heap.cc revision b5de3bb65556950d5cce1dea3ea6d80adcc5051d
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 "art_field-inl.h" 27#include "base/allocator.h" 28#include "base/dumpable.h" 29#include "base/histogram-inl.h" 30#include "base/stl_util.h" 31#include "base/time_utils.h" 32#include "common_throws.h" 33#include "cutils/sched_policy.h" 34#include "debugger.h" 35#include "dex_file-inl.h" 36#include "gc/accounting/atomic_stack.h" 37#include "gc/accounting/card_table-inl.h" 38#include "gc/accounting/heap_bitmap-inl.h" 39#include "gc/accounting/mod_union_table.h" 40#include "gc/accounting/mod_union_table-inl.h" 41#include "gc/accounting/remembered_set.h" 42#include "gc/accounting/space_bitmap-inl.h" 43#include "gc/collector/concurrent_copying.h" 44#include "gc/collector/mark_compact.h" 45#include "gc/collector/mark_sweep-inl.h" 46#include "gc/collector/partial_mark_sweep.h" 47#include "gc/collector/semi_space.h" 48#include "gc/collector/sticky_mark_sweep.h" 49#include "gc/reference_processor.h" 50#include "gc/space/bump_pointer_space.h" 51#include "gc/space/dlmalloc_space-inl.h" 52#include "gc/space/image_space.h" 53#include "gc/space/large_object_space.h" 54#include "gc/space/region_space.h" 55#include "gc/space/rosalloc_space-inl.h" 56#include "gc/space/space-inl.h" 57#include "gc/space/zygote_space.h" 58#include "gc/task_processor.h" 59#include "entrypoints/quick/quick_alloc_entrypoints.h" 60#include "heap-inl.h" 61#include "image.h" 62#include "intern_table.h" 63#include "mirror/class-inl.h" 64#include "mirror/object.h" 65#include "mirror/object-inl.h" 66#include "mirror/object_array-inl.h" 67#include "mirror/reference-inl.h" 68#include "os.h" 69#include "reflection.h" 70#include "runtime.h" 71#include "ScopedLocalRef.h" 72#include "scoped_thread_state_change.h" 73#include "handle_scope-inl.h" 74#include "thread_list.h" 75#include "well_known_classes.h" 76 77namespace art { 78 79namespace gc { 80 81static constexpr size_t kCollectorTransitionStressIterations = 0; 82static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 83// Minimum amount of remaining bytes before a concurrent GC is triggered. 84static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 85static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 86// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 87// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 88// threads (lower pauses, use less memory bandwidth). 89static constexpr double kStickyGcThroughputAdjustment = 1.0; 90// Whether or not we compact the zygote in PreZygoteFork. 91static constexpr bool kCompactZygote = kMovingCollector; 92// How many reserve entries are at the end of the allocation stack, these are only needed if the 93// allocation stack overflows. 94static constexpr size_t kAllocationStackReserveSize = 1024; 95// Default mark stack size in bytes. 96static const size_t kDefaultMarkStackSize = 64 * KB; 97// Define space name. 98static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 99static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 100static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 101static const char* kNonMovingSpaceName = "non moving space"; 102static const char* kZygoteSpaceName = "zygote space"; 103static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 104static constexpr bool kGCALotMode = false; 105// GC alot mode uses a small allocation stack to stress test a lot of GC. 106static constexpr size_t kGcAlotAllocationStackSize = 4 * KB / 107 sizeof(mirror::HeapReference<mirror::Object>); 108// Verify objet has a small allocation stack size since searching the allocation stack is slow. 109static constexpr size_t kVerifyObjectAllocationStackSize = 16 * KB / 110 sizeof(mirror::HeapReference<mirror::Object>); 111static constexpr size_t kDefaultAllocationStackSize = 8 * MB / 112 sizeof(mirror::HeapReference<mirror::Object>); 113// System.runFinalization can deadlock with native allocations, to deal with this, we have a 114// timeout on how long we wait for finalizers to run. b/21544853 115static constexpr uint64_t kNativeAllocationFinalizeTimeout = MsToNs(250u); 116 117Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 118 double target_utilization, double foreground_heap_growth_multiplier, 119 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 120 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 121 CollectorType background_collector_type, 122 space::LargeObjectSpaceType large_object_space_type, size_t large_object_threshold, 123 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 124 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 125 bool ignore_max_footprint, bool use_tlab, 126 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 127 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 128 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 129 uint64_t min_interval_homogeneous_space_compaction_by_oom) 130 : non_moving_space_(nullptr), 131 rosalloc_space_(nullptr), 132 dlmalloc_space_(nullptr), 133 main_space_(nullptr), 134 collector_type_(kCollectorTypeNone), 135 foreground_collector_type_(foreground_collector_type), 136 background_collector_type_(background_collector_type), 137 desired_collector_type_(foreground_collector_type_), 138 pending_task_lock_(nullptr), 139 parallel_gc_threads_(parallel_gc_threads), 140 conc_gc_threads_(conc_gc_threads), 141 low_memory_mode_(low_memory_mode), 142 long_pause_log_threshold_(long_pause_log_threshold), 143 long_gc_log_threshold_(long_gc_log_threshold), 144 ignore_max_footprint_(ignore_max_footprint), 145 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 146 zygote_space_(nullptr), 147 large_object_threshold_(large_object_threshold), 148 collector_type_running_(kCollectorTypeNone), 149 last_gc_type_(collector::kGcTypeNone), 150 next_gc_type_(collector::kGcTypePartial), 151 capacity_(capacity), 152 growth_limit_(growth_limit), 153 max_allowed_footprint_(initial_size), 154 native_footprint_gc_watermark_(initial_size), 155 native_need_to_run_finalization_(false), 156 // Initially assume we perceive jank in case the process state is never updated. 157 process_state_(kProcessStateJankPerceptible), 158 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 159 total_bytes_freed_ever_(0), 160 total_objects_freed_ever_(0), 161 num_bytes_allocated_(0), 162 native_bytes_allocated_(0), 163 num_bytes_freed_revoke_(0), 164 verify_missing_card_marks_(false), 165 verify_system_weaks_(false), 166 verify_pre_gc_heap_(verify_pre_gc_heap), 167 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 168 verify_post_gc_heap_(verify_post_gc_heap), 169 verify_mod_union_table_(false), 170 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 171 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 172 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 173 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 174 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 175 * verification is enabled, we limit the size of allocation stacks to speed up their 176 * searching. 177 */ 178 max_allocation_stack_size_(kGCALotMode ? kGcAlotAllocationStackSize 179 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? kVerifyObjectAllocationStackSize : 180 kDefaultAllocationStackSize), 181 current_allocator_(kAllocatorTypeDlMalloc), 182 current_non_moving_allocator_(kAllocatorTypeNonMoving), 183 bump_pointer_space_(nullptr), 184 temp_space_(nullptr), 185 region_space_(nullptr), 186 min_free_(min_free), 187 max_free_(max_free), 188 target_utilization_(target_utilization), 189 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 190 total_wait_time_(0), 191 total_allocation_time_(0), 192 verify_object_mode_(kVerifyObjectModeDisabled), 193 disable_moving_gc_count_(0), 194 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 195 use_tlab_(use_tlab), 196 main_space_backup_(nullptr), 197 min_interval_homogeneous_space_compaction_by_oom_( 198 min_interval_homogeneous_space_compaction_by_oom), 199 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 200 pending_collector_transition_(nullptr), 201 pending_heap_trim_(nullptr), 202 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom), 203 running_collection_is_blocking_(false), 204 blocking_gc_count_(0U), 205 blocking_gc_time_(0U), 206 last_update_time_gc_count_rate_histograms_( // Round down by the window duration. 207 (NanoTime() / kGcCountRateHistogramWindowDuration) * kGcCountRateHistogramWindowDuration), 208 gc_count_last_window_(0U), 209 blocking_gc_count_last_window_(0U), 210 gc_count_rate_histogram_("gc count rate histogram", 1U, kGcCountRateMaxBucketCount), 211 blocking_gc_count_rate_histogram_("blocking gc count rate histogram", 1U, 212 kGcCountRateMaxBucketCount) { 213 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 214 LOG(INFO) << "Heap() entering"; 215 } 216 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 217 // entrypoints. 218 const bool is_zygote = Runtime::Current()->IsZygote(); 219 if (!is_zygote) { 220 // Background compaction is currently not supported for command line runs. 221 if (background_collector_type_ != foreground_collector_type_) { 222 VLOG(heap) << "Disabling background compaction for non zygote"; 223 background_collector_type_ = foreground_collector_type_; 224 } 225 } 226 ChangeCollector(desired_collector_type_); 227 live_bitmap_.reset(new accounting::HeapBitmap(this)); 228 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 229 // Requested begin for the alloc space, to follow the mapped image and oat files 230 uint8_t* requested_alloc_space_begin = nullptr; 231 if (foreground_collector_type_ == kCollectorTypeCC) { 232 // Need to use a low address so that we can allocate a contiguous 233 // 2 * Xmx space when there's no image (dex2oat for target). 234 CHECK_GE(300 * MB, non_moving_space_capacity); 235 requested_alloc_space_begin = reinterpret_cast<uint8_t*>(300 * MB) - non_moving_space_capacity; 236 } 237 if (!image_file_name.empty()) { 238 ATRACE_BEGIN("ImageSpace::Create"); 239 std::string error_msg; 240 auto* image_space = space::ImageSpace::Create(image_file_name.c_str(), image_instruction_set, 241 &error_msg); 242 ATRACE_END(); 243 if (image_space != nullptr) { 244 AddSpace(image_space); 245 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 246 // isn't going to get in the middle 247 uint8_t* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 248 CHECK_GT(oat_file_end_addr, image_space->End()); 249 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 250 } else { 251 LOG(ERROR) << "Could not create image space with image file '" << image_file_name << "'. " 252 << "Attempting to fall back to imageless running. Error was: " << error_msg; 253 } 254 } 255 /* 256 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 257 +- nonmoving space (non_moving_space_capacity)+- 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 259 +-????????????????????????????????????????????+- 260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 261 +-main alloc space / bump space 1 (capacity_) +- 262 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 263 +-????????????????????????????????????????????+- 264 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 265 +-main alloc space2 / bump space 2 (capacity_)+- 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 267 */ 268 // We don't have hspace compaction enabled with GSS or CC. 269 if (foreground_collector_type_ == kCollectorTypeGSS || 270 foreground_collector_type_ == kCollectorTypeCC) { 271 use_homogeneous_space_compaction_for_oom_ = false; 272 } 273 bool support_homogeneous_space_compaction = 274 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 275 use_homogeneous_space_compaction_for_oom_; 276 // We may use the same space the main space for the non moving space if we don't need to compact 277 // from the main space. 278 // This is not the case if we support homogeneous compaction or have a moving background 279 // collector type. 280 bool separate_non_moving_space = is_zygote || 281 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 282 IsMovingGc(background_collector_type_); 283 if (foreground_collector_type == kCollectorTypeGSS) { 284 separate_non_moving_space = false; 285 } 286 std::unique_ptr<MemMap> main_mem_map_1; 287 std::unique_ptr<MemMap> main_mem_map_2; 288 uint8_t* request_begin = requested_alloc_space_begin; 289 if (request_begin != nullptr && separate_non_moving_space) { 290 request_begin += non_moving_space_capacity; 291 } 292 std::string error_str; 293 std::unique_ptr<MemMap> non_moving_space_mem_map; 294 ATRACE_BEGIN("Create heap maps"); 295 if (separate_non_moving_space) { 296 // If we are the zygote, the non moving space becomes the zygote space when we run 297 // PreZygoteFork the first time. In this case, call the map "zygote space" since we can't 298 // rename the mem map later. 299 const char* space_name = is_zygote ? kZygoteSpaceName: kNonMovingSpaceName; 300 // Reserve the non moving mem map before the other two since it needs to be at a specific 301 // address. 302 non_moving_space_mem_map.reset( 303 MemMap::MapAnonymous(space_name, requested_alloc_space_begin, 304 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, false, 305 &error_str)); 306 CHECK(non_moving_space_mem_map != nullptr) << error_str; 307 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 308 request_begin = reinterpret_cast<uint8_t*>(300 * MB); 309 } 310 // Attempt to create 2 mem maps at or after the requested begin. 311 if (foreground_collector_type_ != kCollectorTypeCC) { 312 if (separate_non_moving_space) { 313 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, 314 capacity_, &error_str)); 315 } else { 316 // If no separate non-moving space, the main space must come 317 // right after the image space to avoid a gap. 318 main_mem_map_1.reset(MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity_, 319 PROT_READ | PROT_WRITE, true, false, 320 &error_str)); 321 } 322 CHECK(main_mem_map_1.get() != nullptr) << error_str; 323 } 324 if (support_homogeneous_space_compaction || 325 background_collector_type_ == kCollectorTypeSS || 326 foreground_collector_type_ == kCollectorTypeSS) { 327 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 328 capacity_, &error_str)); 329 CHECK(main_mem_map_2.get() != nullptr) << error_str; 330 } 331 ATRACE_END(); 332 ATRACE_BEGIN("Create spaces"); 333 // Create the non moving space first so that bitmaps don't take up the address range. 334 if (separate_non_moving_space) { 335 // Non moving space is always dlmalloc since we currently don't have support for multiple 336 // active rosalloc spaces. 337 const size_t size = non_moving_space_mem_map->Size(); 338 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 339 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 340 initial_size, size, size, false); 341 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 342 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 343 << requested_alloc_space_begin; 344 AddSpace(non_moving_space_); 345 } 346 // Create other spaces based on whether or not we have a moving GC. 347 if (foreground_collector_type_ == kCollectorTypeCC) { 348 region_space_ = space::RegionSpace::Create("Region space", capacity_ * 2, request_begin); 349 AddSpace(region_space_); 350 } else if (IsMovingGc(foreground_collector_type_) && 351 foreground_collector_type_ != kCollectorTypeGSS) { 352 // Create bump pointer spaces. 353 // We only to create the bump pointer if the foreground collector is a compacting GC. 354 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 355 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 356 main_mem_map_1.release()); 357 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 358 AddSpace(bump_pointer_space_); 359 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 360 main_mem_map_2.release()); 361 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 362 AddSpace(temp_space_); 363 CHECK(separate_non_moving_space); 364 } else { 365 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 366 CHECK(main_space_ != nullptr); 367 AddSpace(main_space_); 368 if (!separate_non_moving_space) { 369 non_moving_space_ = main_space_; 370 CHECK(!non_moving_space_->CanMoveObjects()); 371 } 372 if (foreground_collector_type_ == kCollectorTypeGSS) { 373 CHECK_EQ(foreground_collector_type_, background_collector_type_); 374 // Create bump pointer spaces instead of a backup space. 375 main_mem_map_2.release(); 376 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 377 kGSSBumpPointerSpaceCapacity, nullptr); 378 CHECK(bump_pointer_space_ != nullptr); 379 AddSpace(bump_pointer_space_); 380 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 381 kGSSBumpPointerSpaceCapacity, nullptr); 382 CHECK(temp_space_ != nullptr); 383 AddSpace(temp_space_); 384 } else if (main_mem_map_2.get() != nullptr) { 385 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 386 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 387 growth_limit_, capacity_, name, true)); 388 CHECK(main_space_backup_.get() != nullptr); 389 // Add the space so its accounted for in the heap_begin and heap_end. 390 AddSpace(main_space_backup_.get()); 391 } 392 } 393 CHECK(non_moving_space_ != nullptr); 394 CHECK(!non_moving_space_->CanMoveObjects()); 395 // Allocate the large object space. 396 if (large_object_space_type == space::LargeObjectSpaceType::kFreeList) { 397 large_object_space_ = space::FreeListSpace::Create("free list large object space", nullptr, 398 capacity_); 399 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 400 } else if (large_object_space_type == space::LargeObjectSpaceType::kMap) { 401 large_object_space_ = space::LargeObjectMapSpace::Create("mem map large object space"); 402 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 403 } else { 404 // Disable the large object space by making the cutoff excessively large. 405 large_object_threshold_ = std::numeric_limits<size_t>::max(); 406 large_object_space_ = nullptr; 407 } 408 if (large_object_space_ != nullptr) { 409 AddSpace(large_object_space_); 410 } 411 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 412 CHECK(!continuous_spaces_.empty()); 413 // Relies on the spaces being sorted. 414 uint8_t* heap_begin = continuous_spaces_.front()->Begin(); 415 uint8_t* heap_end = continuous_spaces_.back()->Limit(); 416 size_t heap_capacity = heap_end - heap_begin; 417 // Remove the main backup space since it slows down the GC to have unused extra spaces. 418 // TODO: Avoid needing to do this. 419 if (main_space_backup_.get() != nullptr) { 420 RemoveSpace(main_space_backup_.get()); 421 } 422 ATRACE_END(); 423 // Allocate the card table. 424 ATRACE_BEGIN("Create card table"); 425 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 426 CHECK(card_table_.get() != nullptr) << "Failed to create card table"; 427 ATRACE_END(); 428 if (foreground_collector_type_ == kCollectorTypeCC && kUseTableLookupReadBarrier) { 429 rb_table_.reset(new accounting::ReadBarrierTable()); 430 DCHECK(rb_table_->IsAllCleared()); 431 } 432 if (GetImageSpace() != nullptr) { 433 // Don't add the image mod union table if we are running without an image, this can crash if 434 // we use the CardCache implementation. 435 accounting::ModUnionTable* mod_union_table = new accounting::ModUnionTableToZygoteAllocspace( 436 "Image mod-union table", this, GetImageSpace()); 437 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 438 AddModUnionTable(mod_union_table); 439 } 440 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 441 accounting::RememberedSet* non_moving_space_rem_set = 442 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 443 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 444 AddRememberedSet(non_moving_space_rem_set); 445 } 446 // TODO: Count objects in the image space here? 447 num_bytes_allocated_.StoreRelaxed(0); 448 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 449 kDefaultMarkStackSize)); 450 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 451 allocation_stack_.reset(accounting::ObjectStack::Create( 452 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 453 live_stack_.reset(accounting::ObjectStack::Create( 454 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 455 // It's still too early to take a lock because there are no threads yet, but we can create locks 456 // now. We don't create it earlier to make it clear that you can't use locks during heap 457 // initialization. 458 gc_complete_lock_ = new Mutex("GC complete lock"); 459 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 460 *gc_complete_lock_)); 461 task_processor_.reset(new TaskProcessor()); 462 pending_task_lock_ = new Mutex("Pending task lock"); 463 if (ignore_max_footprint_) { 464 SetIdealFootprint(std::numeric_limits<size_t>::max()); 465 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 466 } 467 CHECK_NE(max_allowed_footprint_, 0U); 468 // Create our garbage collectors. 469 for (size_t i = 0; i < 2; ++i) { 470 const bool concurrent = i != 0; 471 if ((MayUseCollector(kCollectorTypeCMS) && concurrent) || 472 (MayUseCollector(kCollectorTypeMS) && !concurrent)) { 473 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 474 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 475 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 476 } 477 } 478 if (kMovingCollector) { 479 if (MayUseCollector(kCollectorTypeSS) || MayUseCollector(kCollectorTypeGSS) || 480 MayUseCollector(kCollectorTypeHomogeneousSpaceCompact) || 481 use_homogeneous_space_compaction_for_oom_) { 482 // TODO: Clean this up. 483 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 484 semi_space_collector_ = new collector::SemiSpace(this, generational, 485 generational ? "generational" : ""); 486 garbage_collectors_.push_back(semi_space_collector_); 487 } 488 if (MayUseCollector(kCollectorTypeCC)) { 489 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 490 garbage_collectors_.push_back(concurrent_copying_collector_); 491 } 492 if (MayUseCollector(kCollectorTypeMC)) { 493 mark_compact_collector_ = new collector::MarkCompact(this); 494 garbage_collectors_.push_back(mark_compact_collector_); 495 } 496 } 497 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 498 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 499 // Check that there's no gap between the image space and the non moving space so that the 500 // immune region won't break (eg. due to a large object allocated in the gap). This is only 501 // required when we're the zygote or using GSS. 502 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 503 non_moving_space_->GetMemMap()); 504 if (!no_gap) { 505 MemMap::DumpMaps(LOG(ERROR), true); 506 LOG(FATAL) << "There's a gap between the image space and the non-moving space"; 507 } 508 } 509 if (running_on_valgrind_) { 510 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 511 } 512 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 513 LOG(INFO) << "Heap() exiting"; 514 } 515} 516 517MemMap* Heap::MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 518 size_t capacity, std::string* out_error_str) { 519 while (true) { 520 MemMap* map = MemMap::MapAnonymous(name, request_begin, capacity, 521 PROT_READ | PROT_WRITE, true, false, out_error_str); 522 if (map != nullptr || request_begin == nullptr) { 523 return map; 524 } 525 // Retry a second time with no specified request begin. 526 request_begin = nullptr; 527 } 528} 529 530bool Heap::MayUseCollector(CollectorType type) const { 531 return foreground_collector_type_ == type || background_collector_type_ == type; 532} 533 534space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 535 size_t growth_limit, size_t capacity, 536 const char* name, bool can_move_objects) { 537 space::MallocSpace* malloc_space = nullptr; 538 if (kUseRosAlloc) { 539 // Create rosalloc space. 540 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 541 initial_size, growth_limit, capacity, 542 low_memory_mode_, can_move_objects); 543 } else { 544 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 545 initial_size, growth_limit, capacity, 546 can_move_objects); 547 } 548 if (collector::SemiSpace::kUseRememberedSet) { 549 accounting::RememberedSet* rem_set = 550 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 551 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 552 AddRememberedSet(rem_set); 553 } 554 CHECK(malloc_space != nullptr) << "Failed to create " << name; 555 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 556 return malloc_space; 557} 558 559void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 560 size_t capacity) { 561 // Is background compaction is enabled? 562 bool can_move_objects = IsMovingGc(background_collector_type_) != 563 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 564 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 565 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 566 // from the main space to the zygote space. If background compaction is enabled, always pass in 567 // that we can move objets. 568 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 569 // After the zygote we want this to be false if we don't have background compaction enabled so 570 // that getting primitive array elements is faster. 571 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 572 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 573 } 574 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 575 RemoveRememberedSet(main_space_); 576 } 577 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 578 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 579 can_move_objects); 580 SetSpaceAsDefault(main_space_); 581 VLOG(heap) << "Created main space " << main_space_; 582} 583 584void Heap::ChangeAllocator(AllocatorType allocator) { 585 if (current_allocator_ != allocator) { 586 // These two allocators are only used internally and don't have any entrypoints. 587 CHECK_NE(allocator, kAllocatorTypeLOS); 588 CHECK_NE(allocator, kAllocatorTypeNonMoving); 589 current_allocator_ = allocator; 590 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 591 SetQuickAllocEntryPointsAllocator(current_allocator_); 592 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 593 } 594} 595 596void Heap::DisableMovingGc() { 597 if (IsMovingGc(foreground_collector_type_)) { 598 foreground_collector_type_ = kCollectorTypeCMS; 599 } 600 if (IsMovingGc(background_collector_type_)) { 601 background_collector_type_ = foreground_collector_type_; 602 } 603 TransitionCollector(foreground_collector_type_); 604 ThreadList* tl = Runtime::Current()->GetThreadList(); 605 Thread* self = Thread::Current(); 606 ScopedThreadStateChange tsc(self, kSuspended); 607 tl->SuspendAll(__FUNCTION__); 608 // Something may have caused the transition to fail. 609 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 610 CHECK(main_space_ != nullptr); 611 // The allocation stack may have non movable objects in it. We need to flush it since the GC 612 // can't only handle marking allocation stack objects of one non moving space and one main 613 // space. 614 { 615 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 616 FlushAllocStack(); 617 } 618 main_space_->DisableMovingObjects(); 619 non_moving_space_ = main_space_; 620 CHECK(!non_moving_space_->CanMoveObjects()); 621 } 622 tl->ResumeAll(); 623} 624 625std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 626 if (!IsValidContinuousSpaceObjectAddress(klass)) { 627 return StringPrintf("<non heap address klass %p>", klass); 628 } 629 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 630 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 631 std::string result("["); 632 result += SafeGetClassDescriptor(component_type); 633 return result; 634 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 635 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 636 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 637 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 638 } else { 639 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 640 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 641 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 642 } 643 const DexFile* dex_file = dex_cache->GetDexFile(); 644 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 645 if (class_def_idx == DexFile::kDexNoIndex16) { 646 return "<class def not found>"; 647 } 648 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 649 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 650 return dex_file->GetTypeDescriptor(type_id); 651 } 652} 653 654std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 655 if (obj == nullptr) { 656 return "null"; 657 } 658 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 659 if (klass == nullptr) { 660 return "(class=null)"; 661 } 662 std::string result(SafeGetClassDescriptor(klass)); 663 if (obj->IsClass()) { 664 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 665 } 666 return result; 667} 668 669void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 670 if (obj == nullptr) { 671 stream << "(obj=null)"; 672 return; 673 } 674 if (IsAligned<kObjectAlignment>(obj)) { 675 space::Space* space = nullptr; 676 // Don't use find space since it only finds spaces which actually contain objects instead of 677 // spaces which may contain objects (e.g. cleared bump pointer spaces). 678 for (const auto& cur_space : continuous_spaces_) { 679 if (cur_space->HasAddress(obj)) { 680 space = cur_space; 681 break; 682 } 683 } 684 // Unprotect all the spaces. 685 for (const auto& con_space : continuous_spaces_) { 686 mprotect(con_space->Begin(), con_space->Capacity(), PROT_READ | PROT_WRITE); 687 } 688 stream << "Object " << obj; 689 if (space != nullptr) { 690 stream << " in space " << *space; 691 } 692 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 693 stream << "\nclass=" << klass; 694 if (klass != nullptr) { 695 stream << " type= " << SafePrettyTypeOf(obj); 696 } 697 // Re-protect the address we faulted on. 698 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 699 } 700} 701 702bool Heap::IsCompilingBoot() const { 703 if (!Runtime::Current()->IsAotCompiler()) { 704 return false; 705 } 706 for (const auto& space : continuous_spaces_) { 707 if (space->IsImageSpace() || space->IsZygoteSpace()) { 708 return false; 709 } 710 } 711 return true; 712} 713 714bool Heap::HasImageSpace() const { 715 for (const auto& space : continuous_spaces_) { 716 if (space->IsImageSpace()) { 717 return true; 718 } 719 } 720 return false; 721} 722 723void Heap::IncrementDisableMovingGC(Thread* self) { 724 // Need to do this holding the lock to prevent races where the GC is about to run / running when 725 // we attempt to disable it. 726 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 727 MutexLock mu(self, *gc_complete_lock_); 728 ++disable_moving_gc_count_; 729 if (IsMovingGc(collector_type_running_)) { 730 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 731 } 732} 733 734void Heap::DecrementDisableMovingGC(Thread* self) { 735 MutexLock mu(self, *gc_complete_lock_); 736 CHECK_GE(disable_moving_gc_count_, 0U); 737 --disable_moving_gc_count_; 738} 739 740void Heap::UpdateProcessState(ProcessState process_state) { 741 if (process_state_ != process_state) { 742 process_state_ = process_state; 743 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 744 // Start at index 1 to avoid "is always false" warning. 745 // Have iteration 1 always transition the collector. 746 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 747 ? foreground_collector_type_ : background_collector_type_); 748 usleep(kCollectorTransitionStressWait); 749 } 750 if (process_state_ == kProcessStateJankPerceptible) { 751 // Transition back to foreground right away to prevent jank. 752 RequestCollectorTransition(foreground_collector_type_, 0); 753 } else { 754 // Don't delay for debug builds since we may want to stress test the GC. 755 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 756 // special handling which does a homogenous space compaction once but then doesn't transition 757 // the collector. 758 RequestCollectorTransition(background_collector_type_, 759 kIsDebugBuild ? 0 : kCollectorTransitionWait); 760 } 761 } 762} 763 764void Heap::CreateThreadPool() { 765 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 766 if (num_threads != 0) { 767 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 768 } 769} 770 771// Visit objects when threads aren't suspended. If concurrent moving 772// GC, disable moving GC and suspend threads and then visit objects. 773void Heap::VisitObjects(ObjectCallback callback, void* arg) { 774 Thread* self = Thread::Current(); 775 Locks::mutator_lock_->AssertSharedHeld(self); 776 DCHECK(!Locks::mutator_lock_->IsExclusiveHeld(self)) << "Call VisitObjectsPaused() instead"; 777 if (IsGcConcurrentAndMoving()) { 778 // Concurrent moving GC. Just suspending threads isn't sufficient 779 // because a collection isn't one big pause and we could suspend 780 // threads in the middle (between phases) of a concurrent moving 781 // collection where it's not easily known which objects are alive 782 // (both the region space and the non-moving space) or which 783 // copies of objects to visit, and the to-space invariant could be 784 // easily broken. Visit objects while GC isn't running by using 785 // IncrementDisableMovingGC() and threads are suspended. 786 IncrementDisableMovingGC(self); 787 self->TransitionFromRunnableToSuspended(kWaitingForVisitObjects); 788 ThreadList* tl = Runtime::Current()->GetThreadList(); 789 tl->SuspendAll(__FUNCTION__); 790 VisitObjectsInternalRegionSpace(callback, arg); 791 VisitObjectsInternal(callback, arg); 792 tl->ResumeAll(); 793 self->TransitionFromSuspendedToRunnable(); 794 DecrementDisableMovingGC(self); 795 } else { 796 // GCs can move objects, so don't allow this. 797 ScopedAssertNoThreadSuspension ants(self, "Visiting objects"); 798 DCHECK(region_space_ == nullptr); 799 VisitObjectsInternal(callback, arg); 800 } 801} 802 803// Visit objects when threads are already suspended. 804void Heap::VisitObjectsPaused(ObjectCallback callback, void* arg) { 805 Thread* self = Thread::Current(); 806 Locks::mutator_lock_->AssertExclusiveHeld(self); 807 VisitObjectsInternalRegionSpace(callback, arg); 808 VisitObjectsInternal(callback, arg); 809} 810 811// Visit objects in the region spaces. 812void Heap::VisitObjectsInternalRegionSpace(ObjectCallback callback, void* arg) { 813 Thread* self = Thread::Current(); 814 Locks::mutator_lock_->AssertExclusiveHeld(self); 815 if (region_space_ != nullptr) { 816 DCHECK(IsGcConcurrentAndMoving()); 817 if (!zygote_creation_lock_.IsExclusiveHeld(self)) { 818 // Exclude the pre-zygote fork time where the semi-space collector 819 // calls VerifyHeapReferences() as part of the zygote compaction 820 // which then would call here without the moving GC disabled, 821 // which is fine. 822 DCHECK(IsMovingGCDisabled(self)); 823 } 824 region_space_->Walk(callback, arg); 825 } 826} 827 828// Visit objects in the other spaces. 829void Heap::VisitObjectsInternal(ObjectCallback callback, void* arg) { 830 if (bump_pointer_space_ != nullptr) { 831 // Visit objects in bump pointer space. 832 bump_pointer_space_->Walk(callback, arg); 833 } 834 // TODO: Switch to standard begin and end to use ranged a based loop. 835 for (auto* it = allocation_stack_->Begin(), *end = allocation_stack_->End(); it < end; ++it) { 836 mirror::Object* const obj = it->AsMirrorPtr(); 837 if (obj != nullptr && obj->GetClass() != nullptr) { 838 // Avoid the race condition caused by the object not yet being written into the allocation 839 // stack or the class not yet being written in the object. Or, if 840 // kUseThreadLocalAllocationStack, there can be nulls on the allocation stack. 841 callback(obj, arg); 842 } 843 } 844 { 845 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 846 GetLiveBitmap()->Walk(callback, arg); 847 } 848} 849 850void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 851 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 852 space::ContinuousSpace* space2 = non_moving_space_; 853 // TODO: Generalize this to n bitmaps? 854 CHECK(space1 != nullptr); 855 CHECK(space2 != nullptr); 856 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 857 (large_object_space_ != nullptr ? large_object_space_->GetLiveBitmap() : nullptr), 858 stack); 859} 860 861void Heap::DeleteThreadPool() { 862 thread_pool_.reset(nullptr); 863} 864 865void Heap::AddSpace(space::Space* space) { 866 CHECK(space != nullptr); 867 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 868 if (space->IsContinuousSpace()) { 869 DCHECK(!space->IsDiscontinuousSpace()); 870 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 871 // Continuous spaces don't necessarily have bitmaps. 872 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 873 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 874 if (live_bitmap != nullptr) { 875 CHECK(mark_bitmap != nullptr); 876 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 877 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 878 } 879 continuous_spaces_.push_back(continuous_space); 880 // Ensure that spaces remain sorted in increasing order of start address. 881 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 882 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 883 return a->Begin() < b->Begin(); 884 }); 885 } else { 886 CHECK(space->IsDiscontinuousSpace()); 887 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 888 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 889 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 890 discontinuous_spaces_.push_back(discontinuous_space); 891 } 892 if (space->IsAllocSpace()) { 893 alloc_spaces_.push_back(space->AsAllocSpace()); 894 } 895} 896 897void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 898 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 899 if (continuous_space->IsDlMallocSpace()) { 900 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 901 } else if (continuous_space->IsRosAllocSpace()) { 902 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 903 } 904} 905 906void Heap::RemoveSpace(space::Space* space) { 907 DCHECK(space != nullptr); 908 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 909 if (space->IsContinuousSpace()) { 910 DCHECK(!space->IsDiscontinuousSpace()); 911 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 912 // Continuous spaces don't necessarily have bitmaps. 913 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 914 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 915 if (live_bitmap != nullptr) { 916 DCHECK(mark_bitmap != nullptr); 917 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 918 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 919 } 920 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 921 DCHECK(it != continuous_spaces_.end()); 922 continuous_spaces_.erase(it); 923 } else { 924 DCHECK(space->IsDiscontinuousSpace()); 925 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 926 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 927 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 928 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 929 discontinuous_space); 930 DCHECK(it != discontinuous_spaces_.end()); 931 discontinuous_spaces_.erase(it); 932 } 933 if (space->IsAllocSpace()) { 934 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 935 DCHECK(it != alloc_spaces_.end()); 936 alloc_spaces_.erase(it); 937 } 938} 939 940void Heap::DumpGcPerformanceInfo(std::ostream& os) { 941 // Dump cumulative timings. 942 os << "Dumping cumulative Gc timings\n"; 943 uint64_t total_duration = 0; 944 // Dump cumulative loggers for each GC type. 945 uint64_t total_paused_time = 0; 946 for (auto& collector : garbage_collectors_) { 947 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 948 total_paused_time += collector->GetTotalPausedTimeNs(); 949 collector->DumpPerformanceInfo(os); 950 } 951 uint64_t allocation_time = 952 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 953 if (total_duration != 0) { 954 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 955 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 956 os << "Mean GC size throughput: " 957 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 958 os << "Mean GC object throughput: " 959 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 960 } 961 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 962 os << "Total number of allocations " << total_objects_allocated << "\n"; 963 os << "Total bytes allocated " << PrettySize(GetBytesAllocatedEver()) << "\n"; 964 os << "Total bytes freed " << PrettySize(GetBytesFreedEver()) << "\n"; 965 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 966 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 967 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 968 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 969 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 970 if (kMeasureAllocationTime) { 971 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 972 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 973 << "\n"; 974 } 975 if (HasZygoteSpace()) { 976 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 977 } 978 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 979 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 980 os << "Total GC count: " << GetGcCount() << "\n"; 981 os << "Total GC time: " << PrettyDuration(GetGcTime()) << "\n"; 982 os << "Total blocking GC count: " << GetBlockingGcCount() << "\n"; 983 os << "Total blocking GC time: " << PrettyDuration(GetBlockingGcTime()) << "\n"; 984 985 { 986 MutexLock mu(Thread::Current(), *gc_complete_lock_); 987 if (gc_count_rate_histogram_.SampleSize() > 0U) { 988 os << "Histogram of GC count per " << NsToMs(kGcCountRateHistogramWindowDuration) << " ms: "; 989 gc_count_rate_histogram_.DumpBins(os); 990 os << "\n"; 991 } 992 if (blocking_gc_count_rate_histogram_.SampleSize() > 0U) { 993 os << "Histogram of blocking GC count per " 994 << NsToMs(kGcCountRateHistogramWindowDuration) << " ms: "; 995 blocking_gc_count_rate_histogram_.DumpBins(os); 996 os << "\n"; 997 } 998 } 999 1000 BaseMutex::DumpAll(os); 1001} 1002 1003uint64_t Heap::GetGcCount() const { 1004 uint64_t gc_count = 0U; 1005 for (auto& collector : garbage_collectors_) { 1006 gc_count += collector->GetCumulativeTimings().GetIterations(); 1007 } 1008 return gc_count; 1009} 1010 1011uint64_t Heap::GetGcTime() const { 1012 uint64_t gc_time = 0U; 1013 for (auto& collector : garbage_collectors_) { 1014 gc_time += collector->GetCumulativeTimings().GetTotalNs(); 1015 } 1016 return gc_time; 1017} 1018 1019uint64_t Heap::GetBlockingGcCount() const { 1020 return blocking_gc_count_; 1021} 1022 1023uint64_t Heap::GetBlockingGcTime() const { 1024 return blocking_gc_time_; 1025} 1026 1027void Heap::DumpGcCountRateHistogram(std::ostream& os) const { 1028 MutexLock mu(Thread::Current(), *gc_complete_lock_); 1029 if (gc_count_rate_histogram_.SampleSize() > 0U) { 1030 gc_count_rate_histogram_.DumpBins(os); 1031 } 1032} 1033 1034void Heap::DumpBlockingGcCountRateHistogram(std::ostream& os) const { 1035 MutexLock mu(Thread::Current(), *gc_complete_lock_); 1036 if (blocking_gc_count_rate_histogram_.SampleSize() > 0U) { 1037 blocking_gc_count_rate_histogram_.DumpBins(os); 1038 } 1039} 1040 1041Heap::~Heap() { 1042 VLOG(heap) << "Starting ~Heap()"; 1043 STLDeleteElements(&garbage_collectors_); 1044 // If we don't reset then the mark stack complains in its destructor. 1045 allocation_stack_->Reset(); 1046 live_stack_->Reset(); 1047 STLDeleteValues(&mod_union_tables_); 1048 STLDeleteValues(&remembered_sets_); 1049 STLDeleteElements(&continuous_spaces_); 1050 STLDeleteElements(&discontinuous_spaces_); 1051 delete gc_complete_lock_; 1052 delete pending_task_lock_; 1053 VLOG(heap) << "Finished ~Heap()"; 1054} 1055 1056space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 1057 bool fail_ok) const { 1058 for (const auto& space : continuous_spaces_) { 1059 if (space->Contains(obj)) { 1060 return space; 1061 } 1062 } 1063 if (!fail_ok) { 1064 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 1065 } 1066 return nullptr; 1067} 1068 1069space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 1070 bool fail_ok) const { 1071 for (const auto& space : discontinuous_spaces_) { 1072 if (space->Contains(obj)) { 1073 return space; 1074 } 1075 } 1076 if (!fail_ok) { 1077 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 1078 } 1079 return nullptr; 1080} 1081 1082space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 1083 space::Space* result = FindContinuousSpaceFromObject(obj, true); 1084 if (result != nullptr) { 1085 return result; 1086 } 1087 return FindDiscontinuousSpaceFromObject(obj, fail_ok); 1088} 1089 1090space::ImageSpace* Heap::GetImageSpace() const { 1091 for (const auto& space : continuous_spaces_) { 1092 if (space->IsImageSpace()) { 1093 return space->AsImageSpace(); 1094 } 1095 } 1096 return nullptr; 1097} 1098 1099void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 1100 std::ostringstream oss; 1101 size_t total_bytes_free = GetFreeMemory(); 1102 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 1103 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 1104 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 1105 if (total_bytes_free >= byte_count) { 1106 space::AllocSpace* space = nullptr; 1107 if (allocator_type == kAllocatorTypeNonMoving) { 1108 space = non_moving_space_; 1109 } else if (allocator_type == kAllocatorTypeRosAlloc || 1110 allocator_type == kAllocatorTypeDlMalloc) { 1111 space = main_space_; 1112 } else if (allocator_type == kAllocatorTypeBumpPointer || 1113 allocator_type == kAllocatorTypeTLAB) { 1114 space = bump_pointer_space_; 1115 } else if (allocator_type == kAllocatorTypeRegion || 1116 allocator_type == kAllocatorTypeRegionTLAB) { 1117 space = region_space_; 1118 } 1119 if (space != nullptr) { 1120 space->LogFragmentationAllocFailure(oss, byte_count); 1121 } 1122 } 1123 self->ThrowOutOfMemoryError(oss.str().c_str()); 1124} 1125 1126void Heap::DoPendingCollectorTransition() { 1127 CollectorType desired_collector_type = desired_collector_type_; 1128 // Launch homogeneous space compaction if it is desired. 1129 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 1130 if (!CareAboutPauseTimes()) { 1131 PerformHomogeneousSpaceCompact(); 1132 } else { 1133 VLOG(gc) << "Homogeneous compaction ignored due to jank perceptible process state"; 1134 } 1135 } else { 1136 TransitionCollector(desired_collector_type); 1137 } 1138} 1139 1140void Heap::Trim(Thread* self) { 1141 if (!CareAboutPauseTimes()) { 1142 ATRACE_BEGIN("Deflating monitors"); 1143 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 1144 // about pauses. 1145 Runtime* runtime = Runtime::Current(); 1146 runtime->GetThreadList()->SuspendAll(__FUNCTION__); 1147 uint64_t start_time = NanoTime(); 1148 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 1149 VLOG(heap) << "Deflating " << count << " monitors took " 1150 << PrettyDuration(NanoTime() - start_time); 1151 runtime->GetThreadList()->ResumeAll(); 1152 ATRACE_END(); 1153 } 1154 TrimIndirectReferenceTables(self); 1155 TrimSpaces(self); 1156} 1157 1158class TrimIndirectReferenceTableClosure : public Closure { 1159 public: 1160 explicit TrimIndirectReferenceTableClosure(Barrier* barrier) : barrier_(barrier) { 1161 } 1162 virtual void Run(Thread* thread) OVERRIDE NO_THREAD_SAFETY_ANALYSIS { 1163 ATRACE_BEGIN("Trimming reference table"); 1164 thread->GetJniEnv()->locals.Trim(); 1165 ATRACE_END(); 1166 // If thread is a running mutator, then act on behalf of the trim thread. 1167 // See the code in ThreadList::RunCheckpoint. 1168 if (thread->GetState() == kRunnable) { 1169 barrier_->Pass(Thread::Current()); 1170 } 1171 } 1172 1173 private: 1174 Barrier* const barrier_; 1175}; 1176 1177void Heap::TrimIndirectReferenceTables(Thread* self) { 1178 ScopedObjectAccess soa(self); 1179 ATRACE_BEGIN(__FUNCTION__); 1180 JavaVMExt* vm = soa.Vm(); 1181 // Trim globals indirect reference table. 1182 vm->TrimGlobals(); 1183 // Trim locals indirect reference tables. 1184 Barrier barrier(0); 1185 TrimIndirectReferenceTableClosure closure(&barrier); 1186 ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); 1187 size_t barrier_count = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure); 1188 if (barrier_count != 0) { 1189 barrier.Increment(self, barrier_count); 1190 } 1191 ATRACE_END(); 1192} 1193 1194void Heap::TrimSpaces(Thread* self) { 1195 { 1196 // Need to do this before acquiring the locks since we don't want to get suspended while 1197 // holding any locks. 1198 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1199 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 1200 // trimming. 1201 MutexLock mu(self, *gc_complete_lock_); 1202 // Ensure there is only one GC at a time. 1203 WaitForGcToCompleteLocked(kGcCauseTrim, self); 1204 collector_type_running_ = kCollectorTypeHeapTrim; 1205 } 1206 ATRACE_BEGIN(__FUNCTION__); 1207 const uint64_t start_ns = NanoTime(); 1208 // Trim the managed spaces. 1209 uint64_t total_alloc_space_allocated = 0; 1210 uint64_t total_alloc_space_size = 0; 1211 uint64_t managed_reclaimed = 0; 1212 for (const auto& space : continuous_spaces_) { 1213 if (space->IsMallocSpace()) { 1214 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1215 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1216 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1217 // for a long period of time. 1218 managed_reclaimed += malloc_space->Trim(); 1219 } 1220 total_alloc_space_size += malloc_space->Size(); 1221 } 1222 } 1223 total_alloc_space_allocated = GetBytesAllocated(); 1224 if (large_object_space_ != nullptr) { 1225 total_alloc_space_allocated -= large_object_space_->GetBytesAllocated(); 1226 } 1227 if (bump_pointer_space_ != nullptr) { 1228 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1229 } 1230 if (region_space_ != nullptr) { 1231 total_alloc_space_allocated -= region_space_->GetBytesAllocated(); 1232 } 1233 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1234 static_cast<float>(total_alloc_space_size); 1235 uint64_t gc_heap_end_ns = NanoTime(); 1236 // We never move things in the native heap, so we can finish the GC at this point. 1237 FinishGC(self, collector::kGcTypeNone); 1238 size_t native_reclaimed = 0; 1239 1240#ifdef HAVE_ANDROID_OS 1241 // Only trim the native heap if we don't care about pauses. 1242 if (!CareAboutPauseTimes()) { 1243#if defined(USE_DLMALLOC) 1244 // Trim the native heap. 1245 dlmalloc_trim(0); 1246 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1247#elif defined(USE_JEMALLOC) 1248 // Jemalloc does it's own internal trimming. 1249#else 1250 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1251#endif 1252 } 1253#endif // HAVE_ANDROID_OS 1254 uint64_t end_ns = NanoTime(); 1255 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1256 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1257 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1258 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1259 << "%."; 1260 ATRACE_END(); 1261} 1262 1263bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1264 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1265 // taking the lock. 1266 if (obj == nullptr) { 1267 return true; 1268 } 1269 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1270} 1271 1272bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1273 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1274} 1275 1276bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1277 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1278 return false; 1279 } 1280 for (const auto& space : continuous_spaces_) { 1281 if (space->HasAddress(obj)) { 1282 return true; 1283 } 1284 } 1285 return false; 1286} 1287 1288bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1289 bool search_live_stack, bool sorted) { 1290 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1291 return false; 1292 } 1293 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1294 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1295 if (obj == klass) { 1296 // This case happens for java.lang.Class. 1297 return true; 1298 } 1299 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1300 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1301 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1302 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1303 return temp_space_->Contains(obj); 1304 } 1305 if (region_space_ != nullptr && region_space_->HasAddress(obj)) { 1306 return true; 1307 } 1308 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1309 space::DiscontinuousSpace* d_space = nullptr; 1310 if (c_space != nullptr) { 1311 if (c_space->GetLiveBitmap()->Test(obj)) { 1312 return true; 1313 } 1314 } else { 1315 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1316 if (d_space != nullptr) { 1317 if (d_space->GetLiveBitmap()->Test(obj)) { 1318 return true; 1319 } 1320 } 1321 } 1322 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1323 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1324 if (i > 0) { 1325 NanoSleep(MsToNs(10)); 1326 } 1327 if (search_allocation_stack) { 1328 if (sorted) { 1329 if (allocation_stack_->ContainsSorted(obj)) { 1330 return true; 1331 } 1332 } else if (allocation_stack_->Contains(obj)) { 1333 return true; 1334 } 1335 } 1336 1337 if (search_live_stack) { 1338 if (sorted) { 1339 if (live_stack_->ContainsSorted(obj)) { 1340 return true; 1341 } 1342 } else if (live_stack_->Contains(obj)) { 1343 return true; 1344 } 1345 } 1346 } 1347 // We need to check the bitmaps again since there is a race where we mark something as live and 1348 // then clear the stack containing it. 1349 if (c_space != nullptr) { 1350 if (c_space->GetLiveBitmap()->Test(obj)) { 1351 return true; 1352 } 1353 } else { 1354 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1355 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1356 return true; 1357 } 1358 } 1359 return false; 1360} 1361 1362std::string Heap::DumpSpaces() const { 1363 std::ostringstream oss; 1364 DumpSpaces(oss); 1365 return oss.str(); 1366} 1367 1368void Heap::DumpSpaces(std::ostream& stream) const { 1369 for (const auto& space : continuous_spaces_) { 1370 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1371 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1372 stream << space << " " << *space << "\n"; 1373 if (live_bitmap != nullptr) { 1374 stream << live_bitmap << " " << *live_bitmap << "\n"; 1375 } 1376 if (mark_bitmap != nullptr) { 1377 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1378 } 1379 } 1380 for (const auto& space : discontinuous_spaces_) { 1381 stream << space << " " << *space << "\n"; 1382 } 1383} 1384 1385void Heap::VerifyObjectBody(mirror::Object* obj) { 1386 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1387 return; 1388 } 1389 1390 // Ignore early dawn of the universe verifications. 1391 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1392 return; 1393 } 1394 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1395 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1396 CHECK(c != nullptr) << "Null class in object " << obj; 1397 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1398 CHECK(VerifyClassClass(c)); 1399 1400 if (verify_object_mode_ > kVerifyObjectModeFast) { 1401 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1402 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1403 } 1404} 1405 1406void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1407 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1408} 1409 1410void Heap::VerifyHeap() { 1411 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1412 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1413} 1414 1415void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1416 // Use signed comparison since freed bytes can be negative when background compaction foreground 1417 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1418 // free list backed space typically increasing memory footprint due to padding and binning. 1419 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1420 // Note: This relies on 2s complement for handling negative freed_bytes. 1421 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1422 if (Runtime::Current()->HasStatsEnabled()) { 1423 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1424 thread_stats->freed_objects += freed_objects; 1425 thread_stats->freed_bytes += freed_bytes; 1426 // TODO: Do this concurrently. 1427 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1428 global_stats->freed_objects += freed_objects; 1429 global_stats->freed_bytes += freed_bytes; 1430 } 1431} 1432 1433void Heap::RecordFreeRevoke() { 1434 // Subtract num_bytes_freed_revoke_ from num_bytes_allocated_ to cancel out the 1435 // the ahead-of-time, bulk counting of bytes allocated in rosalloc thread-local buffers. 1436 // If there's a concurrent revoke, ok to not necessarily reset num_bytes_freed_revoke_ 1437 // all the way to zero exactly as the remainder will be subtracted at the next GC. 1438 size_t bytes_freed = num_bytes_freed_revoke_.LoadSequentiallyConsistent(); 1439 CHECK_GE(num_bytes_freed_revoke_.FetchAndSubSequentiallyConsistent(bytes_freed), 1440 bytes_freed) << "num_bytes_freed_revoke_ underflow"; 1441 CHECK_GE(num_bytes_allocated_.FetchAndSubSequentiallyConsistent(bytes_freed), 1442 bytes_freed) << "num_bytes_allocated_ underflow"; 1443 GetCurrentGcIteration()->SetFreedRevoke(bytes_freed); 1444} 1445 1446space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1447 for (const auto& space : continuous_spaces_) { 1448 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1449 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1450 return space->AsContinuousSpace()->AsRosAllocSpace(); 1451 } 1452 } 1453 } 1454 return nullptr; 1455} 1456 1457mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1458 size_t alloc_size, size_t* bytes_allocated, 1459 size_t* usable_size, 1460 size_t* bytes_tl_bulk_allocated, 1461 mirror::Class** klass) { 1462 bool was_default_allocator = allocator == GetCurrentAllocator(); 1463 // Make sure there is no pending exception since we may need to throw an OOME. 1464 self->AssertNoPendingException(); 1465 DCHECK(klass != nullptr); 1466 StackHandleScope<1> hs(self); 1467 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1468 klass = nullptr; // Invalidate for safety. 1469 // The allocation failed. If the GC is running, block until it completes, and then retry the 1470 // allocation. 1471 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1472 if (last_gc != collector::kGcTypeNone) { 1473 // If we were the default allocator but the allocator changed while we were suspended, 1474 // abort the allocation. 1475 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1476 return nullptr; 1477 } 1478 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1479 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1480 usable_size, bytes_tl_bulk_allocated); 1481 if (ptr != nullptr) { 1482 return ptr; 1483 } 1484 } 1485 1486 collector::GcType tried_type = next_gc_type_; 1487 const bool gc_ran = 1488 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1489 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1490 return nullptr; 1491 } 1492 if (gc_ran) { 1493 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1494 usable_size, bytes_tl_bulk_allocated); 1495 if (ptr != nullptr) { 1496 return ptr; 1497 } 1498 } 1499 1500 // Loop through our different Gc types and try to Gc until we get enough free memory. 1501 for (collector::GcType gc_type : gc_plan_) { 1502 if (gc_type == tried_type) { 1503 continue; 1504 } 1505 // Attempt to run the collector, if we succeed, re-try the allocation. 1506 const bool plan_gc_ran = 1507 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1508 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1509 return nullptr; 1510 } 1511 if (plan_gc_ran) { 1512 // Did we free sufficient memory for the allocation to succeed? 1513 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1514 usable_size, bytes_tl_bulk_allocated); 1515 if (ptr != nullptr) { 1516 return ptr; 1517 } 1518 } 1519 } 1520 // Allocations have failed after GCs; this is an exceptional state. 1521 // Try harder, growing the heap if necessary. 1522 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1523 usable_size, bytes_tl_bulk_allocated); 1524 if (ptr != nullptr) { 1525 return ptr; 1526 } 1527 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1528 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1529 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1530 // OOME. 1531 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1532 << " allocation"; 1533 // TODO: Run finalization, but this may cause more allocations to occur. 1534 // We don't need a WaitForGcToComplete here either. 1535 DCHECK(!gc_plan_.empty()); 1536 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1537 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1538 return nullptr; 1539 } 1540 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size, 1541 bytes_tl_bulk_allocated); 1542 if (ptr == nullptr) { 1543 const uint64_t current_time = NanoTime(); 1544 switch (allocator) { 1545 case kAllocatorTypeRosAlloc: 1546 // Fall-through. 1547 case kAllocatorTypeDlMalloc: { 1548 if (use_homogeneous_space_compaction_for_oom_ && 1549 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1550 min_interval_homogeneous_space_compaction_by_oom_) { 1551 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1552 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1553 switch (result) { 1554 case HomogeneousSpaceCompactResult::kSuccess: 1555 // If the allocation succeeded, we delayed an oom. 1556 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1557 usable_size, bytes_tl_bulk_allocated); 1558 if (ptr != nullptr) { 1559 count_delayed_oom_++; 1560 } 1561 break; 1562 case HomogeneousSpaceCompactResult::kErrorReject: 1563 // Reject due to disabled moving GC. 1564 break; 1565 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1566 // Throw OOM by default. 1567 break; 1568 default: { 1569 UNIMPLEMENTED(FATAL) << "homogeneous space compaction result: " 1570 << static_cast<size_t>(result); 1571 UNREACHABLE(); 1572 } 1573 } 1574 // Always print that we ran homogeneous space compation since this can cause jank. 1575 VLOG(heap) << "Ran heap homogeneous space compaction, " 1576 << " requested defragmentation " 1577 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1578 << " performed defragmentation " 1579 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1580 << " ignored homogeneous space compaction " 1581 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1582 << " delayed count = " 1583 << count_delayed_oom_.LoadSequentiallyConsistent(); 1584 } 1585 break; 1586 } 1587 case kAllocatorTypeNonMoving: { 1588 // Try to transition the heap if the allocation failure was due to the space being full. 1589 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1590 // If we aren't out of memory then the OOM was probably from the non moving space being 1591 // full. Attempt to disable compaction and turn the main space into a non moving space. 1592 DisableMovingGc(); 1593 // If we are still a moving GC then something must have caused the transition to fail. 1594 if (IsMovingGc(collector_type_)) { 1595 MutexLock mu(self, *gc_complete_lock_); 1596 // If we couldn't disable moving GC, just throw OOME and return null. 1597 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1598 << disable_moving_gc_count_; 1599 } else { 1600 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1601 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1602 usable_size, bytes_tl_bulk_allocated); 1603 } 1604 } 1605 break; 1606 } 1607 default: { 1608 // Do nothing for others allocators. 1609 } 1610 } 1611 } 1612 // If the allocation hasn't succeeded by this point, throw an OOM error. 1613 if (ptr == nullptr) { 1614 ThrowOutOfMemoryError(self, alloc_size, allocator); 1615 } 1616 return ptr; 1617} 1618 1619void Heap::SetTargetHeapUtilization(float target) { 1620 DCHECK_GT(target, 0.0f); // asserted in Java code 1621 DCHECK_LT(target, 1.0f); 1622 target_utilization_ = target; 1623} 1624 1625size_t Heap::GetObjectsAllocated() const { 1626 Thread* self = Thread::Current(); 1627 ScopedThreadStateChange tsc(self, kWaitingForGetObjectsAllocated); 1628 auto* tl = Runtime::Current()->GetThreadList(); 1629 // Need SuspendAll here to prevent lock violation if RosAlloc does it during InspectAll. 1630 tl->SuspendAll(__FUNCTION__); 1631 size_t total = 0; 1632 { 1633 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 1634 for (space::AllocSpace* space : alloc_spaces_) { 1635 total += space->GetObjectsAllocated(); 1636 } 1637 } 1638 tl->ResumeAll(); 1639 return total; 1640} 1641 1642uint64_t Heap::GetObjectsAllocatedEver() const { 1643 uint64_t total = GetObjectsFreedEver(); 1644 // If we are detached, we can't use GetObjectsAllocated since we can't change thread states. 1645 if (Thread::Current() != nullptr) { 1646 total += GetObjectsAllocated(); 1647 } 1648 return total; 1649} 1650 1651uint64_t Heap::GetBytesAllocatedEver() const { 1652 return GetBytesFreedEver() + GetBytesAllocated(); 1653} 1654 1655class InstanceCounter { 1656 public: 1657 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1658 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1659 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1660 } 1661 static void Callback(mirror::Object* obj, void* arg) 1662 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1663 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1664 mirror::Class* instance_class = obj->GetClass(); 1665 CHECK(instance_class != nullptr); 1666 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1667 if (instance_counter->use_is_assignable_from_) { 1668 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1669 ++instance_counter->counts_[i]; 1670 } 1671 } else if (instance_class == instance_counter->classes_[i]) { 1672 ++instance_counter->counts_[i]; 1673 } 1674 } 1675 } 1676 1677 private: 1678 const std::vector<mirror::Class*>& classes_; 1679 bool use_is_assignable_from_; 1680 uint64_t* const counts_; 1681 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1682}; 1683 1684void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1685 uint64_t* counts) { 1686 InstanceCounter counter(classes, use_is_assignable_from, counts); 1687 VisitObjects(InstanceCounter::Callback, &counter); 1688} 1689 1690class InstanceCollector { 1691 public: 1692 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1693 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1694 : class_(c), max_count_(max_count), instances_(instances) { 1695 } 1696 static void Callback(mirror::Object* obj, void* arg) 1697 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1698 DCHECK(arg != nullptr); 1699 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1700 if (obj->GetClass() == instance_collector->class_) { 1701 if (instance_collector->max_count_ == 0 || 1702 instance_collector->instances_.size() < instance_collector->max_count_) { 1703 instance_collector->instances_.push_back(obj); 1704 } 1705 } 1706 } 1707 1708 private: 1709 const mirror::Class* const class_; 1710 const uint32_t max_count_; 1711 std::vector<mirror::Object*>& instances_; 1712 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1713}; 1714 1715void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1716 std::vector<mirror::Object*>& instances) { 1717 InstanceCollector collector(c, max_count, instances); 1718 VisitObjects(&InstanceCollector::Callback, &collector); 1719} 1720 1721class ReferringObjectsFinder { 1722 public: 1723 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1724 std::vector<mirror::Object*>& referring_objects) 1725 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1726 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1727 } 1728 1729 static void Callback(mirror::Object* obj, void* arg) 1730 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1731 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1732 } 1733 1734 // For bitmap Visit. 1735 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1736 // annotalysis on visitors. 1737 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1738 o->VisitReferences<true>(*this, VoidFunctor()); 1739 } 1740 1741 // For Object::VisitReferences. 1742 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1743 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1744 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1745 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1746 referring_objects_.push_back(obj); 1747 } 1748 } 1749 1750 private: 1751 const mirror::Object* const object_; 1752 const uint32_t max_count_; 1753 std::vector<mirror::Object*>& referring_objects_; 1754 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1755}; 1756 1757void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1758 std::vector<mirror::Object*>& referring_objects) { 1759 ReferringObjectsFinder finder(o, max_count, referring_objects); 1760 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1761} 1762 1763void Heap::CollectGarbage(bool clear_soft_references) { 1764 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1765 // last GC will not have necessarily been cleared. 1766 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1767} 1768 1769HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1770 Thread* self = Thread::Current(); 1771 // Inc requested homogeneous space compaction. 1772 count_requested_homogeneous_space_compaction_++; 1773 // Store performed homogeneous space compaction at a new request arrival. 1774 ThreadList* tl = Runtime::Current()->GetThreadList(); 1775 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1776 Locks::mutator_lock_->AssertNotHeld(self); 1777 { 1778 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1779 MutexLock mu(self, *gc_complete_lock_); 1780 // Ensure there is only one GC at a time. 1781 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1782 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1783 // is non zero. 1784 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1785 // exit. 1786 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1787 !main_space_->CanMoveObjects()) { 1788 return HomogeneousSpaceCompactResult::kErrorReject; 1789 } 1790 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1791 } 1792 if (Runtime::Current()->IsShuttingDown(self)) { 1793 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1794 // cause objects to get finalized. 1795 FinishGC(self, collector::kGcTypeNone); 1796 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1797 } 1798 // Suspend all threads. 1799 tl->SuspendAll(__FUNCTION__); 1800 uint64_t start_time = NanoTime(); 1801 // Launch compaction. 1802 space::MallocSpace* to_space = main_space_backup_.release(); 1803 space::MallocSpace* from_space = main_space_; 1804 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1805 const uint64_t space_size_before_compaction = from_space->Size(); 1806 AddSpace(to_space); 1807 // Make sure that we will have enough room to copy. 1808 CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit()); 1809 collector::GarbageCollector* collector = Compact(to_space, from_space, 1810 kGcCauseHomogeneousSpaceCompact); 1811 const uint64_t space_size_after_compaction = to_space->Size(); 1812 main_space_ = to_space; 1813 main_space_backup_.reset(from_space); 1814 RemoveSpace(from_space); 1815 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1816 // Update performed homogeneous space compaction count. 1817 count_performed_homogeneous_space_compaction_++; 1818 // Print statics log and resume all threads. 1819 uint64_t duration = NanoTime() - start_time; 1820 VLOG(heap) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1821 << PrettySize(space_size_before_compaction) << " -> " 1822 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1823 << std::fixed << static_cast<double>(space_size_after_compaction) / 1824 static_cast<double>(space_size_before_compaction); 1825 tl->ResumeAll(); 1826 // Finish GC. 1827 reference_processor_.EnqueueClearedReferences(self); 1828 GrowForUtilization(semi_space_collector_); 1829 LogGC(kGcCauseHomogeneousSpaceCompact, collector); 1830 FinishGC(self, collector::kGcTypeFull); 1831 return HomogeneousSpaceCompactResult::kSuccess; 1832} 1833 1834void Heap::TransitionCollector(CollectorType collector_type) { 1835 if (collector_type == collector_type_) { 1836 return; 1837 } 1838 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1839 << " -> " << static_cast<int>(collector_type); 1840 uint64_t start_time = NanoTime(); 1841 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1842 Runtime* const runtime = Runtime::Current(); 1843 ThreadList* const tl = runtime->GetThreadList(); 1844 Thread* const self = Thread::Current(); 1845 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1846 Locks::mutator_lock_->AssertNotHeld(self); 1847 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1848 // compacting_gc_disable_count_, this should rarely occurs). 1849 for (;;) { 1850 { 1851 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1852 MutexLock mu(self, *gc_complete_lock_); 1853 // Ensure there is only one GC at a time. 1854 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1855 // Currently we only need a heap transition if we switch from a moving collector to a 1856 // non-moving one, or visa versa. 1857 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1858 // If someone else beat us to it and changed the collector before we could, exit. 1859 // This is safe to do before the suspend all since we set the collector_type_running_ before 1860 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1861 // then it would get blocked on WaitForGcToCompleteLocked. 1862 if (collector_type == collector_type_) { 1863 return; 1864 } 1865 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1866 if (!copying_transition || disable_moving_gc_count_ == 0) { 1867 // TODO: Not hard code in semi-space collector? 1868 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1869 break; 1870 } 1871 } 1872 usleep(1000); 1873 } 1874 if (runtime->IsShuttingDown(self)) { 1875 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1876 // cause objects to get finalized. 1877 FinishGC(self, collector::kGcTypeNone); 1878 return; 1879 } 1880 collector::GarbageCollector* collector = nullptr; 1881 tl->SuspendAll(__FUNCTION__); 1882 switch (collector_type) { 1883 case kCollectorTypeSS: { 1884 if (!IsMovingGc(collector_type_)) { 1885 // Create the bump pointer space from the backup space. 1886 CHECK(main_space_backup_ != nullptr); 1887 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1888 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1889 // pointer space last transition it will be protected. 1890 CHECK(mem_map != nullptr); 1891 mem_map->Protect(PROT_READ | PROT_WRITE); 1892 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1893 mem_map.release()); 1894 AddSpace(bump_pointer_space_); 1895 collector = Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1896 // Use the now empty main space mem map for the bump pointer temp space. 1897 mem_map.reset(main_space_->ReleaseMemMap()); 1898 // Unset the pointers just in case. 1899 if (dlmalloc_space_ == main_space_) { 1900 dlmalloc_space_ = nullptr; 1901 } else if (rosalloc_space_ == main_space_) { 1902 rosalloc_space_ = nullptr; 1903 } 1904 // Remove the main space so that we don't try to trim it, this doens't work for debug 1905 // builds since RosAlloc attempts to read the magic number from a protected page. 1906 RemoveSpace(main_space_); 1907 RemoveRememberedSet(main_space_); 1908 delete main_space_; // Delete the space since it has been removed. 1909 main_space_ = nullptr; 1910 RemoveRememberedSet(main_space_backup_.get()); 1911 main_space_backup_.reset(nullptr); // Deletes the space. 1912 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1913 mem_map.release()); 1914 AddSpace(temp_space_); 1915 } 1916 break; 1917 } 1918 case kCollectorTypeMS: 1919 // Fall through. 1920 case kCollectorTypeCMS: { 1921 if (IsMovingGc(collector_type_)) { 1922 CHECK(temp_space_ != nullptr); 1923 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1924 RemoveSpace(temp_space_); 1925 temp_space_ = nullptr; 1926 mem_map->Protect(PROT_READ | PROT_WRITE); 1927 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, 1928 std::min(mem_map->Size(), growth_limit_), mem_map->Size()); 1929 mem_map.release(); 1930 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1931 AddSpace(main_space_); 1932 collector = Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1933 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1934 RemoveSpace(bump_pointer_space_); 1935 bump_pointer_space_ = nullptr; 1936 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1937 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1938 if (kIsDebugBuild && kUseRosAlloc) { 1939 mem_map->Protect(PROT_READ | PROT_WRITE); 1940 } 1941 main_space_backup_.reset(CreateMallocSpaceFromMemMap( 1942 mem_map.get(), kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1943 mem_map->Size(), name, true)); 1944 if (kIsDebugBuild && kUseRosAlloc) { 1945 mem_map->Protect(PROT_NONE); 1946 } 1947 mem_map.release(); 1948 } 1949 break; 1950 } 1951 default: { 1952 LOG(FATAL) << "Attempted to transition to invalid collector type " 1953 << static_cast<size_t>(collector_type); 1954 break; 1955 } 1956 } 1957 ChangeCollector(collector_type); 1958 tl->ResumeAll(); 1959 // Can't call into java code with all threads suspended. 1960 reference_processor_.EnqueueClearedReferences(self); 1961 uint64_t duration = NanoTime() - start_time; 1962 GrowForUtilization(semi_space_collector_); 1963 DCHECK(collector != nullptr); 1964 LogGC(kGcCauseCollectorTransition, collector); 1965 FinishGC(self, collector::kGcTypeFull); 1966 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1967 int32_t delta_allocated = before_allocated - after_allocated; 1968 std::string saved_str; 1969 if (delta_allocated >= 0) { 1970 saved_str = " saved at least " + PrettySize(delta_allocated); 1971 } else { 1972 saved_str = " expanded " + PrettySize(-delta_allocated); 1973 } 1974 VLOG(heap) << "Heap transition to " << process_state_ << " took " 1975 << PrettyDuration(duration) << saved_str; 1976} 1977 1978void Heap::ChangeCollector(CollectorType collector_type) { 1979 // TODO: Only do this with all mutators suspended to avoid races. 1980 if (collector_type != collector_type_) { 1981 if (collector_type == kCollectorTypeMC) { 1982 // Don't allow mark compact unless support is compiled in. 1983 CHECK(kMarkCompactSupport); 1984 } 1985 collector_type_ = collector_type; 1986 gc_plan_.clear(); 1987 switch (collector_type_) { 1988 case kCollectorTypeCC: { 1989 gc_plan_.push_back(collector::kGcTypeFull); 1990 if (use_tlab_) { 1991 ChangeAllocator(kAllocatorTypeRegionTLAB); 1992 } else { 1993 ChangeAllocator(kAllocatorTypeRegion); 1994 } 1995 break; 1996 } 1997 case kCollectorTypeMC: // Fall-through. 1998 case kCollectorTypeSS: // Fall-through. 1999 case kCollectorTypeGSS: { 2000 gc_plan_.push_back(collector::kGcTypeFull); 2001 if (use_tlab_) { 2002 ChangeAllocator(kAllocatorTypeTLAB); 2003 } else { 2004 ChangeAllocator(kAllocatorTypeBumpPointer); 2005 } 2006 break; 2007 } 2008 case kCollectorTypeMS: { 2009 gc_plan_.push_back(collector::kGcTypeSticky); 2010 gc_plan_.push_back(collector::kGcTypePartial); 2011 gc_plan_.push_back(collector::kGcTypeFull); 2012 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 2013 break; 2014 } 2015 case kCollectorTypeCMS: { 2016 gc_plan_.push_back(collector::kGcTypeSticky); 2017 gc_plan_.push_back(collector::kGcTypePartial); 2018 gc_plan_.push_back(collector::kGcTypeFull); 2019 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 2020 break; 2021 } 2022 default: { 2023 UNIMPLEMENTED(FATAL); 2024 UNREACHABLE(); 2025 } 2026 } 2027 if (IsGcConcurrent()) { 2028 concurrent_start_bytes_ = 2029 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 2030 } else { 2031 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2032 } 2033 } 2034} 2035 2036// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 2037class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 2038 public: 2039 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 2040 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 2041 } 2042 2043 void BuildBins(space::ContinuousSpace* space) { 2044 bin_live_bitmap_ = space->GetLiveBitmap(); 2045 bin_mark_bitmap_ = space->GetMarkBitmap(); 2046 BinContext context; 2047 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 2048 context.collector_ = this; 2049 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 2050 // Note: This requires traversing the space in increasing order of object addresses. 2051 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 2052 // Add the last bin which spans after the last object to the end of the space. 2053 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 2054 } 2055 2056 private: 2057 struct BinContext { 2058 uintptr_t prev_; // The end of the previous object. 2059 ZygoteCompactingCollector* collector_; 2060 }; 2061 // Maps from bin sizes to locations. 2062 std::multimap<size_t, uintptr_t> bins_; 2063 // Live bitmap of the space which contains the bins. 2064 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 2065 // Mark bitmap of the space which contains the bins. 2066 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 2067 2068 static void Callback(mirror::Object* obj, void* arg) 2069 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2070 DCHECK(arg != nullptr); 2071 BinContext* context = reinterpret_cast<BinContext*>(arg); 2072 ZygoteCompactingCollector* collector = context->collector_; 2073 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 2074 size_t bin_size = object_addr - context->prev_; 2075 // Add the bin consisting of the end of the previous object to the start of the current object. 2076 collector->AddBin(bin_size, context->prev_); 2077 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 2078 } 2079 2080 void AddBin(size_t size, uintptr_t position) { 2081 if (size != 0) { 2082 bins_.insert(std::make_pair(size, position)); 2083 } 2084 } 2085 2086 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 2087 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 2088 // allocator. 2089 UNUSED(space); 2090 return false; 2091 } 2092 2093 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 2094 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 2095 size_t obj_size = obj->SizeOf(); 2096 size_t alloc_size = RoundUp(obj_size, kObjectAlignment); 2097 mirror::Object* forward_address; 2098 // Find the smallest bin which we can move obj in. 2099 auto it = bins_.lower_bound(alloc_size); 2100 if (it == bins_.end()) { 2101 // No available space in the bins, place it in the target space instead (grows the zygote 2102 // space). 2103 size_t bytes_allocated, dummy; 2104 forward_address = to_space_->Alloc(self_, alloc_size, &bytes_allocated, nullptr, &dummy); 2105 if (to_space_live_bitmap_ != nullptr) { 2106 to_space_live_bitmap_->Set(forward_address); 2107 } else { 2108 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 2109 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 2110 } 2111 } else { 2112 size_t size = it->first; 2113 uintptr_t pos = it->second; 2114 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 2115 forward_address = reinterpret_cast<mirror::Object*>(pos); 2116 // Set the live and mark bits so that sweeping system weaks works properly. 2117 bin_live_bitmap_->Set(forward_address); 2118 bin_mark_bitmap_->Set(forward_address); 2119 DCHECK_GE(size, alloc_size); 2120 // Add a new bin with the remaining space. 2121 AddBin(size - alloc_size, pos + alloc_size); 2122 } 2123 // Copy the object over to its new location. Don't use alloc_size to avoid valgrind error. 2124 memcpy(reinterpret_cast<void*>(forward_address), obj, obj_size); 2125 if (kUseBakerOrBrooksReadBarrier) { 2126 obj->AssertReadBarrierPointer(); 2127 if (kUseBrooksReadBarrier) { 2128 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 2129 forward_address->SetReadBarrierPointer(forward_address); 2130 } 2131 forward_address->AssertReadBarrierPointer(); 2132 } 2133 return forward_address; 2134 } 2135}; 2136 2137void Heap::UnBindBitmaps() { 2138 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 2139 for (const auto& space : GetContinuousSpaces()) { 2140 if (space->IsContinuousMemMapAllocSpace()) { 2141 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 2142 if (alloc_space->HasBoundBitmaps()) { 2143 alloc_space->UnBindBitmaps(); 2144 } 2145 } 2146 } 2147} 2148 2149void Heap::PreZygoteFork() { 2150 if (!HasZygoteSpace()) { 2151 // We still want to GC in case there is some unreachable non moving objects that could cause a 2152 // suboptimal bin packing when we compact the zygote space. 2153 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 2154 } 2155 Thread* self = Thread::Current(); 2156 MutexLock mu(self, zygote_creation_lock_); 2157 // Try to see if we have any Zygote spaces. 2158 if (HasZygoteSpace()) { 2159 return; 2160 } 2161 Runtime::Current()->GetInternTable()->SwapPostZygoteWithPreZygote(); 2162 Runtime::Current()->GetClassLinker()->MoveClassTableToPreZygote(); 2163 VLOG(heap) << "Starting PreZygoteFork"; 2164 // Trim the pages at the end of the non moving space. 2165 non_moving_space_->Trim(); 2166 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 2167 // there. 2168 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2169 const bool same_space = non_moving_space_ == main_space_; 2170 if (kCompactZygote) { 2171 // Temporarily disable rosalloc verification because the zygote 2172 // compaction will mess up the rosalloc internal metadata. 2173 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 2174 ZygoteCompactingCollector zygote_collector(this); 2175 zygote_collector.BuildBins(non_moving_space_); 2176 // Create a new bump pointer space which we will compact into. 2177 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 2178 non_moving_space_->Limit()); 2179 // Compact the bump pointer space to a new zygote bump pointer space. 2180 bool reset_main_space = false; 2181 if (IsMovingGc(collector_type_)) { 2182 if (collector_type_ == kCollectorTypeCC) { 2183 zygote_collector.SetFromSpace(region_space_); 2184 } else { 2185 zygote_collector.SetFromSpace(bump_pointer_space_); 2186 } 2187 } else { 2188 CHECK(main_space_ != nullptr); 2189 CHECK_NE(main_space_, non_moving_space_) 2190 << "Does not make sense to compact within the same space"; 2191 // Copy from the main space. 2192 zygote_collector.SetFromSpace(main_space_); 2193 reset_main_space = true; 2194 } 2195 zygote_collector.SetToSpace(&target_space); 2196 zygote_collector.SetSwapSemiSpaces(false); 2197 zygote_collector.Run(kGcCauseCollectorTransition, false); 2198 if (reset_main_space) { 2199 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2200 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 2201 MemMap* mem_map = main_space_->ReleaseMemMap(); 2202 RemoveSpace(main_space_); 2203 space::Space* old_main_space = main_space_; 2204 CreateMainMallocSpace(mem_map, kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 2205 mem_map->Size()); 2206 delete old_main_space; 2207 AddSpace(main_space_); 2208 } else { 2209 if (collector_type_ == kCollectorTypeCC) { 2210 region_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2211 } else { 2212 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2213 } 2214 } 2215 if (temp_space_ != nullptr) { 2216 CHECK(temp_space_->IsEmpty()); 2217 } 2218 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2219 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2220 // Update the end and write out image. 2221 non_moving_space_->SetEnd(target_space.End()); 2222 non_moving_space_->SetLimit(target_space.Limit()); 2223 VLOG(heap) << "Create zygote space with size=" << non_moving_space_->Size() << " bytes"; 2224 } 2225 // Change the collector to the post zygote one. 2226 ChangeCollector(foreground_collector_type_); 2227 // Save the old space so that we can remove it after we complete creating the zygote space. 2228 space::MallocSpace* old_alloc_space = non_moving_space_; 2229 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 2230 // the remaining available space. 2231 // Remove the old space before creating the zygote space since creating the zygote space sets 2232 // the old alloc space's bitmaps to null. 2233 RemoveSpace(old_alloc_space); 2234 if (collector::SemiSpace::kUseRememberedSet) { 2235 // Sanity bound check. 2236 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 2237 // Remove the remembered set for the now zygote space (the old 2238 // non-moving space). Note now that we have compacted objects into 2239 // the zygote space, the data in the remembered set is no longer 2240 // needed. The zygote space will instead have a mod-union table 2241 // from this point on. 2242 RemoveRememberedSet(old_alloc_space); 2243 } 2244 // Remaining space becomes the new non moving space. 2245 zygote_space_ = old_alloc_space->CreateZygoteSpace(kNonMovingSpaceName, low_memory_mode_, 2246 &non_moving_space_); 2247 CHECK(!non_moving_space_->CanMoveObjects()); 2248 if (same_space) { 2249 main_space_ = non_moving_space_; 2250 SetSpaceAsDefault(main_space_); 2251 } 2252 delete old_alloc_space; 2253 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 2254 AddSpace(zygote_space_); 2255 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 2256 AddSpace(non_moving_space_); 2257 // Create the zygote space mod union table. 2258 accounting::ModUnionTable* mod_union_table = 2259 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 2260 zygote_space_); 2261 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 2262 // Set all the cards in the mod-union table since we don't know which objects contain references 2263 // to large objects. 2264 mod_union_table->SetCards(); 2265 AddModUnionTable(mod_union_table); 2266 large_object_space_->SetAllLargeObjectsAsZygoteObjects(self); 2267 if (collector::SemiSpace::kUseRememberedSet) { 2268 // Add a new remembered set for the post-zygote non-moving space. 2269 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 2270 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2271 non_moving_space_); 2272 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2273 << "Failed to create post-zygote non-moving space remembered set"; 2274 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2275 } 2276} 2277 2278void Heap::FlushAllocStack() { 2279 MarkAllocStackAsLive(allocation_stack_.get()); 2280 allocation_stack_->Reset(); 2281} 2282 2283void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2284 accounting::ContinuousSpaceBitmap* bitmap2, 2285 accounting::LargeObjectBitmap* large_objects, 2286 accounting::ObjectStack* stack) { 2287 DCHECK(bitmap1 != nullptr); 2288 DCHECK(bitmap2 != nullptr); 2289 const auto* limit = stack->End(); 2290 for (auto* it = stack->Begin(); it != limit; ++it) { 2291 const mirror::Object* obj = it->AsMirrorPtr(); 2292 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2293 if (bitmap1->HasAddress(obj)) { 2294 bitmap1->Set(obj); 2295 } else if (bitmap2->HasAddress(obj)) { 2296 bitmap2->Set(obj); 2297 } else { 2298 DCHECK(large_objects != nullptr); 2299 large_objects->Set(obj); 2300 } 2301 } 2302 } 2303} 2304 2305void Heap::SwapSemiSpaces() { 2306 CHECK(bump_pointer_space_ != nullptr); 2307 CHECK(temp_space_ != nullptr); 2308 std::swap(bump_pointer_space_, temp_space_); 2309} 2310 2311collector::GarbageCollector* Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2312 space::ContinuousMemMapAllocSpace* source_space, 2313 GcCause gc_cause) { 2314 CHECK(kMovingCollector); 2315 if (target_space != source_space) { 2316 // Don't swap spaces since this isn't a typical semi space collection. 2317 semi_space_collector_->SetSwapSemiSpaces(false); 2318 semi_space_collector_->SetFromSpace(source_space); 2319 semi_space_collector_->SetToSpace(target_space); 2320 semi_space_collector_->Run(gc_cause, false); 2321 return semi_space_collector_; 2322 } else { 2323 CHECK(target_space->IsBumpPointerSpace()) 2324 << "In-place compaction is only supported for bump pointer spaces"; 2325 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2326 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2327 return mark_compact_collector_; 2328 } 2329} 2330 2331collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2332 bool clear_soft_references) { 2333 Thread* self = Thread::Current(); 2334 Runtime* runtime = Runtime::Current(); 2335 // If the heap can't run the GC, silently fail and return that no GC was run. 2336 switch (gc_type) { 2337 case collector::kGcTypePartial: { 2338 if (!HasZygoteSpace()) { 2339 return collector::kGcTypeNone; 2340 } 2341 break; 2342 } 2343 default: { 2344 // Other GC types don't have any special cases which makes them not runnable. The main case 2345 // here is full GC. 2346 } 2347 } 2348 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2349 Locks::mutator_lock_->AssertNotHeld(self); 2350 if (self->IsHandlingStackOverflow()) { 2351 // If we are throwing a stack overflow error we probably don't have enough remaining stack 2352 // space to run the GC. 2353 return collector::kGcTypeNone; 2354 } 2355 bool compacting_gc; 2356 { 2357 gc_complete_lock_->AssertNotHeld(self); 2358 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 2359 MutexLock mu(self, *gc_complete_lock_); 2360 // Ensure there is only one GC at a time. 2361 WaitForGcToCompleteLocked(gc_cause, self); 2362 compacting_gc = IsMovingGc(collector_type_); 2363 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2364 if (compacting_gc && disable_moving_gc_count_ != 0) { 2365 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2366 return collector::kGcTypeNone; 2367 } 2368 collector_type_running_ = collector_type_; 2369 } 2370 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2371 ++runtime->GetStats()->gc_for_alloc_count; 2372 ++self->GetStats()->gc_for_alloc_count; 2373 } 2374 const uint64_t bytes_allocated_before_gc = GetBytesAllocated(); 2375 // Approximate heap size. 2376 ATRACE_INT("Heap size (KB)", bytes_allocated_before_gc / KB); 2377 2378 DCHECK_LT(gc_type, collector::kGcTypeMax); 2379 DCHECK_NE(gc_type, collector::kGcTypeNone); 2380 2381 collector::GarbageCollector* collector = nullptr; 2382 // TODO: Clean this up. 2383 if (compacting_gc) { 2384 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2385 current_allocator_ == kAllocatorTypeTLAB || 2386 current_allocator_ == kAllocatorTypeRegion || 2387 current_allocator_ == kAllocatorTypeRegionTLAB); 2388 switch (collector_type_) { 2389 case kCollectorTypeSS: 2390 // Fall-through. 2391 case kCollectorTypeGSS: 2392 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2393 semi_space_collector_->SetToSpace(temp_space_); 2394 semi_space_collector_->SetSwapSemiSpaces(true); 2395 collector = semi_space_collector_; 2396 break; 2397 case kCollectorTypeCC: 2398 concurrent_copying_collector_->SetRegionSpace(region_space_); 2399 collector = concurrent_copying_collector_; 2400 break; 2401 case kCollectorTypeMC: 2402 mark_compact_collector_->SetSpace(bump_pointer_space_); 2403 collector = mark_compact_collector_; 2404 break; 2405 default: 2406 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2407 } 2408 if (collector != mark_compact_collector_ && collector != concurrent_copying_collector_) { 2409 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2410 CHECK(temp_space_->IsEmpty()); 2411 } 2412 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2413 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2414 current_allocator_ == kAllocatorTypeDlMalloc) { 2415 collector = FindCollectorByGcType(gc_type); 2416 } else { 2417 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2418 } 2419 if (IsGcConcurrent()) { 2420 // Disable concurrent GC check so that we don't have spammy JNI requests. 2421 // This gets recalculated in GrowForUtilization. It is important that it is disabled / 2422 // calculated in the same thread so that there aren't any races that can cause it to become 2423 // permanantly disabled. b/17942071 2424 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2425 } 2426 CHECK(collector != nullptr) 2427 << "Could not find garbage collector with collector_type=" 2428 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2429 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2430 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2431 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2432 RequestTrim(self); 2433 // Enqueue cleared references. 2434 reference_processor_.EnqueueClearedReferences(self); 2435 // Grow the heap so that we know when to perform the next GC. 2436 GrowForUtilization(collector, bytes_allocated_before_gc); 2437 LogGC(gc_cause, collector); 2438 FinishGC(self, gc_type); 2439 // Inform DDMS that a GC completed. 2440 Dbg::GcDidFinish(); 2441 return gc_type; 2442} 2443 2444void Heap::LogGC(GcCause gc_cause, collector::GarbageCollector* collector) { 2445 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2446 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2447 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2448 // (mutator time blocked >= long_pause_log_threshold_). 2449 bool log_gc = gc_cause == kGcCauseExplicit; 2450 if (!log_gc && CareAboutPauseTimes()) { 2451 // GC for alloc pauses the allocating thread, so consider it as a pause. 2452 log_gc = duration > long_gc_log_threshold_ || 2453 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2454 for (uint64_t pause : pause_times) { 2455 log_gc = log_gc || pause >= long_pause_log_threshold_; 2456 } 2457 } 2458 if (log_gc) { 2459 const size_t percent_free = GetPercentFree(); 2460 const size_t current_heap_size = GetBytesAllocated(); 2461 const size_t total_memory = GetTotalMemory(); 2462 std::ostringstream pause_string; 2463 for (size_t i = 0; i < pause_times.size(); ++i) { 2464 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2465 << ((i != pause_times.size() - 1) ? "," : ""); 2466 } 2467 LOG(INFO) << gc_cause << " " << collector->GetName() 2468 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2469 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2470 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2471 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2472 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2473 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2474 << " total " << PrettyDuration((duration / 1000) * 1000); 2475 VLOG(heap) << Dumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2476 } 2477} 2478 2479void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2480 MutexLock mu(self, *gc_complete_lock_); 2481 collector_type_running_ = kCollectorTypeNone; 2482 if (gc_type != collector::kGcTypeNone) { 2483 last_gc_type_ = gc_type; 2484 2485 // Update stats. 2486 ++gc_count_last_window_; 2487 if (running_collection_is_blocking_) { 2488 // If the currently running collection was a blocking one, 2489 // increment the counters and reset the flag. 2490 ++blocking_gc_count_; 2491 blocking_gc_time_ += GetCurrentGcIteration()->GetDurationNs(); 2492 ++blocking_gc_count_last_window_; 2493 } 2494 // Update the gc count rate histograms if due. 2495 UpdateGcCountRateHistograms(); 2496 } 2497 // Reset. 2498 running_collection_is_blocking_ = false; 2499 // Wake anyone who may have been waiting for the GC to complete. 2500 gc_complete_cond_->Broadcast(self); 2501} 2502 2503void Heap::UpdateGcCountRateHistograms() { 2504 // Invariant: if the time since the last update includes more than 2505 // one windows, all the GC runs (if > 0) must have happened in first 2506 // window because otherwise the update must have already taken place 2507 // at an earlier GC run. So, we report the non-first windows with 2508 // zero counts to the histograms. 2509 DCHECK_EQ(last_update_time_gc_count_rate_histograms_ % kGcCountRateHistogramWindowDuration, 0U); 2510 uint64_t now = NanoTime(); 2511 DCHECK_GE(now, last_update_time_gc_count_rate_histograms_); 2512 uint64_t time_since_last_update = now - last_update_time_gc_count_rate_histograms_; 2513 uint64_t num_of_windows = time_since_last_update / kGcCountRateHistogramWindowDuration; 2514 if (time_since_last_update >= kGcCountRateHistogramWindowDuration) { 2515 // Record the first window. 2516 gc_count_rate_histogram_.AddValue(gc_count_last_window_ - 1); // Exclude the current run. 2517 blocking_gc_count_rate_histogram_.AddValue(running_collection_is_blocking_ ? 2518 blocking_gc_count_last_window_ - 1 : blocking_gc_count_last_window_); 2519 // Record the other windows (with zero counts). 2520 for (uint64_t i = 0; i < num_of_windows - 1; ++i) { 2521 gc_count_rate_histogram_.AddValue(0); 2522 blocking_gc_count_rate_histogram_.AddValue(0); 2523 } 2524 // Update the last update time and reset the counters. 2525 last_update_time_gc_count_rate_histograms_ = 2526 (now / kGcCountRateHistogramWindowDuration) * kGcCountRateHistogramWindowDuration; 2527 gc_count_last_window_ = 1; // Include the current run. 2528 blocking_gc_count_last_window_ = running_collection_is_blocking_ ? 1 : 0; 2529 } 2530 DCHECK_EQ(last_update_time_gc_count_rate_histograms_ % kGcCountRateHistogramWindowDuration, 0U); 2531} 2532 2533class RootMatchesObjectVisitor : public SingleRootVisitor { 2534 public: 2535 explicit RootMatchesObjectVisitor(const mirror::Object* obj) : obj_(obj) { } 2536 2537 void VisitRoot(mirror::Object* root, const RootInfo& info) 2538 OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2539 if (root == obj_) { 2540 LOG(INFO) << "Object " << obj_ << " is a root " << info.ToString(); 2541 } 2542 } 2543 2544 private: 2545 const mirror::Object* const obj_; 2546}; 2547 2548 2549class ScanVisitor { 2550 public: 2551 void operator()(const mirror::Object* obj) const { 2552 LOG(ERROR) << "Would have rescanned object " << obj; 2553 } 2554}; 2555 2556// Verify a reference from an object. 2557class VerifyReferenceVisitor : public SingleRootVisitor { 2558 public: 2559 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2560 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2561 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2562 2563 size_t GetFailureCount() const { 2564 return fail_count_->LoadSequentiallyConsistent(); 2565 } 2566 2567 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2568 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2569 UNUSED(klass); 2570 if (verify_referent_) { 2571 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2572 } 2573 } 2574 2575 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2576 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2577 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2578 } 2579 2580 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2581 return heap_->IsLiveObjectLocked(obj, true, false, true); 2582 } 2583 2584 void VisitRoot(mirror::Object* root, const RootInfo& root_info) OVERRIDE 2585 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2586 if (root == nullptr) { 2587 LOG(ERROR) << "Root is null with info " << root_info.GetType(); 2588 } else if (!VerifyReference(nullptr, root, MemberOffset(0))) { 2589 LOG(ERROR) << "Root " << root << " is dead with type " << PrettyTypeOf(root) 2590 << " thread_id= " << root_info.GetThreadId() << " root_type= " << root_info.GetType(); 2591 } 2592 } 2593 2594 private: 2595 // TODO: Fix the no thread safety analysis. 2596 // Returns false on failure. 2597 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2598 NO_THREAD_SAFETY_ANALYSIS { 2599 if (ref == nullptr || IsLive(ref)) { 2600 // Verify that the reference is live. 2601 return true; 2602 } 2603 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2604 // Print message on only on first failure to prevent spam. 2605 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2606 } 2607 if (obj != nullptr) { 2608 // Only do this part for non roots. 2609 accounting::CardTable* card_table = heap_->GetCardTable(); 2610 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2611 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2612 uint8_t* card_addr = card_table->CardFromAddr(obj); 2613 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2614 << offset << "\n card value = " << static_cast<int>(*card_addr); 2615 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2616 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2617 } else { 2618 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2619 } 2620 2621 // Attempt to find the class inside of the recently freed objects. 2622 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2623 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2624 space::MallocSpace* space = ref_space->AsMallocSpace(); 2625 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2626 if (ref_class != nullptr) { 2627 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2628 << PrettyClass(ref_class); 2629 } else { 2630 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2631 } 2632 } 2633 2634 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2635 ref->GetClass()->IsClass()) { 2636 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2637 } else { 2638 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2639 << ") is not a valid heap address"; 2640 } 2641 2642 card_table->CheckAddrIsInCardTable(reinterpret_cast<const uint8_t*>(obj)); 2643 void* cover_begin = card_table->AddrFromCard(card_addr); 2644 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2645 accounting::CardTable::kCardSize); 2646 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2647 << "-" << cover_end; 2648 accounting::ContinuousSpaceBitmap* bitmap = 2649 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2650 2651 if (bitmap == nullptr) { 2652 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2653 if (!VerifyClassClass(obj->GetClass())) { 2654 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2655 } 2656 } else { 2657 // Print out how the object is live. 2658 if (bitmap->Test(obj)) { 2659 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2660 } 2661 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2662 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2663 } 2664 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2665 LOG(ERROR) << "Object " << obj << " found in live stack"; 2666 } 2667 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2668 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2669 } 2670 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2671 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2672 } 2673 // Attempt to see if the card table missed the reference. 2674 ScanVisitor scan_visitor; 2675 uint8_t* byte_cover_begin = reinterpret_cast<uint8_t*>(card_table->AddrFromCard(card_addr)); 2676 card_table->Scan<false>(bitmap, byte_cover_begin, 2677 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2678 } 2679 2680 // Search to see if any of the roots reference our object. 2681 RootMatchesObjectVisitor visitor1(obj); 2682 Runtime::Current()->VisitRoots(&visitor1); 2683 // Search to see if any of the roots reference our reference. 2684 RootMatchesObjectVisitor visitor2(ref); 2685 Runtime::Current()->VisitRoots(&visitor2); 2686 } 2687 return false; 2688 } 2689 2690 Heap* const heap_; 2691 Atomic<size_t>* const fail_count_; 2692 const bool verify_referent_; 2693}; 2694 2695// Verify all references within an object, for use with HeapBitmap::Visit. 2696class VerifyObjectVisitor { 2697 public: 2698 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2699 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2700 } 2701 2702 void operator()(mirror::Object* obj) const 2703 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2704 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2705 // be live or else how did we find it in the live bitmap? 2706 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2707 // The class doesn't count as a reference but we should verify it anyways. 2708 obj->VisitReferences<true>(visitor, visitor); 2709 } 2710 2711 static void VisitCallback(mirror::Object* obj, void* arg) 2712 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2713 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2714 visitor->operator()(obj); 2715 } 2716 2717 void VerifyRoots() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 2718 LOCKS_EXCLUDED(Locks::heap_bitmap_lock_) { 2719 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 2720 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2721 Runtime::Current()->VisitRoots(&visitor); 2722 } 2723 2724 size_t GetFailureCount() const { 2725 return fail_count_->LoadSequentiallyConsistent(); 2726 } 2727 2728 private: 2729 Heap* const heap_; 2730 Atomic<size_t>* const fail_count_; 2731 const bool verify_referent_; 2732}; 2733 2734void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2735 // Slow path, the allocation stack push back must have already failed. 2736 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2737 do { 2738 // TODO: Add handle VerifyObject. 2739 StackHandleScope<1> hs(self); 2740 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2741 // Push our object into the reserve region of the allocaiton stack. This is only required due 2742 // to heap verification requiring that roots are live (either in the live bitmap or in the 2743 // allocation stack). 2744 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2745 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2746 } while (!allocation_stack_->AtomicPushBack(*obj)); 2747} 2748 2749void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2750 // Slow path, the allocation stack push back must have already failed. 2751 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2752 StackReference<mirror::Object>* start_address; 2753 StackReference<mirror::Object>* end_address; 2754 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2755 &end_address)) { 2756 // TODO: Add handle VerifyObject. 2757 StackHandleScope<1> hs(self); 2758 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2759 // Push our object into the reserve region of the allocaiton stack. This is only required due 2760 // to heap verification requiring that roots are live (either in the live bitmap or in the 2761 // allocation stack). 2762 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2763 // Push into the reserve allocation stack. 2764 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2765 } 2766 self->SetThreadLocalAllocationStack(start_address, end_address); 2767 // Retry on the new thread-local allocation stack. 2768 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2769} 2770 2771// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2772size_t Heap::VerifyHeapReferences(bool verify_referents) { 2773 Thread* self = Thread::Current(); 2774 Locks::mutator_lock_->AssertExclusiveHeld(self); 2775 // Lets sort our allocation stacks so that we can efficiently binary search them. 2776 allocation_stack_->Sort(); 2777 live_stack_->Sort(); 2778 // Since we sorted the allocation stack content, need to revoke all 2779 // thread-local allocation stacks. 2780 RevokeAllThreadLocalAllocationStacks(self); 2781 Atomic<size_t> fail_count_(0); 2782 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2783 // Verify objects in the allocation stack since these will be objects which were: 2784 // 1. Allocated prior to the GC (pre GC verification). 2785 // 2. Allocated during the GC (pre sweep GC verification). 2786 // We don't want to verify the objects in the live stack since they themselves may be 2787 // pointing to dead objects if they are not reachable. 2788 VisitObjectsPaused(VerifyObjectVisitor::VisitCallback, &visitor); 2789 // Verify the roots: 2790 visitor.VerifyRoots(); 2791 if (visitor.GetFailureCount() > 0) { 2792 // Dump mod-union tables. 2793 for (const auto& table_pair : mod_union_tables_) { 2794 accounting::ModUnionTable* mod_union_table = table_pair.second; 2795 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2796 } 2797 // Dump remembered sets. 2798 for (const auto& table_pair : remembered_sets_) { 2799 accounting::RememberedSet* remembered_set = table_pair.second; 2800 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2801 } 2802 DumpSpaces(LOG(ERROR)); 2803 } 2804 return visitor.GetFailureCount(); 2805} 2806 2807class VerifyReferenceCardVisitor { 2808 public: 2809 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2810 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2811 Locks::heap_bitmap_lock_) 2812 : heap_(heap), failed_(failed) { 2813 } 2814 2815 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2816 // annotalysis on visitors. 2817 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2818 NO_THREAD_SAFETY_ANALYSIS { 2819 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2820 // Filter out class references since changing an object's class does not mark the card as dirty. 2821 // Also handles large objects, since the only reference they hold is a class reference. 2822 if (ref != nullptr && !ref->IsClass()) { 2823 accounting::CardTable* card_table = heap_->GetCardTable(); 2824 // If the object is not dirty and it is referencing something in the live stack other than 2825 // class, then it must be on a dirty card. 2826 if (!card_table->AddrIsInCardTable(obj)) { 2827 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2828 *failed_ = true; 2829 } else if (!card_table->IsDirty(obj)) { 2830 // TODO: Check mod-union tables. 2831 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2832 // kCardDirty - 1 if it didnt get touched since we aged it. 2833 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2834 if (live_stack->ContainsSorted(ref)) { 2835 if (live_stack->ContainsSorted(obj)) { 2836 LOG(ERROR) << "Object " << obj << " found in live stack"; 2837 } 2838 if (heap_->GetLiveBitmap()->Test(obj)) { 2839 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2840 } 2841 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2842 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2843 2844 // Print which field of the object is dead. 2845 if (!obj->IsObjectArray()) { 2846 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2847 CHECK(klass != nullptr); 2848 auto* fields = is_static ? klass->GetSFields() : klass->GetIFields(); 2849 auto num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); 2850 CHECK_EQ(fields == nullptr, num_fields == 0u); 2851 for (size_t i = 0; i < num_fields; ++i) { 2852 ArtField* cur = &fields[i]; 2853 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2854 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2855 << PrettyField(cur); 2856 break; 2857 } 2858 } 2859 } else { 2860 mirror::ObjectArray<mirror::Object>* object_array = 2861 obj->AsObjectArray<mirror::Object>(); 2862 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2863 if (object_array->Get(i) == ref) { 2864 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2865 } 2866 } 2867 } 2868 2869 *failed_ = true; 2870 } 2871 } 2872 } 2873 } 2874 2875 private: 2876 Heap* const heap_; 2877 bool* const failed_; 2878}; 2879 2880class VerifyLiveStackReferences { 2881 public: 2882 explicit VerifyLiveStackReferences(Heap* heap) 2883 : heap_(heap), 2884 failed_(false) {} 2885 2886 void operator()(mirror::Object* obj) const 2887 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2888 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2889 obj->VisitReferences<true>(visitor, VoidFunctor()); 2890 } 2891 2892 bool Failed() const { 2893 return failed_; 2894 } 2895 2896 private: 2897 Heap* const heap_; 2898 bool failed_; 2899}; 2900 2901bool Heap::VerifyMissingCardMarks() { 2902 Thread* self = Thread::Current(); 2903 Locks::mutator_lock_->AssertExclusiveHeld(self); 2904 // We need to sort the live stack since we binary search it. 2905 live_stack_->Sort(); 2906 // Since we sorted the allocation stack content, need to revoke all 2907 // thread-local allocation stacks. 2908 RevokeAllThreadLocalAllocationStacks(self); 2909 VerifyLiveStackReferences visitor(this); 2910 GetLiveBitmap()->Visit(visitor); 2911 // We can verify objects in the live stack since none of these should reference dead objects. 2912 for (auto* it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2913 if (!kUseThreadLocalAllocationStack || it->AsMirrorPtr() != nullptr) { 2914 visitor(it->AsMirrorPtr()); 2915 } 2916 } 2917 return !visitor.Failed(); 2918} 2919 2920void Heap::SwapStacks(Thread* self) { 2921 UNUSED(self); 2922 if (kUseThreadLocalAllocationStack) { 2923 live_stack_->AssertAllZero(); 2924 } 2925 allocation_stack_.swap(live_stack_); 2926} 2927 2928void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2929 // This must be called only during the pause. 2930 DCHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2931 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2932 MutexLock mu2(self, *Locks::thread_list_lock_); 2933 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2934 for (Thread* t : thread_list) { 2935 t->RevokeThreadLocalAllocationStack(); 2936 } 2937} 2938 2939void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2940 if (kIsDebugBuild) { 2941 if (rosalloc_space_ != nullptr) { 2942 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2943 } 2944 if (bump_pointer_space_ != nullptr) { 2945 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2946 } 2947 } 2948} 2949 2950void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2951 if (kIsDebugBuild) { 2952 if (bump_pointer_space_ != nullptr) { 2953 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2954 } 2955 } 2956} 2957 2958accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2959 auto it = mod_union_tables_.find(space); 2960 if (it == mod_union_tables_.end()) { 2961 return nullptr; 2962 } 2963 return it->second; 2964} 2965 2966accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2967 auto it = remembered_sets_.find(space); 2968 if (it == remembered_sets_.end()) { 2969 return nullptr; 2970 } 2971 return it->second; 2972} 2973 2974void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets, bool process_alloc_space_cards, 2975 bool clear_alloc_space_cards) { 2976 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2977 // Clear cards and keep track of cards cleared in the mod-union table. 2978 for (const auto& space : continuous_spaces_) { 2979 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2980 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2981 if (table != nullptr) { 2982 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2983 "ImageModUnionClearCards"; 2984 TimingLogger::ScopedTiming t2(name, timings); 2985 table->ClearCards(); 2986 } else if (use_rem_sets && rem_set != nullptr) { 2987 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2988 << static_cast<int>(collector_type_); 2989 TimingLogger::ScopedTiming t2("AllocSpaceRemSetClearCards", timings); 2990 rem_set->ClearCards(); 2991 } else if (process_alloc_space_cards) { 2992 TimingLogger::ScopedTiming t2("AllocSpaceClearCards", timings); 2993 if (clear_alloc_space_cards) { 2994 card_table_->ClearCardRange(space->Begin(), space->End()); 2995 } else { 2996 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these 2997 // cards were dirty before the GC started. 2998 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2999 // -> clean(cleaning thread). 3000 // The races are we either end up with: Aged card, unaged card. Since we have the 3001 // checkpoint roots and then we scan / update mod union tables after. We will always 3002 // scan either card. If we end up with the non aged card, we scan it it in the pause. 3003 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 3004 VoidFunctor()); 3005 } 3006 } 3007 } 3008} 3009 3010static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 3011} 3012 3013void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 3014 Thread* const self = Thread::Current(); 3015 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 3016 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 3017 if (verify_pre_gc_heap_) { 3018 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyHeapReferences", timings); 3019 size_t failures = VerifyHeapReferences(); 3020 if (failures > 0) { 3021 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 3022 << " failures"; 3023 } 3024 } 3025 // Check that all objects which reference things in the live stack are on dirty cards. 3026 if (verify_missing_card_marks_) { 3027 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyMissingCardMarks", timings); 3028 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 3029 SwapStacks(self); 3030 // Sort the live stack so that we can quickly binary search it later. 3031 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 3032 << " missing card mark verification failed\n" << DumpSpaces(); 3033 SwapStacks(self); 3034 } 3035 if (verify_mod_union_table_) { 3036 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyModUnionTables", timings); 3037 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 3038 for (const auto& table_pair : mod_union_tables_) { 3039 accounting::ModUnionTable* mod_union_table = table_pair.second; 3040 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 3041 mod_union_table->Verify(); 3042 } 3043 } 3044} 3045 3046void Heap::PreGcVerification(collector::GarbageCollector* gc) { 3047 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 3048 collector::GarbageCollector::ScopedPause pause(gc); 3049 PreGcVerificationPaused(gc); 3050 } 3051} 3052 3053void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 3054 UNUSED(gc); 3055 // TODO: Add a new runtime option for this? 3056 if (verify_pre_gc_rosalloc_) { 3057 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 3058 } 3059} 3060 3061void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 3062 Thread* const self = Thread::Current(); 3063 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 3064 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 3065 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 3066 // reachable objects. 3067 if (verify_pre_sweeping_heap_) { 3068 TimingLogger::ScopedTiming t2("(Paused)PostSweepingVerifyHeapReferences", timings); 3069 CHECK_NE(self->GetState(), kRunnable); 3070 { 3071 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 3072 // Swapping bound bitmaps does nothing. 3073 gc->SwapBitmaps(); 3074 } 3075 // Pass in false since concurrent reference processing can mean that the reference referents 3076 // may point to dead objects at the point which PreSweepingGcVerification is called. 3077 size_t failures = VerifyHeapReferences(false); 3078 if (failures > 0) { 3079 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 3080 << " failures"; 3081 } 3082 { 3083 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 3084 gc->SwapBitmaps(); 3085 } 3086 } 3087 if (verify_pre_sweeping_rosalloc_) { 3088 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 3089 } 3090} 3091 3092void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 3093 // Only pause if we have to do some verification. 3094 Thread* const self = Thread::Current(); 3095 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 3096 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 3097 if (verify_system_weaks_) { 3098 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 3099 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 3100 mark_sweep->VerifySystemWeaks(); 3101 } 3102 if (verify_post_gc_rosalloc_) { 3103 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 3104 } 3105 if (verify_post_gc_heap_) { 3106 TimingLogger::ScopedTiming t2("(Paused)PostGcVerifyHeapReferences", timings); 3107 size_t failures = VerifyHeapReferences(); 3108 if (failures > 0) { 3109 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 3110 << " failures"; 3111 } 3112 } 3113} 3114 3115void Heap::PostGcVerification(collector::GarbageCollector* gc) { 3116 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 3117 collector::GarbageCollector::ScopedPause pause(gc); 3118 PostGcVerificationPaused(gc); 3119 } 3120} 3121 3122void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 3123 TimingLogger::ScopedTiming t(name, timings); 3124 for (const auto& space : continuous_spaces_) { 3125 if (space->IsRosAllocSpace()) { 3126 VLOG(heap) << name << " : " << space->GetName(); 3127 space->AsRosAllocSpace()->Verify(); 3128 } 3129 } 3130} 3131 3132collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 3133 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 3134 MutexLock mu(self, *gc_complete_lock_); 3135 return WaitForGcToCompleteLocked(cause, self); 3136} 3137 3138collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 3139 collector::GcType last_gc_type = collector::kGcTypeNone; 3140 uint64_t wait_start = NanoTime(); 3141 while (collector_type_running_ != kCollectorTypeNone) { 3142 if (self != task_processor_->GetRunningThread()) { 3143 // The current thread is about to wait for a currently running 3144 // collection to finish. If the waiting thread is not the heap 3145 // task daemon thread, the currently running collection is 3146 // considered as a blocking GC. 3147 running_collection_is_blocking_ = true; 3148 VLOG(gc) << "Waiting for a blocking GC " << cause; 3149 } 3150 ATRACE_BEGIN("GC: Wait For Completion"); 3151 // We must wait, change thread state then sleep on gc_complete_cond_; 3152 gc_complete_cond_->Wait(self); 3153 last_gc_type = last_gc_type_; 3154 ATRACE_END(); 3155 } 3156 uint64_t wait_time = NanoTime() - wait_start; 3157 total_wait_time_ += wait_time; 3158 if (wait_time > long_pause_log_threshold_) { 3159 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 3160 << " for cause " << cause; 3161 } 3162 if (self != task_processor_->GetRunningThread()) { 3163 // The current thread is about to run a collection. If the thread 3164 // is not the heap task daemon thread, it's considered as a 3165 // blocking GC (i.e., blocking itself). 3166 running_collection_is_blocking_ = true; 3167 VLOG(gc) << "Starting a blocking GC " << cause; 3168 } 3169 return last_gc_type; 3170} 3171 3172void Heap::DumpForSigQuit(std::ostream& os) { 3173 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 3174 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 3175 DumpGcPerformanceInfo(os); 3176} 3177 3178size_t Heap::GetPercentFree() { 3179 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 3180} 3181 3182void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 3183 if (max_allowed_footprint > GetMaxMemory()) { 3184 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 3185 << PrettySize(GetMaxMemory()); 3186 max_allowed_footprint = GetMaxMemory(); 3187 } 3188 max_allowed_footprint_ = max_allowed_footprint; 3189} 3190 3191bool Heap::IsMovableObject(const mirror::Object* obj) const { 3192 if (kMovingCollector) { 3193 space::Space* space = FindContinuousSpaceFromObject(obj, true); 3194 if (space != nullptr) { 3195 // TODO: Check large object? 3196 return space->CanMoveObjects(); 3197 } 3198 } 3199 return false; 3200} 3201 3202void Heap::UpdateMaxNativeFootprint() { 3203 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 3204 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 3205 size_t target_size = native_size / GetTargetHeapUtilization(); 3206 if (target_size > native_size + max_free_) { 3207 target_size = native_size + max_free_; 3208 } else if (target_size < native_size + min_free_) { 3209 target_size = native_size + min_free_; 3210 } 3211 native_footprint_gc_watermark_ = std::min(growth_limit_, target_size); 3212} 3213 3214collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 3215 for (const auto& collector : garbage_collectors_) { 3216 if (collector->GetCollectorType() == collector_type_ && 3217 collector->GetGcType() == gc_type) { 3218 return collector; 3219 } 3220 } 3221 return nullptr; 3222} 3223 3224double Heap::HeapGrowthMultiplier() const { 3225 // If we don't care about pause times we are background, so return 1.0. 3226 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 3227 return 1.0; 3228 } 3229 return foreground_heap_growth_multiplier_; 3230} 3231 3232void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran, 3233 uint64_t bytes_allocated_before_gc) { 3234 // We know what our utilization is at this moment. 3235 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 3236 const uint64_t bytes_allocated = GetBytesAllocated(); 3237 uint64_t target_size; 3238 collector::GcType gc_type = collector_ran->GetGcType(); 3239 const double multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 3240 // foreground. 3241 const uint64_t adjusted_min_free = static_cast<uint64_t>(min_free_ * multiplier); 3242 const uint64_t adjusted_max_free = static_cast<uint64_t>(max_free_ * multiplier); 3243 if (gc_type != collector::kGcTypeSticky) { 3244 // Grow the heap for non sticky GC. 3245 ssize_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 3246 CHECK_GE(delta, 0); 3247 target_size = bytes_allocated + delta * multiplier; 3248 target_size = std::min(target_size, bytes_allocated + adjusted_max_free); 3249 target_size = std::max(target_size, bytes_allocated + adjusted_min_free); 3250 native_need_to_run_finalization_ = true; 3251 next_gc_type_ = collector::kGcTypeSticky; 3252 } else { 3253 collector::GcType non_sticky_gc_type = 3254 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 3255 // Find what the next non sticky collector will be. 3256 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 3257 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 3258 // do another sticky collection next. 3259 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 3260 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 3261 // if the sticky GC throughput always remained >= the full/partial throughput. 3262 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 3263 non_sticky_collector->GetEstimatedMeanThroughput() && 3264 non_sticky_collector->NumberOfIterations() > 0 && 3265 bytes_allocated <= max_allowed_footprint_) { 3266 next_gc_type_ = collector::kGcTypeSticky; 3267 } else { 3268 next_gc_type_ = non_sticky_gc_type; 3269 } 3270 // If we have freed enough memory, shrink the heap back down. 3271 if (bytes_allocated + adjusted_max_free < max_allowed_footprint_) { 3272 target_size = bytes_allocated + adjusted_max_free; 3273 } else { 3274 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 3275 } 3276 } 3277 if (!ignore_max_footprint_) { 3278 SetIdealFootprint(target_size); 3279 if (IsGcConcurrent()) { 3280 const uint64_t freed_bytes = current_gc_iteration_.GetFreedBytes() + 3281 current_gc_iteration_.GetFreedLargeObjectBytes() + 3282 current_gc_iteration_.GetFreedRevokeBytes(); 3283 // Bytes allocated will shrink by freed_bytes after the GC runs, so if we want to figure out 3284 // how many bytes were allocated during the GC we need to add freed_bytes back on. 3285 CHECK_GE(bytes_allocated + freed_bytes, bytes_allocated_before_gc); 3286 const uint64_t bytes_allocated_during_gc = bytes_allocated + freed_bytes - 3287 bytes_allocated_before_gc; 3288 // Calculate when to perform the next ConcurrentGC. 3289 // Calculate the estimated GC duration. 3290 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 3291 // Estimate how many remaining bytes we will have when we need to start the next GC. 3292 size_t remaining_bytes = bytes_allocated_during_gc * gc_duration_seconds; 3293 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 3294 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 3295 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 3296 // A never going to happen situation that from the estimated allocation rate we will exceed 3297 // the applications entire footprint with the given estimated allocation rate. Schedule 3298 // another GC nearly straight away. 3299 remaining_bytes = kMinConcurrentRemainingBytes; 3300 } 3301 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 3302 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 3303 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 3304 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 3305 // right away. 3306 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 3307 static_cast<size_t>(bytes_allocated)); 3308 } 3309 } 3310} 3311 3312void Heap::ClampGrowthLimit() { 3313 // Use heap bitmap lock to guard against races with BindLiveToMarkBitmap. 3314 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 3315 capacity_ = growth_limit_; 3316 for (const auto& space : continuous_spaces_) { 3317 if (space->IsMallocSpace()) { 3318 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3319 malloc_space->ClampGrowthLimit(); 3320 } 3321 } 3322 // This space isn't added for performance reasons. 3323 if (main_space_backup_.get() != nullptr) { 3324 main_space_backup_->ClampGrowthLimit(); 3325 } 3326} 3327 3328void Heap::ClearGrowthLimit() { 3329 growth_limit_ = capacity_; 3330 for (const auto& space : continuous_spaces_) { 3331 if (space->IsMallocSpace()) { 3332 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3333 malloc_space->ClearGrowthLimit(); 3334 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 3335 } 3336 } 3337 // This space isn't added for performance reasons. 3338 if (main_space_backup_.get() != nullptr) { 3339 main_space_backup_->ClearGrowthLimit(); 3340 main_space_backup_->SetFootprintLimit(main_space_backup_->Capacity()); 3341 } 3342} 3343 3344void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 3345 ScopedObjectAccess soa(self); 3346 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 3347 jvalue args[1]; 3348 args[0].l = arg.get(); 3349 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 3350 // Restore object in case it gets moved. 3351 *object = soa.Decode<mirror::Object*>(arg.get()); 3352} 3353 3354void Heap::RequestConcurrentGCAndSaveObject(Thread* self, bool force_full, mirror::Object** obj) { 3355 StackHandleScope<1> hs(self); 3356 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 3357 RequestConcurrentGC(self, force_full); 3358} 3359 3360class Heap::ConcurrentGCTask : public HeapTask { 3361 public: 3362 explicit ConcurrentGCTask(uint64_t target_time, bool force_full) 3363 : HeapTask(target_time), force_full_(force_full) { } 3364 virtual void Run(Thread* self) OVERRIDE { 3365 gc::Heap* heap = Runtime::Current()->GetHeap(); 3366 heap->ConcurrentGC(self, force_full_); 3367 heap->ClearConcurrentGCRequest(); 3368 } 3369 3370 private: 3371 const bool force_full_; // If true, force full (or partial) collection. 3372}; 3373 3374static bool CanAddHeapTask(Thread* self) LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_) { 3375 Runtime* runtime = Runtime::Current(); 3376 return runtime != nullptr && runtime->IsFinishedStarting() && !runtime->IsShuttingDown(self) && 3377 !self->IsHandlingStackOverflow(); 3378} 3379 3380void Heap::ClearConcurrentGCRequest() { 3381 concurrent_gc_pending_.StoreRelaxed(false); 3382} 3383 3384void Heap::RequestConcurrentGC(Thread* self, bool force_full) { 3385 if (CanAddHeapTask(self) && 3386 concurrent_gc_pending_.CompareExchangeStrongSequentiallyConsistent(false, true)) { 3387 task_processor_->AddTask(self, new ConcurrentGCTask(NanoTime(), // Start straight away. 3388 force_full)); 3389 } 3390} 3391 3392void Heap::ConcurrentGC(Thread* self, bool force_full) { 3393 if (!Runtime::Current()->IsShuttingDown(self)) { 3394 // Wait for any GCs currently running to finish. 3395 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 3396 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 3397 // instead. E.g. can't do partial, so do full instead. 3398 collector::GcType next_gc_type = next_gc_type_; 3399 // If forcing full and next gc type is sticky, override with a non-sticky type. 3400 if (force_full && next_gc_type == collector::kGcTypeSticky) { 3401 next_gc_type = HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 3402 } 3403 if (CollectGarbageInternal(next_gc_type, kGcCauseBackground, false) == 3404 collector::kGcTypeNone) { 3405 for (collector::GcType gc_type : gc_plan_) { 3406 // Attempt to run the collector, if we succeed, we are done. 3407 if (gc_type > next_gc_type && 3408 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != 3409 collector::kGcTypeNone) { 3410 break; 3411 } 3412 } 3413 } 3414 } 3415 } 3416} 3417 3418class Heap::CollectorTransitionTask : public HeapTask { 3419 public: 3420 explicit CollectorTransitionTask(uint64_t target_time) : HeapTask(target_time) { } 3421 virtual void Run(Thread* self) OVERRIDE { 3422 gc::Heap* heap = Runtime::Current()->GetHeap(); 3423 heap->DoPendingCollectorTransition(); 3424 heap->ClearPendingCollectorTransition(self); 3425 } 3426}; 3427 3428void Heap::ClearPendingCollectorTransition(Thread* self) { 3429 MutexLock mu(self, *pending_task_lock_); 3430 pending_collector_transition_ = nullptr; 3431} 3432 3433void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 3434 Thread* self = Thread::Current(); 3435 desired_collector_type_ = desired_collector_type; 3436 if (desired_collector_type_ == collector_type_ || !CanAddHeapTask(self)) { 3437 return; 3438 } 3439 CollectorTransitionTask* added_task = nullptr; 3440 const uint64_t target_time = NanoTime() + delta_time; 3441 { 3442 MutexLock mu(self, *pending_task_lock_); 3443 // If we have an existing collector transition, update the targe time to be the new target. 3444 if (pending_collector_transition_ != nullptr) { 3445 task_processor_->UpdateTargetRunTime(self, pending_collector_transition_, target_time); 3446 return; 3447 } 3448 added_task = new CollectorTransitionTask(target_time); 3449 pending_collector_transition_ = added_task; 3450 } 3451 task_processor_->AddTask(self, added_task); 3452} 3453 3454class Heap::HeapTrimTask : public HeapTask { 3455 public: 3456 explicit HeapTrimTask(uint64_t delta_time) : HeapTask(NanoTime() + delta_time) { } 3457 virtual void Run(Thread* self) OVERRIDE { 3458 gc::Heap* heap = Runtime::Current()->GetHeap(); 3459 heap->Trim(self); 3460 heap->ClearPendingTrim(self); 3461 } 3462}; 3463 3464void Heap::ClearPendingTrim(Thread* self) { 3465 MutexLock mu(self, *pending_task_lock_); 3466 pending_heap_trim_ = nullptr; 3467} 3468 3469void Heap::RequestTrim(Thread* self) { 3470 if (!CanAddHeapTask(self)) { 3471 return; 3472 } 3473 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3474 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3475 // a space it will hold its lock and can become a cause of jank. 3476 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3477 // forking. 3478 3479 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3480 // because that only marks object heads, so a large array looks like lots of empty space. We 3481 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3482 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3483 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3484 // not how much use we're making of those pages. 3485 HeapTrimTask* added_task = nullptr; 3486 { 3487 MutexLock mu(self, *pending_task_lock_); 3488 if (pending_heap_trim_ != nullptr) { 3489 // Already have a heap trim request in task processor, ignore this request. 3490 return; 3491 } 3492 added_task = new HeapTrimTask(kHeapTrimWait); 3493 pending_heap_trim_ = added_task; 3494 } 3495 task_processor_->AddTask(self, added_task); 3496} 3497 3498void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3499 if (rosalloc_space_ != nullptr) { 3500 size_t freed_bytes_revoke = rosalloc_space_->RevokeThreadLocalBuffers(thread); 3501 if (freed_bytes_revoke > 0U) { 3502 num_bytes_freed_revoke_.FetchAndAddSequentiallyConsistent(freed_bytes_revoke); 3503 CHECK_GE(num_bytes_allocated_.LoadRelaxed(), num_bytes_freed_revoke_.LoadRelaxed()); 3504 } 3505 } 3506 if (bump_pointer_space_ != nullptr) { 3507 CHECK_EQ(bump_pointer_space_->RevokeThreadLocalBuffers(thread), 0U); 3508 } 3509 if (region_space_ != nullptr) { 3510 CHECK_EQ(region_space_->RevokeThreadLocalBuffers(thread), 0U); 3511 } 3512} 3513 3514void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3515 if (rosalloc_space_ != nullptr) { 3516 size_t freed_bytes_revoke = rosalloc_space_->RevokeThreadLocalBuffers(thread); 3517 if (freed_bytes_revoke > 0U) { 3518 num_bytes_freed_revoke_.FetchAndAddSequentiallyConsistent(freed_bytes_revoke); 3519 CHECK_GE(num_bytes_allocated_.LoadRelaxed(), num_bytes_freed_revoke_.LoadRelaxed()); 3520 } 3521 } 3522} 3523 3524void Heap::RevokeAllThreadLocalBuffers() { 3525 if (rosalloc_space_ != nullptr) { 3526 size_t freed_bytes_revoke = rosalloc_space_->RevokeAllThreadLocalBuffers(); 3527 if (freed_bytes_revoke > 0U) { 3528 num_bytes_freed_revoke_.FetchAndAddSequentiallyConsistent(freed_bytes_revoke); 3529 CHECK_GE(num_bytes_allocated_.LoadRelaxed(), num_bytes_freed_revoke_.LoadRelaxed()); 3530 } 3531 } 3532 if (bump_pointer_space_ != nullptr) { 3533 CHECK_EQ(bump_pointer_space_->RevokeAllThreadLocalBuffers(), 0U); 3534 } 3535 if (region_space_ != nullptr) { 3536 CHECK_EQ(region_space_->RevokeAllThreadLocalBuffers(), 0U); 3537 } 3538} 3539 3540bool Heap::IsGCRequestPending() const { 3541 return concurrent_gc_pending_.LoadRelaxed(); 3542} 3543 3544void Heap::RunFinalization(JNIEnv* env, uint64_t timeout) { 3545 env->CallStaticVoidMethod(WellKnownClasses::dalvik_system_VMRuntime, 3546 WellKnownClasses::dalvik_system_VMRuntime_runFinalization, 3547 static_cast<jlong>(timeout)); 3548} 3549 3550void Heap::RegisterNativeAllocation(JNIEnv* env, size_t bytes) { 3551 Thread* self = ThreadForEnv(env); 3552 if (native_need_to_run_finalization_) { 3553 RunFinalization(env, kNativeAllocationFinalizeTimeout); 3554 UpdateMaxNativeFootprint(); 3555 native_need_to_run_finalization_ = false; 3556 } 3557 // Total number of native bytes allocated. 3558 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3559 new_native_bytes_allocated += bytes; 3560 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3561 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3562 collector::kGcTypeFull; 3563 3564 // The second watermark is higher than the gc watermark. If you hit this it means you are 3565 // allocating native objects faster than the GC can keep up with. 3566 if (new_native_bytes_allocated > growth_limit_) { 3567 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3568 // Just finished a GC, attempt to run finalizers. 3569 RunFinalization(env, kNativeAllocationFinalizeTimeout); 3570 CHECK(!env->ExceptionCheck()); 3571 // Native bytes allocated may be updated by finalization, refresh it. 3572 new_native_bytes_allocated = native_bytes_allocated_.LoadRelaxed(); 3573 } 3574 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3575 if (new_native_bytes_allocated > growth_limit_) { 3576 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3577 RunFinalization(env, kNativeAllocationFinalizeTimeout); 3578 native_need_to_run_finalization_ = false; 3579 CHECK(!env->ExceptionCheck()); 3580 } 3581 // We have just run finalizers, update the native watermark since it is very likely that 3582 // finalizers released native managed allocations. 3583 UpdateMaxNativeFootprint(); 3584 } else if (!IsGCRequestPending()) { 3585 if (IsGcConcurrent()) { 3586 RequestConcurrentGC(self, true); // Request non-sticky type. 3587 } else { 3588 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3589 } 3590 } 3591 } 3592} 3593 3594void Heap::RegisterNativeFree(JNIEnv* env, size_t bytes) { 3595 size_t expected_size; 3596 do { 3597 expected_size = native_bytes_allocated_.LoadRelaxed(); 3598 if (UNLIKELY(bytes > expected_size)) { 3599 ScopedObjectAccess soa(env); 3600 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3601 StringPrintf("Attempted to free %zd native bytes with only %zd native bytes " 3602 "registered as allocated", bytes, expected_size).c_str()); 3603 break; 3604 } 3605 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, 3606 expected_size - bytes)); 3607} 3608 3609size_t Heap::GetTotalMemory() const { 3610 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3611} 3612 3613void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3614 DCHECK(mod_union_table != nullptr); 3615 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3616} 3617 3618void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3619 CHECK(c == nullptr || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3620 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3621 CHECK_GE(byte_count, sizeof(mirror::Object)); 3622} 3623 3624void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3625 CHECK(remembered_set != nullptr); 3626 space::Space* space = remembered_set->GetSpace(); 3627 CHECK(space != nullptr); 3628 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3629 remembered_sets_.Put(space, remembered_set); 3630 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3631} 3632 3633void Heap::RemoveRememberedSet(space::Space* space) { 3634 CHECK(space != nullptr); 3635 auto it = remembered_sets_.find(space); 3636 CHECK(it != remembered_sets_.end()); 3637 delete it->second; 3638 remembered_sets_.erase(it); 3639 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3640} 3641 3642void Heap::ClearMarkedObjects() { 3643 // Clear all of the spaces' mark bitmaps. 3644 for (const auto& space : GetContinuousSpaces()) { 3645 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3646 if (space->GetLiveBitmap() != mark_bitmap) { 3647 mark_bitmap->Clear(); 3648 } 3649 } 3650 // Clear the marked objects in the discontinous space object sets. 3651 for (const auto& space : GetDiscontinuousSpaces()) { 3652 space->GetMarkBitmap()->Clear(); 3653 } 3654} 3655 3656} // namespace gc 3657} // namespace art 3658