heap.cc revision 17a924abde2b0f1f37f6008b451a0a75190c71ff
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 "common_throws.h" 32#include "cutils/sched_policy.h" 33#include "debugger.h" 34#include "dex_file-inl.h" 35#include "gc/accounting/atomic_stack.h" 36#include "gc/accounting/card_table-inl.h" 37#include "gc/accounting/heap_bitmap-inl.h" 38#include "gc/accounting/mod_union_table.h" 39#include "gc/accounting/mod_union_table-inl.h" 40#include "gc/accounting/remembered_set.h" 41#include "gc/accounting/space_bitmap-inl.h" 42#include "gc/collector/concurrent_copying.h" 43#include "gc/collector/mark_compact.h" 44#include "gc/collector/mark_sweep-inl.h" 45#include "gc/collector/partial_mark_sweep.h" 46#include "gc/collector/semi_space.h" 47#include "gc/collector/sticky_mark_sweep.h" 48#include "gc/reference_processor.h" 49#include "gc/space/bump_pointer_space.h" 50#include "gc/space/dlmalloc_space-inl.h" 51#include "gc/space/image_space.h" 52#include "gc/space/large_object_space.h" 53#include "gc/space/region_space.h" 54#include "gc/space/rosalloc_space-inl.h" 55#include "gc/space/space-inl.h" 56#include "gc/space/zygote_space.h" 57#include "gc/task_processor.h" 58#include "entrypoints/quick/quick_alloc_entrypoints.h" 59#include "heap-inl.h" 60#include "image.h" 61#include "intern_table.h" 62#include "mirror/class-inl.h" 63#include "mirror/object.h" 64#include "mirror/object-inl.h" 65#include "mirror/object_array-inl.h" 66#include "mirror/reference-inl.h" 67#include "os.h" 68#include "reflection.h" 69#include "runtime.h" 70#include "ScopedLocalRef.h" 71#include "scoped_thread_state_change.h" 72#include "handle_scope-inl.h" 73#include "thread_list.h" 74#include "well_known_classes.h" 75 76namespace art { 77 78namespace gc { 79 80static constexpr size_t kCollectorTransitionStressIterations = 0; 81static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 82// Minimum amount of remaining bytes before a concurrent GC is triggered. 83static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 84static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 85// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 86// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 87// threads (lower pauses, use less memory bandwidth). 88static constexpr double kStickyGcThroughputAdjustment = 1.0; 89// Whether or not we compact the zygote in PreZygoteFork. 90static constexpr bool kCompactZygote = kMovingCollector; 91// How many reserve entries are at the end of the allocation stack, these are only needed if the 92// allocation stack overflows. 93static constexpr size_t kAllocationStackReserveSize = 1024; 94// Default mark stack size in bytes. 95static const size_t kDefaultMarkStackSize = 64 * KB; 96// Define space name. 97static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 98static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 99static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 100static const char* kNonMovingSpaceName = "non moving space"; 101static const char* kZygoteSpaceName = "zygote space"; 102static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 103static constexpr bool kGCALotMode = false; 104// GC alot mode uses a small allocation stack to stress test a lot of GC. 105static constexpr size_t kGcAlotAllocationStackSize = 4 * KB / 106 sizeof(mirror::HeapReference<mirror::Object>); 107// Verify objet has a small allocation stack size since searching the allocation stack is slow. 108static constexpr size_t kVerifyObjectAllocationStackSize = 16 * KB / 109 sizeof(mirror::HeapReference<mirror::Object>); 110static constexpr size_t kDefaultAllocationStackSize = 8 * MB / 111 sizeof(mirror::HeapReference<mirror::Object>); 112 113Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 114 double target_utilization, double foreground_heap_growth_multiplier, 115 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 116 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 117 CollectorType background_collector_type, 118 space::LargeObjectSpaceType large_object_space_type, size_t large_object_threshold, 119 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 120 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 121 bool ignore_max_footprint, bool use_tlab, 122 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 123 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 124 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 125 uint64_t min_interval_homogeneous_space_compaction_by_oom) 126 : non_moving_space_(nullptr), 127 rosalloc_space_(nullptr), 128 dlmalloc_space_(nullptr), 129 main_space_(nullptr), 130 collector_type_(kCollectorTypeNone), 131 foreground_collector_type_(foreground_collector_type), 132 background_collector_type_(background_collector_type), 133 desired_collector_type_(foreground_collector_type_), 134 pending_task_lock_(nullptr), 135 parallel_gc_threads_(parallel_gc_threads), 136 conc_gc_threads_(conc_gc_threads), 137 low_memory_mode_(low_memory_mode), 138 long_pause_log_threshold_(long_pause_log_threshold), 139 long_gc_log_threshold_(long_gc_log_threshold), 140 ignore_max_footprint_(ignore_max_footprint), 141 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 142 zygote_space_(nullptr), 143 large_object_threshold_(large_object_threshold), 144 collector_type_running_(kCollectorTypeNone), 145 last_gc_type_(collector::kGcTypeNone), 146 next_gc_type_(collector::kGcTypePartial), 147 capacity_(capacity), 148 growth_limit_(growth_limit), 149 max_allowed_footprint_(initial_size), 150 native_footprint_gc_watermark_(initial_size), 151 native_need_to_run_finalization_(false), 152 // Initially assume we perceive jank in case the process state is never updated. 153 process_state_(kProcessStateJankPerceptible), 154 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 155 total_bytes_freed_ever_(0), 156 total_objects_freed_ever_(0), 157 num_bytes_allocated_(0), 158 native_bytes_allocated_(0), 159 num_bytes_freed_revoke_(0), 160 verify_missing_card_marks_(false), 161 verify_system_weaks_(false), 162 verify_pre_gc_heap_(verify_pre_gc_heap), 163 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 164 verify_post_gc_heap_(verify_post_gc_heap), 165 verify_mod_union_table_(false), 166 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 167 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 168 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 169 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 170 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 171 * verification is enabled, we limit the size of allocation stacks to speed up their 172 * searching. 173 */ 174 max_allocation_stack_size_(kGCALotMode ? kGcAlotAllocationStackSize 175 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? kVerifyObjectAllocationStackSize : 176 kDefaultAllocationStackSize), 177 current_allocator_(kAllocatorTypeDlMalloc), 178 current_non_moving_allocator_(kAllocatorTypeNonMoving), 179 bump_pointer_space_(nullptr), 180 temp_space_(nullptr), 181 region_space_(nullptr), 182 min_free_(min_free), 183 max_free_(max_free), 184 target_utilization_(target_utilization), 185 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 186 total_wait_time_(0), 187 total_allocation_time_(0), 188 verify_object_mode_(kVerifyObjectModeDisabled), 189 disable_moving_gc_count_(0), 190 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 191 use_tlab_(use_tlab), 192 main_space_backup_(nullptr), 193 min_interval_homogeneous_space_compaction_by_oom_( 194 min_interval_homogeneous_space_compaction_by_oom), 195 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 196 pending_collector_transition_(nullptr), 197 pending_heap_trim_(nullptr), 198 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom), 199 running_collection_is_blocking_(false), 200 blocking_gc_count_(0U), 201 blocking_gc_time_(0U), 202 last_update_time_gc_count_rate_histograms_( // Round down by the window duration. 203 (NanoTime() / kGcCountRateHistogramWindowDuration) * kGcCountRateHistogramWindowDuration), 204 gc_count_last_window_(0U), 205 blocking_gc_count_last_window_(0U), 206 gc_count_rate_histogram_("gc count rate histogram", 1U, kGcCountRateMaxBucketCount), 207 blocking_gc_count_rate_histogram_("blocking gc count rate histogram", 1U, 208 kGcCountRateMaxBucketCount) { 209 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 210 LOG(INFO) << "Heap() entering"; 211 } 212 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 213 // entrypoints. 214 const bool is_zygote = Runtime::Current()->IsZygote(); 215 if (!is_zygote) { 216 // Background compaction is currently not supported for command line runs. 217 if (background_collector_type_ != foreground_collector_type_) { 218 VLOG(heap) << "Disabling background compaction for non zygote"; 219 background_collector_type_ = foreground_collector_type_; 220 } 221 } 222 ChangeCollector(desired_collector_type_); 223 live_bitmap_.reset(new accounting::HeapBitmap(this)); 224 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 225 // Requested begin for the alloc space, to follow the mapped image and oat files 226 uint8_t* requested_alloc_space_begin = nullptr; 227 if (foreground_collector_type_ == kCollectorTypeCC) { 228 // Need to use a low address so that we can allocate a contiguous 229 // 2 * Xmx space when there's no image (dex2oat for target). 230 CHECK_GE(300 * MB, non_moving_space_capacity); 231 requested_alloc_space_begin = reinterpret_cast<uint8_t*>(300 * MB) - non_moving_space_capacity; 232 } 233 if (!image_file_name.empty()) { 234 std::string error_msg; 235 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 236 image_instruction_set, 237 &error_msg); 238 if (image_space != nullptr) { 239 AddSpace(image_space); 240 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 241 // isn't going to get in the middle 242 uint8_t* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 243 CHECK_GT(oat_file_end_addr, image_space->End()); 244 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 245 } else { 246 LOG(ERROR) << "Could not create image space with image file '" << image_file_name << "'. " 247 << "Attempting to fall back to imageless running. Error was: " << error_msg; 248 } 249 } 250 /* 251 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 252 +- nonmoving space (non_moving_space_capacity)+- 253 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 254 +-????????????????????????????????????????????+- 255 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 256 +-main alloc space / bump space 1 (capacity_) +- 257 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 258 +-????????????????????????????????????????????+- 259 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 260 +-main alloc space2 / bump space 2 (capacity_)+- 261 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 262 */ 263 // We don't have hspace compaction enabled with GSS or CC. 264 if (foreground_collector_type_ == kCollectorTypeGSS || 265 foreground_collector_type_ == kCollectorTypeCC) { 266 use_homogeneous_space_compaction_for_oom_ = false; 267 } 268 bool support_homogeneous_space_compaction = 269 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 270 use_homogeneous_space_compaction_for_oom_; 271 // We may use the same space the main space for the non moving space if we don't need to compact 272 // from the main space. 273 // This is not the case if we support homogeneous compaction or have a moving background 274 // collector type. 275 bool separate_non_moving_space = is_zygote || 276 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 277 IsMovingGc(background_collector_type_); 278 if (foreground_collector_type == kCollectorTypeGSS) { 279 separate_non_moving_space = false; 280 } 281 std::unique_ptr<MemMap> main_mem_map_1; 282 std::unique_ptr<MemMap> main_mem_map_2; 283 uint8_t* request_begin = requested_alloc_space_begin; 284 if (request_begin != nullptr && separate_non_moving_space) { 285 request_begin += non_moving_space_capacity; 286 } 287 std::string error_str; 288 std::unique_ptr<MemMap> non_moving_space_mem_map; 289 if (separate_non_moving_space) { 290 // If we are the zygote, the non moving space becomes the zygote space when we run 291 // PreZygoteFork the first time. In this case, call the map "zygote space" since we can't 292 // rename the mem map later. 293 const char* space_name = is_zygote ? kZygoteSpaceName: kNonMovingSpaceName; 294 // Reserve the non moving mem map before the other two since it needs to be at a specific 295 // address. 296 non_moving_space_mem_map.reset( 297 MemMap::MapAnonymous(space_name, requested_alloc_space_begin, 298 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, false, 299 &error_str)); 300 CHECK(non_moving_space_mem_map != nullptr) << error_str; 301 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 302 request_begin = reinterpret_cast<uint8_t*>(300 * MB); 303 } 304 // Attempt to create 2 mem maps at or after the requested begin. 305 if (foreground_collector_type_ != kCollectorTypeCC) { 306 if (separate_non_moving_space) { 307 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, 308 capacity_, &error_str)); 309 } else { 310 // If no separate non-moving space, the main space must come 311 // right after the image space to avoid a gap. 312 main_mem_map_1.reset(MemMap::MapAnonymous(kMemMapSpaceName[0], request_begin, capacity_, 313 PROT_READ | PROT_WRITE, true, false, 314 &error_str)); 315 } 316 CHECK(main_mem_map_1.get() != nullptr) << error_str; 317 } 318 if (support_homogeneous_space_compaction || 319 background_collector_type_ == kCollectorTypeSS || 320 foreground_collector_type_ == kCollectorTypeSS) { 321 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 322 capacity_, &error_str)); 323 CHECK(main_mem_map_2.get() != nullptr) << error_str; 324 } 325 // Create the non moving space first so that bitmaps don't take up the address range. 326 if (separate_non_moving_space) { 327 // Non moving space is always dlmalloc since we currently don't have support for multiple 328 // active rosalloc spaces. 329 const size_t size = non_moving_space_mem_map->Size(); 330 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 331 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 332 initial_size, size, size, false); 333 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 334 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 335 << requested_alloc_space_begin; 336 AddSpace(non_moving_space_); 337 } 338 // Create other spaces based on whether or not we have a moving GC. 339 if (foreground_collector_type_ == kCollectorTypeCC) { 340 region_space_ = space::RegionSpace::Create("Region space", capacity_ * 2, request_begin); 341 AddSpace(region_space_); 342 } else if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 343 // Create bump pointer spaces. 344 // We only to create the bump pointer if the foreground collector is a compacting GC. 345 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 346 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 347 main_mem_map_1.release()); 348 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 349 AddSpace(bump_pointer_space_); 350 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 351 main_mem_map_2.release()); 352 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 353 AddSpace(temp_space_); 354 CHECK(separate_non_moving_space); 355 } else { 356 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 357 CHECK(main_space_ != nullptr); 358 AddSpace(main_space_); 359 if (!separate_non_moving_space) { 360 non_moving_space_ = main_space_; 361 CHECK(!non_moving_space_->CanMoveObjects()); 362 } 363 if (foreground_collector_type_ == kCollectorTypeGSS) { 364 CHECK_EQ(foreground_collector_type_, background_collector_type_); 365 // Create bump pointer spaces instead of a backup space. 366 main_mem_map_2.release(); 367 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 368 kGSSBumpPointerSpaceCapacity, nullptr); 369 CHECK(bump_pointer_space_ != nullptr); 370 AddSpace(bump_pointer_space_); 371 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 372 kGSSBumpPointerSpaceCapacity, nullptr); 373 CHECK(temp_space_ != nullptr); 374 AddSpace(temp_space_); 375 } else if (main_mem_map_2.get() != nullptr) { 376 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 377 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 378 growth_limit_, capacity_, name, true)); 379 CHECK(main_space_backup_.get() != nullptr); 380 // Add the space so its accounted for in the heap_begin and heap_end. 381 AddSpace(main_space_backup_.get()); 382 } 383 } 384 CHECK(non_moving_space_ != nullptr); 385 CHECK(!non_moving_space_->CanMoveObjects()); 386 // Allocate the large object space. 387 if (large_object_space_type == space::LargeObjectSpaceType::kFreeList) { 388 large_object_space_ = space::FreeListSpace::Create("free list large object space", nullptr, 389 capacity_); 390 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 391 } else if (large_object_space_type == space::LargeObjectSpaceType::kMap) { 392 large_object_space_ = space::LargeObjectMapSpace::Create("mem map large object space"); 393 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 394 } else { 395 // Disable the large object space by making the cutoff excessively large. 396 large_object_threshold_ = std::numeric_limits<size_t>::max(); 397 large_object_space_ = nullptr; 398 } 399 if (large_object_space_ != nullptr) { 400 AddSpace(large_object_space_); 401 } 402 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 403 CHECK(!continuous_spaces_.empty()); 404 // Relies on the spaces being sorted. 405 uint8_t* heap_begin = continuous_spaces_.front()->Begin(); 406 uint8_t* heap_end = continuous_spaces_.back()->Limit(); 407 size_t heap_capacity = heap_end - heap_begin; 408 // Remove the main backup space since it slows down the GC to have unused extra spaces. 409 // TODO: Avoid needing to do this. 410 if (main_space_backup_.get() != nullptr) { 411 RemoveSpace(main_space_backup_.get()); 412 } 413 // Allocate the card table. 414 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 415 CHECK(card_table_.get() != nullptr) << "Failed to create card table"; 416 417 if (foreground_collector_type_ == kCollectorTypeCC && kUseTableLookupReadBarrier) { 418 rb_table_.reset(new accounting::ReadBarrierTable()); 419 DCHECK(rb_table_->IsAllCleared()); 420 } 421 if (GetImageSpace() != nullptr) { 422 // Don't add the image mod union table if we are running without an image, this can crash if 423 // we use the CardCache implementation. 424 accounting::ModUnionTable* mod_union_table = new accounting::ModUnionTableToZygoteAllocspace( 425 "Image mod-union table", this, GetImageSpace()); 426 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 427 AddModUnionTable(mod_union_table); 428 } 429 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 430 accounting::RememberedSet* non_moving_space_rem_set = 431 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 432 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 433 AddRememberedSet(non_moving_space_rem_set); 434 } 435 // TODO: Count objects in the image space here? 436 num_bytes_allocated_.StoreRelaxed(0); 437 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 438 kDefaultMarkStackSize)); 439 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 440 allocation_stack_.reset(accounting::ObjectStack::Create( 441 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 442 live_stack_.reset(accounting::ObjectStack::Create( 443 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 444 // It's still too early to take a lock because there are no threads yet, but we can create locks 445 // now. We don't create it earlier to make it clear that you can't use locks during heap 446 // initialization. 447 gc_complete_lock_ = new Mutex("GC complete lock"); 448 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 449 *gc_complete_lock_)); 450 task_processor_.reset(new TaskProcessor()); 451 pending_task_lock_ = new Mutex("Pending task lock"); 452 if (ignore_max_footprint_) { 453 SetIdealFootprint(std::numeric_limits<size_t>::max()); 454 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 455 } 456 CHECK_NE(max_allowed_footprint_, 0U); 457 // Create our garbage collectors. 458 for (size_t i = 0; i < 2; ++i) { 459 const bool concurrent = i != 0; 460 if ((MayUseCollector(kCollectorTypeCMS) && concurrent) || 461 (MayUseCollector(kCollectorTypeMS) && !concurrent)) { 462 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 463 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 464 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 465 } 466 } 467 if (kMovingCollector) { 468 if (MayUseCollector(kCollectorTypeSS) || MayUseCollector(kCollectorTypeGSS) || 469 MayUseCollector(kCollectorTypeHomogeneousSpaceCompact) || 470 use_homogeneous_space_compaction_for_oom_) { 471 // TODO: Clean this up. 472 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 473 semi_space_collector_ = new collector::SemiSpace(this, generational, 474 generational ? "generational" : ""); 475 garbage_collectors_.push_back(semi_space_collector_); 476 } 477 if (MayUseCollector(kCollectorTypeCC)) { 478 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 479 garbage_collectors_.push_back(concurrent_copying_collector_); 480 } 481 if (MayUseCollector(kCollectorTypeMC)) { 482 mark_compact_collector_ = new collector::MarkCompact(this); 483 garbage_collectors_.push_back(mark_compact_collector_); 484 } 485 } 486 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 487 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 488 // Check that there's no gap between the image space and the non moving space so that the 489 // immune region won't break (eg. due to a large object allocated in the gap). This is only 490 // required when we're the zygote or using GSS. 491 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 492 non_moving_space_->GetMemMap()); 493 if (!no_gap) { 494 MemMap::DumpMaps(LOG(ERROR), true); 495 LOG(FATAL) << "There's a gap between the image space and the non-moving space"; 496 } 497 } 498 if (running_on_valgrind_) { 499 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 500 } 501 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 502 LOG(INFO) << "Heap() exiting"; 503 } 504} 505 506MemMap* Heap::MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 507 size_t capacity, std::string* out_error_str) { 508 while (true) { 509 MemMap* map = MemMap::MapAnonymous(name, request_begin, capacity, 510 PROT_READ | PROT_WRITE, true, false, out_error_str); 511 if (map != nullptr || request_begin == nullptr) { 512 return map; 513 } 514 // Retry a second time with no specified request begin. 515 request_begin = nullptr; 516 } 517} 518 519bool Heap::MayUseCollector(CollectorType type) const { 520 return foreground_collector_type_ == type || background_collector_type_ == type; 521} 522 523space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 524 size_t growth_limit, size_t capacity, 525 const char* name, bool can_move_objects) { 526 space::MallocSpace* malloc_space = nullptr; 527 if (kUseRosAlloc) { 528 // Create rosalloc space. 529 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 530 initial_size, growth_limit, capacity, 531 low_memory_mode_, can_move_objects); 532 } else { 533 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 534 initial_size, growth_limit, capacity, 535 can_move_objects); 536 } 537 if (collector::SemiSpace::kUseRememberedSet) { 538 accounting::RememberedSet* rem_set = 539 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 540 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 541 AddRememberedSet(rem_set); 542 } 543 CHECK(malloc_space != nullptr) << "Failed to create " << name; 544 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 545 return malloc_space; 546} 547 548void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 549 size_t capacity) { 550 // Is background compaction is enabled? 551 bool can_move_objects = IsMovingGc(background_collector_type_) != 552 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 553 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 554 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 555 // from the main space to the zygote space. If background compaction is enabled, always pass in 556 // that we can move objets. 557 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 558 // After the zygote we want this to be false if we don't have background compaction enabled so 559 // that getting primitive array elements is faster. 560 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 561 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 562 } 563 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 564 RemoveRememberedSet(main_space_); 565 } 566 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 567 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 568 can_move_objects); 569 SetSpaceAsDefault(main_space_); 570 VLOG(heap) << "Created main space " << main_space_; 571} 572 573void Heap::ChangeAllocator(AllocatorType allocator) { 574 if (current_allocator_ != allocator) { 575 // These two allocators are only used internally and don't have any entrypoints. 576 CHECK_NE(allocator, kAllocatorTypeLOS); 577 CHECK_NE(allocator, kAllocatorTypeNonMoving); 578 current_allocator_ = allocator; 579 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 580 SetQuickAllocEntryPointsAllocator(current_allocator_); 581 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 582 } 583} 584 585void Heap::DisableMovingGc() { 586 if (IsMovingGc(foreground_collector_type_)) { 587 foreground_collector_type_ = kCollectorTypeCMS; 588 } 589 if (IsMovingGc(background_collector_type_)) { 590 background_collector_type_ = foreground_collector_type_; 591 } 592 TransitionCollector(foreground_collector_type_); 593 ThreadList* tl = Runtime::Current()->GetThreadList(); 594 Thread* self = Thread::Current(); 595 ScopedThreadStateChange tsc(self, kSuspended); 596 tl->SuspendAll(__FUNCTION__); 597 // Something may have caused the transition to fail. 598 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 599 CHECK(main_space_ != nullptr); 600 // The allocation stack may have non movable objects in it. We need to flush it since the GC 601 // can't only handle marking allocation stack objects of one non moving space and one main 602 // space. 603 { 604 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 605 FlushAllocStack(); 606 } 607 main_space_->DisableMovingObjects(); 608 non_moving_space_ = main_space_; 609 CHECK(!non_moving_space_->CanMoveObjects()); 610 } 611 tl->ResumeAll(); 612} 613 614std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 615 if (!IsValidContinuousSpaceObjectAddress(klass)) { 616 return StringPrintf("<non heap address klass %p>", klass); 617 } 618 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 619 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 620 std::string result("["); 621 result += SafeGetClassDescriptor(component_type); 622 return result; 623 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 624 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 625 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 626 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 627 } else { 628 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 629 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 630 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 631 } 632 const DexFile* dex_file = dex_cache->GetDexFile(); 633 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 634 if (class_def_idx == DexFile::kDexNoIndex16) { 635 return "<class def not found>"; 636 } 637 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 638 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 639 return dex_file->GetTypeDescriptor(type_id); 640 } 641} 642 643std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 644 if (obj == nullptr) { 645 return "null"; 646 } 647 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 648 if (klass == nullptr) { 649 return "(class=null)"; 650 } 651 std::string result(SafeGetClassDescriptor(klass)); 652 if (obj->IsClass()) { 653 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 654 } 655 return result; 656} 657 658void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 659 if (obj == nullptr) { 660 stream << "(obj=null)"; 661 return; 662 } 663 if (IsAligned<kObjectAlignment>(obj)) { 664 space::Space* space = nullptr; 665 // Don't use find space since it only finds spaces which actually contain objects instead of 666 // spaces which may contain objects (e.g. cleared bump pointer spaces). 667 for (const auto& cur_space : continuous_spaces_) { 668 if (cur_space->HasAddress(obj)) { 669 space = cur_space; 670 break; 671 } 672 } 673 // Unprotect all the spaces. 674 for (const auto& con_space : continuous_spaces_) { 675 mprotect(con_space->Begin(), con_space->Capacity(), PROT_READ | PROT_WRITE); 676 } 677 stream << "Object " << obj; 678 if (space != nullptr) { 679 stream << " in space " << *space; 680 } 681 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 682 stream << "\nclass=" << klass; 683 if (klass != nullptr) { 684 stream << " type= " << SafePrettyTypeOf(obj); 685 } 686 // Re-protect the address we faulted on. 687 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 688 } 689} 690 691bool Heap::IsCompilingBoot() const { 692 if (!Runtime::Current()->IsAotCompiler()) { 693 return false; 694 } 695 for (const auto& space : continuous_spaces_) { 696 if (space->IsImageSpace() || space->IsZygoteSpace()) { 697 return false; 698 } 699 } 700 return true; 701} 702 703bool Heap::HasImageSpace() const { 704 for (const auto& space : continuous_spaces_) { 705 if (space->IsImageSpace()) { 706 return true; 707 } 708 } 709 return false; 710} 711 712void Heap::IncrementDisableMovingGC(Thread* self) { 713 // Need to do this holding the lock to prevent races where the GC is about to run / running when 714 // we attempt to disable it. 715 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 716 MutexLock mu(self, *gc_complete_lock_); 717 ++disable_moving_gc_count_; 718 if (IsMovingGc(collector_type_running_)) { 719 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 720 } 721} 722 723void Heap::DecrementDisableMovingGC(Thread* self) { 724 MutexLock mu(self, *gc_complete_lock_); 725 CHECK_GE(disable_moving_gc_count_, 0U); 726 --disable_moving_gc_count_; 727} 728 729void Heap::UpdateProcessState(ProcessState process_state) { 730 if (process_state_ != process_state) { 731 process_state_ = process_state; 732 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 733 // Start at index 1 to avoid "is always false" warning. 734 // Have iteration 1 always transition the collector. 735 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 736 ? foreground_collector_type_ : background_collector_type_); 737 usleep(kCollectorTransitionStressWait); 738 } 739 if (process_state_ == kProcessStateJankPerceptible) { 740 // Transition back to foreground right away to prevent jank. 741 RequestCollectorTransition(foreground_collector_type_, 0); 742 } else { 743 // Don't delay for debug builds since we may want to stress test the GC. 744 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 745 // special handling which does a homogenous space compaction once but then doesn't transition 746 // the collector. 747 RequestCollectorTransition(background_collector_type_, 748 kIsDebugBuild ? 0 : kCollectorTransitionWait); 749 } 750 } 751} 752 753void Heap::CreateThreadPool() { 754 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 755 if (num_threads != 0) { 756 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 757 } 758} 759 760// Visit objects when threads aren't suspended. If concurrent moving 761// GC, disable moving GC and suspend threads and then visit objects. 762void Heap::VisitObjects(ObjectCallback callback, void* arg) { 763 Thread* self = Thread::Current(); 764 Locks::mutator_lock_->AssertSharedHeld(self); 765 DCHECK(!Locks::mutator_lock_->IsExclusiveHeld(self)) << "Call VisitObjectsPaused() instead"; 766 if (IsGcConcurrentAndMoving()) { 767 // Concurrent moving GC. Just suspending threads isn't sufficient 768 // because a collection isn't one big pause and we could suspend 769 // threads in the middle (between phases) of a concurrent moving 770 // collection where it's not easily known which objects are alive 771 // (both the region space and the non-moving space) or which 772 // copies of objects to visit, and the to-space invariant could be 773 // easily broken. Visit objects while GC isn't running by using 774 // IncrementDisableMovingGC() and threads are suspended. 775 IncrementDisableMovingGC(self); 776 self->TransitionFromRunnableToSuspended(kWaitingForVisitObjects); 777 ThreadList* tl = Runtime::Current()->GetThreadList(); 778 tl->SuspendAll(__FUNCTION__); 779 VisitObjectsInternalRegionSpace(callback, arg); 780 VisitObjectsInternal(callback, arg); 781 tl->ResumeAll(); 782 self->TransitionFromSuspendedToRunnable(); 783 DecrementDisableMovingGC(self); 784 } else { 785 // GCs can move objects, so don't allow this. 786 ScopedAssertNoThreadSuspension ants(self, "Visiting objects"); 787 DCHECK(region_space_ == nullptr); 788 VisitObjectsInternal(callback, arg); 789 } 790} 791 792// Visit objects when threads are already suspended. 793void Heap::VisitObjectsPaused(ObjectCallback callback, void* arg) { 794 Thread* self = Thread::Current(); 795 Locks::mutator_lock_->AssertExclusiveHeld(self); 796 VisitObjectsInternalRegionSpace(callback, arg); 797 VisitObjectsInternal(callback, arg); 798} 799 800// Visit objects in the region spaces. 801void Heap::VisitObjectsInternalRegionSpace(ObjectCallback callback, void* arg) { 802 Thread* self = Thread::Current(); 803 Locks::mutator_lock_->AssertExclusiveHeld(self); 804 if (region_space_ != nullptr) { 805 DCHECK(IsGcConcurrentAndMoving()); 806 if (!zygote_creation_lock_.IsExclusiveHeld(self)) { 807 // Exclude the pre-zygote fork time where the semi-space collector 808 // calls VerifyHeapReferences() as part of the zygote compaction 809 // which then would call here without the moving GC disabled, 810 // which is fine. 811 DCHECK(IsMovingGCDisabled(self)); 812 } 813 region_space_->Walk(callback, arg); 814 } 815} 816 817// Visit objects in the other spaces. 818void Heap::VisitObjectsInternal(ObjectCallback callback, void* arg) { 819 if (bump_pointer_space_ != nullptr) { 820 // Visit objects in bump pointer space. 821 bump_pointer_space_->Walk(callback, arg); 822 } 823 // TODO: Switch to standard begin and end to use ranged a based loop. 824 for (auto* it = allocation_stack_->Begin(), *end = allocation_stack_->End(); it < end; ++it) { 825 mirror::Object* const obj = it->AsMirrorPtr(); 826 if (obj != nullptr && obj->GetClass() != nullptr) { 827 // Avoid the race condition caused by the object not yet being written into the allocation 828 // stack or the class not yet being written in the object. Or, if 829 // kUseThreadLocalAllocationStack, there can be nulls on the allocation stack. 830 callback(obj, arg); 831 } 832 } 833 { 834 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 835 GetLiveBitmap()->Walk(callback, arg); 836 } 837} 838 839void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 840 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 841 space::ContinuousSpace* space2 = non_moving_space_; 842 // TODO: Generalize this to n bitmaps? 843 CHECK(space1 != nullptr); 844 CHECK(space2 != nullptr); 845 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 846 (large_object_space_ != nullptr ? large_object_space_->GetLiveBitmap() : nullptr), 847 stack); 848} 849 850void Heap::DeleteThreadPool() { 851 thread_pool_.reset(nullptr); 852} 853 854void Heap::AddSpace(space::Space* space) { 855 CHECK(space != nullptr); 856 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 857 if (space->IsContinuousSpace()) { 858 DCHECK(!space->IsDiscontinuousSpace()); 859 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 860 // Continuous spaces don't necessarily have bitmaps. 861 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 862 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 863 if (live_bitmap != nullptr) { 864 CHECK(mark_bitmap != nullptr); 865 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 866 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 867 } 868 continuous_spaces_.push_back(continuous_space); 869 // Ensure that spaces remain sorted in increasing order of start address. 870 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 871 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 872 return a->Begin() < b->Begin(); 873 }); 874 } else { 875 CHECK(space->IsDiscontinuousSpace()); 876 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 877 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 878 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 879 discontinuous_spaces_.push_back(discontinuous_space); 880 } 881 if (space->IsAllocSpace()) { 882 alloc_spaces_.push_back(space->AsAllocSpace()); 883 } 884} 885 886void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 887 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 888 if (continuous_space->IsDlMallocSpace()) { 889 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 890 } else if (continuous_space->IsRosAllocSpace()) { 891 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 892 } 893} 894 895void Heap::RemoveSpace(space::Space* space) { 896 DCHECK(space != nullptr); 897 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 898 if (space->IsContinuousSpace()) { 899 DCHECK(!space->IsDiscontinuousSpace()); 900 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 901 // Continuous spaces don't necessarily have bitmaps. 902 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 903 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 904 if (live_bitmap != nullptr) { 905 DCHECK(mark_bitmap != nullptr); 906 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 907 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 908 } 909 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 910 DCHECK(it != continuous_spaces_.end()); 911 continuous_spaces_.erase(it); 912 } else { 913 DCHECK(space->IsDiscontinuousSpace()); 914 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 915 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 916 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 917 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 918 discontinuous_space); 919 DCHECK(it != discontinuous_spaces_.end()); 920 discontinuous_spaces_.erase(it); 921 } 922 if (space->IsAllocSpace()) { 923 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 924 DCHECK(it != alloc_spaces_.end()); 925 alloc_spaces_.erase(it); 926 } 927} 928 929void Heap::DumpGcPerformanceInfo(std::ostream& os) { 930 // Dump cumulative timings. 931 os << "Dumping cumulative Gc timings\n"; 932 uint64_t total_duration = 0; 933 // Dump cumulative loggers for each GC type. 934 uint64_t total_paused_time = 0; 935 for (auto& collector : garbage_collectors_) { 936 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 937 total_paused_time += collector->GetTotalPausedTimeNs(); 938 collector->DumpPerformanceInfo(os); 939 } 940 uint64_t allocation_time = 941 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 942 if (total_duration != 0) { 943 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 944 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 945 os << "Mean GC size throughput: " 946 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 947 os << "Mean GC object throughput: " 948 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 949 } 950 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 951 os << "Total number of allocations " << total_objects_allocated << "\n"; 952 os << "Total bytes allocated " << PrettySize(GetBytesAllocatedEver()) << "\n"; 953 os << "Total bytes freed " << PrettySize(GetBytesFreedEver()) << "\n"; 954 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 955 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 956 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 957 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 958 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 959 if (kMeasureAllocationTime) { 960 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 961 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 962 << "\n"; 963 } 964 if (HasZygoteSpace()) { 965 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 966 } 967 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 968 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 969 os << "Total GC count: " << GetGcCount() << "\n"; 970 os << "Total GC time: " << PrettyDuration(GetGcTime()) << "\n"; 971 os << "Total blocking GC count: " << GetBlockingGcCount() << "\n"; 972 os << "Total blocking GC time: " << PrettyDuration(GetBlockingGcTime()) << "\n"; 973 974 { 975 MutexLock mu(Thread::Current(), *gc_complete_lock_); 976 if (gc_count_rate_histogram_.SampleSize() > 0U) { 977 os << "Histogram of GC count per " << NsToMs(kGcCountRateHistogramWindowDuration) << " ms: "; 978 gc_count_rate_histogram_.DumpBins(os); 979 os << "\n"; 980 } 981 if (blocking_gc_count_rate_histogram_.SampleSize() > 0U) { 982 os << "Histogram of blocking GC count per " 983 << NsToMs(kGcCountRateHistogramWindowDuration) << " ms: "; 984 blocking_gc_count_rate_histogram_.DumpBins(os); 985 os << "\n"; 986 } 987 } 988 989 BaseMutex::DumpAll(os); 990} 991 992uint64_t Heap::GetGcCount() const { 993 uint64_t gc_count = 0U; 994 for (auto& collector : garbage_collectors_) { 995 gc_count += collector->GetCumulativeTimings().GetIterations(); 996 } 997 return gc_count; 998} 999 1000uint64_t Heap::GetGcTime() const { 1001 uint64_t gc_time = 0U; 1002 for (auto& collector : garbage_collectors_) { 1003 gc_time += collector->GetCumulativeTimings().GetTotalNs(); 1004 } 1005 return gc_time; 1006} 1007 1008uint64_t Heap::GetBlockingGcCount() const { 1009 return blocking_gc_count_; 1010} 1011 1012uint64_t Heap::GetBlockingGcTime() const { 1013 return blocking_gc_time_; 1014} 1015 1016void Heap::DumpGcCountRateHistogram(std::ostream& os) const { 1017 MutexLock mu(Thread::Current(), *gc_complete_lock_); 1018 if (gc_count_rate_histogram_.SampleSize() > 0U) { 1019 gc_count_rate_histogram_.DumpBins(os); 1020 } 1021} 1022 1023void Heap::DumpBlockingGcCountRateHistogram(std::ostream& os) const { 1024 MutexLock mu(Thread::Current(), *gc_complete_lock_); 1025 if (blocking_gc_count_rate_histogram_.SampleSize() > 0U) { 1026 blocking_gc_count_rate_histogram_.DumpBins(os); 1027 } 1028} 1029 1030Heap::~Heap() { 1031 VLOG(heap) << "Starting ~Heap()"; 1032 STLDeleteElements(&garbage_collectors_); 1033 // If we don't reset then the mark stack complains in its destructor. 1034 allocation_stack_->Reset(); 1035 live_stack_->Reset(); 1036 STLDeleteValues(&mod_union_tables_); 1037 STLDeleteValues(&remembered_sets_); 1038 STLDeleteElements(&continuous_spaces_); 1039 STLDeleteElements(&discontinuous_spaces_); 1040 delete gc_complete_lock_; 1041 delete pending_task_lock_; 1042 VLOG(heap) << "Finished ~Heap()"; 1043} 1044 1045space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 1046 bool fail_ok) const { 1047 for (const auto& space : continuous_spaces_) { 1048 if (space->Contains(obj)) { 1049 return space; 1050 } 1051 } 1052 if (!fail_ok) { 1053 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 1054 } 1055 return nullptr; 1056} 1057 1058space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 1059 bool fail_ok) const { 1060 for (const auto& space : discontinuous_spaces_) { 1061 if (space->Contains(obj)) { 1062 return space; 1063 } 1064 } 1065 if (!fail_ok) { 1066 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 1067 } 1068 return nullptr; 1069} 1070 1071space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 1072 space::Space* result = FindContinuousSpaceFromObject(obj, true); 1073 if (result != nullptr) { 1074 return result; 1075 } 1076 return FindDiscontinuousSpaceFromObject(obj, fail_ok); 1077} 1078 1079space::ImageSpace* Heap::GetImageSpace() const { 1080 for (const auto& space : continuous_spaces_) { 1081 if (space->IsImageSpace()) { 1082 return space->AsImageSpace(); 1083 } 1084 } 1085 return nullptr; 1086} 1087 1088void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 1089 std::ostringstream oss; 1090 size_t total_bytes_free = GetFreeMemory(); 1091 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 1092 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 1093 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 1094 if (total_bytes_free >= byte_count) { 1095 space::AllocSpace* space = nullptr; 1096 if (allocator_type == kAllocatorTypeNonMoving) { 1097 space = non_moving_space_; 1098 } else if (allocator_type == kAllocatorTypeRosAlloc || 1099 allocator_type == kAllocatorTypeDlMalloc) { 1100 space = main_space_; 1101 } else if (allocator_type == kAllocatorTypeBumpPointer || 1102 allocator_type == kAllocatorTypeTLAB) { 1103 space = bump_pointer_space_; 1104 } else if (allocator_type == kAllocatorTypeRegion || 1105 allocator_type == kAllocatorTypeRegionTLAB) { 1106 space = region_space_; 1107 } 1108 if (space != nullptr) { 1109 space->LogFragmentationAllocFailure(oss, byte_count); 1110 } 1111 } 1112 self->ThrowOutOfMemoryError(oss.str().c_str()); 1113} 1114 1115void Heap::DoPendingCollectorTransition() { 1116 CollectorType desired_collector_type = desired_collector_type_; 1117 // Launch homogeneous space compaction if it is desired. 1118 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 1119 if (!CareAboutPauseTimes()) { 1120 PerformHomogeneousSpaceCompact(); 1121 } else { 1122 VLOG(gc) << "Homogeneous compaction ignored due to jank perceptible process state"; 1123 } 1124 } else { 1125 TransitionCollector(desired_collector_type); 1126 } 1127} 1128 1129void Heap::Trim(Thread* self) { 1130 if (!CareAboutPauseTimes()) { 1131 ATRACE_BEGIN("Deflating monitors"); 1132 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 1133 // about pauses. 1134 Runtime* runtime = Runtime::Current(); 1135 runtime->GetThreadList()->SuspendAll(__FUNCTION__); 1136 uint64_t start_time = NanoTime(); 1137 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 1138 VLOG(heap) << "Deflating " << count << " monitors took " 1139 << PrettyDuration(NanoTime() - start_time); 1140 runtime->GetThreadList()->ResumeAll(); 1141 ATRACE_END(); 1142 } 1143 TrimIndirectReferenceTables(self); 1144 TrimSpaces(self); 1145} 1146 1147class TrimIndirectReferenceTableClosure : public Closure { 1148 public: 1149 explicit TrimIndirectReferenceTableClosure(Barrier* barrier) : barrier_(barrier) { 1150 } 1151 virtual void Run(Thread* thread) OVERRIDE NO_THREAD_SAFETY_ANALYSIS { 1152 ATRACE_BEGIN("Trimming reference table"); 1153 thread->GetJniEnv()->locals.Trim(); 1154 ATRACE_END(); 1155 // If thread is a running mutator, then act on behalf of the trim thread. 1156 // See the code in ThreadList::RunCheckpoint. 1157 if (thread->GetState() == kRunnable) { 1158 barrier_->Pass(Thread::Current()); 1159 } 1160 } 1161 1162 private: 1163 Barrier* const barrier_; 1164}; 1165 1166void Heap::TrimIndirectReferenceTables(Thread* self) { 1167 ScopedObjectAccess soa(self); 1168 ATRACE_BEGIN(__FUNCTION__); 1169 JavaVMExt* vm = soa.Vm(); 1170 // Trim globals indirect reference table. 1171 vm->TrimGlobals(); 1172 // Trim locals indirect reference tables. 1173 Barrier barrier(0); 1174 TrimIndirectReferenceTableClosure closure(&barrier); 1175 ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); 1176 size_t barrier_count = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure); 1177 if (barrier_count != 0) { 1178 barrier.Increment(self, barrier_count); 1179 } 1180 ATRACE_END(); 1181} 1182 1183void Heap::TrimSpaces(Thread* self) { 1184 { 1185 // Need to do this before acquiring the locks since we don't want to get suspended while 1186 // holding any locks. 1187 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1188 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 1189 // trimming. 1190 MutexLock mu(self, *gc_complete_lock_); 1191 // Ensure there is only one GC at a time. 1192 WaitForGcToCompleteLocked(kGcCauseTrim, self); 1193 collector_type_running_ = kCollectorTypeHeapTrim; 1194 } 1195 ATRACE_BEGIN(__FUNCTION__); 1196 const uint64_t start_ns = NanoTime(); 1197 // Trim the managed spaces. 1198 uint64_t total_alloc_space_allocated = 0; 1199 uint64_t total_alloc_space_size = 0; 1200 uint64_t managed_reclaimed = 0; 1201 for (const auto& space : continuous_spaces_) { 1202 if (space->IsMallocSpace()) { 1203 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1204 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1205 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1206 // for a long period of time. 1207 managed_reclaimed += malloc_space->Trim(); 1208 } 1209 total_alloc_space_size += malloc_space->Size(); 1210 } 1211 } 1212 total_alloc_space_allocated = GetBytesAllocated(); 1213 if (large_object_space_ != nullptr) { 1214 total_alloc_space_allocated -= large_object_space_->GetBytesAllocated(); 1215 } 1216 if (bump_pointer_space_ != nullptr) { 1217 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1218 } 1219 if (region_space_ != nullptr) { 1220 total_alloc_space_allocated -= region_space_->GetBytesAllocated(); 1221 } 1222 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1223 static_cast<float>(total_alloc_space_size); 1224 uint64_t gc_heap_end_ns = NanoTime(); 1225 // We never move things in the native heap, so we can finish the GC at this point. 1226 FinishGC(self, collector::kGcTypeNone); 1227 size_t native_reclaimed = 0; 1228 1229#ifdef HAVE_ANDROID_OS 1230 // Only trim the native heap if we don't care about pauses. 1231 if (!CareAboutPauseTimes()) { 1232#if defined(USE_DLMALLOC) 1233 // Trim the native heap. 1234 dlmalloc_trim(0); 1235 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1236#elif defined(USE_JEMALLOC) 1237 // Jemalloc does it's own internal trimming. 1238#else 1239 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1240#endif 1241 } 1242#endif // HAVE_ANDROID_OS 1243 uint64_t end_ns = NanoTime(); 1244 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1245 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1246 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1247 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1248 << "%."; 1249 ATRACE_END(); 1250} 1251 1252bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1253 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1254 // taking the lock. 1255 if (obj == nullptr) { 1256 return true; 1257 } 1258 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1259} 1260 1261bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1262 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1263} 1264 1265bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1266 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1267 return false; 1268 } 1269 for (const auto& space : continuous_spaces_) { 1270 if (space->HasAddress(obj)) { 1271 return true; 1272 } 1273 } 1274 return false; 1275} 1276 1277bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1278 bool search_live_stack, bool sorted) { 1279 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1280 return false; 1281 } 1282 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1283 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1284 if (obj == klass) { 1285 // This case happens for java.lang.Class. 1286 return true; 1287 } 1288 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1289 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1290 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1291 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1292 return temp_space_->Contains(obj); 1293 } 1294 if (region_space_ != nullptr && region_space_->HasAddress(obj)) { 1295 return true; 1296 } 1297 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1298 space::DiscontinuousSpace* d_space = nullptr; 1299 if (c_space != nullptr) { 1300 if (c_space->GetLiveBitmap()->Test(obj)) { 1301 return true; 1302 } 1303 } else { 1304 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1305 if (d_space != nullptr) { 1306 if (d_space->GetLiveBitmap()->Test(obj)) { 1307 return true; 1308 } 1309 } 1310 } 1311 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1312 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1313 if (i > 0) { 1314 NanoSleep(MsToNs(10)); 1315 } 1316 if (search_allocation_stack) { 1317 if (sorted) { 1318 if (allocation_stack_->ContainsSorted(obj)) { 1319 return true; 1320 } 1321 } else if (allocation_stack_->Contains(obj)) { 1322 return true; 1323 } 1324 } 1325 1326 if (search_live_stack) { 1327 if (sorted) { 1328 if (live_stack_->ContainsSorted(obj)) { 1329 return true; 1330 } 1331 } else if (live_stack_->Contains(obj)) { 1332 return true; 1333 } 1334 } 1335 } 1336 // We need to check the bitmaps again since there is a race where we mark something as live and 1337 // then clear the stack containing it. 1338 if (c_space != nullptr) { 1339 if (c_space->GetLiveBitmap()->Test(obj)) { 1340 return true; 1341 } 1342 } else { 1343 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1344 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1345 return true; 1346 } 1347 } 1348 return false; 1349} 1350 1351std::string Heap::DumpSpaces() const { 1352 std::ostringstream oss; 1353 DumpSpaces(oss); 1354 return oss.str(); 1355} 1356 1357void Heap::DumpSpaces(std::ostream& stream) const { 1358 for (const auto& space : continuous_spaces_) { 1359 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1360 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1361 stream << space << " " << *space << "\n"; 1362 if (live_bitmap != nullptr) { 1363 stream << live_bitmap << " " << *live_bitmap << "\n"; 1364 } 1365 if (mark_bitmap != nullptr) { 1366 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1367 } 1368 } 1369 for (const auto& space : discontinuous_spaces_) { 1370 stream << space << " " << *space << "\n"; 1371 } 1372} 1373 1374void Heap::VerifyObjectBody(mirror::Object* obj) { 1375 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1376 return; 1377 } 1378 1379 // Ignore early dawn of the universe verifications. 1380 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1381 return; 1382 } 1383 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1384 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1385 CHECK(c != nullptr) << "Null class in object " << obj; 1386 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1387 CHECK(VerifyClassClass(c)); 1388 1389 if (verify_object_mode_ > kVerifyObjectModeFast) { 1390 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1391 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1392 } 1393} 1394 1395void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1396 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1397} 1398 1399void Heap::VerifyHeap() { 1400 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1401 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1402} 1403 1404void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1405 // Use signed comparison since freed bytes can be negative when background compaction foreground 1406 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1407 // free list backed space typically increasing memory footprint due to padding and binning. 1408 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1409 // Note: This relies on 2s complement for handling negative freed_bytes. 1410 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1411 if (Runtime::Current()->HasStatsEnabled()) { 1412 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1413 thread_stats->freed_objects += freed_objects; 1414 thread_stats->freed_bytes += freed_bytes; 1415 // TODO: Do this concurrently. 1416 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1417 global_stats->freed_objects += freed_objects; 1418 global_stats->freed_bytes += freed_bytes; 1419 } 1420} 1421 1422void Heap::RecordFreeRevoke() { 1423 // Subtract num_bytes_freed_revoke_ from num_bytes_allocated_ to cancel out the 1424 // the ahead-of-time, bulk counting of bytes allocated in rosalloc thread-local buffers. 1425 // If there's a concurrent revoke, ok to not necessarily reset num_bytes_freed_revoke_ 1426 // all the way to zero exactly as the remainder will be subtracted at the next GC. 1427 size_t bytes_freed = num_bytes_freed_revoke_.LoadSequentiallyConsistent(); 1428 CHECK_GE(num_bytes_freed_revoke_.FetchAndSubSequentiallyConsistent(bytes_freed), 1429 bytes_freed) << "num_bytes_freed_revoke_ underflow"; 1430 CHECK_GE(num_bytes_allocated_.FetchAndSubSequentiallyConsistent(bytes_freed), 1431 bytes_freed) << "num_bytes_allocated_ underflow"; 1432 GetCurrentGcIteration()->SetFreedRevoke(bytes_freed); 1433} 1434 1435space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1436 for (const auto& space : continuous_spaces_) { 1437 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1438 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1439 return space->AsContinuousSpace()->AsRosAllocSpace(); 1440 } 1441 } 1442 } 1443 return nullptr; 1444} 1445 1446mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1447 size_t alloc_size, size_t* bytes_allocated, 1448 size_t* usable_size, 1449 size_t* bytes_tl_bulk_allocated, 1450 mirror::Class** klass) { 1451 bool was_default_allocator = allocator == GetCurrentAllocator(); 1452 // Make sure there is no pending exception since we may need to throw an OOME. 1453 self->AssertNoPendingException(); 1454 DCHECK(klass != nullptr); 1455 StackHandleScope<1> hs(self); 1456 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1457 klass = nullptr; // Invalidate for safety. 1458 // The allocation failed. If the GC is running, block until it completes, and then retry the 1459 // allocation. 1460 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1461 if (last_gc != collector::kGcTypeNone) { 1462 // If we were the default allocator but the allocator changed while we were suspended, 1463 // abort the allocation. 1464 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1465 return nullptr; 1466 } 1467 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1468 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1469 usable_size, bytes_tl_bulk_allocated); 1470 if (ptr != nullptr) { 1471 return ptr; 1472 } 1473 } 1474 1475 collector::GcType tried_type = next_gc_type_; 1476 const bool gc_ran = 1477 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1478 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1479 return nullptr; 1480 } 1481 if (gc_ran) { 1482 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1483 usable_size, bytes_tl_bulk_allocated); 1484 if (ptr != nullptr) { 1485 return ptr; 1486 } 1487 } 1488 1489 // Loop through our different Gc types and try to Gc until we get enough free memory. 1490 for (collector::GcType gc_type : gc_plan_) { 1491 if (gc_type == tried_type) { 1492 continue; 1493 } 1494 // Attempt to run the collector, if we succeed, re-try the allocation. 1495 const bool plan_gc_ran = 1496 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1497 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1498 return nullptr; 1499 } 1500 if (plan_gc_ran) { 1501 // Did we free sufficient memory for the allocation to succeed? 1502 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1503 usable_size, bytes_tl_bulk_allocated); 1504 if (ptr != nullptr) { 1505 return ptr; 1506 } 1507 } 1508 } 1509 // Allocations have failed after GCs; this is an exceptional state. 1510 // Try harder, growing the heap if necessary. 1511 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1512 usable_size, bytes_tl_bulk_allocated); 1513 if (ptr != nullptr) { 1514 return ptr; 1515 } 1516 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1517 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1518 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1519 // OOME. 1520 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1521 << " allocation"; 1522 // TODO: Run finalization, but this may cause more allocations to occur. 1523 // We don't need a WaitForGcToComplete here either. 1524 DCHECK(!gc_plan_.empty()); 1525 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1526 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1527 return nullptr; 1528 } 1529 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size, 1530 bytes_tl_bulk_allocated); 1531 if (ptr == nullptr) { 1532 const uint64_t current_time = NanoTime(); 1533 switch (allocator) { 1534 case kAllocatorTypeRosAlloc: 1535 // Fall-through. 1536 case kAllocatorTypeDlMalloc: { 1537 if (use_homogeneous_space_compaction_for_oom_ && 1538 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1539 min_interval_homogeneous_space_compaction_by_oom_) { 1540 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1541 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1542 switch (result) { 1543 case HomogeneousSpaceCompactResult::kSuccess: 1544 // If the allocation succeeded, we delayed an oom. 1545 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1546 usable_size, bytes_tl_bulk_allocated); 1547 if (ptr != nullptr) { 1548 count_delayed_oom_++; 1549 } 1550 break; 1551 case HomogeneousSpaceCompactResult::kErrorReject: 1552 // Reject due to disabled moving GC. 1553 break; 1554 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1555 // Throw OOM by default. 1556 break; 1557 default: { 1558 UNIMPLEMENTED(FATAL) << "homogeneous space compaction result: " 1559 << static_cast<size_t>(result); 1560 UNREACHABLE(); 1561 } 1562 } 1563 // Always print that we ran homogeneous space compation since this can cause jank. 1564 VLOG(heap) << "Ran heap homogeneous space compaction, " 1565 << " requested defragmentation " 1566 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1567 << " performed defragmentation " 1568 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1569 << " ignored homogeneous space compaction " 1570 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1571 << " delayed count = " 1572 << count_delayed_oom_.LoadSequentiallyConsistent(); 1573 } 1574 break; 1575 } 1576 case kAllocatorTypeNonMoving: { 1577 // Try to transition the heap if the allocation failure was due to the space being full. 1578 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1579 // If we aren't out of memory then the OOM was probably from the non moving space being 1580 // full. Attempt to disable compaction and turn the main space into a non moving space. 1581 DisableMovingGc(); 1582 // If we are still a moving GC then something must have caused the transition to fail. 1583 if (IsMovingGc(collector_type_)) { 1584 MutexLock mu(self, *gc_complete_lock_); 1585 // If we couldn't disable moving GC, just throw OOME and return null. 1586 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1587 << disable_moving_gc_count_; 1588 } else { 1589 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1590 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1591 usable_size, bytes_tl_bulk_allocated); 1592 } 1593 } 1594 break; 1595 } 1596 default: { 1597 // Do nothing for others allocators. 1598 } 1599 } 1600 } 1601 // If the allocation hasn't succeeded by this point, throw an OOM error. 1602 if (ptr == nullptr) { 1603 ThrowOutOfMemoryError(self, alloc_size, allocator); 1604 } 1605 return ptr; 1606} 1607 1608void Heap::SetTargetHeapUtilization(float target) { 1609 DCHECK_GT(target, 0.0f); // asserted in Java code 1610 DCHECK_LT(target, 1.0f); 1611 target_utilization_ = target; 1612} 1613 1614size_t Heap::GetObjectsAllocated() const { 1615 size_t total = 0; 1616 for (space::AllocSpace* space : alloc_spaces_) { 1617 total += space->GetObjectsAllocated(); 1618 } 1619 return total; 1620} 1621 1622uint64_t Heap::GetObjectsAllocatedEver() const { 1623 return GetObjectsFreedEver() + GetObjectsAllocated(); 1624} 1625 1626uint64_t Heap::GetBytesAllocatedEver() const { 1627 return GetBytesFreedEver() + GetBytesAllocated(); 1628} 1629 1630class InstanceCounter { 1631 public: 1632 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1633 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1634 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1635 } 1636 static void Callback(mirror::Object* obj, void* arg) 1637 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1638 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1639 mirror::Class* instance_class = obj->GetClass(); 1640 CHECK(instance_class != nullptr); 1641 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1642 if (instance_counter->use_is_assignable_from_) { 1643 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1644 ++instance_counter->counts_[i]; 1645 } 1646 } else if (instance_class == instance_counter->classes_[i]) { 1647 ++instance_counter->counts_[i]; 1648 } 1649 } 1650 } 1651 1652 private: 1653 const std::vector<mirror::Class*>& classes_; 1654 bool use_is_assignable_from_; 1655 uint64_t* const counts_; 1656 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1657}; 1658 1659void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1660 uint64_t* counts) { 1661 InstanceCounter counter(classes, use_is_assignable_from, counts); 1662 VisitObjects(InstanceCounter::Callback, &counter); 1663} 1664 1665class InstanceCollector { 1666 public: 1667 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1668 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1669 : class_(c), max_count_(max_count), instances_(instances) { 1670 } 1671 static void Callback(mirror::Object* obj, void* arg) 1672 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1673 DCHECK(arg != nullptr); 1674 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1675 if (obj->GetClass() == instance_collector->class_) { 1676 if (instance_collector->max_count_ == 0 || 1677 instance_collector->instances_.size() < instance_collector->max_count_) { 1678 instance_collector->instances_.push_back(obj); 1679 } 1680 } 1681 } 1682 1683 private: 1684 const mirror::Class* const class_; 1685 const uint32_t max_count_; 1686 std::vector<mirror::Object*>& instances_; 1687 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1688}; 1689 1690void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1691 std::vector<mirror::Object*>& instances) { 1692 InstanceCollector collector(c, max_count, instances); 1693 VisitObjects(&InstanceCollector::Callback, &collector); 1694} 1695 1696class ReferringObjectsFinder { 1697 public: 1698 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1699 std::vector<mirror::Object*>& referring_objects) 1700 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1701 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1702 } 1703 1704 static void Callback(mirror::Object* obj, void* arg) 1705 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1706 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1707 } 1708 1709 // For bitmap Visit. 1710 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1711 // annotalysis on visitors. 1712 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1713 o->VisitReferences<true>(*this, VoidFunctor()); 1714 } 1715 1716 // For Object::VisitReferences. 1717 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1718 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1719 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1720 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1721 referring_objects_.push_back(obj); 1722 } 1723 } 1724 1725 private: 1726 const mirror::Object* const object_; 1727 const uint32_t max_count_; 1728 std::vector<mirror::Object*>& referring_objects_; 1729 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1730}; 1731 1732void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1733 std::vector<mirror::Object*>& referring_objects) { 1734 ReferringObjectsFinder finder(o, max_count, referring_objects); 1735 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1736} 1737 1738void Heap::CollectGarbage(bool clear_soft_references) { 1739 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1740 // last GC will not have necessarily been cleared. 1741 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1742} 1743 1744HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1745 Thread* self = Thread::Current(); 1746 // Inc requested homogeneous space compaction. 1747 count_requested_homogeneous_space_compaction_++; 1748 // Store performed homogeneous space compaction at a new request arrival. 1749 ThreadList* tl = Runtime::Current()->GetThreadList(); 1750 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1751 Locks::mutator_lock_->AssertNotHeld(self); 1752 { 1753 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1754 MutexLock mu(self, *gc_complete_lock_); 1755 // Ensure there is only one GC at a time. 1756 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1757 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1758 // is non zero. 1759 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1760 // exit. 1761 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1762 !main_space_->CanMoveObjects()) { 1763 return HomogeneousSpaceCompactResult::kErrorReject; 1764 } 1765 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1766 } 1767 if (Runtime::Current()->IsShuttingDown(self)) { 1768 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1769 // cause objects to get finalized. 1770 FinishGC(self, collector::kGcTypeNone); 1771 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1772 } 1773 // Suspend all threads. 1774 tl->SuspendAll(__FUNCTION__); 1775 uint64_t start_time = NanoTime(); 1776 // Launch compaction. 1777 space::MallocSpace* to_space = main_space_backup_.release(); 1778 space::MallocSpace* from_space = main_space_; 1779 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1780 const uint64_t space_size_before_compaction = from_space->Size(); 1781 AddSpace(to_space); 1782 // Make sure that we will have enough room to copy. 1783 CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit()); 1784 collector::GarbageCollector* collector = Compact(to_space, from_space, 1785 kGcCauseHomogeneousSpaceCompact); 1786 const uint64_t space_size_after_compaction = to_space->Size(); 1787 main_space_ = to_space; 1788 main_space_backup_.reset(from_space); 1789 RemoveSpace(from_space); 1790 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1791 // Update performed homogeneous space compaction count. 1792 count_performed_homogeneous_space_compaction_++; 1793 // Print statics log and resume all threads. 1794 uint64_t duration = NanoTime() - start_time; 1795 VLOG(heap) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1796 << PrettySize(space_size_before_compaction) << " -> " 1797 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1798 << std::fixed << static_cast<double>(space_size_after_compaction) / 1799 static_cast<double>(space_size_before_compaction); 1800 tl->ResumeAll(); 1801 // Finish GC. 1802 reference_processor_.EnqueueClearedReferences(self); 1803 GrowForUtilization(semi_space_collector_); 1804 LogGC(kGcCauseHomogeneousSpaceCompact, collector); 1805 FinishGC(self, collector::kGcTypeFull); 1806 return HomogeneousSpaceCompactResult::kSuccess; 1807} 1808 1809void Heap::TransitionCollector(CollectorType collector_type) { 1810 if (collector_type == collector_type_) { 1811 return; 1812 } 1813 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1814 << " -> " << static_cast<int>(collector_type); 1815 uint64_t start_time = NanoTime(); 1816 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1817 Runtime* const runtime = Runtime::Current(); 1818 ThreadList* const tl = runtime->GetThreadList(); 1819 Thread* const self = Thread::Current(); 1820 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1821 Locks::mutator_lock_->AssertNotHeld(self); 1822 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1823 // compacting_gc_disable_count_, this should rarely occurs). 1824 for (;;) { 1825 { 1826 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1827 MutexLock mu(self, *gc_complete_lock_); 1828 // Ensure there is only one GC at a time. 1829 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1830 // Currently we only need a heap transition if we switch from a moving collector to a 1831 // non-moving one, or visa versa. 1832 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1833 // If someone else beat us to it and changed the collector before we could, exit. 1834 // This is safe to do before the suspend all since we set the collector_type_running_ before 1835 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1836 // then it would get blocked on WaitForGcToCompleteLocked. 1837 if (collector_type == collector_type_) { 1838 return; 1839 } 1840 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1841 if (!copying_transition || disable_moving_gc_count_ == 0) { 1842 // TODO: Not hard code in semi-space collector? 1843 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1844 break; 1845 } 1846 } 1847 usleep(1000); 1848 } 1849 if (runtime->IsShuttingDown(self)) { 1850 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1851 // cause objects to get finalized. 1852 FinishGC(self, collector::kGcTypeNone); 1853 return; 1854 } 1855 collector::GarbageCollector* collector = nullptr; 1856 tl->SuspendAll(__FUNCTION__); 1857 switch (collector_type) { 1858 case kCollectorTypeSS: { 1859 if (!IsMovingGc(collector_type_)) { 1860 // Create the bump pointer space from the backup space. 1861 CHECK(main_space_backup_ != nullptr); 1862 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1863 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1864 // pointer space last transition it will be protected. 1865 CHECK(mem_map != nullptr); 1866 mem_map->Protect(PROT_READ | PROT_WRITE); 1867 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1868 mem_map.release()); 1869 AddSpace(bump_pointer_space_); 1870 collector = Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1871 // Use the now empty main space mem map for the bump pointer temp space. 1872 mem_map.reset(main_space_->ReleaseMemMap()); 1873 // Unset the pointers just in case. 1874 if (dlmalloc_space_ == main_space_) { 1875 dlmalloc_space_ = nullptr; 1876 } else if (rosalloc_space_ == main_space_) { 1877 rosalloc_space_ = nullptr; 1878 } 1879 // Remove the main space so that we don't try to trim it, this doens't work for debug 1880 // builds since RosAlloc attempts to read the magic number from a protected page. 1881 RemoveSpace(main_space_); 1882 RemoveRememberedSet(main_space_); 1883 delete main_space_; // Delete the space since it has been removed. 1884 main_space_ = nullptr; 1885 RemoveRememberedSet(main_space_backup_.get()); 1886 main_space_backup_.reset(nullptr); // Deletes the space. 1887 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1888 mem_map.release()); 1889 AddSpace(temp_space_); 1890 } 1891 break; 1892 } 1893 case kCollectorTypeMS: 1894 // Fall through. 1895 case kCollectorTypeCMS: { 1896 if (IsMovingGc(collector_type_)) { 1897 CHECK(temp_space_ != nullptr); 1898 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1899 RemoveSpace(temp_space_); 1900 temp_space_ = nullptr; 1901 mem_map->Protect(PROT_READ | PROT_WRITE); 1902 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, 1903 std::min(mem_map->Size(), growth_limit_), mem_map->Size()); 1904 mem_map.release(); 1905 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1906 AddSpace(main_space_); 1907 collector = Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1908 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1909 RemoveSpace(bump_pointer_space_); 1910 bump_pointer_space_ = nullptr; 1911 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1912 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1913 if (kIsDebugBuild && kUseRosAlloc) { 1914 mem_map->Protect(PROT_READ | PROT_WRITE); 1915 } 1916 main_space_backup_.reset(CreateMallocSpaceFromMemMap( 1917 mem_map.get(), kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1918 mem_map->Size(), name, true)); 1919 if (kIsDebugBuild && kUseRosAlloc) { 1920 mem_map->Protect(PROT_NONE); 1921 } 1922 mem_map.release(); 1923 } 1924 break; 1925 } 1926 default: { 1927 LOG(FATAL) << "Attempted to transition to invalid collector type " 1928 << static_cast<size_t>(collector_type); 1929 break; 1930 } 1931 } 1932 ChangeCollector(collector_type); 1933 tl->ResumeAll(); 1934 // Can't call into java code with all threads suspended. 1935 reference_processor_.EnqueueClearedReferences(self); 1936 uint64_t duration = NanoTime() - start_time; 1937 GrowForUtilization(semi_space_collector_); 1938 DCHECK(collector != nullptr); 1939 LogGC(kGcCauseCollectorTransition, collector); 1940 FinishGC(self, collector::kGcTypeFull); 1941 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1942 int32_t delta_allocated = before_allocated - after_allocated; 1943 std::string saved_str; 1944 if (delta_allocated >= 0) { 1945 saved_str = " saved at least " + PrettySize(delta_allocated); 1946 } else { 1947 saved_str = " expanded " + PrettySize(-delta_allocated); 1948 } 1949 VLOG(heap) << "Heap transition to " << process_state_ << " took " 1950 << PrettyDuration(duration) << saved_str; 1951} 1952 1953void Heap::ChangeCollector(CollectorType collector_type) { 1954 // TODO: Only do this with all mutators suspended to avoid races. 1955 if (collector_type != collector_type_) { 1956 if (collector_type == kCollectorTypeMC) { 1957 // Don't allow mark compact unless support is compiled in. 1958 CHECK(kMarkCompactSupport); 1959 } 1960 collector_type_ = collector_type; 1961 gc_plan_.clear(); 1962 switch (collector_type_) { 1963 case kCollectorTypeCC: { 1964 gc_plan_.push_back(collector::kGcTypeFull); 1965 if (use_tlab_) { 1966 ChangeAllocator(kAllocatorTypeRegionTLAB); 1967 } else { 1968 ChangeAllocator(kAllocatorTypeRegion); 1969 } 1970 break; 1971 } 1972 case kCollectorTypeMC: // Fall-through. 1973 case kCollectorTypeSS: // Fall-through. 1974 case kCollectorTypeGSS: { 1975 gc_plan_.push_back(collector::kGcTypeFull); 1976 if (use_tlab_) { 1977 ChangeAllocator(kAllocatorTypeTLAB); 1978 } else { 1979 ChangeAllocator(kAllocatorTypeBumpPointer); 1980 } 1981 break; 1982 } 1983 case kCollectorTypeMS: { 1984 gc_plan_.push_back(collector::kGcTypeSticky); 1985 gc_plan_.push_back(collector::kGcTypePartial); 1986 gc_plan_.push_back(collector::kGcTypeFull); 1987 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1988 break; 1989 } 1990 case kCollectorTypeCMS: { 1991 gc_plan_.push_back(collector::kGcTypeSticky); 1992 gc_plan_.push_back(collector::kGcTypePartial); 1993 gc_plan_.push_back(collector::kGcTypeFull); 1994 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1995 break; 1996 } 1997 default: { 1998 UNIMPLEMENTED(FATAL); 1999 UNREACHABLE(); 2000 } 2001 } 2002 if (IsGcConcurrent()) { 2003 concurrent_start_bytes_ = 2004 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 2005 } else { 2006 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2007 } 2008 } 2009} 2010 2011// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 2012class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 2013 public: 2014 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 2015 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 2016 } 2017 2018 void BuildBins(space::ContinuousSpace* space) { 2019 bin_live_bitmap_ = space->GetLiveBitmap(); 2020 bin_mark_bitmap_ = space->GetMarkBitmap(); 2021 BinContext context; 2022 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 2023 context.collector_ = this; 2024 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 2025 // Note: This requires traversing the space in increasing order of object addresses. 2026 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 2027 // Add the last bin which spans after the last object to the end of the space. 2028 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 2029 } 2030 2031 private: 2032 struct BinContext { 2033 uintptr_t prev_; // The end of the previous object. 2034 ZygoteCompactingCollector* collector_; 2035 }; 2036 // Maps from bin sizes to locations. 2037 std::multimap<size_t, uintptr_t> bins_; 2038 // Live bitmap of the space which contains the bins. 2039 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 2040 // Mark bitmap of the space which contains the bins. 2041 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 2042 2043 static void Callback(mirror::Object* obj, void* arg) 2044 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2045 DCHECK(arg != nullptr); 2046 BinContext* context = reinterpret_cast<BinContext*>(arg); 2047 ZygoteCompactingCollector* collector = context->collector_; 2048 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 2049 size_t bin_size = object_addr - context->prev_; 2050 // Add the bin consisting of the end of the previous object to the start of the current object. 2051 collector->AddBin(bin_size, context->prev_); 2052 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 2053 } 2054 2055 void AddBin(size_t size, uintptr_t position) { 2056 if (size != 0) { 2057 bins_.insert(std::make_pair(size, position)); 2058 } 2059 } 2060 2061 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 2062 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 2063 // allocator. 2064 UNUSED(space); 2065 return false; 2066 } 2067 2068 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 2069 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 2070 size_t obj_size = obj->SizeOf(); 2071 size_t alloc_size = RoundUp(obj_size, kObjectAlignment); 2072 mirror::Object* forward_address; 2073 // Find the smallest bin which we can move obj in. 2074 auto it = bins_.lower_bound(alloc_size); 2075 if (it == bins_.end()) { 2076 // No available space in the bins, place it in the target space instead (grows the zygote 2077 // space). 2078 size_t bytes_allocated, dummy; 2079 forward_address = to_space_->Alloc(self_, alloc_size, &bytes_allocated, nullptr, &dummy); 2080 if (to_space_live_bitmap_ != nullptr) { 2081 to_space_live_bitmap_->Set(forward_address); 2082 } else { 2083 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 2084 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 2085 } 2086 } else { 2087 size_t size = it->first; 2088 uintptr_t pos = it->second; 2089 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 2090 forward_address = reinterpret_cast<mirror::Object*>(pos); 2091 // Set the live and mark bits so that sweeping system weaks works properly. 2092 bin_live_bitmap_->Set(forward_address); 2093 bin_mark_bitmap_->Set(forward_address); 2094 DCHECK_GE(size, alloc_size); 2095 // Add a new bin with the remaining space. 2096 AddBin(size - alloc_size, pos + alloc_size); 2097 } 2098 // Copy the object over to its new location. Don't use alloc_size to avoid valgrind error. 2099 memcpy(reinterpret_cast<void*>(forward_address), obj, obj_size); 2100 if (kUseBakerOrBrooksReadBarrier) { 2101 obj->AssertReadBarrierPointer(); 2102 if (kUseBrooksReadBarrier) { 2103 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 2104 forward_address->SetReadBarrierPointer(forward_address); 2105 } 2106 forward_address->AssertReadBarrierPointer(); 2107 } 2108 return forward_address; 2109 } 2110}; 2111 2112void Heap::UnBindBitmaps() { 2113 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 2114 for (const auto& space : GetContinuousSpaces()) { 2115 if (space->IsContinuousMemMapAllocSpace()) { 2116 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 2117 if (alloc_space->HasBoundBitmaps()) { 2118 alloc_space->UnBindBitmaps(); 2119 } 2120 } 2121 } 2122} 2123 2124void Heap::PreZygoteFork() { 2125 if (!HasZygoteSpace()) { 2126 // We still want to GC in case there is some unreachable non moving objects that could cause a 2127 // suboptimal bin packing when we compact the zygote space. 2128 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 2129 } 2130 Thread* self = Thread::Current(); 2131 MutexLock mu(self, zygote_creation_lock_); 2132 // Try to see if we have any Zygote spaces. 2133 if (HasZygoteSpace()) { 2134 return; 2135 } 2136 Runtime::Current()->GetInternTable()->SwapPostZygoteWithPreZygote(); 2137 Runtime::Current()->GetClassLinker()->MoveClassTableToPreZygote(); 2138 VLOG(heap) << "Starting PreZygoteFork"; 2139 // Trim the pages at the end of the non moving space. 2140 non_moving_space_->Trim(); 2141 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 2142 // there. 2143 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2144 const bool same_space = non_moving_space_ == main_space_; 2145 if (kCompactZygote) { 2146 // Temporarily disable rosalloc verification because the zygote 2147 // compaction will mess up the rosalloc internal metadata. 2148 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 2149 ZygoteCompactingCollector zygote_collector(this); 2150 zygote_collector.BuildBins(non_moving_space_); 2151 // Create a new bump pointer space which we will compact into. 2152 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 2153 non_moving_space_->Limit()); 2154 // Compact the bump pointer space to a new zygote bump pointer space. 2155 bool reset_main_space = false; 2156 if (IsMovingGc(collector_type_)) { 2157 if (collector_type_ == kCollectorTypeCC) { 2158 zygote_collector.SetFromSpace(region_space_); 2159 } else { 2160 zygote_collector.SetFromSpace(bump_pointer_space_); 2161 } 2162 } else { 2163 CHECK(main_space_ != nullptr); 2164 CHECK_NE(main_space_, non_moving_space_) 2165 << "Does not make sense to compact within the same space"; 2166 // Copy from the main space. 2167 zygote_collector.SetFromSpace(main_space_); 2168 reset_main_space = true; 2169 } 2170 zygote_collector.SetToSpace(&target_space); 2171 zygote_collector.SetSwapSemiSpaces(false); 2172 zygote_collector.Run(kGcCauseCollectorTransition, false); 2173 if (reset_main_space) { 2174 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2175 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 2176 MemMap* mem_map = main_space_->ReleaseMemMap(); 2177 RemoveSpace(main_space_); 2178 space::Space* old_main_space = main_space_; 2179 CreateMainMallocSpace(mem_map, kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 2180 mem_map->Size()); 2181 delete old_main_space; 2182 AddSpace(main_space_); 2183 } else { 2184 if (collector_type_ == kCollectorTypeCC) { 2185 region_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2186 } else { 2187 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2188 } 2189 } 2190 if (temp_space_ != nullptr) { 2191 CHECK(temp_space_->IsEmpty()); 2192 } 2193 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2194 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2195 // Update the end and write out image. 2196 non_moving_space_->SetEnd(target_space.End()); 2197 non_moving_space_->SetLimit(target_space.Limit()); 2198 VLOG(heap) << "Create zygote space with size=" << non_moving_space_->Size() << " bytes"; 2199 } 2200 // Change the collector to the post zygote one. 2201 ChangeCollector(foreground_collector_type_); 2202 // Save the old space so that we can remove it after we complete creating the zygote space. 2203 space::MallocSpace* old_alloc_space = non_moving_space_; 2204 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 2205 // the remaining available space. 2206 // Remove the old space before creating the zygote space since creating the zygote space sets 2207 // the old alloc space's bitmaps to null. 2208 RemoveSpace(old_alloc_space); 2209 if (collector::SemiSpace::kUseRememberedSet) { 2210 // Sanity bound check. 2211 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 2212 // Remove the remembered set for the now zygote space (the old 2213 // non-moving space). Note now that we have compacted objects into 2214 // the zygote space, the data in the remembered set is no longer 2215 // needed. The zygote space will instead have a mod-union table 2216 // from this point on. 2217 RemoveRememberedSet(old_alloc_space); 2218 } 2219 // Remaining space becomes the new non moving space. 2220 zygote_space_ = old_alloc_space->CreateZygoteSpace(kNonMovingSpaceName, low_memory_mode_, 2221 &non_moving_space_); 2222 CHECK(!non_moving_space_->CanMoveObjects()); 2223 if (same_space) { 2224 main_space_ = non_moving_space_; 2225 SetSpaceAsDefault(main_space_); 2226 } 2227 delete old_alloc_space; 2228 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 2229 AddSpace(zygote_space_); 2230 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 2231 AddSpace(non_moving_space_); 2232 // Create the zygote space mod union table. 2233 accounting::ModUnionTable* mod_union_table = 2234 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 2235 zygote_space_); 2236 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 2237 // Set all the cards in the mod-union table since we don't know which objects contain references 2238 // to large objects. 2239 mod_union_table->SetCards(); 2240 AddModUnionTable(mod_union_table); 2241 if (collector::SemiSpace::kUseRememberedSet) { 2242 // Add a new remembered set for the post-zygote non-moving space. 2243 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 2244 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2245 non_moving_space_); 2246 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2247 << "Failed to create post-zygote non-moving space remembered set"; 2248 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2249 } 2250} 2251 2252void Heap::FlushAllocStack() { 2253 MarkAllocStackAsLive(allocation_stack_.get()); 2254 allocation_stack_->Reset(); 2255} 2256 2257void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2258 accounting::ContinuousSpaceBitmap* bitmap2, 2259 accounting::LargeObjectBitmap* large_objects, 2260 accounting::ObjectStack* stack) { 2261 DCHECK(bitmap1 != nullptr); 2262 DCHECK(bitmap2 != nullptr); 2263 const auto* limit = stack->End(); 2264 for (auto* it = stack->Begin(); it != limit; ++it) { 2265 const mirror::Object* obj = it->AsMirrorPtr(); 2266 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2267 if (bitmap1->HasAddress(obj)) { 2268 bitmap1->Set(obj); 2269 } else if (bitmap2->HasAddress(obj)) { 2270 bitmap2->Set(obj); 2271 } else { 2272 DCHECK(large_objects != nullptr); 2273 large_objects->Set(obj); 2274 } 2275 } 2276 } 2277} 2278 2279void Heap::SwapSemiSpaces() { 2280 CHECK(bump_pointer_space_ != nullptr); 2281 CHECK(temp_space_ != nullptr); 2282 std::swap(bump_pointer_space_, temp_space_); 2283} 2284 2285collector::GarbageCollector* Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2286 space::ContinuousMemMapAllocSpace* source_space, 2287 GcCause gc_cause) { 2288 CHECK(kMovingCollector); 2289 if (target_space != source_space) { 2290 // Don't swap spaces since this isn't a typical semi space collection. 2291 semi_space_collector_->SetSwapSemiSpaces(false); 2292 semi_space_collector_->SetFromSpace(source_space); 2293 semi_space_collector_->SetToSpace(target_space); 2294 semi_space_collector_->Run(gc_cause, false); 2295 return semi_space_collector_; 2296 } else { 2297 CHECK(target_space->IsBumpPointerSpace()) 2298 << "In-place compaction is only supported for bump pointer spaces"; 2299 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2300 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2301 return mark_compact_collector_; 2302 } 2303} 2304 2305collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2306 bool clear_soft_references) { 2307 Thread* self = Thread::Current(); 2308 Runtime* runtime = Runtime::Current(); 2309 // If the heap can't run the GC, silently fail and return that no GC was run. 2310 switch (gc_type) { 2311 case collector::kGcTypePartial: { 2312 if (!HasZygoteSpace()) { 2313 return collector::kGcTypeNone; 2314 } 2315 break; 2316 } 2317 default: { 2318 // Other GC types don't have any special cases which makes them not runnable. The main case 2319 // here is full GC. 2320 } 2321 } 2322 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2323 Locks::mutator_lock_->AssertNotHeld(self); 2324 if (self->IsHandlingStackOverflow()) { 2325 // If we are throwing a stack overflow error we probably don't have enough remaining stack 2326 // space to run the GC. 2327 return collector::kGcTypeNone; 2328 } 2329 bool compacting_gc; 2330 { 2331 gc_complete_lock_->AssertNotHeld(self); 2332 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 2333 MutexLock mu(self, *gc_complete_lock_); 2334 // Ensure there is only one GC at a time. 2335 WaitForGcToCompleteLocked(gc_cause, self); 2336 compacting_gc = IsMovingGc(collector_type_); 2337 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2338 if (compacting_gc && disable_moving_gc_count_ != 0) { 2339 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2340 return collector::kGcTypeNone; 2341 } 2342 collector_type_running_ = collector_type_; 2343 } 2344 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2345 ++runtime->GetStats()->gc_for_alloc_count; 2346 ++self->GetStats()->gc_for_alloc_count; 2347 } 2348 const uint64_t bytes_allocated_before_gc = GetBytesAllocated(); 2349 // Approximate heap size. 2350 ATRACE_INT("Heap size (KB)", bytes_allocated_before_gc / KB); 2351 2352 DCHECK_LT(gc_type, collector::kGcTypeMax); 2353 DCHECK_NE(gc_type, collector::kGcTypeNone); 2354 2355 collector::GarbageCollector* collector = nullptr; 2356 // TODO: Clean this up. 2357 if (compacting_gc) { 2358 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2359 current_allocator_ == kAllocatorTypeTLAB || 2360 current_allocator_ == kAllocatorTypeRegion || 2361 current_allocator_ == kAllocatorTypeRegionTLAB); 2362 switch (collector_type_) { 2363 case kCollectorTypeSS: 2364 // Fall-through. 2365 case kCollectorTypeGSS: 2366 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2367 semi_space_collector_->SetToSpace(temp_space_); 2368 semi_space_collector_->SetSwapSemiSpaces(true); 2369 collector = semi_space_collector_; 2370 break; 2371 case kCollectorTypeCC: 2372 concurrent_copying_collector_->SetRegionSpace(region_space_); 2373 collector = concurrent_copying_collector_; 2374 break; 2375 case kCollectorTypeMC: 2376 mark_compact_collector_->SetSpace(bump_pointer_space_); 2377 collector = mark_compact_collector_; 2378 break; 2379 default: 2380 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2381 } 2382 if (collector != mark_compact_collector_ && collector != concurrent_copying_collector_) { 2383 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2384 CHECK(temp_space_->IsEmpty()); 2385 } 2386 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2387 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2388 current_allocator_ == kAllocatorTypeDlMalloc) { 2389 collector = FindCollectorByGcType(gc_type); 2390 } else { 2391 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2392 } 2393 if (IsGcConcurrent()) { 2394 // Disable concurrent GC check so that we don't have spammy JNI requests. 2395 // This gets recalculated in GrowForUtilization. It is important that it is disabled / 2396 // calculated in the same thread so that there aren't any races that can cause it to become 2397 // permanantly disabled. b/17942071 2398 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2399 } 2400 CHECK(collector != nullptr) 2401 << "Could not find garbage collector with collector_type=" 2402 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2403 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2404 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2405 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2406 RequestTrim(self); 2407 // Enqueue cleared references. 2408 reference_processor_.EnqueueClearedReferences(self); 2409 // Grow the heap so that we know when to perform the next GC. 2410 GrowForUtilization(collector, bytes_allocated_before_gc); 2411 LogGC(gc_cause, collector); 2412 FinishGC(self, gc_type); 2413 // Inform DDMS that a GC completed. 2414 Dbg::GcDidFinish(); 2415 return gc_type; 2416} 2417 2418void Heap::LogGC(GcCause gc_cause, collector::GarbageCollector* collector) { 2419 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2420 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2421 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2422 // (mutator time blocked >= long_pause_log_threshold_). 2423 bool log_gc = gc_cause == kGcCauseExplicit; 2424 if (!log_gc && CareAboutPauseTimes()) { 2425 // GC for alloc pauses the allocating thread, so consider it as a pause. 2426 log_gc = duration > long_gc_log_threshold_ || 2427 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2428 for (uint64_t pause : pause_times) { 2429 log_gc = log_gc || pause >= long_pause_log_threshold_; 2430 } 2431 } 2432 if (log_gc) { 2433 const size_t percent_free = GetPercentFree(); 2434 const size_t current_heap_size = GetBytesAllocated(); 2435 const size_t total_memory = GetTotalMemory(); 2436 std::ostringstream pause_string; 2437 for (size_t i = 0; i < pause_times.size(); ++i) { 2438 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2439 << ((i != pause_times.size() - 1) ? "," : ""); 2440 } 2441 LOG(INFO) << gc_cause << " " << collector->GetName() 2442 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2443 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2444 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2445 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2446 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2447 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2448 << " total " << PrettyDuration((duration / 1000) * 1000); 2449 VLOG(heap) << Dumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2450 } 2451} 2452 2453void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2454 MutexLock mu(self, *gc_complete_lock_); 2455 collector_type_running_ = kCollectorTypeNone; 2456 if (gc_type != collector::kGcTypeNone) { 2457 last_gc_type_ = gc_type; 2458 2459 // Update stats. 2460 ++gc_count_last_window_; 2461 if (running_collection_is_blocking_) { 2462 // If the currently running collection was a blocking one, 2463 // increment the counters and reset the flag. 2464 ++blocking_gc_count_; 2465 blocking_gc_time_ += GetCurrentGcIteration()->GetDurationNs(); 2466 ++blocking_gc_count_last_window_; 2467 } 2468 // Update the gc count rate histograms if due. 2469 UpdateGcCountRateHistograms(); 2470 } 2471 // Reset. 2472 running_collection_is_blocking_ = false; 2473 // Wake anyone who may have been waiting for the GC to complete. 2474 gc_complete_cond_->Broadcast(self); 2475} 2476 2477void Heap::UpdateGcCountRateHistograms() { 2478 // Invariant: if the time since the last update includes more than 2479 // one windows, all the GC runs (if > 0) must have happened in first 2480 // window because otherwise the update must have already taken place 2481 // at an earlier GC run. So, we report the non-first windows with 2482 // zero counts to the histograms. 2483 DCHECK_EQ(last_update_time_gc_count_rate_histograms_ % kGcCountRateHistogramWindowDuration, 0U); 2484 uint64_t now = NanoTime(); 2485 DCHECK_GE(now, last_update_time_gc_count_rate_histograms_); 2486 uint64_t time_since_last_update = now - last_update_time_gc_count_rate_histograms_; 2487 uint64_t num_of_windows = time_since_last_update / kGcCountRateHistogramWindowDuration; 2488 if (time_since_last_update >= kGcCountRateHistogramWindowDuration) { 2489 // Record the first window. 2490 gc_count_rate_histogram_.AddValue(gc_count_last_window_ - 1); // Exclude the current run. 2491 blocking_gc_count_rate_histogram_.AddValue(running_collection_is_blocking_ ? 2492 blocking_gc_count_last_window_ - 1 : blocking_gc_count_last_window_); 2493 // Record the other windows (with zero counts). 2494 for (uint64_t i = 0; i < num_of_windows - 1; ++i) { 2495 gc_count_rate_histogram_.AddValue(0); 2496 blocking_gc_count_rate_histogram_.AddValue(0); 2497 } 2498 // Update the last update time and reset the counters. 2499 last_update_time_gc_count_rate_histograms_ = 2500 (now / kGcCountRateHistogramWindowDuration) * kGcCountRateHistogramWindowDuration; 2501 gc_count_last_window_ = 1; // Include the current run. 2502 blocking_gc_count_last_window_ = running_collection_is_blocking_ ? 1 : 0; 2503 } 2504 DCHECK_EQ(last_update_time_gc_count_rate_histograms_ % kGcCountRateHistogramWindowDuration, 0U); 2505} 2506 2507class RootMatchesObjectVisitor : public SingleRootVisitor { 2508 public: 2509 explicit RootMatchesObjectVisitor(const mirror::Object* obj) : obj_(obj) { } 2510 2511 void VisitRoot(mirror::Object* root, const RootInfo& info) 2512 OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2513 if (root == obj_) { 2514 LOG(INFO) << "Object " << obj_ << " is a root " << info.ToString(); 2515 } 2516 } 2517 2518 private: 2519 const mirror::Object* const obj_; 2520}; 2521 2522 2523class ScanVisitor { 2524 public: 2525 void operator()(const mirror::Object* obj) const { 2526 LOG(ERROR) << "Would have rescanned object " << obj; 2527 } 2528}; 2529 2530// Verify a reference from an object. 2531class VerifyReferenceVisitor : public SingleRootVisitor { 2532 public: 2533 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2534 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2535 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2536 2537 size_t GetFailureCount() const { 2538 return fail_count_->LoadSequentiallyConsistent(); 2539 } 2540 2541 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2542 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2543 UNUSED(klass); 2544 if (verify_referent_) { 2545 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2546 } 2547 } 2548 2549 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2550 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2551 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2552 } 2553 2554 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2555 return heap_->IsLiveObjectLocked(obj, true, false, true); 2556 } 2557 2558 void VisitRoot(mirror::Object* root, const RootInfo& root_info) OVERRIDE 2559 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2560 if (root == nullptr) { 2561 LOG(ERROR) << "Root is null with info " << root_info.GetType(); 2562 } else if (!VerifyReference(nullptr, root, MemberOffset(0))) { 2563 LOG(ERROR) << "Root " << root << " is dead with type " << PrettyTypeOf(root) 2564 << " thread_id= " << root_info.GetThreadId() << " root_type= " << root_info.GetType(); 2565 } 2566 } 2567 2568 private: 2569 // TODO: Fix the no thread safety analysis. 2570 // Returns false on failure. 2571 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2572 NO_THREAD_SAFETY_ANALYSIS { 2573 if (ref == nullptr || IsLive(ref)) { 2574 // Verify that the reference is live. 2575 return true; 2576 } 2577 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2578 // Print message on only on first failure to prevent spam. 2579 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2580 } 2581 if (obj != nullptr) { 2582 // Only do this part for non roots. 2583 accounting::CardTable* card_table = heap_->GetCardTable(); 2584 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2585 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2586 uint8_t* card_addr = card_table->CardFromAddr(obj); 2587 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2588 << offset << "\n card value = " << static_cast<int>(*card_addr); 2589 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2590 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2591 } else { 2592 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2593 } 2594 2595 // Attempt to find the class inside of the recently freed objects. 2596 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2597 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2598 space::MallocSpace* space = ref_space->AsMallocSpace(); 2599 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2600 if (ref_class != nullptr) { 2601 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2602 << PrettyClass(ref_class); 2603 } else { 2604 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2605 } 2606 } 2607 2608 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2609 ref->GetClass()->IsClass()) { 2610 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2611 } else { 2612 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2613 << ") is not a valid heap address"; 2614 } 2615 2616 card_table->CheckAddrIsInCardTable(reinterpret_cast<const uint8_t*>(obj)); 2617 void* cover_begin = card_table->AddrFromCard(card_addr); 2618 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2619 accounting::CardTable::kCardSize); 2620 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2621 << "-" << cover_end; 2622 accounting::ContinuousSpaceBitmap* bitmap = 2623 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2624 2625 if (bitmap == nullptr) { 2626 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2627 if (!VerifyClassClass(obj->GetClass())) { 2628 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2629 } 2630 } else { 2631 // Print out how the object is live. 2632 if (bitmap->Test(obj)) { 2633 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2634 } 2635 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2636 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2637 } 2638 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2639 LOG(ERROR) << "Object " << obj << " found in live stack"; 2640 } 2641 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2642 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2643 } 2644 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2645 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2646 } 2647 // Attempt to see if the card table missed the reference. 2648 ScanVisitor scan_visitor; 2649 uint8_t* byte_cover_begin = reinterpret_cast<uint8_t*>(card_table->AddrFromCard(card_addr)); 2650 card_table->Scan<false>(bitmap, byte_cover_begin, 2651 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2652 } 2653 2654 // Search to see if any of the roots reference our object. 2655 RootMatchesObjectVisitor visitor1(obj); 2656 Runtime::Current()->VisitRoots(&visitor1); 2657 // Search to see if any of the roots reference our reference. 2658 RootMatchesObjectVisitor visitor2(ref); 2659 Runtime::Current()->VisitRoots(&visitor2); 2660 } 2661 return false; 2662 } 2663 2664 Heap* const heap_; 2665 Atomic<size_t>* const fail_count_; 2666 const bool verify_referent_; 2667}; 2668 2669// Verify all references within an object, for use with HeapBitmap::Visit. 2670class VerifyObjectVisitor { 2671 public: 2672 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2673 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2674 } 2675 2676 void operator()(mirror::Object* obj) const 2677 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2678 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2679 // be live or else how did we find it in the live bitmap? 2680 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2681 // The class doesn't count as a reference but we should verify it anyways. 2682 obj->VisitReferences<true>(visitor, visitor); 2683 } 2684 2685 static void VisitCallback(mirror::Object* obj, void* arg) 2686 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2687 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2688 visitor->operator()(obj); 2689 } 2690 2691 void VerifyRoots() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 2692 LOCKS_EXCLUDED(Locks::heap_bitmap_lock_) { 2693 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 2694 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2695 Runtime::Current()->VisitRoots(&visitor); 2696 } 2697 2698 size_t GetFailureCount() const { 2699 return fail_count_->LoadSequentiallyConsistent(); 2700 } 2701 2702 private: 2703 Heap* const heap_; 2704 Atomic<size_t>* const fail_count_; 2705 const bool verify_referent_; 2706}; 2707 2708void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2709 // Slow path, the allocation stack push back must have already failed. 2710 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2711 do { 2712 // TODO: Add handle VerifyObject. 2713 StackHandleScope<1> hs(self); 2714 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2715 // Push our object into the reserve region of the allocaiton stack. This is only required due 2716 // to heap verification requiring that roots are live (either in the live bitmap or in the 2717 // allocation stack). 2718 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2719 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2720 } while (!allocation_stack_->AtomicPushBack(*obj)); 2721} 2722 2723void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2724 // Slow path, the allocation stack push back must have already failed. 2725 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2726 StackReference<mirror::Object>* start_address; 2727 StackReference<mirror::Object>* end_address; 2728 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2729 &end_address)) { 2730 // TODO: Add handle VerifyObject. 2731 StackHandleScope<1> hs(self); 2732 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2733 // Push our object into the reserve region of the allocaiton stack. This is only required due 2734 // to heap verification requiring that roots are live (either in the live bitmap or in the 2735 // allocation stack). 2736 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2737 // Push into the reserve allocation stack. 2738 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2739 } 2740 self->SetThreadLocalAllocationStack(start_address, end_address); 2741 // Retry on the new thread-local allocation stack. 2742 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2743} 2744 2745// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2746size_t Heap::VerifyHeapReferences(bool verify_referents) { 2747 Thread* self = Thread::Current(); 2748 Locks::mutator_lock_->AssertExclusiveHeld(self); 2749 // Lets sort our allocation stacks so that we can efficiently binary search them. 2750 allocation_stack_->Sort(); 2751 live_stack_->Sort(); 2752 // Since we sorted the allocation stack content, need to revoke all 2753 // thread-local allocation stacks. 2754 RevokeAllThreadLocalAllocationStacks(self); 2755 Atomic<size_t> fail_count_(0); 2756 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2757 // Verify objects in the allocation stack since these will be objects which were: 2758 // 1. Allocated prior to the GC (pre GC verification). 2759 // 2. Allocated during the GC (pre sweep GC verification). 2760 // We don't want to verify the objects in the live stack since they themselves may be 2761 // pointing to dead objects if they are not reachable. 2762 VisitObjectsPaused(VerifyObjectVisitor::VisitCallback, &visitor); 2763 // Verify the roots: 2764 visitor.VerifyRoots(); 2765 if (visitor.GetFailureCount() > 0) { 2766 // Dump mod-union tables. 2767 for (const auto& table_pair : mod_union_tables_) { 2768 accounting::ModUnionTable* mod_union_table = table_pair.second; 2769 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2770 } 2771 // Dump remembered sets. 2772 for (const auto& table_pair : remembered_sets_) { 2773 accounting::RememberedSet* remembered_set = table_pair.second; 2774 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2775 } 2776 DumpSpaces(LOG(ERROR)); 2777 } 2778 return visitor.GetFailureCount(); 2779} 2780 2781class VerifyReferenceCardVisitor { 2782 public: 2783 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2784 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2785 Locks::heap_bitmap_lock_) 2786 : heap_(heap), failed_(failed) { 2787 } 2788 2789 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2790 // annotalysis on visitors. 2791 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2792 NO_THREAD_SAFETY_ANALYSIS { 2793 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2794 // Filter out class references since changing an object's class does not mark the card as dirty. 2795 // Also handles large objects, since the only reference they hold is a class reference. 2796 if (ref != nullptr && !ref->IsClass()) { 2797 accounting::CardTable* card_table = heap_->GetCardTable(); 2798 // If the object is not dirty and it is referencing something in the live stack other than 2799 // class, then it must be on a dirty card. 2800 if (!card_table->AddrIsInCardTable(obj)) { 2801 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2802 *failed_ = true; 2803 } else if (!card_table->IsDirty(obj)) { 2804 // TODO: Check mod-union tables. 2805 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2806 // kCardDirty - 1 if it didnt get touched since we aged it. 2807 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2808 if (live_stack->ContainsSorted(ref)) { 2809 if (live_stack->ContainsSorted(obj)) { 2810 LOG(ERROR) << "Object " << obj << " found in live stack"; 2811 } 2812 if (heap_->GetLiveBitmap()->Test(obj)) { 2813 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2814 } 2815 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2816 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2817 2818 // Print which field of the object is dead. 2819 if (!obj->IsObjectArray()) { 2820 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2821 CHECK(klass != nullptr); 2822 auto* fields = is_static ? klass->GetSFields() : klass->GetIFields(); 2823 auto num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); 2824 CHECK_EQ(fields == nullptr, num_fields == 0u); 2825 for (size_t i = 0; i < num_fields; ++i) { 2826 ArtField* cur = &fields[i]; 2827 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2828 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2829 << PrettyField(cur); 2830 break; 2831 } 2832 } 2833 } else { 2834 mirror::ObjectArray<mirror::Object>* object_array = 2835 obj->AsObjectArray<mirror::Object>(); 2836 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2837 if (object_array->Get(i) == ref) { 2838 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2839 } 2840 } 2841 } 2842 2843 *failed_ = true; 2844 } 2845 } 2846 } 2847 } 2848 2849 private: 2850 Heap* const heap_; 2851 bool* const failed_; 2852}; 2853 2854class VerifyLiveStackReferences { 2855 public: 2856 explicit VerifyLiveStackReferences(Heap* heap) 2857 : heap_(heap), 2858 failed_(false) {} 2859 2860 void operator()(mirror::Object* obj) const 2861 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2862 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2863 obj->VisitReferences<true>(visitor, VoidFunctor()); 2864 } 2865 2866 bool Failed() const { 2867 return failed_; 2868 } 2869 2870 private: 2871 Heap* const heap_; 2872 bool failed_; 2873}; 2874 2875bool Heap::VerifyMissingCardMarks() { 2876 Thread* self = Thread::Current(); 2877 Locks::mutator_lock_->AssertExclusiveHeld(self); 2878 // We need to sort the live stack since we binary search it. 2879 live_stack_->Sort(); 2880 // Since we sorted the allocation stack content, need to revoke all 2881 // thread-local allocation stacks. 2882 RevokeAllThreadLocalAllocationStacks(self); 2883 VerifyLiveStackReferences visitor(this); 2884 GetLiveBitmap()->Visit(visitor); 2885 // We can verify objects in the live stack since none of these should reference dead objects. 2886 for (auto* it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2887 if (!kUseThreadLocalAllocationStack || it->AsMirrorPtr() != nullptr) { 2888 visitor(it->AsMirrorPtr()); 2889 } 2890 } 2891 return !visitor.Failed(); 2892} 2893 2894void Heap::SwapStacks(Thread* self) { 2895 UNUSED(self); 2896 if (kUseThreadLocalAllocationStack) { 2897 live_stack_->AssertAllZero(); 2898 } 2899 allocation_stack_.swap(live_stack_); 2900} 2901 2902void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2903 // This must be called only during the pause. 2904 DCHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2905 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2906 MutexLock mu2(self, *Locks::thread_list_lock_); 2907 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2908 for (Thread* t : thread_list) { 2909 t->RevokeThreadLocalAllocationStack(); 2910 } 2911} 2912 2913void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2914 if (kIsDebugBuild) { 2915 if (rosalloc_space_ != nullptr) { 2916 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2917 } 2918 if (bump_pointer_space_ != nullptr) { 2919 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2920 } 2921 } 2922} 2923 2924void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2925 if (kIsDebugBuild) { 2926 if (bump_pointer_space_ != nullptr) { 2927 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2928 } 2929 } 2930} 2931 2932accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2933 auto it = mod_union_tables_.find(space); 2934 if (it == mod_union_tables_.end()) { 2935 return nullptr; 2936 } 2937 return it->second; 2938} 2939 2940accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2941 auto it = remembered_sets_.find(space); 2942 if (it == remembered_sets_.end()) { 2943 return nullptr; 2944 } 2945 return it->second; 2946} 2947 2948void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets, bool process_alloc_space_cards, 2949 bool clear_alloc_space_cards) { 2950 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2951 // Clear cards and keep track of cards cleared in the mod-union table. 2952 for (const auto& space : continuous_spaces_) { 2953 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2954 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2955 if (table != nullptr) { 2956 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2957 "ImageModUnionClearCards"; 2958 TimingLogger::ScopedTiming t2(name, timings); 2959 table->ClearCards(); 2960 } else if (use_rem_sets && rem_set != nullptr) { 2961 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2962 << static_cast<int>(collector_type_); 2963 TimingLogger::ScopedTiming t2("AllocSpaceRemSetClearCards", timings); 2964 rem_set->ClearCards(); 2965 } else if (process_alloc_space_cards) { 2966 TimingLogger::ScopedTiming t2("AllocSpaceClearCards", timings); 2967 if (clear_alloc_space_cards) { 2968 card_table_->ClearCardRange(space->Begin(), space->End()); 2969 } else { 2970 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these 2971 // cards were dirty before the GC started. 2972 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2973 // -> clean(cleaning thread). 2974 // The races are we either end up with: Aged card, unaged card. Since we have the 2975 // checkpoint roots and then we scan / update mod union tables after. We will always 2976 // scan either card. If we end up with the non aged card, we scan it it in the pause. 2977 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2978 VoidFunctor()); 2979 } 2980 } 2981 } 2982} 2983 2984static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2985} 2986 2987void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2988 Thread* const self = Thread::Current(); 2989 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2990 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2991 if (verify_pre_gc_heap_) { 2992 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyHeapReferences", timings); 2993 size_t failures = VerifyHeapReferences(); 2994 if (failures > 0) { 2995 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2996 << " failures"; 2997 } 2998 } 2999 // Check that all objects which reference things in the live stack are on dirty cards. 3000 if (verify_missing_card_marks_) { 3001 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyMissingCardMarks", timings); 3002 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 3003 SwapStacks(self); 3004 // Sort the live stack so that we can quickly binary search it later. 3005 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 3006 << " missing card mark verification failed\n" << DumpSpaces(); 3007 SwapStacks(self); 3008 } 3009 if (verify_mod_union_table_) { 3010 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyModUnionTables", timings); 3011 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 3012 for (const auto& table_pair : mod_union_tables_) { 3013 accounting::ModUnionTable* mod_union_table = table_pair.second; 3014 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 3015 mod_union_table->Verify(); 3016 } 3017 } 3018} 3019 3020void Heap::PreGcVerification(collector::GarbageCollector* gc) { 3021 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 3022 collector::GarbageCollector::ScopedPause pause(gc); 3023 PreGcVerificationPaused(gc); 3024 } 3025} 3026 3027void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 3028 UNUSED(gc); 3029 // TODO: Add a new runtime option for this? 3030 if (verify_pre_gc_rosalloc_) { 3031 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 3032 } 3033} 3034 3035void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 3036 Thread* const self = Thread::Current(); 3037 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 3038 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 3039 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 3040 // reachable objects. 3041 if (verify_pre_sweeping_heap_) { 3042 TimingLogger::ScopedTiming t2("(Paused)PostSweepingVerifyHeapReferences", timings); 3043 CHECK_NE(self->GetState(), kRunnable); 3044 { 3045 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 3046 // Swapping bound bitmaps does nothing. 3047 gc->SwapBitmaps(); 3048 } 3049 // Pass in false since concurrent reference processing can mean that the reference referents 3050 // may point to dead objects at the point which PreSweepingGcVerification is called. 3051 size_t failures = VerifyHeapReferences(false); 3052 if (failures > 0) { 3053 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 3054 << " failures"; 3055 } 3056 { 3057 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 3058 gc->SwapBitmaps(); 3059 } 3060 } 3061 if (verify_pre_sweeping_rosalloc_) { 3062 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 3063 } 3064} 3065 3066void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 3067 // Only pause if we have to do some verification. 3068 Thread* const self = Thread::Current(); 3069 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 3070 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 3071 if (verify_system_weaks_) { 3072 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 3073 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 3074 mark_sweep->VerifySystemWeaks(); 3075 } 3076 if (verify_post_gc_rosalloc_) { 3077 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 3078 } 3079 if (verify_post_gc_heap_) { 3080 TimingLogger::ScopedTiming t2("(Paused)PostGcVerifyHeapReferences", timings); 3081 size_t failures = VerifyHeapReferences(); 3082 if (failures > 0) { 3083 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 3084 << " failures"; 3085 } 3086 } 3087} 3088 3089void Heap::PostGcVerification(collector::GarbageCollector* gc) { 3090 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 3091 collector::GarbageCollector::ScopedPause pause(gc); 3092 PostGcVerificationPaused(gc); 3093 } 3094} 3095 3096void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 3097 TimingLogger::ScopedTiming t(name, timings); 3098 for (const auto& space : continuous_spaces_) { 3099 if (space->IsRosAllocSpace()) { 3100 VLOG(heap) << name << " : " << space->GetName(); 3101 space->AsRosAllocSpace()->Verify(); 3102 } 3103 } 3104} 3105 3106collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 3107 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 3108 MutexLock mu(self, *gc_complete_lock_); 3109 return WaitForGcToCompleteLocked(cause, self); 3110} 3111 3112collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 3113 collector::GcType last_gc_type = collector::kGcTypeNone; 3114 uint64_t wait_start = NanoTime(); 3115 while (collector_type_running_ != kCollectorTypeNone) { 3116 if (self != task_processor_->GetRunningThread()) { 3117 // The current thread is about to wait for a currently running 3118 // collection to finish. If the waiting thread is not the heap 3119 // task daemon thread, the currently running collection is 3120 // considered as a blocking GC. 3121 running_collection_is_blocking_ = true; 3122 VLOG(gc) << "Waiting for a blocking GC " << cause; 3123 } 3124 ATRACE_BEGIN("GC: Wait For Completion"); 3125 // We must wait, change thread state then sleep on gc_complete_cond_; 3126 gc_complete_cond_->Wait(self); 3127 last_gc_type = last_gc_type_; 3128 ATRACE_END(); 3129 } 3130 uint64_t wait_time = NanoTime() - wait_start; 3131 total_wait_time_ += wait_time; 3132 if (wait_time > long_pause_log_threshold_) { 3133 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 3134 << " for cause " << cause; 3135 } 3136 if (self != task_processor_->GetRunningThread()) { 3137 // The current thread is about to run a collection. If the thread 3138 // is not the heap task daemon thread, it's considered as a 3139 // blocking GC (i.e., blocking itself). 3140 running_collection_is_blocking_ = true; 3141 VLOG(gc) << "Starting a blocking GC " << cause; 3142 } 3143 return last_gc_type; 3144} 3145 3146void Heap::DumpForSigQuit(std::ostream& os) { 3147 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 3148 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 3149 DumpGcPerformanceInfo(os); 3150} 3151 3152size_t Heap::GetPercentFree() { 3153 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 3154} 3155 3156void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 3157 if (max_allowed_footprint > GetMaxMemory()) { 3158 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 3159 << PrettySize(GetMaxMemory()); 3160 max_allowed_footprint = GetMaxMemory(); 3161 } 3162 max_allowed_footprint_ = max_allowed_footprint; 3163} 3164 3165bool Heap::IsMovableObject(const mirror::Object* obj) const { 3166 if (kMovingCollector) { 3167 space::Space* space = FindContinuousSpaceFromObject(obj, true); 3168 if (space != nullptr) { 3169 // TODO: Check large object? 3170 return space->CanMoveObjects(); 3171 } 3172 } 3173 return false; 3174} 3175 3176void Heap::UpdateMaxNativeFootprint() { 3177 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 3178 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 3179 size_t target_size = native_size / GetTargetHeapUtilization(); 3180 if (target_size > native_size + max_free_) { 3181 target_size = native_size + max_free_; 3182 } else if (target_size < native_size + min_free_) { 3183 target_size = native_size + min_free_; 3184 } 3185 native_footprint_gc_watermark_ = std::min(growth_limit_, target_size); 3186} 3187 3188collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 3189 for (const auto& collector : garbage_collectors_) { 3190 if (collector->GetCollectorType() == collector_type_ && 3191 collector->GetGcType() == gc_type) { 3192 return collector; 3193 } 3194 } 3195 return nullptr; 3196} 3197 3198double Heap::HeapGrowthMultiplier() const { 3199 // If we don't care about pause times we are background, so return 1.0. 3200 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 3201 return 1.0; 3202 } 3203 return foreground_heap_growth_multiplier_; 3204} 3205 3206void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran, 3207 uint64_t bytes_allocated_before_gc) { 3208 // We know what our utilization is at this moment. 3209 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 3210 const uint64_t bytes_allocated = GetBytesAllocated(); 3211 uint64_t target_size; 3212 collector::GcType gc_type = collector_ran->GetGcType(); 3213 const double multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 3214 // foreground. 3215 const uint64_t adjusted_min_free = static_cast<uint64_t>(min_free_ * multiplier); 3216 const uint64_t adjusted_max_free = static_cast<uint64_t>(max_free_ * multiplier); 3217 if (gc_type != collector::kGcTypeSticky) { 3218 // Grow the heap for non sticky GC. 3219 ssize_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 3220 CHECK_GE(delta, 0); 3221 target_size = bytes_allocated + delta * multiplier; 3222 target_size = std::min(target_size, bytes_allocated + adjusted_max_free); 3223 target_size = std::max(target_size, bytes_allocated + adjusted_min_free); 3224 native_need_to_run_finalization_ = true; 3225 next_gc_type_ = collector::kGcTypeSticky; 3226 } else { 3227 collector::GcType non_sticky_gc_type = 3228 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 3229 // Find what the next non sticky collector will be. 3230 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 3231 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 3232 // do another sticky collection next. 3233 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 3234 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 3235 // if the sticky GC throughput always remained >= the full/partial throughput. 3236 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 3237 non_sticky_collector->GetEstimatedMeanThroughput() && 3238 non_sticky_collector->NumberOfIterations() > 0 && 3239 bytes_allocated <= max_allowed_footprint_) { 3240 next_gc_type_ = collector::kGcTypeSticky; 3241 } else { 3242 next_gc_type_ = non_sticky_gc_type; 3243 } 3244 // If we have freed enough memory, shrink the heap back down. 3245 if (bytes_allocated + adjusted_max_free < max_allowed_footprint_) { 3246 target_size = bytes_allocated + adjusted_max_free; 3247 } else { 3248 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 3249 } 3250 } 3251 if (!ignore_max_footprint_) { 3252 SetIdealFootprint(target_size); 3253 if (IsGcConcurrent()) { 3254 const uint64_t freed_bytes = current_gc_iteration_.GetFreedBytes() + 3255 current_gc_iteration_.GetFreedLargeObjectBytes() + 3256 current_gc_iteration_.GetFreedRevokeBytes(); 3257 // Bytes allocated will shrink by freed_bytes after the GC runs, so if we want to figure out 3258 // how many bytes were allocated during the GC we need to add freed_bytes back on. 3259 CHECK_GE(bytes_allocated + freed_bytes, bytes_allocated_before_gc); 3260 const uint64_t bytes_allocated_during_gc = bytes_allocated + freed_bytes - 3261 bytes_allocated_before_gc; 3262 // Calculate when to perform the next ConcurrentGC. 3263 // Calculate the estimated GC duration. 3264 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 3265 // Estimate how many remaining bytes we will have when we need to start the next GC. 3266 size_t remaining_bytes = bytes_allocated_during_gc * gc_duration_seconds; 3267 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 3268 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 3269 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 3270 // A never going to happen situation that from the estimated allocation rate we will exceed 3271 // the applications entire footprint with the given estimated allocation rate. Schedule 3272 // another GC nearly straight away. 3273 remaining_bytes = kMinConcurrentRemainingBytes; 3274 } 3275 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 3276 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 3277 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 3278 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 3279 // right away. 3280 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 3281 static_cast<size_t>(bytes_allocated)); 3282 } 3283 } 3284} 3285 3286void Heap::ClampGrowthLimit() { 3287 // Use heap bitmap lock to guard against races with BindLiveToMarkBitmap. 3288 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 3289 capacity_ = growth_limit_; 3290 for (const auto& space : continuous_spaces_) { 3291 if (space->IsMallocSpace()) { 3292 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3293 malloc_space->ClampGrowthLimit(); 3294 } 3295 } 3296 // This space isn't added for performance reasons. 3297 if (main_space_backup_.get() != nullptr) { 3298 main_space_backup_->ClampGrowthLimit(); 3299 } 3300} 3301 3302void Heap::ClearGrowthLimit() { 3303 growth_limit_ = capacity_; 3304 for (const auto& space : continuous_spaces_) { 3305 if (space->IsMallocSpace()) { 3306 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3307 malloc_space->ClearGrowthLimit(); 3308 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 3309 } 3310 } 3311 // This space isn't added for performance reasons. 3312 if (main_space_backup_.get() != nullptr) { 3313 main_space_backup_->ClearGrowthLimit(); 3314 main_space_backup_->SetFootprintLimit(main_space_backup_->Capacity()); 3315 } 3316} 3317 3318void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 3319 ScopedObjectAccess soa(self); 3320 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 3321 jvalue args[1]; 3322 args[0].l = arg.get(); 3323 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 3324 // Restore object in case it gets moved. 3325 *object = soa.Decode<mirror::Object*>(arg.get()); 3326} 3327 3328void Heap::RequestConcurrentGCAndSaveObject(Thread* self, bool force_full, mirror::Object** obj) { 3329 StackHandleScope<1> hs(self); 3330 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 3331 RequestConcurrentGC(self, force_full); 3332} 3333 3334class Heap::ConcurrentGCTask : public HeapTask { 3335 public: 3336 explicit ConcurrentGCTask(uint64_t target_time, bool force_full) 3337 : HeapTask(target_time), force_full_(force_full) { } 3338 virtual void Run(Thread* self) OVERRIDE { 3339 gc::Heap* heap = Runtime::Current()->GetHeap(); 3340 heap->ConcurrentGC(self, force_full_); 3341 heap->ClearConcurrentGCRequest(); 3342 } 3343 3344 private: 3345 const bool force_full_; // If true, force full (or partial) collection. 3346}; 3347 3348static bool CanAddHeapTask(Thread* self) LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_) { 3349 Runtime* runtime = Runtime::Current(); 3350 return runtime != nullptr && runtime->IsFinishedStarting() && !runtime->IsShuttingDown(self) && 3351 !self->IsHandlingStackOverflow(); 3352} 3353 3354void Heap::ClearConcurrentGCRequest() { 3355 concurrent_gc_pending_.StoreRelaxed(false); 3356} 3357 3358void Heap::RequestConcurrentGC(Thread* self, bool force_full) { 3359 if (CanAddHeapTask(self) && 3360 concurrent_gc_pending_.CompareExchangeStrongSequentiallyConsistent(false, true)) { 3361 task_processor_->AddTask(self, new ConcurrentGCTask(NanoTime(), // Start straight away. 3362 force_full)); 3363 } 3364} 3365 3366void Heap::ConcurrentGC(Thread* self, bool force_full) { 3367 if (!Runtime::Current()->IsShuttingDown(self)) { 3368 // Wait for any GCs currently running to finish. 3369 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 3370 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 3371 // instead. E.g. can't do partial, so do full instead. 3372 collector::GcType next_gc_type = next_gc_type_; 3373 // If forcing full and next gc type is sticky, override with a non-sticky type. 3374 if (force_full && next_gc_type == collector::kGcTypeSticky) { 3375 next_gc_type = HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 3376 } 3377 if (CollectGarbageInternal(next_gc_type, kGcCauseBackground, false) == 3378 collector::kGcTypeNone) { 3379 for (collector::GcType gc_type : gc_plan_) { 3380 // Attempt to run the collector, if we succeed, we are done. 3381 if (gc_type > next_gc_type && 3382 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != 3383 collector::kGcTypeNone) { 3384 break; 3385 } 3386 } 3387 } 3388 } 3389 } 3390} 3391 3392class Heap::CollectorTransitionTask : public HeapTask { 3393 public: 3394 explicit CollectorTransitionTask(uint64_t target_time) : HeapTask(target_time) { } 3395 virtual void Run(Thread* self) OVERRIDE { 3396 gc::Heap* heap = Runtime::Current()->GetHeap(); 3397 heap->DoPendingCollectorTransition(); 3398 heap->ClearPendingCollectorTransition(self); 3399 } 3400}; 3401 3402void Heap::ClearPendingCollectorTransition(Thread* self) { 3403 MutexLock mu(self, *pending_task_lock_); 3404 pending_collector_transition_ = nullptr; 3405} 3406 3407void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 3408 Thread* self = Thread::Current(); 3409 desired_collector_type_ = desired_collector_type; 3410 if (desired_collector_type_ == collector_type_ || !CanAddHeapTask(self)) { 3411 return; 3412 } 3413 CollectorTransitionTask* added_task = nullptr; 3414 const uint64_t target_time = NanoTime() + delta_time; 3415 { 3416 MutexLock mu(self, *pending_task_lock_); 3417 // If we have an existing collector transition, update the targe time to be the new target. 3418 if (pending_collector_transition_ != nullptr) { 3419 task_processor_->UpdateTargetRunTime(self, pending_collector_transition_, target_time); 3420 return; 3421 } 3422 added_task = new CollectorTransitionTask(target_time); 3423 pending_collector_transition_ = added_task; 3424 } 3425 task_processor_->AddTask(self, added_task); 3426} 3427 3428class Heap::HeapTrimTask : public HeapTask { 3429 public: 3430 explicit HeapTrimTask(uint64_t delta_time) : HeapTask(NanoTime() + delta_time) { } 3431 virtual void Run(Thread* self) OVERRIDE { 3432 gc::Heap* heap = Runtime::Current()->GetHeap(); 3433 heap->Trim(self); 3434 heap->ClearPendingTrim(self); 3435 } 3436}; 3437 3438void Heap::ClearPendingTrim(Thread* self) { 3439 MutexLock mu(self, *pending_task_lock_); 3440 pending_heap_trim_ = nullptr; 3441} 3442 3443void Heap::RequestTrim(Thread* self) { 3444 if (!CanAddHeapTask(self)) { 3445 return; 3446 } 3447 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3448 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3449 // a space it will hold its lock and can become a cause of jank. 3450 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3451 // forking. 3452 3453 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3454 // because that only marks object heads, so a large array looks like lots of empty space. We 3455 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3456 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3457 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3458 // not how much use we're making of those pages. 3459 HeapTrimTask* added_task = nullptr; 3460 { 3461 MutexLock mu(self, *pending_task_lock_); 3462 if (pending_heap_trim_ != nullptr) { 3463 // Already have a heap trim request in task processor, ignore this request. 3464 return; 3465 } 3466 added_task = new HeapTrimTask(kHeapTrimWait); 3467 pending_heap_trim_ = added_task; 3468 } 3469 task_processor_->AddTask(self, added_task); 3470} 3471 3472void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3473 if (rosalloc_space_ != nullptr) { 3474 size_t freed_bytes_revoke = rosalloc_space_->RevokeThreadLocalBuffers(thread); 3475 if (freed_bytes_revoke > 0U) { 3476 num_bytes_freed_revoke_.FetchAndAddSequentiallyConsistent(freed_bytes_revoke); 3477 CHECK_GE(num_bytes_allocated_.LoadRelaxed(), num_bytes_freed_revoke_.LoadRelaxed()); 3478 } 3479 } 3480 if (bump_pointer_space_ != nullptr) { 3481 CHECK_EQ(bump_pointer_space_->RevokeThreadLocalBuffers(thread), 0U); 3482 } 3483 if (region_space_ != nullptr) { 3484 CHECK_EQ(region_space_->RevokeThreadLocalBuffers(thread), 0U); 3485 } 3486} 3487 3488void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3489 if (rosalloc_space_ != nullptr) { 3490 size_t freed_bytes_revoke = rosalloc_space_->RevokeThreadLocalBuffers(thread); 3491 if (freed_bytes_revoke > 0U) { 3492 num_bytes_freed_revoke_.FetchAndAddSequentiallyConsistent(freed_bytes_revoke); 3493 CHECK_GE(num_bytes_allocated_.LoadRelaxed(), num_bytes_freed_revoke_.LoadRelaxed()); 3494 } 3495 } 3496} 3497 3498void Heap::RevokeAllThreadLocalBuffers() { 3499 if (rosalloc_space_ != nullptr) { 3500 size_t freed_bytes_revoke = rosalloc_space_->RevokeAllThreadLocalBuffers(); 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_->RevokeAllThreadLocalBuffers(), 0U); 3508 } 3509 if (region_space_ != nullptr) { 3510 CHECK_EQ(region_space_->RevokeAllThreadLocalBuffers(), 0U); 3511 } 3512} 3513 3514bool Heap::IsGCRequestPending() const { 3515 return concurrent_gc_pending_.LoadRelaxed(); 3516} 3517 3518void Heap::RunFinalization(JNIEnv* env) { 3519 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3520 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3521 CHECK(WellKnownClasses::java_lang_System != nullptr); 3522 WellKnownClasses::java_lang_System_runFinalization = 3523 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3524 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3525 } 3526 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3527 WellKnownClasses::java_lang_System_runFinalization); 3528} 3529 3530void Heap::RegisterNativeAllocation(JNIEnv* env, size_t bytes) { 3531 Thread* self = ThreadForEnv(env); 3532 if (native_need_to_run_finalization_) { 3533 RunFinalization(env); 3534 UpdateMaxNativeFootprint(); 3535 native_need_to_run_finalization_ = false; 3536 } 3537 // Total number of native bytes allocated. 3538 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3539 new_native_bytes_allocated += bytes; 3540 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3541 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3542 collector::kGcTypeFull; 3543 3544 // The second watermark is higher than the gc watermark. If you hit this it means you are 3545 // allocating native objects faster than the GC can keep up with. 3546 if (new_native_bytes_allocated > growth_limit_) { 3547 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3548 // Just finished a GC, attempt to run finalizers. 3549 RunFinalization(env); 3550 CHECK(!env->ExceptionCheck()); 3551 // Native bytes allocated may be updated by finalization, refresh it. 3552 new_native_bytes_allocated = native_bytes_allocated_.LoadRelaxed(); 3553 } 3554 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3555 if (new_native_bytes_allocated > growth_limit_) { 3556 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3557 RunFinalization(env); 3558 native_need_to_run_finalization_ = false; 3559 CHECK(!env->ExceptionCheck()); 3560 } 3561 // We have just run finalizers, update the native watermark since it is very likely that 3562 // finalizers released native managed allocations. 3563 UpdateMaxNativeFootprint(); 3564 } else if (!IsGCRequestPending()) { 3565 if (IsGcConcurrent()) { 3566 RequestConcurrentGC(self, true); // Request non-sticky type. 3567 } else { 3568 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3569 } 3570 } 3571 } 3572} 3573 3574void Heap::RegisterNativeFree(JNIEnv* env, size_t bytes) { 3575 size_t expected_size; 3576 do { 3577 expected_size = native_bytes_allocated_.LoadRelaxed(); 3578 if (UNLIKELY(bytes > expected_size)) { 3579 ScopedObjectAccess soa(env); 3580 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3581 StringPrintf("Attempted to free %zd native bytes with only %zd native bytes " 3582 "registered as allocated", bytes, expected_size).c_str()); 3583 break; 3584 } 3585 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, 3586 expected_size - bytes)); 3587} 3588 3589size_t Heap::GetTotalMemory() const { 3590 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3591} 3592 3593void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3594 DCHECK(mod_union_table != nullptr); 3595 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3596} 3597 3598void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3599 CHECK(c == nullptr || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3600 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3601 CHECK_GE(byte_count, sizeof(mirror::Object)); 3602} 3603 3604void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3605 CHECK(remembered_set != nullptr); 3606 space::Space* space = remembered_set->GetSpace(); 3607 CHECK(space != nullptr); 3608 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3609 remembered_sets_.Put(space, remembered_set); 3610 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3611} 3612 3613void Heap::RemoveRememberedSet(space::Space* space) { 3614 CHECK(space != nullptr); 3615 auto it = remembered_sets_.find(space); 3616 CHECK(it != remembered_sets_.end()); 3617 delete it->second; 3618 remembered_sets_.erase(it); 3619 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3620} 3621 3622void Heap::ClearMarkedObjects() { 3623 // Clear all of the spaces' mark bitmaps. 3624 for (const auto& space : GetContinuousSpaces()) { 3625 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3626 if (space->GetLiveBitmap() != mark_bitmap) { 3627 mark_bitmap->Clear(); 3628 } 3629 } 3630 // Clear the marked objects in the discontinous space object sets. 3631 for (const auto& space : GetDiscontinuousSpaces()) { 3632 space->GetMarkBitmap()->Clear(); 3633 } 3634} 3635 3636} // namespace gc 3637} // namespace art 3638