needs to be at a specific 251 // address. 252 non_moving_space_mem_map.reset( 253 MemMap::MapAnonymous("non moving space", requested_alloc_space_begin, 254 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str)); 255 CHECK(non_moving_space_mem_map != nullptr) << error_str; 256 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 257 request_begin = reinterpret_cast<byte*>(0x1000000); 258 } 259 // Attempt to create 2 mem maps at or after the requested begin. 260 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 261 PROT_READ | PROT_WRITE, &error_str)); 262 CHECK(main_mem_map_1.get() != nullptr) << error_str; 263 if (support_homogeneous_space_compaction || 264 background_collector_type_ == kCollectorTypeSS || 265 foreground_collector_type_ == kCollectorTypeSS) { 266 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 267 capacity_, PROT_READ | PROT_WRITE, 268 &error_str)); 269 CHECK(main_mem_map_2.get() != nullptr) << error_str; 270 } 271 // Create the non moving space first so that bitmaps don't take up the address range. 272 if (separate_non_moving_space) { 273 // Non moving space is always dlmalloc since we currently don't have support for multiple 274 // active rosalloc spaces. 275 const size_t size = non_moving_space_mem_map->Size(); 276 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 277 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 278 initial_size, size, size, false); 279 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 280 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 281 << requested_alloc_space_begin; 282 AddSpace(non_moving_space_); 283 } 284 // Create other spaces based on whether or not we have a moving GC. 285 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 286 // Create bump pointer spaces. 287 // We only to create the bump pointer if the foreground collector is a compacting GC. 288 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 289 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 290 main_mem_map_1.release()); 291 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 292 AddSpace(bump_pointer_space_); 293 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 294 main_mem_map_2.release()); 295 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 296 AddSpace(temp_space_); 297 CHECK(separate_non_moving_space); 298 } else { 299 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 300 CHECK(main_space_ != nullptr); 301 AddSpace(main_space_); 302 if (!separate_non_moving_space) { 303 non_moving_space_ = main_space_; 304 CHECK(!non_moving_space_->CanMoveObjects()); 305 } 306 if (foreground_collector_type_ == kCollectorTypeGSS) { 307 CHECK_EQ(foreground_collector_type_, background_collector_type_); 308 // Create bump pointer spaces instead of a backup space. 309 main_mem_map_2.release(); 310 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 311 kGSSBumpPointerSpaceCapacity, nullptr); 312 CHECK(bump_pointer_space_ != nullptr); 313 AddSpace(bump_pointer_space_); 314 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 315 kGSSBumpPointerSpaceCapacity, nullptr); 316 CHECK(temp_space_ != nullptr); 317 AddSpace(temp_space_); 318 } else if (main_mem_map_2.get() != nullptr) { 319 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 320 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 321 growth_limit_, capacity_, name, true)); 322 CHECK(main_space_backup_.get() != nullptr); 323 // Add the space so its accounted for in the heap_begin and heap_end. 324 AddSpace(main_space_backup_.get()); 325 } 326 } 327 CHECK(non_moving_space_ != nullptr); 328 CHECK(!non_moving_space_->CanMoveObjects()); 329 // Allocate the large object space. 330 if (kUseFreeListSpaceForLOS) { 331 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity_); 332 } else { 333 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 334 } 335 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 336 AddSpace(large_object_space_); 337 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 338 CHECK(!continuous_spaces_.empty()); 339 // Relies on the spaces being sorted. 340 byte* heap_begin = continuous_spaces_.front()->Begin(); 341 byte* heap_end = continuous_spaces_.back()->Limit(); 342 size_t heap_capacity = heap_end - heap_begin; 343 // Remove the main backup space since it slows down the GC to have unused extra spaces. 344 if (main_space_backup_.get() != nullptr) { 345 RemoveSpace(main_space_backup_.get()); 346 } 347 // Allocate the card table. 348 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 349 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 350 // Card cache for now since it makes it easier for us to update the references to the copying 351 // spaces. 352 accounting::ModUnionTable* mod_union_table = 353 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 354 GetImageSpace()); 355 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 356 AddModUnionTable(mod_union_table); 357 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 358 accounting::RememberedSet* non_moving_space_rem_set = 359 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 360 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 361 AddRememberedSet(non_moving_space_rem_set); 362 } 363 // TODO: Count objects in the image space here? 364 num_bytes_allocated_.StoreRelaxed(0); 365 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 366 kDefaultMarkStackSize)); 367 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 368 allocation_stack_.reset(accounting::ObjectStack::Create( 369 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 370 live_stack_.reset(accounting::ObjectStack::Create( 371 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 372 // It's still too early to take a lock because there are no threads yet, but we can create locks 373 // now. We don't create it earlier to make it clear that you can't use locks during heap 374 // initialization. 375 gc_complete_lock_ = new Mutex("GC complete lock"); 376 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 377 *gc_complete_lock_)); 378 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 379 last_gc_size_ = GetBytesAllocated(); 380 if (ignore_max_footprint_) { 381 SetIdealFootprint(std::numeric_limits<size_t>::max()); 382 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 383 } 384 CHECK_NE(max_allowed_footprint_, 0U); 385 // Create our garbage collectors. 386 for (size_t i = 0; i < 2; ++i) { 387 const bool concurrent = i != 0; 388 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 389 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 390 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 391 } 392 if (kMovingCollector) { 393 // TODO: Clean this up. 394 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 395 semi_space_collector_ = new collector::SemiSpace(this, generational, 396 generational ? "generational" : ""); 397 garbage_collectors_.push_back(semi_space_collector_); 398 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 399 garbage_collectors_.push_back(concurrent_copying_collector_); 400 mark_compact_collector_ = new collector::MarkCompact(this); 401 garbage_collectors_.push_back(mark_compact_collector_); 402 } 403 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr) { 404 // Check that there's no gap between the image space and the non moving space so that the 405 // immune region won't break (eg. due to a large object allocated in the gap). 406 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 407 non_moving_space_->GetMemMap()); 408 if (!no_gap) { 409 MemMap::DumpMaps(LOG(ERROR)); 410 LOG(FATAL) << "There's a gap between the image space and the main space"; 411 } 412 } 413 if (running_on_valgrind_) { 414 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 415 } 416 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 417 LOG(INFO) << "Heap() exiting"; 418 } 419} 420 421MemMap* Heap::MapAnonymousPreferredAddress(const char* name, byte* request_begin, size_t capacity, 422 int prot_flags, std::string* out_error_str) { 423 while (true) { 424 MemMap* map = MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity, 425 PROT_READ | PROT_WRITE, true, out_error_str); 426 if (map != nullptr || request_begin == nullptr) { 427 return map; 428 } 429 // Retry a second time with no specified request begin. 430 request_begin = nullptr; 431 } 432 return nullptr; 433} 434 435space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 436 size_t growth_limit, size_t capacity, 437 const char* name, bool can_move_objects) { 438 space::MallocSpace* malloc_space = nullptr; 439 if (kUseRosAlloc) { 440 // Create rosalloc space. 441 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 442 initial_size, growth_limit, capacity, 443 low_memory_mode_, can_move_objects); 444 } else { 445 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 446 initial_size, growth_limit, capacity, 447 can_move_objects); 448 } 449 if (collector::SemiSpace::kUseRememberedSet) { 450 accounting::RememberedSet* rem_set = 451 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 452 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 453 AddRememberedSet(rem_set); 454 } 455 CHECK(malloc_space != nullptr) << "Failed to create " << name; 456 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 457 return malloc_space; 458} 459 460void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 461 size_t capacity) { 462 // Is background compaction is enabled? 463 bool can_move_objects = IsMovingGc(background_collector_type_) != 464 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 465 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 466 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 467 // from the main space to the zygote space. If background compaction is enabled, always pass in 468 // that we can move objets. 469 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 470 // After the zygote we want this to be false if we don't have background compaction enabled so 471 // that getting primitive array elements is faster. 472 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 473 can_move_objects = !have_zygote_space_ && foreground_collector_type_ != kCollectorTypeGSS; 474 } 475 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 476 RemoveRememberedSet(main_space_); 477 } 478 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 479 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 480 can_move_objects); 481 SetSpaceAsDefault(main_space_); 482 VLOG(heap) << "Created main space " << main_space_; 483} 484 485void Heap::ChangeAllocator(AllocatorType allocator) { 486 if (current_allocator_ != allocator) { 487 // These two allocators are only used internally and don't have any entrypoints. 488 CHECK_NE(allocator, kAllocatorTypeLOS); 489 CHECK_NE(allocator, kAllocatorTypeNonMoving); 490 current_allocator_ = allocator; 491 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 492 SetQuickAllocEntryPointsAllocator(current_allocator_); 493 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 494 } 495} 496 497void Heap::DisableMovingGc() { 498 if (IsMovingGc(foreground_collector_type_)) { 499 foreground_collector_type_ = kCollectorTypeCMS; 500 } 501 if (IsMovingGc(background_collector_type_)) { 502 background_collector_type_ = foreground_collector_type_; 503 } 504 TransitionCollector(foreground_collector_type_); 505 ThreadList* tl = Runtime::Current()->GetThreadList(); 506 Thread* self = Thread::Current(); 507 ScopedThreadStateChange tsc(self, kSuspended); 508 tl->SuspendAll(); 509 // Something may have caused the transition to fail. 510 if (!IsMovingGc(foreground_collector_type_) && non_moving_space_ != main_space_) { 511 CHECK(main_space_ != nullptr); 512 // The allocation stack may have non movable objects in it. We need to flush it since the GC 513 // can't only handle marking allocation stack objects of one non moving space and one main 514 // space. 515 { 516 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 517 FlushAllocStack(); 518 } 519 main_space_->DisableMovingObjects(); 520 non_moving_space_ = main_space_; 521 CHECK(!non_moving_space_->CanMoveObjects()); 522 } 523 tl->ResumeAll(); 524} 525 526std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 527 if (!IsValidContinuousSpaceObjectAddress(klass)) { 528 return StringPrintf("<non heap address klass %p>", klass); 529 } 530 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 531 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 532 std::string result("["); 533 result += SafeGetClassDescriptor(component_type); 534 return result; 535 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 536 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 537 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 538 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 539 } else { 540 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 541 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 542 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 543 } 544 const DexFile* dex_file = dex_cache->GetDexFile(); 545 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 546 if (class_def_idx == DexFile::kDexNoIndex16) { 547 return "<class def not found>"; 548 } 549 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 550 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 551 return dex_file->GetTypeDescriptor(type_id); 552 } 553} 554 555std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 556 if (obj == nullptr) { 557 return "null"; 558 } 559 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 560 if (klass == nullptr) { 561 return "(class=null)"; 562 } 563 std::string result(SafeGetClassDescriptor(klass)); 564 if (obj->IsClass()) { 565 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 566 } 567 return result; 568} 569 570void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 571 if (obj == nullptr) { 572 stream << "(obj=null)"; 573 return; 574 } 575 if (IsAligned<kObjectAlignment>(obj)) { 576 space::Space* space = nullptr; 577 // Don't use find space since it only finds spaces which actually contain objects instead of 578 // spaces which may contain objects (e.g. cleared bump pointer spaces). 579 for (const auto& cur_space : continuous_spaces_) { 580 if (cur_space->HasAddress(obj)) { 581 space = cur_space; 582 break; 583 } 584 } 585 // Unprotect all the spaces. 586 for (const auto& space : continuous_spaces_) { 587 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 588 } 589 stream << "Object " << obj; 590 if (space != nullptr) { 591 stream << " in space " << *space; 592 } 593 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 594 stream << "\nclass=" << klass; 595 if (klass != nullptr) { 596 stream << " type= " << SafePrettyTypeOf(obj); 597 } 598 // Re-protect the address we faulted on. 599 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 600 } 601} 602 603bool Heap::IsCompilingBoot() const { 604 for (const auto& space : continuous_spaces_) { 605 if (space->IsImageSpace() || space->IsZygoteSpace()) { 606 return false; 607 } 608 } 609 return true; 610} 611 612bool Heap::HasImageSpace() const { 613 for (const auto& space : continuous_spaces_) { 614 if (space->IsImageSpace()) { 615 return true; 616 } 617 } 618 return false; 619} 620 621void Heap::IncrementDisableMovingGC(Thread* self) { 622 // Need to do this holding the lock to prevent races where the GC is about to run / running when 623 // we attempt to disable it. 624 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 625 MutexLock mu(self, *gc_complete_lock_); 626 ++disable_moving_gc_count_; 627 if (IsMovingGc(collector_type_running_)) { 628 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 629 } 630} 631 632void Heap::DecrementDisableMovingGC(Thread* self) { 633 MutexLock mu(self, *gc_complete_lock_); 634 CHECK_GE(disable_moving_gc_count_, 0U); 635 --disable_moving_gc_count_; 636} 637 638void Heap::UpdateProcessState(ProcessState process_state) { 639 if (process_state_ != process_state) { 640 process_state_ = process_state; 641 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 642 // Start at index 1 to avoid "is always false" warning. 643 // Have iteration 1 always transition the collector. 644 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 645 ? foreground_collector_type_ : background_collector_type_); 646 usleep(kCollectorTransitionStressWait); 647 } 648 if (process_state_ == kProcessStateJankPerceptible) { 649 // Transition back to foreground right away to prevent jank. 650 RequestCollectorTransition(foreground_collector_type_, 0); 651 } else { 652 // Don't delay for debug builds since we may want to stress test the GC. 653 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 654 // special handling which does a homogenous space compaction once but then doesn't transition 655 // the collector. 656 RequestCollectorTransition(background_collector_type_, 657 kIsDebugBuild ? 0 : kCollectorTransitionWait); 658 } 659 } 660} 661 662void Heap::CreateThreadPool() { 663 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 664 if (num_threads != 0) { 665 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 666 } 667} 668 669void Heap::VisitObjects(ObjectCallback callback, void* arg) { 670 Thread* self = Thread::Current(); 671 // GCs can move objects, so don't allow this. 672 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 673 if (bump_pointer_space_ != nullptr) { 674 // Visit objects in bump pointer space. 675 bump_pointer_space_->Walk(callback, arg); 676 } 677 // TODO: Switch to standard begin and end to use ranged a based loop. 678 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 679 it < end; ++it) { 680 mirror::Object* obj = *it; 681 if (obj != nullptr && obj->GetClass() != nullptr) { 682 // Avoid the race condition caused by the object not yet being written into the allocation 683 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 684 // there can be nulls on the allocation stack. 685 callback(obj, arg); 686 } 687 } 688 GetLiveBitmap()->Walk(callback, arg); 689 self->EndAssertNoThreadSuspension(old_cause); 690} 691 692void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 693 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 694 space::ContinuousSpace* space2 = non_moving_space_; 695 // TODO: Generalize this to n bitmaps? 696 CHECK(space1 != nullptr); 697 CHECK(space2 != nullptr); 698 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 699 large_object_space_->GetLiveBitmap(), stack); 700} 701 702void Heap::DeleteThreadPool() { 703 thread_pool_.reset(nullptr); 704} 705 706void Heap::AddSpace(space::Space* space) { 707 CHECK(space != nullptr); 708 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 709 if (space->IsContinuousSpace()) { 710 DCHECK(!space->IsDiscontinuousSpace()); 711 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 712 // Continuous spaces don't necessarily have bitmaps. 713 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 714 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 715 if (live_bitmap != nullptr) { 716 CHECK(mark_bitmap != nullptr); 717 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 718 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 719 } 720 continuous_spaces_.push_back(continuous_space); 721 // Ensure that spaces remain sorted in increasing order of start address. 722 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 723 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 724 return a->Begin() < b->Begin(); 725 }); 726 } else { 727 CHECK(space->IsDiscontinuousSpace()); 728 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 729 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 730 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 731 discontinuous_spaces_.push_back(discontinuous_space); 732 } 733 if (space->IsAllocSpace()) { 734 alloc_spaces_.push_back(space->AsAllocSpace()); 735 } 736} 737 738void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 739 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 740 if (continuous_space->IsDlMallocSpace()) { 741 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 742 } else if (continuous_space->IsRosAllocSpace()) { 743 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 744 } 745} 746 747void Heap::RemoveSpace(space::Space* space) { 748 DCHECK(space != nullptr); 749 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 750 if (space->IsContinuousSpace()) { 751 DCHECK(!space->IsDiscontinuousSpace()); 752 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 753 // Continuous spaces don't necessarily have bitmaps. 754 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 755 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 756 if (live_bitmap != nullptr) { 757 DCHECK(mark_bitmap != nullptr); 758 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 759 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 760 } 761 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 762 DCHECK(it != continuous_spaces_.end()); 763 continuous_spaces_.erase(it); 764 } else { 765 DCHECK(space->IsDiscontinuousSpace()); 766 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 767 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 768 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 769 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 770 discontinuous_space); 771 DCHECK(it != discontinuous_spaces_.end()); 772 discontinuous_spaces_.erase(it); 773 } 774 if (space->IsAllocSpace()) { 775 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 776 DCHECK(it != alloc_spaces_.end()); 777 alloc_spaces_.erase(it); 778 } 779} 780 781void Heap::RegisterGCAllocation(size_t bytes) { 782 gc_memory_overhead_.FetchAndAddSequentiallyConsistent(bytes); 783} 784 785void Heap::RegisterGCDeAllocation(size_t bytes) { 786 gc_memory_overhead_.FetchAndSubSequentiallyConsistent(bytes); 787} 788 789void Heap::DumpGcPerformanceInfo(std::ostream& os) { 790 // Dump cumulative timings. 791 os << "Dumping cumulative Gc timings\n"; 792 uint64_t total_duration = 0; 793 // Dump cumulative loggers for each GC type. 794 uint64_t total_paused_time = 0; 795 for (auto& collector : garbage_collectors_) { 796 const CumulativeLogger& logger = collector->GetCumulativeTimings(); 797 const size_t iterations = logger.GetIterations(); 798 const Histogram<uint64_t>& pause_histogram = collector->GetPauseHistogram(); 799 if (iterations != 0 && pause_histogram.SampleSize() != 0) { 800 os << ConstDumpable<CumulativeLogger>(logger); 801 const uint64_t total_ns = logger.GetTotalNs(); 802 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 803 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 804 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 805 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 806 Histogram<uint64_t>::CumulativeData cumulative_data; 807 pause_histogram.CreateHistogram(&cumulative_data); 808 pause_histogram.PrintConfidenceIntervals(os, 0.99, cumulative_data); 809 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) 810 << " mean time: " << PrettyDuration(total_ns / iterations) << "\n" 811 << collector->GetName() << " freed: " << freed_objects 812 << " objects with total size " << PrettySize(freed_bytes) << "\n" 813 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 814 << PrettySize(freed_bytes / seconds) << "/s\n"; 815 total_duration += total_ns; 816 total_paused_time += total_pause_ns; 817 } 818 collector->ResetMeasurements(); 819 } 820 uint64_t allocation_time = 821 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 822 if (total_duration != 0) { 823 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 824 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 825 os << "Mean GC size throughput: " 826 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 827 os << "Mean GC object throughput: " 828 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 829 } 830 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 831 os << "Total number of allocations " << total_objects_allocated << "\n"; 832 uint64_t total_bytes_allocated = GetBytesAllocatedEver(); 833 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 834 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 835 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 836 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 837 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 838 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 839 if (kMeasureAllocationTime) { 840 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 841 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 842 << "\n"; 843 } 844 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 845 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 846 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_.LoadRelaxed(); 847 BaseMutex::DumpAll(os); 848} 849 850Heap::~Heap() { 851 VLOG(heap) << "Starting ~Heap()"; 852 STLDeleteElements(&garbage_collectors_); 853 // If we don't reset then the mark stack complains in its destructor. 854 allocation_stack_->Reset(); 855 live_stack_->Reset(); 856 STLDeleteValues(&mod_union_tables_); 857 STLDeleteValues(&remembered_sets_); 858 STLDeleteElements(&continuous_spaces_); 859 STLDeleteElements(&discontinuous_spaces_); 860 delete gc_complete_lock_; 861 delete heap_trim_request_lock_; 862 VLOG(heap) << "Finished ~Heap()"; 863} 864 865space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 866 bool fail_ok) const { 867 for (const auto& space : continuous_spaces_) { 868 if (space->Contains(obj)) { 869 return space; 870 } 871 } 872 if (!fail_ok) { 873 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 874 } 875 return NULL; 876} 877 878space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 879 bool fail_ok) const { 880 for (const auto& space : discontinuous_spaces_) { 881 if (space->Contains(obj)) { 882 return space; 883 } 884 } 885 if (!fail_ok) { 886 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 887 } 888 return NULL; 889} 890 891space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 892 space::Space* result = FindContinuousSpaceFromObject(obj, true); 893 if (result != NULL) { 894 return result; 895 } 896 return FindDiscontinuousSpaceFromObject(obj, true); 897} 898 899space::ImageSpace* Heap::GetImageSpace() const { 900 for (const auto& space : continuous_spaces_) { 901 if (space->IsImageSpace()) { 902 return space->AsImageSpace(); 903 } 904 } 905 return NULL; 906} 907 908void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 909 std::ostringstream oss; 910 size_t total_bytes_free = GetFreeMemory(); 911 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 912 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 913 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 914 if (total_bytes_free >= byte_count) { 915 space::AllocSpace* space = nullptr; 916 if (allocator_type == kAllocatorTypeNonMoving) { 917 space = non_moving_space_; 918 } else if (allocator_type == kAllocatorTypeRosAlloc || 919 allocator_type == kAllocatorTypeDlMalloc) { 920 space = main_space_; 921 } else if (allocator_type == kAllocatorTypeBumpPointer || 922 allocator_type == kAllocatorTypeTLAB) { 923 space = bump_pointer_space_; 924 } 925 if (space != nullptr) { 926 space->LogFragmentationAllocFailure(oss, byte_count); 927 } 928 } 929 self->ThrowOutOfMemoryError(oss.str().c_str()); 930} 931 932void Heap::DoPendingTransitionOrTrim() { 933 Thread* self = Thread::Current(); 934 CollectorType desired_collector_type; 935 // Wait until we reach the desired transition time. 936 while (true) { 937 uint64_t wait_time; 938 { 939 MutexLock mu(self, *heap_trim_request_lock_); 940 desired_collector_type = desired_collector_type_; 941 uint64_t current_time = NanoTime(); 942 if (current_time >= heap_transition_or_trim_target_time_) { 943 break; 944 } 945 wait_time = heap_transition_or_trim_target_time_ - current_time; 946 } 947 ScopedThreadStateChange tsc(self, kSleeping); 948 usleep(wait_time / 1000); // Usleep takes microseconds. 949 } 950 // Launch homogeneous space compaction if it is desired. 951 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 952 if (!CareAboutPauseTimes()) { 953 PerformHomogeneousSpaceCompact(); 954 } 955 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 956 desired_collector_type = collector_type_; 957 return; 958 } 959 // Transition the collector if the desired collector type is not the same as the current 960 // collector type. 961 TransitionCollector(desired_collector_type); 962 if (!CareAboutPauseTimes()) { 963 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 964 // about pauses. 965 Runtime* runtime = Runtime::Current(); 966 runtime->GetThreadList()->SuspendAll(); 967 uint64_t start_time = NanoTime(); 968 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 969 VLOG(heap) << "Deflating " << count << " monitors took " 970 << PrettyDuration(NanoTime() - start_time); 971 runtime->GetThreadList()->ResumeAll(); 972 } 973 // Do a heap trim if it is needed. 974 Trim(); 975} 976 977void Heap::Trim() { 978 Thread* self = Thread::Current(); 979 { 980 MutexLock mu(self, *heap_trim_request_lock_); 981 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 982 return; 983 } 984 last_trim_time_ = NanoTime(); 985 heap_trim_request_pending_ = false; 986 } 987 { 988 // Need to do this before acquiring the locks since we don't want to get suspended while 989 // holding any locks. 990 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 991 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 992 // trimming. 993 MutexLock mu(self, *gc_complete_lock_); 994 // Ensure there is only one GC at a time. 995 WaitForGcToCompleteLocked(kGcCauseTrim, self); 996 collector_type_running_ = kCollectorTypeHeapTrim; 997 } 998 uint64_t start_ns = NanoTime(); 999 // Trim the managed spaces. 1000 uint64_t total_alloc_space_allocated = 0; 1001 uint64_t total_alloc_space_size = 0; 1002 uint64_t managed_reclaimed = 0; 1003 for (const auto& space : continuous_spaces_) { 1004 if (space->IsMallocSpace()) { 1005 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1006 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1007 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1008 // for a long period of time. 1009 managed_reclaimed += malloc_space->Trim(); 1010 } 1011 total_alloc_space_size += malloc_space->Size(); 1012 } 1013 } 1014 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated(); 1015 if (bump_pointer_space_ != nullptr) { 1016 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1017 } 1018 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1019 static_cast<float>(total_alloc_space_size); 1020 uint64_t gc_heap_end_ns = NanoTime(); 1021 // We never move things in the native heap, so we can finish the GC at this point. 1022 FinishGC(self, collector::kGcTypeNone); 1023 size_t native_reclaimed = 0; 1024 // Only trim the native heap if we don't care about pauses. 1025 if (!CareAboutPauseTimes()) { 1026#if defined(USE_DLMALLOC) 1027 // Trim the native heap. 1028 dlmalloc_trim(0); 1029 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1030#elif defined(USE_JEMALLOC) 1031 // Jemalloc does it's own internal trimming. 1032#else 1033 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1034#endif 1035 } 1036 uint64_t end_ns = NanoTime(); 1037 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1038 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1039 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1040 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1041 << "%."; 1042} 1043 1044bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1045 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1046 // taking the lock. 1047 if (obj == nullptr) { 1048 return true; 1049 } 1050 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1051} 1052 1053bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1054 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1055} 1056 1057bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1058 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1059 return false; 1060 } 1061 for (const auto& space : continuous_spaces_) { 1062 if (space->HasAddress(obj)) { 1063 return true; 1064 } 1065 } 1066 return false; 1067} 1068 1069bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1070 bool search_live_stack, bool sorted) { 1071 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1072 return false; 1073 } 1074 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1075 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1076 if (obj == klass) { 1077 // This case happens for java.lang.Class. 1078 return true; 1079 } 1080 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1081 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1082 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1083 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1084 return temp_space_->Contains(obj); 1085 } 1086 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1087 space::DiscontinuousSpace* d_space = nullptr; 1088 if (c_space != nullptr) { 1089 if (c_space->GetLiveBitmap()->Test(obj)) { 1090 return true; 1091 } 1092 } else { 1093 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1094 if (d_space != nullptr) { 1095 if (d_space->GetLiveBitmap()->Test(obj)) { 1096 return true; 1097 } 1098 } 1099 } 1100 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1101 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1102 if (i > 0) { 1103 NanoSleep(MsToNs(10)); 1104 } 1105 if (search_allocation_stack) { 1106 if (sorted) { 1107 if (allocation_stack_->ContainsSorted(obj)) { 1108 return true; 1109 } 1110 } else if (allocation_stack_->Contains(obj)) { 1111 return true; 1112 } 1113 } 1114 1115 if (search_live_stack) { 1116 if (sorted) { 1117 if (live_stack_->ContainsSorted(obj)) { 1118 return true; 1119 } 1120 } else if (live_stack_->Contains(obj)) { 1121 return true; 1122 } 1123 } 1124 } 1125 // We need to check the bitmaps again since there is a race where we mark something as live and 1126 // then clear the stack containing it. 1127 if (c_space != nullptr) { 1128 if (c_space->GetLiveBitmap()->Test(obj)) { 1129 return true; 1130 } 1131 } else { 1132 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1133 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1134 return true; 1135 } 1136 } 1137 return false; 1138} 1139 1140std::string Heap::DumpSpaces() const { 1141 std::ostringstream oss; 1142 DumpSpaces(oss); 1143 return oss.str(); 1144} 1145 1146void Heap::DumpSpaces(std::ostream& stream) const { 1147 for (const auto& space : continuous_spaces_) { 1148 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1149 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1150 stream << space << " " << *space << "\n"; 1151 if (live_bitmap != nullptr) { 1152 stream << live_bitmap << " " << *live_bitmap << "\n"; 1153 } 1154 if (mark_bitmap != nullptr) { 1155 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1156 } 1157 } 1158 for (const auto& space : discontinuous_spaces_) { 1159 stream << space << " " << *space << "\n"; 1160 } 1161} 1162 1163void Heap::VerifyObjectBody(mirror::Object* obj) { 1164 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1165 return; 1166 } 1167 1168 // Ignore early dawn of the universe verifications. 1169 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1170 return; 1171 } 1172 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1173 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1174 CHECK(c != nullptr) << "Null class in object " << obj; 1175 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1176 CHECK(VerifyClassClass(c)); 1177 1178 if (verify_object_mode_ > kVerifyObjectModeFast) { 1179 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1180 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1181 } 1182} 1183 1184void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1185 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1186} 1187 1188void Heap::VerifyHeap() { 1189 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1190 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1191} 1192 1193void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1194 // Use signed comparison since freed bytes can be negative when background compaction foreground 1195 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1196 // free list backed space typically increasing memory footprint due to padding and binning. 1197 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1198 // Note: This relies on 2s complement for handling negative freed_bytes. 1199 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1200 if (Runtime::Current()->HasStatsEnabled()) { 1201 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1202 thread_stats->freed_objects += freed_objects; 1203 thread_stats->freed_bytes += freed_bytes; 1204 // TODO: Do this concurrently. 1205 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1206 global_stats->freed_objects += freed_objects; 1207 global_stats->freed_bytes += freed_bytes; 1208 } 1209} 1210 1211space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1212 for (const auto& space : continuous_spaces_) { 1213 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1214 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1215 return space->AsContinuousSpace()->AsRosAllocSpace(); 1216 } 1217 } 1218 } 1219 return nullptr; 1220} 1221 1222mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1223 size_t alloc_size, size_t* bytes_allocated, 1224 size_t* usable_size, 1225 mirror::Class** klass) { 1226 bool was_default_allocator = allocator == GetCurrentAllocator(); 1227 DCHECK(klass != nullptr); 1228 StackHandleScope<1> hs(self); 1229 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1230 klass = nullptr; // Invalidate for safety. 1231 // The allocation failed. If the GC is running, block until it completes, and then retry the 1232 // allocation. 1233 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1234 if (last_gc != collector::kGcTypeNone) { 1235 // If we were the default allocator but the allocator changed while we were suspended, 1236 // abort the allocation. 1237 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1238 return nullptr; 1239 } 1240 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1241 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1242 usable_size); 1243 if (ptr != nullptr) { 1244 return ptr; 1245 } 1246 } 1247 1248 collector::GcType tried_type = next_gc_type_; 1249 const bool gc_ran = 1250 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1251 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1252 return nullptr; 1253 } 1254 if (gc_ran) { 1255 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1256 usable_size); 1257 if (ptr != nullptr) { 1258 return ptr; 1259 } 1260 } 1261 1262 // Loop through our different Gc types and try to Gc until we get enough free memory. 1263 for (collector::GcType gc_type : gc_plan_) { 1264 if (gc_type == tried_type) { 1265 continue; 1266 } 1267 // Attempt to run the collector, if we succeed, re-try the allocation. 1268 const bool gc_ran = 1269 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1270 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1271 return nullptr; 1272 } 1273 if (gc_ran) { 1274 // Did we free sufficient memory for the allocation to succeed? 1275 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1276 usable_size); 1277 if (ptr != nullptr) { 1278 return ptr; 1279 } 1280 } 1281 } 1282 // Allocations have failed after GCs; this is an exceptional state. 1283 // Try harder, growing the heap if necessary. 1284 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1285 usable_size); 1286 if (ptr != nullptr) { 1287 return ptr; 1288 } 1289 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1290 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1291 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1292 // OOME. 1293 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1294 << " allocation"; 1295 // TODO: Run finalization, but this may cause more allocations to occur. 1296 // We don't need a WaitForGcToComplete here either. 1297 DCHECK(!gc_plan_.empty()); 1298 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1299 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1300 return nullptr; 1301 } 1302 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1303 if (ptr == nullptr) { 1304 const uint64_t current_time = NanoTime(); 1305 switch (allocator) { 1306 case kAllocatorTypeRosAlloc: 1307 // Fall-through. 1308 case kAllocatorTypeDlMalloc: { 1309 if (use_homogeneous_space_compaction_for_oom_ && 1310 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1311 min_interval_homogeneous_space_compaction_by_oom_) { 1312 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1313 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1314 switch (result) { 1315 case HomogeneousSpaceCompactResult::kSuccess: 1316 // If the allocation succeeded, we delayed an oom. 1317 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1318 usable_size); 1319 if (ptr != nullptr) { 1320 count_delayed_oom_++; 1321 } 1322 break; 1323 case HomogeneousSpaceCompactResult::kErrorReject: 1324 // Reject due to disabled moving GC. 1325 break; 1326 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1327 // Throw OOM by default. 1328 break; 1329 default: { 1330 LOG(FATAL) << "Unimplemented homogeneous space compaction result " 1331 << static_cast<size_t>(result); 1332 } 1333 } 1334 // Always print that we ran homogeneous space compation since this can cause jank. 1335 VLOG(heap) << "Ran heap homogeneous space compaction, " 1336 << " requested defragmentation " 1337 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1338 << " performed defragmentation " 1339 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1340 << " ignored homogeneous space compaction " 1341 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1342 << " delayed count = " 1343 << count_delayed_oom_.LoadSequentiallyConsistent(); 1344 } 1345 break; 1346 } 1347 case kAllocatorTypeNonMoving: { 1348 // Try to transition the heap if the allocation failure was due to the space being full. 1349 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1350 // If we aren't out of memory then the OOM was probably from the non moving space being 1351 // full. Attempt to disable compaction and turn the main space into a non moving space. 1352 DisableMovingGc(); 1353 // If we are still a moving GC then something must have caused the transition to fail. 1354 if (IsMovingGc(collector_type_)) { 1355 MutexLock mu(self, *gc_complete_lock_); 1356 // If we couldn't disable moving GC, just throw OOME and return null. 1357 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1358 << disable_moving_gc_count_; 1359 } else { 1360 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1361 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1362 usable_size); 1363 } 1364 } 1365 break; 1366 } 1367 default: { 1368 // Do nothing for others allocators. 1369 } 1370 } 1371 } 1372 // If the allocation hasn't succeeded by this point, throw an OOM error. 1373 if (ptr == nullptr) { 1374 ThrowOutOfMemoryError(self, alloc_size, allocator); 1375 } 1376 return ptr; 1377} 1378 1379void Heap::SetTargetHeapUtilization(float target) { 1380 DCHECK_GT(target, 0.0f); // asserted in Java code 1381 DCHECK_LT(target, 1.0f); 1382 target_utilization_ = target; 1383} 1384 1385size_t Heap::GetObjectsAllocated() const { 1386 size_t total = 0; 1387 for (space::AllocSpace* space : alloc_spaces_) { 1388 total += space->GetObjectsAllocated(); 1389 } 1390 return total; 1391} 1392 1393uint64_t Heap::GetObjectsAllocatedEver() const { 1394 return GetObjectsFreedEver() + GetObjectsAllocated(); 1395} 1396 1397uint64_t Heap::GetBytesAllocatedEver() const { 1398 return GetBytesFreedEver() + GetBytesAllocated(); 1399} 1400 1401class InstanceCounter { 1402 public: 1403 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1404 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1405 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1406 } 1407 static void Callback(mirror::Object* obj, void* arg) 1408 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1409 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1410 mirror::Class* instance_class = obj->GetClass(); 1411 CHECK(instance_class != nullptr); 1412 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1413 if (instance_counter->use_is_assignable_from_) { 1414 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1415 ++instance_counter->counts_[i]; 1416 } 1417 } else if (instance_class == instance_counter->classes_[i]) { 1418 ++instance_counter->counts_[i]; 1419 } 1420 } 1421 } 1422 1423 private: 1424 const std::vector<mirror::Class*>& classes_; 1425 bool use_is_assignable_from_; 1426 uint64_t* const counts_; 1427 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1428}; 1429 1430void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1431 uint64_t* counts) { 1432 // Can't do any GC in this function since this may move classes. 1433 Thread* self = Thread::Current(); 1434 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1435 InstanceCounter counter(classes, use_is_assignable_from, counts); 1436 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1437 VisitObjects(InstanceCounter::Callback, &counter); 1438 self->EndAssertNoThreadSuspension(old_cause); 1439} 1440 1441class InstanceCollector { 1442 public: 1443 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1444 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1445 : class_(c), max_count_(max_count), instances_(instances) { 1446 } 1447 static void Callback(mirror::Object* obj, void* arg) 1448 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1449 DCHECK(arg != nullptr); 1450 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1451 mirror::Class* instance_class = obj->GetClass(); 1452 if (instance_class == instance_collector->class_) { 1453 if (instance_collector->max_count_ == 0 || 1454 instance_collector->instances_.size() < instance_collector->max_count_) { 1455 instance_collector->instances_.push_back(obj); 1456 } 1457 } 1458 } 1459 1460 private: 1461 mirror::Class* class_; 1462 uint32_t max_count_; 1463 std::vector<mirror::Object*>& instances_; 1464 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1465}; 1466 1467void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1468 std::vector<mirror::Object*>& instances) { 1469 // Can't do any GC in this function since this may move classes. 1470 Thread* self = Thread::Current(); 1471 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1472 InstanceCollector collector(c, max_count, instances); 1473 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1474 VisitObjects(&InstanceCollector::Callback, &collector); 1475 self->EndAssertNoThreadSuspension(old_cause); 1476} 1477 1478class ReferringObjectsFinder { 1479 public: 1480 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1481 std::vector<mirror::Object*>& referring_objects) 1482 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1483 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1484 } 1485 1486 static void Callback(mirror::Object* obj, void* arg) 1487 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1488 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1489 } 1490 1491 // For bitmap Visit. 1492 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1493 // annotalysis on visitors. 1494 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1495 o->VisitReferences<true>(*this, VoidFunctor()); 1496 } 1497 1498 // For Object::VisitReferences. 1499 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1500 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1501 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1502 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1503 referring_objects_.push_back(obj); 1504 } 1505 } 1506 1507 private: 1508 mirror::Object* object_; 1509 uint32_t max_count_; 1510 std::vector<mirror::Object*>& referring_objects_; 1511 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1512}; 1513 1514void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1515 std::vector<mirror::Object*>& referring_objects) { 1516 // Can't do any GC in this function since this may move the object o. 1517 Thread* self = Thread::Current(); 1518 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1519 ReferringObjectsFinder finder(o, max_count, referring_objects); 1520 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1521 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1522 self->EndAssertNoThreadSuspension(old_cause); 1523} 1524 1525void Heap::CollectGarbage(bool clear_soft_references) { 1526 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1527 // last GC will not have necessarily been cleared. 1528 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1529} 1530 1531HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1532 Thread* self = Thread::Current(); 1533 // Inc requested homogeneous space compaction. 1534 count_requested_homogeneous_space_compaction_++; 1535 // Store performed homogeneous space compaction at a new request arrival. 1536 ThreadList* tl = Runtime::Current()->GetThreadList(); 1537 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1538 Locks::mutator_lock_->AssertNotHeld(self); 1539 { 1540 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1541 MutexLock mu(self, *gc_complete_lock_); 1542 // Ensure there is only one GC at a time. 1543 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1544 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1545 // is non zero. 1546 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1547 // exit. 1548 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1549 !main_space_->CanMoveObjects()) { 1550 return HomogeneousSpaceCompactResult::kErrorReject; 1551 } 1552 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1553 } 1554 if (Runtime::Current()->IsShuttingDown(self)) { 1555 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1556 // cause objects to get finalized. 1557 FinishGC(self, collector::kGcTypeNone); 1558 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1559 } 1560 // Suspend all threads. 1561 tl->SuspendAll(); 1562 uint64_t start_time = NanoTime(); 1563 // Launch compaction. 1564 space::MallocSpace* to_space = main_space_backup_.release(); 1565 space::MallocSpace* from_space = main_space_; 1566 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1567 const uint64_t space_size_before_compaction = from_space->Size(); 1568 AddSpace(to_space); 1569 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1570 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1571 from_space->GetMemMap()->Protect(PROT_READ); 1572 const uint64_t space_size_after_compaction = to_space->Size(); 1573 main_space_ = to_space; 1574 main_space_backup_.reset(from_space); 1575 RemoveSpace(from_space); 1576 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1577 // Update performed homogeneous space compaction count. 1578 count_performed_homogeneous_space_compaction_++; 1579 // Print statics log and resume all threads. 1580 uint64_t duration = NanoTime() - start_time; 1581 LOG(INFO) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1582 << PrettySize(space_size_before_compaction) << " -> " 1583 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1584 << std::fixed << static_cast<double>(space_size_after_compaction) / 1585 static_cast<double>(space_size_before_compaction); 1586 tl->ResumeAll(); 1587 // Finish GC. 1588 reference_processor_.EnqueueClearedReferences(self); 1589 GrowForUtilization(semi_space_collector_); 1590 FinishGC(self, collector::kGcTypeFull); 1591 return HomogeneousSpaceCompactResult::kSuccess; 1592} 1593 1594 1595void Heap::TransitionCollector(CollectorType collector_type) { 1596 if (collector_type == collector_type_) { 1597 return; 1598 } 1599 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1600 << " -> " << static_cast<int>(collector_type); 1601 uint64_t start_time = NanoTime(); 1602 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1603 Runtime* const runtime = Runtime::Current(); 1604 ThreadList* const tl = runtime->GetThreadList(); 1605 Thread* const self = Thread::Current(); 1606 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1607 Locks::mutator_lock_->AssertNotHeld(self); 1608 // Currently we only need a heap transition if we switch from a moving collector to a non moving 1609 // one, or visa versa. 1610 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1611 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1612 // compacting_gc_disable_count_, this should rarely occurs). 1613 for (;;) { 1614 { 1615 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1616 MutexLock mu(self, *gc_complete_lock_); 1617 // Ensure there is only one GC at a time. 1618 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1619 // If someone else beat us to it and changed the collector before we could, exit. 1620 // This is safe to do before the suspend all since we set the collector_type_running_ before 1621 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1622 // then it would get blocked on WaitForGcToCompleteLocked. 1623 if (collector_type == collector_type_) { 1624 return; 1625 } 1626 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1627 if (!copying_transition || disable_moving_gc_count_ == 0) { 1628 // TODO: Not hard code in semi-space collector? 1629 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1630 break; 1631 } 1632 } 1633 usleep(1000); 1634 } 1635 if (runtime->IsShuttingDown(self)) { 1636 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1637 // cause objects to get finalized. 1638 FinishGC(self, collector::kGcTypeNone); 1639 return; 1640 } 1641 tl->SuspendAll(); 1642 switch (collector_type) { 1643 case kCollectorTypeSS: { 1644 if (!IsMovingGc(collector_type_)) { 1645 // Create the bump pointer space from the backup space. 1646 CHECK(main_space_backup_ != nullptr); 1647 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1648 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1649 // pointer space last transition it will be protected. 1650 CHECK(mem_map != nullptr); 1651 mem_map->Protect(PROT_READ | PROT_WRITE); 1652 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1653 mem_map.release()); 1654 AddSpace(bump_pointer_space_); 1655 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1656 // Use the now empty main space mem map for the bump pointer temp space. 1657 mem_map.reset(main_space_->ReleaseMemMap()); 1658 // Unset the pointers just in case. 1659 if (dlmalloc_space_ == main_space_) { 1660 dlmalloc_space_ = nullptr; 1661 } else if (rosalloc_space_ == main_space_) { 1662 rosalloc_space_ = nullptr; 1663 } 1664 // Remove the main space so that we don't try to trim it, this doens't work for debug 1665 // builds since RosAlloc attempts to read the magic number from a protected page. 1666 RemoveSpace(main_space_); 1667 RemoveRememberedSet(main_space_); 1668 delete main_space_; // Delete the space since it has been removed. 1669 main_space_ = nullptr; 1670 RemoveRememberedSet(main_space_backup_.get()); 1671 main_space_backup_.reset(nullptr); // Deletes the space. 1672 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1673 mem_map.release()); 1674 AddSpace(temp_space_); 1675 } 1676 break; 1677 } 1678 case kCollectorTypeMS: 1679 // Fall through. 1680 case kCollectorTypeCMS: { 1681 if (IsMovingGc(collector_type_)) { 1682 CHECK(temp_space_ != nullptr); 1683 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1684 RemoveSpace(temp_space_); 1685 temp_space_ = nullptr; 1686 mem_map->Protect(PROT_READ | PROT_WRITE); 1687 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, mem_map->Size(), 1688 mem_map->Size()); 1689 mem_map.release(); 1690 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1691 AddSpace(main_space_); 1692 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1693 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1694 RemoveSpace(bump_pointer_space_); 1695 bump_pointer_space_ = nullptr; 1696 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1697 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1698 if (kIsDebugBuild && kUseRosAlloc) { 1699 mem_map->Protect(PROT_READ | PROT_WRITE); 1700 } 1701 main_space_backup_.reset(CreateMallocSpaceFromMemMap(mem_map.get(), kDefaultInitialSize, 1702 mem_map->Size(), mem_map->Size(), 1703 name, true)); 1704 if (kIsDebugBuild && kUseRosAlloc) { 1705 mem_map->Protect(PROT_NONE); 1706 } 1707 mem_map.release(); 1708 } 1709 break; 1710 } 1711 default: { 1712 LOG(FATAL) << "Attempted to transition to invalid collector type " 1713 << static_cast<size_t>(collector_type); 1714 break; 1715 } 1716 } 1717 ChangeCollector(collector_type); 1718 tl->ResumeAll(); 1719 // Can't call into java code with all threads suspended. 1720 reference_processor_.EnqueueClearedReferences(self); 1721 uint64_t duration = NanoTime() - start_time; 1722 GrowForUtilization(semi_space_collector_); 1723 FinishGC(self, collector::kGcTypeFull); 1724 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1725 int32_t delta_allocated = before_allocated - after_allocated; 1726 std::string saved_str; 1727 if (delta_allocated >= 0) { 1728 saved_str = " saved at least " + PrettySize(delta_allocated); 1729 } else { 1730 saved_str = " expanded " + PrettySize(-delta_allocated); 1731 } 1732 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1733 << PrettyDuration(duration) << saved_str; 1734} 1735 1736void Heap::ChangeCollector(CollectorType collector_type) { 1737 // TODO: Only do this with all mutators suspended to avoid races. 1738 if (collector_type != collector_type_) { 1739 if (collector_type == kCollectorTypeMC) { 1740 // Don't allow mark compact unless support is compiled in. 1741 CHECK(kMarkCompactSupport); 1742 } 1743 collector_type_ = collector_type; 1744 gc_plan_.clear(); 1745 switch (collector_type_) { 1746 case kCollectorTypeCC: // Fall-through. 1747 case kCollectorTypeMC: // Fall-through. 1748 case kCollectorTypeSS: // Fall-through. 1749 case kCollectorTypeGSS: { 1750 gc_plan_.push_back(collector::kGcTypeFull); 1751 if (use_tlab_) { 1752 ChangeAllocator(kAllocatorTypeTLAB); 1753 } else { 1754 ChangeAllocator(kAllocatorTypeBumpPointer); 1755 } 1756 break; 1757 } 1758 case kCollectorTypeMS: { 1759 gc_plan_.push_back(collector::kGcTypeSticky); 1760 gc_plan_.push_back(collector::kGcTypePartial); 1761 gc_plan_.push_back(collector::kGcTypeFull); 1762 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1763 break; 1764 } 1765 case kCollectorTypeCMS: { 1766 gc_plan_.push_back(collector::kGcTypeSticky); 1767 gc_plan_.push_back(collector::kGcTypePartial); 1768 gc_plan_.push_back(collector::kGcTypeFull); 1769 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1770 break; 1771 } 1772 default: { 1773 LOG(FATAL) << "Unimplemented"; 1774 } 1775 } 1776 if (IsGcConcurrent()) { 1777 concurrent_start_bytes_ = 1778 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1779 } else { 1780 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1781 } 1782 } 1783} 1784 1785// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1786class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1787 public: 1788 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1789 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1790 } 1791 1792 void BuildBins(space::ContinuousSpace* space) { 1793 bin_live_bitmap_ = space->GetLiveBitmap(); 1794 bin_mark_bitmap_ = space->GetMarkBitmap(); 1795 BinContext context; 1796 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1797 context.collector_ = this; 1798 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1799 // Note: This requires traversing the space in increasing order of object addresses. 1800 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1801 // Add the last bin which spans after the last object to the end of the space. 1802 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1803 } 1804 1805 private: 1806 struct BinContext { 1807 uintptr_t prev_; // The end of the previous object. 1808 ZygoteCompactingCollector* collector_; 1809 }; 1810 // Maps from bin sizes to locations. 1811 std::multimap<size_t, uintptr_t> bins_; 1812 // Live bitmap of the space which contains the bins. 1813 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1814 // Mark bitmap of the space which contains the bins. 1815 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1816 1817 static void Callback(mirror::Object* obj, void* arg) 1818 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1819 DCHECK(arg != nullptr); 1820 BinContext* context = reinterpret_cast<BinContext*>(arg); 1821 ZygoteCompactingCollector* collector = context->collector_; 1822 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1823 size_t bin_size = object_addr - context->prev_; 1824 // Add the bin consisting of the end of the previous object to the start of the current object. 1825 collector->AddBin(bin_size, context->prev_); 1826 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1827 } 1828 1829 void AddBin(size_t size, uintptr_t position) { 1830 if (size != 0) { 1831 bins_.insert(std::make_pair(size, position)); 1832 } 1833 } 1834 1835 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1836 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1837 // allocator. 1838 return false; 1839 } 1840 1841 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1842 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1843 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1844 mirror::Object* forward_address; 1845 // Find the smallest bin which we can move obj in. 1846 auto it = bins_.lower_bound(object_size); 1847 if (it == bins_.end()) { 1848 // No available space in the bins, place it in the target space instead (grows the zygote 1849 // space). 1850 size_t bytes_allocated; 1851 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1852 if (to_space_live_bitmap_ != nullptr) { 1853 to_space_live_bitmap_->Set(forward_address); 1854 } else { 1855 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1856 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1857 } 1858 } else { 1859 size_t size = it->first; 1860 uintptr_t pos = it->second; 1861 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1862 forward_address = reinterpret_cast<mirror::Object*>(pos); 1863 // Set the live and mark bits so that sweeping system weaks works properly. 1864 bin_live_bitmap_->Set(forward_address); 1865 bin_mark_bitmap_->Set(forward_address); 1866 DCHECK_GE(size, object_size); 1867 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1868 } 1869 // Copy the object over to its new location. 1870 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1871 if (kUseBakerOrBrooksReadBarrier) { 1872 obj->AssertReadBarrierPointer(); 1873 if (kUseBrooksReadBarrier) { 1874 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1875 forward_address->SetReadBarrierPointer(forward_address); 1876 } 1877 forward_address->AssertReadBarrierPointer(); 1878 } 1879 return forward_address; 1880 } 1881}; 1882 1883void Heap::UnBindBitmaps() { 1884 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1885 for (const auto& space : GetContinuousSpaces()) { 1886 if (space->IsContinuousMemMapAllocSpace()) { 1887 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1888 if (alloc_space->HasBoundBitmaps()) { 1889 alloc_space->UnBindBitmaps(); 1890 } 1891 } 1892 } 1893} 1894 1895void Heap::PreZygoteFork() { 1896 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1897 Thread* self = Thread::Current(); 1898 MutexLock mu(self, zygote_creation_lock_); 1899 // Try to see if we have any Zygote spaces. 1900 if (have_zygote_space_) { 1901 return; 1902 } 1903 VLOG(heap) << "Starting PreZygoteFork"; 1904 // Trim the pages at the end of the non moving space. 1905 non_moving_space_->Trim(); 1906 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1907 // there. 1908 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1909 const bool same_space = non_moving_space_ == main_space_; 1910 if (kCompactZygote) { 1911 // Can't compact if the non moving space is the same as the main space. 1912 DCHECK(semi_space_collector_ != nullptr); 1913 // Temporarily disable rosalloc verification because the zygote 1914 // compaction will mess up the rosalloc internal metadata. 1915 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1916 ZygoteCompactingCollector zygote_collector(this); 1917 zygote_collector.BuildBins(non_moving_space_); 1918 // Create a new bump pointer space which we will compact into. 1919 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1920 non_moving_space_->Limit()); 1921 // Compact the bump pointer space to a new zygote bump pointer space. 1922 bool reset_main_space = false; 1923 if (IsMovingGc(collector_type_)) { 1924 zygote_collector.SetFromSpace(bump_pointer_space_); 1925 } else { 1926 CHECK(main_space_ != nullptr); 1927 // Copy from the main space. 1928 zygote_collector.SetFromSpace(main_space_); 1929 reset_main_space = true; 1930 } 1931 zygote_collector.SetToSpace(&target_space); 1932 zygote_collector.SetSwapSemiSpaces(false); 1933 zygote_collector.Run(kGcCauseCollectorTransition, false); 1934 if (reset_main_space) { 1935 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1936 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1937 MemMap* mem_map = main_space_->ReleaseMemMap(); 1938 RemoveSpace(main_space_); 1939 space::Space* old_main_space = main_space_; 1940 CreateMainMallocSpace(mem_map, kDefaultInitialSize, mem_map->Size(), mem_map->Size()); 1941 delete old_main_space; 1942 AddSpace(main_space_); 1943 } else { 1944 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1945 } 1946 if (temp_space_ != nullptr) { 1947 CHECK(temp_space_->IsEmpty()); 1948 } 1949 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1950 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1951 // Update the end and write out image. 1952 non_moving_space_->SetEnd(target_space.End()); 1953 non_moving_space_->SetLimit(target_space.Limit()); 1954 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1955 } 1956 // Change the collector to the post zygote one. 1957 ChangeCollector(foreground_collector_type_); 1958 // Save the old space so that we can remove it after we complete creating the zygote space. 1959 space::MallocSpace* old_alloc_space = non_moving_space_; 1960 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1961 // the remaining available space. 1962 // Remove the old space before creating the zygote space since creating the zygote space sets 1963 // the old alloc space's bitmaps to nullptr. 1964 RemoveSpace(old_alloc_space); 1965 if (collector::SemiSpace::kUseRememberedSet) { 1966 // Sanity bound check. 1967 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1968 // Remove the remembered set for the now zygote space (the old 1969 // non-moving space). Note now that we have compacted objects into 1970 // the zygote space, the data in the remembered set is no longer 1971 // needed. The zygote space will instead have a mod-union table 1972 // from this point on. 1973 RemoveRememberedSet(old_alloc_space); 1974 } 1975 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1976 low_memory_mode_, 1977 &non_moving_space_); 1978 CHECK(!non_moving_space_->CanMoveObjects()); 1979 if (same_space) { 1980 main_space_ = non_moving_space_; 1981 SetSpaceAsDefault(main_space_); 1982 } 1983 delete old_alloc_space; 1984 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1985 AddSpace(zygote_space); 1986 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 1987 AddSpace(non_moving_space_); 1988 have_zygote_space_ = true; 1989 // Enable large object space allocations. 1990 large_object_threshold_ = kDefaultLargeObjectThreshold; 1991 // Create the zygote space mod union table. 1992 accounting::ModUnionTable* mod_union_table = 1993 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1994 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1995 AddModUnionTable(mod_union_table); 1996 if (collector::SemiSpace::kUseRememberedSet) { 1997 // Add a new remembered set for the post-zygote non-moving space. 1998 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1999 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2000 non_moving_space_); 2001 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2002 << "Failed to create post-zygote non-moving space remembered set"; 2003 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2004 } 2005} 2006 2007void Heap::FlushAllocStack() { 2008 MarkAllocStackAsLive(allocation_stack_.get()); 2009 allocation_stack_->Reset(); 2010} 2011 2012void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2013 accounting::ContinuousSpaceBitmap* bitmap2, 2014 accounting::LargeObjectBitmap* large_objects, 2015 accounting::ObjectStack* stack) { 2016 DCHECK(bitmap1 != nullptr); 2017 DCHECK(bitmap2 != nullptr); 2018 mirror::Object** limit = stack->End(); 2019 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 2020 const mirror::Object* obj = *it; 2021 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2022 if (bitmap1->HasAddress(obj)) { 2023 bitmap1->Set(obj); 2024 } else if (bitmap2->HasAddress(obj)) { 2025 bitmap2->Set(obj); 2026 } else { 2027 large_objects->Set(obj); 2028 } 2029 } 2030 } 2031} 2032 2033void Heap::SwapSemiSpaces() { 2034 CHECK(bump_pointer_space_ != nullptr); 2035 CHECK(temp_space_ != nullptr); 2036 std::swap(bump_pointer_space_, temp_space_); 2037} 2038 2039void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2040 space::ContinuousMemMapAllocSpace* source_space, 2041 GcCause gc_cause) { 2042 CHECK(kMovingCollector); 2043 if (target_space != source_space) { 2044 // Don't swap spaces since this isn't a typical semi space collection. 2045 semi_space_collector_->SetSwapSemiSpaces(false); 2046 semi_space_collector_->SetFromSpace(source_space); 2047 semi_space_collector_->SetToSpace(target_space); 2048 semi_space_collector_->Run(gc_cause, false); 2049 } else { 2050 CHECK(target_space->IsBumpPointerSpace()) 2051 << "In-place compaction is only supported for bump pointer spaces"; 2052 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2053 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2054 } 2055} 2056 2057collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2058 bool clear_soft_references) { 2059 Thread* self = Thread::Current(); 2060 Runtime* runtime = Runtime::Current(); 2061 // If the heap can't run the GC, silently fail and return that no GC was run. 2062 switch (gc_type) { 2063 case collector::kGcTypePartial: { 2064 if (!have_zygote_space_) { 2065 return collector::kGcTypeNone; 2066 } 2067 break; 2068 } 2069 default: { 2070 // Other GC types don't have any special cases which makes them not runnable. The main case 2071 // here is full GC. 2072 } 2073 } 2074 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2075 Locks::mutator_lock_->AssertNotHeld(self); 2076 if (self->IsHandlingStackOverflow()) { 2077 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2078 } 2079 bool compacting_gc; 2080 { 2081 gc_complete_lock_->AssertNotHeld(self); 2082 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2083 MutexLock mu(self, *gc_complete_lock_); 2084 // Ensure there is only one GC at a time. 2085 WaitForGcToCompleteLocked(gc_cause, self); 2086 compacting_gc = IsMovingGc(collector_type_); 2087 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2088 if (compacting_gc && disable_moving_gc_count_ != 0) { 2089 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2090 return collector::kGcTypeNone; 2091 } 2092 collector_type_running_ = collector_type_; 2093 } 2094 2095 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2096 ++runtime->GetStats()->gc_for_alloc_count; 2097 ++self->GetStats()->gc_for_alloc_count; 2098 } 2099 uint64_t gc_start_time_ns = NanoTime(); 2100 uint64_t gc_start_size = GetBytesAllocated(); 2101 // Approximate allocation rate in bytes / second. 2102 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2103 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2104 if (LIKELY(ms_delta != 0)) { 2105 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2106 ATRACE_INT("Allocation rate KB/s", allocation_rate_ / KB); 2107 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2108 } 2109 2110 DCHECK_LT(gc_type, collector::kGcTypeMax); 2111 DCHECK_NE(gc_type, collector::kGcTypeNone); 2112 2113 collector::GarbageCollector* collector = nullptr; 2114 // TODO: Clean this up. 2115 if (compacting_gc) { 2116 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2117 current_allocator_ == kAllocatorTypeTLAB); 2118 switch (collector_type_) { 2119 case kCollectorTypeSS: 2120 // Fall-through. 2121 case kCollectorTypeGSS: 2122 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2123 semi_space_collector_->SetToSpace(temp_space_); 2124 semi_space_collector_->SetSwapSemiSpaces(true); 2125 collector = semi_space_collector_; 2126 break; 2127 case kCollectorTypeCC: 2128 collector = concurrent_copying_collector_; 2129 break; 2130 case kCollectorTypeMC: 2131 mark_compact_collector_->SetSpace(bump_pointer_space_); 2132 collector = mark_compact_collector_; 2133 break; 2134 default: 2135 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2136 } 2137 if (collector != mark_compact_collector_) { 2138 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2139 CHECK(temp_space_->IsEmpty()); 2140 } 2141 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2142 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2143 current_allocator_ == kAllocatorTypeDlMalloc) { 2144 collector = FindCollectorByGcType(gc_type); 2145 } else { 2146 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2147 } 2148 CHECK(collector != nullptr) 2149 << "Could not find garbage collector with collector_type=" 2150 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2151 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2152 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2153 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2154 RequestHeapTrim(); 2155 // Enqueue cleared references. 2156 reference_processor_.EnqueueClearedReferences(self); 2157 // Grow the heap so that we know when to perform the next GC. 2158 GrowForUtilization(collector); 2159 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2160 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2161 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2162 // (mutator time blocked >= long_pause_log_threshold_). 2163 bool log_gc = gc_cause == kGcCauseExplicit; 2164 if (!log_gc && CareAboutPauseTimes()) { 2165 // GC for alloc pauses the allocating thread, so consider it as a pause. 2166 log_gc = duration > long_gc_log_threshold_ || 2167 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2168 for (uint64_t pause : pause_times) { 2169 log_gc = log_gc || pause >= long_pause_log_threshold_; 2170 } 2171 } 2172 if (log_gc) { 2173 const size_t percent_free = GetPercentFree(); 2174 const size_t current_heap_size = GetBytesAllocated(); 2175 const size_t total_memory = GetTotalMemory(); 2176 std::ostringstream pause_string; 2177 for (size_t i = 0; i < pause_times.size(); ++i) { 2178 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2179 << ((i != pause_times.size() - 1) ? "," : ""); 2180 } 2181 LOG(INFO) << gc_cause << " " << collector->GetName() 2182 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2183 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2184 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2185 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2186 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2187 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2188 << " total " << PrettyDuration((duration / 1000) * 1000); 2189 VLOG(heap) << ConstDumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2190 } 2191 FinishGC(self, gc_type); 2192 // Inform DDMS that a GC completed. 2193 Dbg::GcDidFinish(); 2194 return gc_type; 2195} 2196 2197void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2198 MutexLock mu(self, *gc_complete_lock_); 2199 collector_type_running_ = kCollectorTypeNone; 2200 if (gc_type != collector::kGcTypeNone) { 2201 last_gc_type_ = gc_type; 2202 } 2203 // Wake anyone who may have been waiting for the GC to complete. 2204 gc_complete_cond_->Broadcast(self); 2205} 2206 2207static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2208 RootType /*root_type*/) { 2209 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2210 if (*root == obj) { 2211 LOG(INFO) << "Object " << obj << " is a root"; 2212 } 2213} 2214 2215class ScanVisitor { 2216 public: 2217 void operator()(const mirror::Object* obj) const { 2218 LOG(ERROR) << "Would have rescanned object " << obj; 2219 } 2220}; 2221 2222// Verify a reference from an object. 2223class VerifyReferenceVisitor { 2224 public: 2225 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2226 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2227 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2228 2229 size_t GetFailureCount() const { 2230 return fail_count_->LoadSequentiallyConsistent(); 2231 } 2232 2233 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2234 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2235 if (verify_referent_) { 2236 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2237 } 2238 } 2239 2240 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2241 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2242 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2243 } 2244 2245 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2246 return heap_->IsLiveObjectLocked(obj, true, false, true); 2247 } 2248 2249 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2250 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2251 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2252 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2253 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2254 << " thread_id= " << thread_id << " root_type= " << root_type; 2255 } 2256 } 2257 2258 private: 2259 // TODO: Fix the no thread safety analysis. 2260 // Returns false on failure. 2261 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2262 NO_THREAD_SAFETY_ANALYSIS { 2263 if (ref == nullptr || IsLive(ref)) { 2264 // Verify that the reference is live. 2265 return true; 2266 } 2267 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2268 // Print message on only on first failure to prevent spam. 2269 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2270 } 2271 if (obj != nullptr) { 2272 // Only do this part for non roots. 2273 accounting::CardTable* card_table = heap_->GetCardTable(); 2274 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2275 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2276 byte* card_addr = card_table->CardFromAddr(obj); 2277 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2278 << offset << "\n card value = " << static_cast<int>(*card_addr); 2279 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2280 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2281 } else { 2282 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2283 } 2284 2285 // Attempt to find the class inside of the recently freed objects. 2286 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2287 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2288 space::MallocSpace* space = ref_space->AsMallocSpace(); 2289 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2290 if (ref_class != nullptr) { 2291 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2292 << PrettyClass(ref_class); 2293 } else { 2294 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2295 } 2296 } 2297 2298 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2299 ref->GetClass()->IsClass()) { 2300 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2301 } else { 2302 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2303 << ") is not a valid heap address"; 2304 } 2305 2306 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 2307 void* cover_begin = card_table->AddrFromCard(card_addr); 2308 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2309 accounting::CardTable::kCardSize); 2310 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2311 << "-" << cover_end; 2312 accounting::ContinuousSpaceBitmap* bitmap = 2313 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2314 2315 if (bitmap == nullptr) { 2316 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2317 if (!VerifyClassClass(obj->GetClass())) { 2318 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2319 } 2320 } else { 2321 // Print out how the object is live. 2322 if (bitmap->Test(obj)) { 2323 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2324 } 2325 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2326 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2327 } 2328 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2329 LOG(ERROR) << "Object " << obj << " found in live stack"; 2330 } 2331 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2332 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2333 } 2334 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2335 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2336 } 2337 // Attempt to see if the card table missed the reference. 2338 ScanVisitor scan_visitor; 2339 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2340 card_table->Scan(bitmap, byte_cover_begin, 2341 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2342 } 2343 2344 // Search to see if any of the roots reference our object. 2345 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2346 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2347 2348 // Search to see if any of the roots reference our reference. 2349 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2350 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2351 } 2352 return false; 2353 } 2354 2355 Heap* const heap_; 2356 Atomic<size_t>* const fail_count_; 2357 const bool verify_referent_; 2358}; 2359 2360// Verify all references within an object, for use with HeapBitmap::Visit. 2361class VerifyObjectVisitor { 2362 public: 2363 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2364 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2365 } 2366 2367 void operator()(mirror::Object* obj) const 2368 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2369 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2370 // be live or else how did we find it in the live bitmap? 2371 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2372 // The class doesn't count as a reference but we should verify it anyways. 2373 obj->VisitReferences<true>(visitor, visitor); 2374 } 2375 2376 static void VisitCallback(mirror::Object* obj, void* arg) 2377 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2378 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2379 visitor->operator()(obj); 2380 } 2381 2382 size_t GetFailureCount() const { 2383 return fail_count_->LoadSequentiallyConsistent(); 2384 } 2385 2386 private: 2387 Heap* const heap_; 2388 Atomic<size_t>* const fail_count_; 2389 const bool verify_referent_; 2390}; 2391 2392void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2393 // Slow path, the allocation stack push back must have already failed. 2394 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2395 do { 2396 // TODO: Add handle VerifyObject. 2397 StackHandleScope<1> hs(self); 2398 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2399 // Push our object into the reserve region of the allocaiton stack. This is only required due 2400 // to heap verification requiring that roots are live (either in the live bitmap or in the 2401 // allocation stack). 2402 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2403 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2404 } while (!allocation_stack_->AtomicPushBack(*obj)); 2405} 2406 2407void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2408 // Slow path, the allocation stack push back must have already failed. 2409 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2410 mirror::Object** start_address; 2411 mirror::Object** end_address; 2412 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2413 &end_address)) { 2414 // TODO: Add handle VerifyObject. 2415 StackHandleScope<1> hs(self); 2416 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2417 // Push our object into the reserve region of the allocaiton stack. This is only required due 2418 // to heap verification requiring that roots are live (either in the live bitmap or in the 2419 // allocation stack). 2420 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2421 // Push into the reserve allocation stack. 2422 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2423 } 2424 self->SetThreadLocalAllocationStack(start_address, end_address); 2425 // Retry on the new thread-local allocation stack. 2426 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2427} 2428 2429// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2430size_t Heap::VerifyHeapReferences(bool verify_referents) { 2431 Thread* self = Thread::Current(); 2432 Locks::mutator_lock_->AssertExclusiveHeld(self); 2433 // Lets sort our allocation stacks so that we can efficiently binary search them. 2434 allocation_stack_->Sort(); 2435 live_stack_->Sort(); 2436 // Since we sorted the allocation stack content, need to revoke all 2437 // thread-local allocation stacks. 2438 RevokeAllThreadLocalAllocationStacks(self); 2439 Atomic<size_t> fail_count_(0); 2440 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2441 // Verify objects in the allocation stack since these will be objects which were: 2442 // 1. Allocated prior to the GC (pre GC verification). 2443 // 2. Allocated during the GC (pre sweep GC verification). 2444 // We don't want to verify the objects in the live stack since they themselves may be 2445 // pointing to dead objects if they are not reachable. 2446 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2447 // Verify the roots: 2448 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2449 if (visitor.GetFailureCount() > 0) { 2450 // Dump mod-union tables. 2451 for (const auto& table_pair : mod_union_tables_) { 2452 accounting::ModUnionTable* mod_union_table = table_pair.second; 2453 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2454 } 2455 // Dump remembered sets. 2456 for (const auto& table_pair : remembered_sets_) { 2457 accounting::RememberedSet* remembered_set = table_pair.second; 2458 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2459 } 2460 DumpSpaces(LOG(ERROR)); 2461 } 2462 return visitor.GetFailureCount(); 2463} 2464 2465class VerifyReferenceCardVisitor { 2466 public: 2467 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2468 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2469 Locks::heap_bitmap_lock_) 2470 : heap_(heap), failed_(failed) { 2471 } 2472 2473 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2474 // annotalysis on visitors. 2475 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2476 NO_THREAD_SAFETY_ANALYSIS { 2477 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2478 // Filter out class references since changing an object's class does not mark the card as dirty. 2479 // Also handles large objects, since the only reference they hold is a class reference. 2480 if (ref != nullptr && !ref->IsClass()) { 2481 accounting::CardTable* card_table = heap_->GetCardTable(); 2482 // If the object is not dirty and it is referencing something in the live stack other than 2483 // class, then it must be on a dirty card. 2484 if (!card_table->AddrIsInCardTable(obj)) { 2485 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2486 *failed_ = true; 2487 } else if (!card_table->IsDirty(obj)) { 2488 // TODO: Check mod-union tables. 2489 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2490 // kCardDirty - 1 if it didnt get touched since we aged it. 2491 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2492 if (live_stack->ContainsSorted(ref)) { 2493 if (live_stack->ContainsSorted(obj)) { 2494 LOG(ERROR) << "Object " << obj << " found in live stack"; 2495 } 2496 if (heap_->GetLiveBitmap()->Test(obj)) { 2497 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2498 } 2499 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2500 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2501 2502 // Print which field of the object is dead. 2503 if (!obj->IsObjectArray()) { 2504 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2505 CHECK(klass != NULL); 2506 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2507 : klass->GetIFields(); 2508 CHECK(fields != NULL); 2509 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2510 mirror::ArtField* cur = fields->Get(i); 2511 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2512 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2513 << PrettyField(cur); 2514 break; 2515 } 2516 } 2517 } else { 2518 mirror::ObjectArray<mirror::Object>* object_array = 2519 obj->AsObjectArray<mirror::Object>(); 2520 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2521 if (object_array->Get(i) == ref) { 2522 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2523 } 2524 } 2525 } 2526 2527 *failed_ = true; 2528 } 2529 } 2530 } 2531 } 2532 2533 private: 2534 Heap* const heap_; 2535 bool* const failed_; 2536}; 2537 2538class VerifyLiveStackReferences { 2539 public: 2540 explicit VerifyLiveStackReferences(Heap* heap) 2541 : heap_(heap), 2542 failed_(false) {} 2543 2544 void operator()(mirror::Object* obj) const 2545 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2546 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2547 obj->VisitReferences<true>(visitor, VoidFunctor()); 2548 } 2549 2550 bool Failed() const { 2551 return failed_; 2552 } 2553 2554 private: 2555 Heap* const heap_; 2556 bool failed_; 2557}; 2558 2559bool Heap::VerifyMissingCardMarks() { 2560 Thread* self = Thread::Current(); 2561 Locks::mutator_lock_->AssertExclusiveHeld(self); 2562 // We need to sort the live stack since we binary search it. 2563 live_stack_->Sort(); 2564 // Since we sorted the allocation stack content, need to revoke all 2565 // thread-local allocation stacks. 2566 RevokeAllThreadLocalAllocationStacks(self); 2567 VerifyLiveStackReferences visitor(this); 2568 GetLiveBitmap()->Visit(visitor); 2569 // We can verify objects in the live stack since none of these should reference dead objects. 2570 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2571 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2572 visitor(*it); 2573 } 2574 } 2575 return !visitor.Failed(); 2576} 2577 2578void Heap::SwapStacks(Thread* self) { 2579 if (kUseThreadLocalAllocationStack) { 2580 live_stack_->AssertAllZero(); 2581 } 2582 allocation_stack_.swap(live_stack_); 2583} 2584 2585void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2586 // This must be called only during the pause. 2587 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2588 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2589 MutexLock mu2(self, *Locks::thread_list_lock_); 2590 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2591 for (Thread* t : thread_list) { 2592 t->RevokeThreadLocalAllocationStack(); 2593 } 2594} 2595 2596void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2597 if (kIsDebugBuild) { 2598 if (bump_pointer_space_ != nullptr) { 2599 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2600 } 2601 } 2602} 2603 2604accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2605 auto it = mod_union_tables_.find(space); 2606 if (it == mod_union_tables_.end()) { 2607 return nullptr; 2608 } 2609 return it->second; 2610} 2611 2612accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2613 auto it = remembered_sets_.find(space); 2614 if (it == remembered_sets_.end()) { 2615 return nullptr; 2616 } 2617 return it->second; 2618} 2619 2620void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2621 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2622 // Clear cards and keep track of cards cleared in the mod-union table. 2623 for (const auto& space : continuous_spaces_) { 2624 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2625 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2626 if (table != nullptr) { 2627 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2628 "ImageModUnionClearCards"; 2629 TimingLogger::ScopedTiming t(name, timings); 2630 table->ClearCards(); 2631 } else if (use_rem_sets && rem_set != nullptr) { 2632 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2633 << static_cast<int>(collector_type_); 2634 TimingLogger::ScopedTiming t("AllocSpaceRemSetClearCards", timings); 2635 rem_set->ClearCards(); 2636 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2637 TimingLogger::ScopedTiming t("AllocSpaceClearCards", timings); 2638 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2639 // were dirty before the GC started. 2640 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2641 // -> clean(cleaning thread). 2642 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2643 // roots and then we scan / update mod union tables after. We will always scan either card. 2644 // If we end up with the non aged card, we scan it it in the pause. 2645 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2646 VoidFunctor()); 2647 } 2648 } 2649} 2650 2651static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2652} 2653 2654void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2655 Thread* const self = Thread::Current(); 2656 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2657 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2658 if (verify_pre_gc_heap_) { 2659 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyHeapReferences", timings); 2660 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2661 size_t failures = VerifyHeapReferences(); 2662 if (failures > 0) { 2663 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2664 << " failures"; 2665 } 2666 } 2667 // Check that all objects which reference things in the live stack are on dirty cards. 2668 if (verify_missing_card_marks_) { 2669 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyMissingCardMarks", timings); 2670 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2671 SwapStacks(self); 2672 // Sort the live stack so that we can quickly binary search it later. 2673 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2674 << " missing card mark verification failed\n" << DumpSpaces(); 2675 SwapStacks(self); 2676 } 2677 if (verify_mod_union_table_) { 2678 TimingLogger::ScopedTiming t("(Paused)PreGcVerifyModUnionTables", timings); 2679 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2680 for (const auto& table_pair : mod_union_tables_) { 2681 accounting::ModUnionTable* mod_union_table = table_pair.second; 2682 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2683 mod_union_table->Verify(); 2684 } 2685 } 2686} 2687 2688void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2689 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2690 collector::GarbageCollector::ScopedPause pause(gc); 2691 PreGcVerificationPaused(gc); 2692 } 2693} 2694 2695void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2696 // TODO: Add a new runtime option for this? 2697 if (verify_pre_gc_rosalloc_) { 2698 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2699 } 2700} 2701 2702void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2703 Thread* const self = Thread::Current(); 2704 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2705 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2706 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2707 // reachable objects. 2708 if (verify_pre_sweeping_heap_) { 2709 TimingLogger::ScopedTiming t("(Paused)PostSweepingVerifyHeapReferences", timings); 2710 CHECK_NE(self->GetState(), kRunnable); 2711 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2712 // Swapping bound bitmaps does nothing. 2713 gc->SwapBitmaps(); 2714 // Pass in false since concurrent reference processing can mean that the reference referents 2715 // may point to dead objects at the point which PreSweepingGcVerification is called. 2716 size_t failures = VerifyHeapReferences(false); 2717 if (failures > 0) { 2718 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2719 << " failures"; 2720 } 2721 gc->SwapBitmaps(); 2722 } 2723 if (verify_pre_sweeping_rosalloc_) { 2724 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2725 } 2726} 2727 2728void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2729 // Only pause if we have to do some verification. 2730 Thread* const self = Thread::Current(); 2731 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2732 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2733 if (verify_system_weaks_) { 2734 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2735 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2736 mark_sweep->VerifySystemWeaks(); 2737 } 2738 if (verify_post_gc_rosalloc_) { 2739 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2740 } 2741 if (verify_post_gc_heap_) { 2742 TimingLogger::ScopedTiming t("(Paused)PostGcVerifyHeapReferences", timings); 2743 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2744 size_t failures = VerifyHeapReferences(); 2745 if (failures > 0) { 2746 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2747 << " failures"; 2748 } 2749 } 2750} 2751 2752void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2753 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2754 collector::GarbageCollector::ScopedPause pause(gc); 2755 PostGcVerificationPaused(gc); 2756 } 2757} 2758 2759void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2760 TimingLogger::ScopedTiming t(name, timings); 2761 for (const auto& space : continuous_spaces_) { 2762 if (space->IsRosAllocSpace()) { 2763 VLOG(heap) << name << " : " << space->GetName(); 2764 space->AsRosAllocSpace()->Verify(); 2765 } 2766 } 2767} 2768 2769collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2770 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2771 MutexLock mu(self, *gc_complete_lock_); 2772 return WaitForGcToCompleteLocked(cause, self); 2773} 2774 2775collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2776 collector::GcType last_gc_type = collector::kGcTypeNone; 2777 uint64_t wait_start = NanoTime(); 2778 while (collector_type_running_ != kCollectorTypeNone) { 2779 ATRACE_BEGIN("GC: Wait For Completion"); 2780 // We must wait, change thread state then sleep on gc_complete_cond_; 2781 gc_complete_cond_->Wait(self); 2782 last_gc_type = last_gc_type_; 2783 ATRACE_END(); 2784 } 2785 uint64_t wait_time = NanoTime() - wait_start; 2786 total_wait_time_ += wait_time; 2787 if (wait_time > long_pause_log_threshold_) { 2788 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2789 << " for cause " << cause; 2790 } 2791 return last_gc_type; 2792} 2793 2794void Heap::DumpForSigQuit(std::ostream& os) { 2795 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2796 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2797 DumpGcPerformanceInfo(os); 2798} 2799 2800size_t Heap::GetPercentFree() { 2801 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2802} 2803 2804void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2805 if (max_allowed_footprint > GetMaxMemory()) { 2806 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2807 << PrettySize(GetMaxMemory()); 2808 max_allowed_footprint = GetMaxMemory(); 2809 } 2810 max_allowed_footprint_ = max_allowed_footprint; 2811} 2812 2813bool Heap::IsMovableObject(const mirror::Object* obj) const { 2814 if (kMovingCollector) { 2815 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2816 if (space != nullptr) { 2817 // TODO: Check large object? 2818 return space->CanMoveObjects(); 2819 } 2820 } 2821 return false; 2822} 2823 2824void Heap::UpdateMaxNativeFootprint() { 2825 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2826 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2827 size_t target_size = native_size / GetTargetHeapUtilization(); 2828 if (target_size > native_size + max_free_) { 2829 target_size = native_size + max_free_; 2830 } else if (target_size < native_size + min_free_) { 2831 target_size = native_size + min_free_; 2832 } 2833 native_footprint_gc_watermark_ = target_size; 2834 native_footprint_limit_ = 2 * target_size - native_size; 2835} 2836 2837collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2838 for (const auto& collector : garbage_collectors_) { 2839 if (collector->GetCollectorType() == collector_type_ && 2840 collector->GetGcType() == gc_type) { 2841 return collector; 2842 } 2843 } 2844 return nullptr; 2845} 2846 2847double Heap::HeapGrowthMultiplier() const { 2848 // If we don't care about pause times we are background, so return 1.0. 2849 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2850 return 1.0; 2851 } 2852 return foreground_heap_growth_multiplier_; 2853} 2854 2855void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2856 // We know what our utilization is at this moment. 2857 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2858 const uint64_t bytes_allocated = GetBytesAllocated(); 2859 last_gc_size_ = bytes_allocated; 2860 last_gc_time_ns_ = NanoTime(); 2861 uint64_t target_size; 2862 collector::GcType gc_type = collector_ran->GetGcType(); 2863 if (gc_type != collector::kGcTypeSticky) { 2864 // Grow the heap for non sticky GC. 2865 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2866 // foreground. 2867 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2868 CHECK_GE(delta, 0); 2869 target_size = bytes_allocated + delta * multiplier; 2870 target_size = std::min(target_size, 2871 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2872 target_size = std::max(target_size, 2873 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2874 native_need_to_run_finalization_ = true; 2875 next_gc_type_ = collector::kGcTypeSticky; 2876 } else { 2877 collector::GcType non_sticky_gc_type = 2878 have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2879 // Find what the next non sticky collector will be. 2880 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2881 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2882 // do another sticky collection next. 2883 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2884 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2885 // if the sticky GC throughput always remained >= the full/partial throughput. 2886 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2887 non_sticky_collector->GetEstimatedMeanThroughput() && 2888 non_sticky_collector->NumberOfIterations() > 0 && 2889 bytes_allocated <= max_allowed_footprint_) { 2890 next_gc_type_ = collector::kGcTypeSticky; 2891 } else { 2892 next_gc_type_ = non_sticky_gc_type; 2893 } 2894 // If we have freed enough memory, shrink the heap back down. 2895 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2896 target_size = bytes_allocated + max_free_; 2897 } else { 2898 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2899 } 2900 } 2901 if (!ignore_max_footprint_) { 2902 SetIdealFootprint(target_size); 2903 if (IsGcConcurrent()) { 2904 // Calculate when to perform the next ConcurrentGC. 2905 // Calculate the estimated GC duration. 2906 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2907 // Estimate how many remaining bytes we will have when we need to start the next GC. 2908 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2909 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2910 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2911 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2912 // A never going to happen situation that from the estimated allocation rate we will exceed 2913 // the applications entire footprint with the given estimated allocation rate. Schedule 2914 // another GC nearly straight away. 2915 remaining_bytes = kMinConcurrentRemainingBytes; 2916 } 2917 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2918 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 2919 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2920 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2921 // right away. 2922 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2923 static_cast<size_t>(bytes_allocated)); 2924 } 2925 } 2926} 2927 2928void Heap::ClearGrowthLimit() { 2929 growth_limit_ = capacity_; 2930 non_moving_space_->ClearGrowthLimit(); 2931} 2932 2933void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 2934 ScopedObjectAccess soa(self); 2935 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 2936 jvalue args[1]; 2937 args[0].l = arg.get(); 2938 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2939 // Restore object in case it gets moved. 2940 *object = soa.Decode<mirror::Object*>(arg.get()); 2941} 2942 2943void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 2944 StackHandleScope<1> hs(self); 2945 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2946 RequestConcurrentGC(self); 2947} 2948 2949void Heap::RequestConcurrentGC(Thread* self) { 2950 // Make sure that we can do a concurrent GC. 2951 Runtime* runtime = Runtime::Current(); 2952 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2953 self->IsHandlingStackOverflow()) { 2954 return; 2955 } 2956 // We already have a request pending, no reason to start more until we update 2957 // concurrent_start_bytes_. 2958 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2959 JNIEnv* env = self->GetJniEnv(); 2960 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2961 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2962 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2963 WellKnownClasses::java_lang_Daemons_requestGC); 2964 CHECK(!env->ExceptionCheck()); 2965} 2966 2967void Heap::ConcurrentGC(Thread* self) { 2968 if (Runtime::Current()->IsShuttingDown(self)) { 2969 return; 2970 } 2971 // Wait for any GCs currently running to finish. 2972 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 2973 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2974 // instead. E.g. can't do partial, so do full instead. 2975 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2976 collector::kGcTypeNone) { 2977 for (collector::GcType gc_type : gc_plan_) { 2978 // Attempt to run the collector, if we succeed, we are done. 2979 if (gc_type > next_gc_type_ && 2980 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2981 break; 2982 } 2983 } 2984 } 2985 } 2986} 2987 2988void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2989 Thread* self = Thread::Current(); 2990 { 2991 MutexLock mu(self, *heap_trim_request_lock_); 2992 if (desired_collector_type_ == desired_collector_type) { 2993 return; 2994 } 2995 heap_transition_or_trim_target_time_ = 2996 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 2997 desired_collector_type_ = desired_collector_type; 2998 } 2999 SignalHeapTrimDaemon(self); 3000} 3001 3002void Heap::RequestHeapTrim() { 3003 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3004 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3005 // a space it will hold its lock and can become a cause of jank. 3006 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3007 // forking. 3008 3009 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3010 // because that only marks object heads, so a large array looks like lots of empty space. We 3011 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3012 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3013 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3014 // not how much use we're making of those pages. 3015 3016 Thread* self = Thread::Current(); 3017 Runtime* runtime = Runtime::Current(); 3018 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 3019 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 3020 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 3021 // as we don't hold the lock while requesting the trim). 3022 return; 3023 } 3024 { 3025 MutexLock mu(self, *heap_trim_request_lock_); 3026 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 3027 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 3028 // just yet. 3029 return; 3030 } 3031 heap_trim_request_pending_ = true; 3032 uint64_t current_time = NanoTime(); 3033 if (heap_transition_or_trim_target_time_ < current_time) { 3034 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 3035 } 3036 } 3037 // Notify the daemon thread which will actually do the heap trim. 3038 SignalHeapTrimDaemon(self); 3039} 3040 3041void Heap::SignalHeapTrimDaemon(Thread* self) { 3042 JNIEnv* env = self->GetJniEnv(); 3043 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 3044 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 3045 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 3046 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 3047 CHECK(!env->ExceptionCheck()); 3048} 3049 3050void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3051 if (rosalloc_space_ != nullptr) { 3052 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3053 } 3054 if (bump_pointer_space_ != nullptr) { 3055 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 3056 } 3057} 3058 3059void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3060 if (rosalloc_space_ != nullptr) { 3061 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3062 } 3063} 3064 3065void Heap::RevokeAllThreadLocalBuffers() { 3066 if (rosalloc_space_ != nullptr) { 3067 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3068 } 3069 if (bump_pointer_space_ != nullptr) { 3070 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3071 } 3072} 3073 3074bool Heap::IsGCRequestPending() const { 3075 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3076} 3077 3078void Heap::RunFinalization(JNIEnv* env) { 3079 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3080 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3081 CHECK(WellKnownClasses::java_lang_System != nullptr); 3082 WellKnownClasses::java_lang_System_runFinalization = 3083 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3084 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3085 } 3086 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3087 WellKnownClasses::java_lang_System_runFinalization); 3088} 3089 3090void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 3091 Thread* self = ThreadForEnv(env); 3092 if (native_need_to_run_finalization_) { 3093 RunFinalization(env); 3094 UpdateMaxNativeFootprint(); 3095 native_need_to_run_finalization_ = false; 3096 } 3097 // Total number of native bytes allocated. 3098 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3099 new_native_bytes_allocated += bytes; 3100 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3101 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 3102 collector::kGcTypeFull; 3103 3104 // The second watermark is higher than the gc watermark. If you hit this it means you are 3105 // allocating native objects faster than the GC can keep up with. 3106 if (new_native_bytes_allocated > native_footprint_limit_) { 3107 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3108 // Just finished a GC, attempt to run finalizers. 3109 RunFinalization(env); 3110 CHECK(!env->ExceptionCheck()); 3111 } 3112 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3113 if (new_native_bytes_allocated > native_footprint_limit_) { 3114 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3115 RunFinalization(env); 3116 native_need_to_run_finalization_ = false; 3117 CHECK(!env->ExceptionCheck()); 3118 } 3119 // We have just run finalizers, update the native watermark since it is very likely that 3120 // finalizers released native managed allocations. 3121 UpdateMaxNativeFootprint(); 3122 } else if (!IsGCRequestPending()) { 3123 if (IsGcConcurrent()) { 3124 RequestConcurrentGC(self); 3125 } else { 3126 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3127 } 3128 } 3129 } 3130} 3131 3132void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 3133 int expected_size, new_size; 3134 do { 3135 expected_size = native_bytes_allocated_.LoadRelaxed(); 3136 new_size = expected_size - bytes; 3137 if (UNLIKELY(new_size < 0)) { 3138 ScopedObjectAccess soa(env); 3139 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3140 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 3141 "registered as allocated", bytes, expected_size).c_str()); 3142 break; 3143 } 3144 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, new_size)); 3145} 3146 3147size_t Heap::GetTotalMemory() const { 3148 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3149} 3150 3151void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3152 DCHECK(mod_union_table != nullptr); 3153 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3154} 3155 3156void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3157 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3158 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3159 CHECK_GE(byte_count, sizeof(mirror::Object)); 3160} 3161 3162void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3163 CHECK(remembered_set != nullptr); 3164 space::Space* space = remembered_set->GetSpace(); 3165 CHECK(space != nullptr); 3166 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3167 remembered_sets_.Put(space, remembered_set); 3168 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3169} 3170 3171void Heap::RemoveRememberedSet(space::Space* space) { 3172 CHECK(space != nullptr); 3173 auto it = remembered_sets_.find(space); 3174 CHECK(it != remembered_sets_.end()); 3175 delete it->second; 3176 remembered_sets_.erase(it); 3177 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3178} 3179 3180void Heap::ClearMarkedObjects() { 3181 // Clear all of the spaces' mark bitmaps. 3182 for (const auto& space : GetContinuousSpaces()) { 3183 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3184 if (space->GetLiveBitmap() != mark_bitmap) { 3185 mark_bitmap->Clear(); 3186 } 3187 } 3188 // Clear the marked objects in the discontinous space object sets. 3189 for (const auto& space : GetDiscontinuousSpaces()) { 3190 space->GetMarkBitmap()->Clear(); 3191 } 3192} 3193 3194} // namespace gc 3195} // namespace art 3196