heap.cc revision 2cd334ae2d4287216523882f0d298cf3901b7ab1
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/allocator.h" 27#include "base/dumpable.h" 28#include "base/histogram-inl.h" 29#include "base/stl_util.h" 30#include "common_throws.h" 31#include "cutils/sched_policy.h" 32#include "debugger.h" 33#include "dex_file-inl.h" 34#include "gc/accounting/atomic_stack.h" 35#include "gc/accounting/card_table-inl.h" 36#include "gc/accounting/heap_bitmap-inl.h" 37#include "gc/accounting/mod_union_table.h" 38#include "gc/accounting/mod_union_table-inl.h" 39#include "gc/accounting/remembered_set.h" 40#include "gc/accounting/space_bitmap-inl.h" 41#include "gc/collector/concurrent_copying.h" 42#include "gc/collector/mark_compact.h" 43#include "gc/collector/mark_sweep-inl.h" 44#include "gc/collector/partial_mark_sweep.h" 45#include "gc/collector/semi_space.h" 46#include "gc/collector/sticky_mark_sweep.h" 47#include "gc/reference_processor.h" 48#include "gc/space/bump_pointer_space.h" 49#include "gc/space/dlmalloc_space-inl.h" 50#include "gc/space/image_space.h" 51#include "gc/space/large_object_space.h" 52#include "gc/space/region_space.h" 53#include "gc/space/rosalloc_space-inl.h" 54#include "gc/space/space-inl.h" 55#include "gc/space/zygote_space.h" 56#include "gc/task_processor.h" 57#include "entrypoints/quick/quick_alloc_entrypoints.h" 58#include "heap-inl.h" 59#include "image.h" 60#include "intern_table.h" 61#include "mirror/art_field-inl.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 verify_missing_card_marks_(false), 160 verify_system_weaks_(false), 161 verify_pre_gc_heap_(verify_pre_gc_heap), 162 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 163 verify_post_gc_heap_(verify_post_gc_heap), 164 verify_mod_union_table_(false), 165 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 166 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 167 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 168 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 169 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 170 * verification is enabled, we limit the size of allocation stacks to speed up their 171 * searching. 172 */ 173 max_allocation_stack_size_(kGCALotMode ? kGcAlotAllocationStackSize 174 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? kVerifyObjectAllocationStackSize : 175 kDefaultAllocationStackSize), 176 current_allocator_(kAllocatorTypeDlMalloc), 177 current_non_moving_allocator_(kAllocatorTypeNonMoving), 178 bump_pointer_space_(nullptr), 179 temp_space_(nullptr), 180 region_space_(nullptr), 181 min_free_(min_free), 182 max_free_(max_free), 183 target_utilization_(target_utilization), 184 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 185 total_wait_time_(0), 186 total_allocation_time_(0), 187 verify_object_mode_(kVerifyObjectModeDisabled), 188 disable_moving_gc_count_(0), 189 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 190 use_tlab_(use_tlab), 191 main_space_backup_(nullptr), 192 min_interval_homogeneous_space_compaction_by_oom_( 193 min_interval_homogeneous_space_compaction_by_oom), 194 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 195 pending_collector_transition_(nullptr), 196 pending_heap_trim_(nullptr), 197 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 198 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 199 LOG(INFO) << "Heap() entering"; 200 } 201 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 202 // entrypoints. 203 const bool is_zygote = Runtime::Current()->IsZygote(); 204 if (!is_zygote) { 205 // Background compaction is currently not supported for command line runs. 206 if (background_collector_type_ != foreground_collector_type_) { 207 VLOG(heap) << "Disabling background compaction for non zygote"; 208 background_collector_type_ = foreground_collector_type_; 209 } 210 } 211 ChangeCollector(desired_collector_type_); 212 live_bitmap_.reset(new accounting::HeapBitmap(this)); 213 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 214 // Requested begin for the alloc space, to follow the mapped image and oat files 215 uint8_t* requested_alloc_space_begin = nullptr; 216 if (foreground_collector_type_ == kCollectorTypeCC) { 217 // Need to use a low address so that we can allocate a contiguous 218 // 2 * Xmx space when there's no image (dex2oat for target). 219 CHECK_GE(300 * MB, non_moving_space_capacity); 220 requested_alloc_space_begin = reinterpret_cast<uint8_t*>(300 * MB) - non_moving_space_capacity; 221 } 222 if (!image_file_name.empty()) { 223 std::string error_msg; 224 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 225 image_instruction_set, 226 &error_msg); 227 if (image_space != nullptr) { 228 AddSpace(image_space); 229 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 230 // isn't going to get in the middle 231 uint8_t* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 232 CHECK_GT(oat_file_end_addr, image_space->End()); 233 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 234 } else { 235 LOG(WARNING) << "Could not create image space with image file '" << image_file_name << "'. " 236 << "Attempting to fall back to imageless running. Error was: " << error_msg; 237 } 238 } 239 /* 240 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 241 +- nonmoving space (non_moving_space_capacity)+- 242 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 243 +-????????????????????????????????????????????+- 244 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 245 +-main alloc space / bump space 1 (capacity_) +- 246 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 247 +-????????????????????????????????????????????+- 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 249 +-main alloc space2 / bump space 2 (capacity_)+- 250 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 251 */ 252 // We don't have hspace compaction enabled with GSS or CC. 253 if (foreground_collector_type_ == kCollectorTypeGSS || 254 foreground_collector_type_ == kCollectorTypeCC) { 255 use_homogeneous_space_compaction_for_oom_ = false; 256 } 257 bool support_homogeneous_space_compaction = 258 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 259 use_homogeneous_space_compaction_for_oom_; 260 // We may use the same space the main space for the non moving space if we don't need to compact 261 // from the main space. 262 // This is not the case if we support homogeneous compaction or have a moving background 263 // collector type. 264 bool separate_non_moving_space = is_zygote || 265 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 266 IsMovingGc(background_collector_type_); 267 if (foreground_collector_type == kCollectorTypeGSS) { 268 separate_non_moving_space = false; 269 } 270 std::unique_ptr<MemMap> main_mem_map_1; 271 std::unique_ptr<MemMap> main_mem_map_2; 272 uint8_t* request_begin = requested_alloc_space_begin; 273 if (request_begin != nullptr && separate_non_moving_space) { 274 request_begin += non_moving_space_capacity; 275 } 276 std::string error_str; 277 std::unique_ptr<MemMap> non_moving_space_mem_map; 278 if (separate_non_moving_space) { 279 // If we are the zygote, the non moving space becomes the zygote space when we run 280 // PreZygoteFork the first time. In this case, call the map "zygote space" since we can't 281 // rename the mem map later. 282 const char* space_name = is_zygote ? kZygoteSpaceName: kNonMovingSpaceName; 283 // Reserve the non moving mem map before the other two since it needs to be at a specific 284 // address. 285 non_moving_space_mem_map.reset( 286 MemMap::MapAnonymous(space_name, requested_alloc_space_begin, 287 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str)); 288 CHECK(non_moving_space_mem_map != nullptr) << error_str; 289 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 290 request_begin = reinterpret_cast<uint8_t*>(300 * MB); 291 } 292 if (foreground_collector_type_ != kCollectorTypeCC) { 293 // Attempt to create 2 mem maps at or after the requested begin. 294 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 295 &error_str)); 296 CHECK(main_mem_map_1.get() != nullptr) << error_str; 297 } 298 if (support_homogeneous_space_compaction || 299 background_collector_type_ == kCollectorTypeSS || 300 foreground_collector_type_ == kCollectorTypeSS) { 301 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 302 capacity_, &error_str)); 303 CHECK(main_mem_map_2.get() != nullptr) << error_str; 304 } 305 // Create the non moving space first so that bitmaps don't take up the address range. 306 if (separate_non_moving_space) { 307 // Non moving space is always dlmalloc since we currently don't have support for multiple 308 // active rosalloc spaces. 309 const size_t size = non_moving_space_mem_map->Size(); 310 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 311 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 312 initial_size, size, size, false); 313 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 314 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 315 << requested_alloc_space_begin; 316 AddSpace(non_moving_space_); 317 } 318 // Create other spaces based on whether or not we have a moving GC. 319 if (foreground_collector_type_ == kCollectorTypeCC) { 320 region_space_ = space::RegionSpace::Create("Region space", capacity_ * 2, request_begin); 321 AddSpace(region_space_); 322 } else if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 323 // Create bump pointer spaces. 324 // We only to create the bump pointer if the foreground collector is a compacting GC. 325 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 326 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 327 main_mem_map_1.release()); 328 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 329 AddSpace(bump_pointer_space_); 330 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 331 main_mem_map_2.release()); 332 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 333 AddSpace(temp_space_); 334 CHECK(separate_non_moving_space); 335 } else { 336 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 337 CHECK(main_space_ != nullptr); 338 AddSpace(main_space_); 339 if (!separate_non_moving_space) { 340 non_moving_space_ = main_space_; 341 CHECK(!non_moving_space_->CanMoveObjects()); 342 } 343 if (foreground_collector_type_ == kCollectorTypeGSS) { 344 CHECK_EQ(foreground_collector_type_, background_collector_type_); 345 // Create bump pointer spaces instead of a backup space. 346 main_mem_map_2.release(); 347 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 348 kGSSBumpPointerSpaceCapacity, nullptr); 349 CHECK(bump_pointer_space_ != nullptr); 350 AddSpace(bump_pointer_space_); 351 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 352 kGSSBumpPointerSpaceCapacity, nullptr); 353 CHECK(temp_space_ != nullptr); 354 AddSpace(temp_space_); 355 } else if (main_mem_map_2.get() != nullptr) { 356 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 357 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 358 growth_limit_, capacity_, name, true)); 359 CHECK(main_space_backup_.get() != nullptr); 360 // Add the space so its accounted for in the heap_begin and heap_end. 361 AddSpace(main_space_backup_.get()); 362 } 363 } 364 CHECK(non_moving_space_ != nullptr); 365 CHECK(!non_moving_space_->CanMoveObjects()); 366 // Allocate the large object space. 367 if (large_object_space_type == space::kLargeObjectSpaceTypeFreeList) { 368 large_object_space_ = space::FreeListSpace::Create("free list large object space", nullptr, 369 capacity_); 370 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 371 } else if (large_object_space_type == space::kLargeObjectSpaceTypeMap) { 372 large_object_space_ = space::LargeObjectMapSpace::Create("mem map large object space"); 373 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 374 } else { 375 // Disable the large object space by making the cutoff excessively large. 376 large_object_threshold_ = std::numeric_limits<size_t>::max(); 377 large_object_space_ = nullptr; 378 } 379 if (large_object_space_ != nullptr) { 380 AddSpace(large_object_space_); 381 } 382 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 383 CHECK(!continuous_spaces_.empty()); 384 // Relies on the spaces being sorted. 385 uint8_t* heap_begin = continuous_spaces_.front()->Begin(); 386 uint8_t* heap_end = continuous_spaces_.back()->Limit(); 387 size_t heap_capacity = heap_end - heap_begin; 388 // Remove the main backup space since it slows down the GC to have unused extra spaces. 389 // TODO: Avoid needing to do this. 390 if (main_space_backup_.get() != nullptr) { 391 RemoveSpace(main_space_backup_.get()); 392 } 393 // Allocate the card table. 394 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 395 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 396 397 if (foreground_collector_type_ == kCollectorTypeCC && kUseTableLookupReadBarrier) { 398 rb_table_.reset(new accounting::ReadBarrierTable()); 399 DCHECK(rb_table_->IsAllCleared()); 400 } 401 402 // Card cache for now since it makes it easier for us to update the references to the copying 403 // spaces. 404 accounting::ModUnionTable* mod_union_table = 405 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 406 GetImageSpace()); 407 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 408 AddModUnionTable(mod_union_table); 409 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 410 accounting::RememberedSet* non_moving_space_rem_set = 411 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 412 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 413 AddRememberedSet(non_moving_space_rem_set); 414 } 415 // TODO: Count objects in the image space here? 416 num_bytes_allocated_.StoreRelaxed(0); 417 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 418 kDefaultMarkStackSize)); 419 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 420 allocation_stack_.reset(accounting::ObjectStack::Create( 421 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 422 live_stack_.reset(accounting::ObjectStack::Create( 423 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 424 // It's still too early to take a lock because there are no threads yet, but we can create locks 425 // now. We don't create it earlier to make it clear that you can't use locks during heap 426 // initialization. 427 gc_complete_lock_ = new Mutex("GC complete lock"); 428 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 429 *gc_complete_lock_)); 430 task_processor_.reset(new TaskProcessor()); 431 pending_task_lock_ = new Mutex("Pending task lock"); 432 if (ignore_max_footprint_) { 433 SetIdealFootprint(std::numeric_limits<size_t>::max()); 434 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 435 } 436 CHECK_NE(max_allowed_footprint_, 0U); 437 // Create our garbage collectors. 438 for (size_t i = 0; i < 2; ++i) { 439 const bool concurrent = i != 0; 440 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 441 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 442 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 443 } 444 if (kMovingCollector) { 445 // TODO: Clean this up. 446 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 447 semi_space_collector_ = new collector::SemiSpace(this, generational, 448 generational ? "generational" : ""); 449 garbage_collectors_.push_back(semi_space_collector_); 450 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 451 garbage_collectors_.push_back(concurrent_copying_collector_); 452 mark_compact_collector_ = new collector::MarkCompact(this); 453 garbage_collectors_.push_back(mark_compact_collector_); 454 } 455 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 456 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 457 // Check that there's no gap between the image space and the non moving space so that the 458 // immune region won't break (eg. due to a large object allocated in the gap). This is only 459 // required when we're the zygote or using GSS. 460 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 461 non_moving_space_->GetMemMap()); 462 if (!no_gap) { 463 MemMap::DumpMaps(LOG(ERROR)); 464 LOG(FATAL) << "There's a gap between the image space and the main space"; 465 } 466 } 467 if (running_on_valgrind_) { 468 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 469 } 470 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 471 LOG(INFO) << "Heap() exiting"; 472 } 473} 474 475MemMap* Heap::MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 476 size_t capacity, std::string* out_error_str) { 477 while (true) { 478 MemMap* map = MemMap::MapAnonymous(name, request_begin, capacity, 479 PROT_READ | PROT_WRITE, true, out_error_str); 480 if (map != nullptr || request_begin == nullptr) { 481 return map; 482 } 483 // Retry a second time with no specified request begin. 484 request_begin = nullptr; 485 } 486 return nullptr; 487} 488 489space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 490 size_t growth_limit, size_t capacity, 491 const char* name, bool can_move_objects) { 492 space::MallocSpace* malloc_space = nullptr; 493 if (kUseRosAlloc) { 494 // Create rosalloc space. 495 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 496 initial_size, growth_limit, capacity, 497 low_memory_mode_, can_move_objects); 498 } else { 499 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 500 initial_size, growth_limit, capacity, 501 can_move_objects); 502 } 503 if (collector::SemiSpace::kUseRememberedSet) { 504 accounting::RememberedSet* rem_set = 505 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 506 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 507 AddRememberedSet(rem_set); 508 } 509 CHECK(malloc_space != nullptr) << "Failed to create " << name; 510 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 511 return malloc_space; 512} 513 514void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 515 size_t capacity) { 516 // Is background compaction is enabled? 517 bool can_move_objects = IsMovingGc(background_collector_type_) != 518 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 519 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 520 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 521 // from the main space to the zygote space. If background compaction is enabled, always pass in 522 // that we can move objets. 523 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 524 // After the zygote we want this to be false if we don't have background compaction enabled so 525 // that getting primitive array elements is faster. 526 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 527 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 528 } 529 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 530 RemoveRememberedSet(main_space_); 531 } 532 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 533 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 534 can_move_objects); 535 SetSpaceAsDefault(main_space_); 536 VLOG(heap) << "Created main space " << main_space_; 537} 538 539void Heap::ChangeAllocator(AllocatorType allocator) { 540 if (current_allocator_ != allocator) { 541 // These two allocators are only used internally and don't have any entrypoints. 542 CHECK_NE(allocator, kAllocatorTypeLOS); 543 CHECK_NE(allocator, kAllocatorTypeNonMoving); 544 current_allocator_ = allocator; 545 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 546 SetQuickAllocEntryPointsAllocator(current_allocator_); 547 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 548 } 549} 550 551void Heap::DisableMovingGc() { 552 if (IsMovingGc(foreground_collector_type_)) { 553 foreground_collector_type_ = kCollectorTypeCMS; 554 } 555 if (IsMovingGc(background_collector_type_)) { 556 background_collector_type_ = foreground_collector_type_; 557 } 558 TransitionCollector(foreground_collector_type_); 559 ThreadList* tl = Runtime::Current()->GetThreadList(); 560 Thread* self = Thread::Current(); 561 ScopedThreadStateChange tsc(self, kSuspended); 562 tl->SuspendAll(); 563 // Something may have caused the transition to fail. 564 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 565 CHECK(main_space_ != nullptr); 566 // The allocation stack may have non movable objects in it. We need to flush it since the GC 567 // can't only handle marking allocation stack objects of one non moving space and one main 568 // space. 569 { 570 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 571 FlushAllocStack(); 572 } 573 main_space_->DisableMovingObjects(); 574 non_moving_space_ = main_space_; 575 CHECK(!non_moving_space_->CanMoveObjects()); 576 } 577 tl->ResumeAll(); 578} 579 580std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 581 if (!IsValidContinuousSpaceObjectAddress(klass)) { 582 return StringPrintf("<non heap address klass %p>", klass); 583 } 584 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 585 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 586 std::string result("["); 587 result += SafeGetClassDescriptor(component_type); 588 return result; 589 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 590 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 591 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 592 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 593 } else { 594 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 595 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 596 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 597 } 598 const DexFile* dex_file = dex_cache->GetDexFile(); 599 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 600 if (class_def_idx == DexFile::kDexNoIndex16) { 601 return "<class def not found>"; 602 } 603 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 604 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 605 return dex_file->GetTypeDescriptor(type_id); 606 } 607} 608 609std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 610 if (obj == nullptr) { 611 return "null"; 612 } 613 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 614 if (klass == nullptr) { 615 return "(class=null)"; 616 } 617 std::string result(SafeGetClassDescriptor(klass)); 618 if (obj->IsClass()) { 619 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 620 } 621 return result; 622} 623 624void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 625 if (obj == nullptr) { 626 stream << "(obj=null)"; 627 return; 628 } 629 if (IsAligned<kObjectAlignment>(obj)) { 630 space::Space* space = nullptr; 631 // Don't use find space since it only finds spaces which actually contain objects instead of 632 // spaces which may contain objects (e.g. cleared bump pointer spaces). 633 for (const auto& cur_space : continuous_spaces_) { 634 if (cur_space->HasAddress(obj)) { 635 space = cur_space; 636 break; 637 } 638 } 639 // Unprotect all the spaces. 640 for (const auto& con_space : continuous_spaces_) { 641 mprotect(con_space->Begin(), con_space->Capacity(), PROT_READ | PROT_WRITE); 642 } 643 stream << "Object " << obj; 644 if (space != nullptr) { 645 stream << " in space " << *space; 646 } 647 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 648 stream << "\nclass=" << klass; 649 if (klass != nullptr) { 650 stream << " type= " << SafePrettyTypeOf(obj); 651 } 652 // Re-protect the address we faulted on. 653 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 654 } 655} 656 657bool Heap::IsCompilingBoot() const { 658 if (!Runtime::Current()->IsCompiler()) { 659 return false; 660 } 661 for (const auto& space : continuous_spaces_) { 662 if (space->IsImageSpace() || space->IsZygoteSpace()) { 663 return false; 664 } 665 } 666 return true; 667} 668 669bool Heap::HasImageSpace() const { 670 for (const auto& space : continuous_spaces_) { 671 if (space->IsImageSpace()) { 672 return true; 673 } 674 } 675 return false; 676} 677 678void Heap::IncrementDisableMovingGC(Thread* self) { 679 // Need to do this holding the lock to prevent races where the GC is about to run / running when 680 // we attempt to disable it. 681 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 682 MutexLock mu(self, *gc_complete_lock_); 683 ++disable_moving_gc_count_; 684 if (IsMovingGc(collector_type_running_)) { 685 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 686 } 687} 688 689void Heap::DecrementDisableMovingGC(Thread* self) { 690 MutexLock mu(self, *gc_complete_lock_); 691 CHECK_GE(disable_moving_gc_count_, 0U); 692 --disable_moving_gc_count_; 693} 694 695void Heap::UpdateProcessState(ProcessState process_state) { 696 if (process_state_ != process_state) { 697 process_state_ = process_state; 698 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 699 // Start at index 1 to avoid "is always false" warning. 700 // Have iteration 1 always transition the collector. 701 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 702 ? foreground_collector_type_ : background_collector_type_); 703 usleep(kCollectorTransitionStressWait); 704 } 705 if (process_state_ == kProcessStateJankPerceptible) { 706 // Transition back to foreground right away to prevent jank. 707 RequestCollectorTransition(foreground_collector_type_, 0); 708 } else { 709 // Don't delay for debug builds since we may want to stress test the GC. 710 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 711 // special handling which does a homogenous space compaction once but then doesn't transition 712 // the collector. 713 RequestCollectorTransition(background_collector_type_, 714 kIsDebugBuild ? 0 : kCollectorTransitionWait); 715 } 716 } 717} 718 719void Heap::CreateThreadPool() { 720 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 721 if (num_threads != 0) { 722 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 723 } 724} 725 726// Visit objects when threads aren't suspended. If concurrent moving 727// GC, disable moving GC and suspend threads and then visit objects. 728void Heap::VisitObjects(ObjectCallback callback, void* arg) { 729 Thread* self = Thread::Current(); 730 Locks::mutator_lock_->AssertSharedHeld(self); 731 DCHECK(!Locks::mutator_lock_->IsExclusiveHeld(self)) << "Call VisitObjectsPaused() instead"; 732 if (IsGcConcurrentAndMoving()) { 733 // Concurrent moving GC. Just suspending threads isn't sufficient 734 // because a collection isn't one big pause and we could suspend 735 // threads in the middle (between phases) of a concurrent moving 736 // collection where it's not easily known which objects are alive 737 // (both the region space and the non-moving space) or which 738 // copies of objects to visit, and the to-space invariant could be 739 // easily broken. Visit objects while GC isn't running by using 740 // IncrementDisableMovingGC() and threads are suspended. 741 IncrementDisableMovingGC(self); 742 self->TransitionFromRunnableToSuspended(kWaitingForVisitObjects); 743 ThreadList* tl = Runtime::Current()->GetThreadList(); 744 tl->SuspendAll(); 745 VisitObjectsInternalRegionSpace(callback, arg); 746 VisitObjectsInternal(callback, arg); 747 tl->ResumeAll(); 748 self->TransitionFromSuspendedToRunnable(); 749 DecrementDisableMovingGC(self); 750 } else { 751 // GCs can move objects, so don't allow this. 752 ScopedAssertNoThreadSuspension ants(self, "Visiting objects"); 753 DCHECK(region_space_ == nullptr); 754 VisitObjectsInternal(callback, arg); 755 } 756} 757 758// Visit objects when threads are already suspended. 759void Heap::VisitObjectsPaused(ObjectCallback callback, void* arg) { 760 Thread* self = Thread::Current(); 761 Locks::mutator_lock_->AssertExclusiveHeld(self); 762 VisitObjectsInternalRegionSpace(callback, arg); 763 VisitObjectsInternal(callback, arg); 764} 765 766// Visit objects in the region spaces. 767void Heap::VisitObjectsInternalRegionSpace(ObjectCallback callback, void* arg) { 768 Thread* self = Thread::Current(); 769 Locks::mutator_lock_->AssertExclusiveHeld(self); 770 if (region_space_ != nullptr) { 771 DCHECK(IsGcConcurrentAndMoving()); 772 if (!zygote_creation_lock_.IsExclusiveHeld(self)) { 773 // Exclude the pre-zygote fork time where the semi-space collector 774 // calls VerifyHeapReferences() as part of the zygote compaction 775 // which then would call here without the moving GC disabled, 776 // which is fine. 777 DCHECK(IsMovingGCDisabled(self)); 778 } 779 region_space_->Walk(callback, arg); 780 } 781} 782 783// Visit objects in the other spaces. 784void Heap::VisitObjectsInternal(ObjectCallback callback, void* arg) { 785 if (bump_pointer_space_ != nullptr) { 786 // Visit objects in bump pointer space. 787 bump_pointer_space_->Walk(callback, arg); 788 } 789 // TODO: Switch to standard begin and end to use ranged a based loop. 790 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 791 it < end; ++it) { 792 mirror::Object* obj = *it; 793 if (obj != nullptr && obj->GetClass() != nullptr) { 794 // Avoid the race condition caused by the object not yet being written into the allocation 795 // stack or the class not yet being written in the object. Or, if 796 // kUseThreadLocalAllocationStack, there can be nulls on the allocation stack. 797 callback(obj, arg); 798 } 799 } 800 { 801 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 802 GetLiveBitmap()->Walk(callback, arg); 803 } 804} 805 806void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 807 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 808 space::ContinuousSpace* space2 = non_moving_space_; 809 // TODO: Generalize this to n bitmaps? 810 CHECK(space1 != nullptr); 811 CHECK(space2 != nullptr); 812 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 813 (large_object_space_ != nullptr ? large_object_space_->GetLiveBitmap() : nullptr), 814 stack); 815} 816 817void Heap::DeleteThreadPool() { 818 thread_pool_.reset(nullptr); 819} 820 821void Heap::AddSpace(space::Space* space) { 822 CHECK(space != nullptr); 823 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 824 if (space->IsContinuousSpace()) { 825 DCHECK(!space->IsDiscontinuousSpace()); 826 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 827 // Continuous spaces don't necessarily have bitmaps. 828 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 829 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 830 if (live_bitmap != nullptr) { 831 CHECK(mark_bitmap != nullptr); 832 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 833 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 834 } 835 continuous_spaces_.push_back(continuous_space); 836 // Ensure that spaces remain sorted in increasing order of start address. 837 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 838 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 839 return a->Begin() < b->Begin(); 840 }); 841 } else { 842 CHECK(space->IsDiscontinuousSpace()); 843 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 844 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 845 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 846 discontinuous_spaces_.push_back(discontinuous_space); 847 } 848 if (space->IsAllocSpace()) { 849 alloc_spaces_.push_back(space->AsAllocSpace()); 850 } 851} 852 853void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 854 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 855 if (continuous_space->IsDlMallocSpace()) { 856 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 857 } else if (continuous_space->IsRosAllocSpace()) { 858 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 859 } 860} 861 862void Heap::RemoveSpace(space::Space* space) { 863 DCHECK(space != nullptr); 864 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 865 if (space->IsContinuousSpace()) { 866 DCHECK(!space->IsDiscontinuousSpace()); 867 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 868 // Continuous spaces don't necessarily have bitmaps. 869 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 870 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 871 if (live_bitmap != nullptr) { 872 DCHECK(mark_bitmap != nullptr); 873 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 874 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 875 } 876 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 877 DCHECK(it != continuous_spaces_.end()); 878 continuous_spaces_.erase(it); 879 } else { 880 DCHECK(space->IsDiscontinuousSpace()); 881 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 882 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 883 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 884 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 885 discontinuous_space); 886 DCHECK(it != discontinuous_spaces_.end()); 887 discontinuous_spaces_.erase(it); 888 } 889 if (space->IsAllocSpace()) { 890 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 891 DCHECK(it != alloc_spaces_.end()); 892 alloc_spaces_.erase(it); 893 } 894} 895 896void Heap::DumpGcPerformanceInfo(std::ostream& os) { 897 // Dump cumulative timings. 898 os << "Dumping cumulative Gc timings\n"; 899 uint64_t total_duration = 0; 900 // Dump cumulative loggers for each GC type. 901 uint64_t total_paused_time = 0; 902 for (auto& collector : garbage_collectors_) { 903 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 904 total_paused_time += collector->GetTotalPausedTimeNs(); 905 collector->DumpPerformanceInfo(os); 906 collector->ResetMeasurements(); 907 } 908 uint64_t allocation_time = 909 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 910 if (total_duration != 0) { 911 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 912 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 913 os << "Mean GC size throughput: " 914 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 915 os << "Mean GC object throughput: " 916 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 917 } 918 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 919 os << "Total number of allocations " << total_objects_allocated << "\n"; 920 uint64_t total_bytes_allocated = GetBytesAllocatedEver(); 921 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 922 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 923 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 924 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 925 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 926 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 927 if (kMeasureAllocationTime) { 928 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 929 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 930 << "\n"; 931 } 932 if (HasZygoteSpace()) { 933 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 934 } 935 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 936 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_); 937 BaseMutex::DumpAll(os); 938} 939 940Heap::~Heap() { 941 VLOG(heap) << "Starting ~Heap()"; 942 STLDeleteElements(&garbage_collectors_); 943 // If we don't reset then the mark stack complains in its destructor. 944 allocation_stack_->Reset(); 945 live_stack_->Reset(); 946 STLDeleteValues(&mod_union_tables_); 947 STLDeleteValues(&remembered_sets_); 948 STLDeleteElements(&continuous_spaces_); 949 STLDeleteElements(&discontinuous_spaces_); 950 delete gc_complete_lock_; 951 delete pending_task_lock_; 952 VLOG(heap) << "Finished ~Heap()"; 953} 954 955space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 956 bool fail_ok) const { 957 for (const auto& space : continuous_spaces_) { 958 if (space->Contains(obj)) { 959 return space; 960 } 961 } 962 if (!fail_ok) { 963 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 964 } 965 return NULL; 966} 967 968space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 969 bool fail_ok) const { 970 for (const auto& space : discontinuous_spaces_) { 971 if (space->Contains(obj)) { 972 return space; 973 } 974 } 975 if (!fail_ok) { 976 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 977 } 978 return NULL; 979} 980 981space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 982 space::Space* result = FindContinuousSpaceFromObject(obj, true); 983 if (result != NULL) { 984 return result; 985 } 986 return FindDiscontinuousSpaceFromObject(obj, fail_ok); 987} 988 989space::ImageSpace* Heap::GetImageSpace() const { 990 for (const auto& space : continuous_spaces_) { 991 if (space->IsImageSpace()) { 992 return space->AsImageSpace(); 993 } 994 } 995 return NULL; 996} 997 998void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 999 std::ostringstream oss; 1000 size_t total_bytes_free = GetFreeMemory(); 1001 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 1002 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 1003 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 1004 if (total_bytes_free >= byte_count) { 1005 space::AllocSpace* space = nullptr; 1006 if (allocator_type == kAllocatorTypeNonMoving) { 1007 space = non_moving_space_; 1008 } else if (allocator_type == kAllocatorTypeRosAlloc || 1009 allocator_type == kAllocatorTypeDlMalloc) { 1010 space = main_space_; 1011 } else if (allocator_type == kAllocatorTypeBumpPointer || 1012 allocator_type == kAllocatorTypeTLAB) { 1013 space = bump_pointer_space_; 1014 } else if (allocator_type == kAllocatorTypeRegion || 1015 allocator_type == kAllocatorTypeRegionTLAB) { 1016 space = region_space_; 1017 } 1018 if (space != nullptr) { 1019 space->LogFragmentationAllocFailure(oss, byte_count); 1020 } 1021 } 1022 self->ThrowOutOfMemoryError(oss.str().c_str()); 1023} 1024 1025void Heap::DoPendingCollectorTransition() { 1026 CollectorType desired_collector_type = desired_collector_type_; 1027 // Launch homogeneous space compaction if it is desired. 1028 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 1029 if (!CareAboutPauseTimes()) { 1030 PerformHomogeneousSpaceCompact(); 1031 } else { 1032 VLOG(gc) << "Homogeneous compaction ignored due to jank perceptible process state"; 1033 } 1034 } else { 1035 TransitionCollector(desired_collector_type); 1036 } 1037} 1038 1039void Heap::Trim(Thread* self) { 1040 if (!CareAboutPauseTimes()) { 1041 ATRACE_BEGIN("Deflating monitors"); 1042 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 1043 // about pauses. 1044 Runtime* runtime = Runtime::Current(); 1045 runtime->GetThreadList()->SuspendAll(); 1046 uint64_t start_time = NanoTime(); 1047 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 1048 VLOG(heap) << "Deflating " << count << " monitors took " 1049 << PrettyDuration(NanoTime() - start_time); 1050 runtime->GetThreadList()->ResumeAll(); 1051 ATRACE_END(); 1052 } 1053 TrimIndirectReferenceTables(self); 1054 TrimSpaces(self); 1055} 1056 1057class TrimIndirectReferenceTableClosure : public Closure { 1058 public: 1059 explicit TrimIndirectReferenceTableClosure(Barrier* barrier) : barrier_(barrier) { 1060 } 1061 virtual void Run(Thread* thread) OVERRIDE NO_THREAD_SAFETY_ANALYSIS { 1062 ATRACE_BEGIN("Trimming reference table"); 1063 thread->GetJniEnv()->locals.Trim(); 1064 ATRACE_END(); 1065 barrier_->Pass(Thread::Current()); 1066 } 1067 1068 private: 1069 Barrier* const barrier_; 1070}; 1071 1072void Heap::TrimIndirectReferenceTables(Thread* self) { 1073 ScopedObjectAccess soa(self); 1074 ATRACE_BEGIN(__FUNCTION__); 1075 JavaVMExt* vm = soa.Vm(); 1076 // Trim globals indirect reference table. 1077 vm->TrimGlobals(); 1078 // Trim locals indirect reference tables. 1079 Barrier barrier(0); 1080 TrimIndirectReferenceTableClosure closure(&barrier); 1081 ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); 1082 size_t barrier_count = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure); 1083 barrier.Increment(self, barrier_count); 1084 ATRACE_END(); 1085} 1086 1087void Heap::TrimSpaces(Thread* self) { 1088 { 1089 // Need to do this before acquiring the locks since we don't want to get suspended while 1090 // holding any locks. 1091 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1092 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 1093 // trimming. 1094 MutexLock mu(self, *gc_complete_lock_); 1095 // Ensure there is only one GC at a time. 1096 WaitForGcToCompleteLocked(kGcCauseTrim, self); 1097 collector_type_running_ = kCollectorTypeHeapTrim; 1098 } 1099 ATRACE_BEGIN(__FUNCTION__); 1100 const uint64_t start_ns = NanoTime(); 1101 // Trim the managed spaces. 1102 uint64_t total_alloc_space_allocated = 0; 1103 uint64_t total_alloc_space_size = 0; 1104 uint64_t managed_reclaimed = 0; 1105 for (const auto& space : continuous_spaces_) { 1106 if (space->IsMallocSpace()) { 1107 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1108 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1109 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1110 // for a long period of time. 1111 managed_reclaimed += malloc_space->Trim(); 1112 } 1113 total_alloc_space_size += malloc_space->Size(); 1114 } 1115 } 1116 total_alloc_space_allocated = GetBytesAllocated(); 1117 if (large_object_space_ != nullptr) { 1118 total_alloc_space_allocated -= large_object_space_->GetBytesAllocated(); 1119 } 1120 if (bump_pointer_space_ != nullptr) { 1121 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1122 } 1123 if (region_space_ != nullptr) { 1124 total_alloc_space_allocated -= region_space_->GetBytesAllocated(); 1125 } 1126 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1127 static_cast<float>(total_alloc_space_size); 1128 uint64_t gc_heap_end_ns = NanoTime(); 1129 // We never move things in the native heap, so we can finish the GC at this point. 1130 FinishGC(self, collector::kGcTypeNone); 1131 size_t native_reclaimed = 0; 1132 1133#ifdef HAVE_ANDROID_OS 1134 // Only trim the native heap if we don't care about pauses. 1135 if (!CareAboutPauseTimes()) { 1136#if defined(USE_DLMALLOC) 1137 // Trim the native heap. 1138 dlmalloc_trim(0); 1139 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1140#elif defined(USE_JEMALLOC) 1141 // Jemalloc does it's own internal trimming. 1142#else 1143 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1144#endif 1145 } 1146#endif // HAVE_ANDROID_OS 1147 uint64_t end_ns = NanoTime(); 1148 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1149 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1150 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1151 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1152 << "%."; 1153 ATRACE_END(); 1154} 1155 1156bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1157 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1158 // taking the lock. 1159 if (obj == nullptr) { 1160 return true; 1161 } 1162 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1163} 1164 1165bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1166 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1167} 1168 1169bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1170 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1171 return false; 1172 } 1173 for (const auto& space : continuous_spaces_) { 1174 if (space->HasAddress(obj)) { 1175 return true; 1176 } 1177 } 1178 return false; 1179} 1180 1181bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1182 bool search_live_stack, bool sorted) { 1183 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1184 return false; 1185 } 1186 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1187 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1188 if (obj == klass) { 1189 // This case happens for java.lang.Class. 1190 return true; 1191 } 1192 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1193 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1194 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1195 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1196 return temp_space_->Contains(obj); 1197 } 1198 if (region_space_ != nullptr && region_space_->HasAddress(obj)) { 1199 return true; 1200 } 1201 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1202 space::DiscontinuousSpace* d_space = nullptr; 1203 if (c_space != nullptr) { 1204 if (c_space->GetLiveBitmap()->Test(obj)) { 1205 return true; 1206 } 1207 } else { 1208 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1209 if (d_space != nullptr) { 1210 if (d_space->GetLiveBitmap()->Test(obj)) { 1211 return true; 1212 } 1213 } 1214 } 1215 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1216 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1217 if (i > 0) { 1218 NanoSleep(MsToNs(10)); 1219 } 1220 if (search_allocation_stack) { 1221 if (sorted) { 1222 if (allocation_stack_->ContainsSorted(obj)) { 1223 return true; 1224 } 1225 } else if (allocation_stack_->Contains(obj)) { 1226 return true; 1227 } 1228 } 1229 1230 if (search_live_stack) { 1231 if (sorted) { 1232 if (live_stack_->ContainsSorted(obj)) { 1233 return true; 1234 } 1235 } else if (live_stack_->Contains(obj)) { 1236 return true; 1237 } 1238 } 1239 } 1240 // We need to check the bitmaps again since there is a race where we mark something as live and 1241 // then clear the stack containing it. 1242 if (c_space != nullptr) { 1243 if (c_space->GetLiveBitmap()->Test(obj)) { 1244 return true; 1245 } 1246 } else { 1247 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1248 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1249 return true; 1250 } 1251 } 1252 return false; 1253} 1254 1255std::string Heap::DumpSpaces() const { 1256 std::ostringstream oss; 1257 DumpSpaces(oss); 1258 return oss.str(); 1259} 1260 1261void Heap::DumpSpaces(std::ostream& stream) const { 1262 for (const auto& space : continuous_spaces_) { 1263 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1264 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1265 stream << space << " " << *space << "\n"; 1266 if (live_bitmap != nullptr) { 1267 stream << live_bitmap << " " << *live_bitmap << "\n"; 1268 } 1269 if (mark_bitmap != nullptr) { 1270 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1271 } 1272 } 1273 for (const auto& space : discontinuous_spaces_) { 1274 stream << space << " " << *space << "\n"; 1275 } 1276} 1277 1278void Heap::VerifyObjectBody(mirror::Object* obj) { 1279 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1280 return; 1281 } 1282 1283 // Ignore early dawn of the universe verifications. 1284 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1285 return; 1286 } 1287 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1288 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1289 CHECK(c != nullptr) << "Null class in object " << obj; 1290 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1291 CHECK(VerifyClassClass(c)); 1292 1293 if (verify_object_mode_ > kVerifyObjectModeFast) { 1294 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1295 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1296 } 1297} 1298 1299void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1300 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1301} 1302 1303void Heap::VerifyHeap() { 1304 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1305 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1306} 1307 1308void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1309 // Use signed comparison since freed bytes can be negative when background compaction foreground 1310 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1311 // free list backed space typically increasing memory footprint due to padding and binning. 1312 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1313 // Note: This relies on 2s complement for handling negative freed_bytes. 1314 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1315 if (Runtime::Current()->HasStatsEnabled()) { 1316 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1317 thread_stats->freed_objects += freed_objects; 1318 thread_stats->freed_bytes += freed_bytes; 1319 // TODO: Do this concurrently. 1320 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1321 global_stats->freed_objects += freed_objects; 1322 global_stats->freed_bytes += freed_bytes; 1323 } 1324} 1325 1326space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1327 for (const auto& space : continuous_spaces_) { 1328 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1329 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1330 return space->AsContinuousSpace()->AsRosAllocSpace(); 1331 } 1332 } 1333 } 1334 return nullptr; 1335} 1336 1337mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1338 size_t alloc_size, size_t* bytes_allocated, 1339 size_t* usable_size, 1340 mirror::Class** klass) { 1341 bool was_default_allocator = allocator == GetCurrentAllocator(); 1342 // Make sure there is no pending exception since we may need to throw an OOME. 1343 self->AssertNoPendingException(); 1344 DCHECK(klass != nullptr); 1345 StackHandleScope<1> hs(self); 1346 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1347 klass = nullptr; // Invalidate for safety. 1348 // The allocation failed. If the GC is running, block until it completes, and then retry the 1349 // allocation. 1350 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1351 if (last_gc != collector::kGcTypeNone) { 1352 // If we were the default allocator but the allocator changed while we were suspended, 1353 // abort the allocation. 1354 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1355 return nullptr; 1356 } 1357 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1358 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1359 usable_size); 1360 if (ptr != nullptr) { 1361 return ptr; 1362 } 1363 } 1364 1365 collector::GcType tried_type = next_gc_type_; 1366 const bool gc_ran = 1367 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1368 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1369 return nullptr; 1370 } 1371 if (gc_ran) { 1372 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1373 usable_size); 1374 if (ptr != nullptr) { 1375 return ptr; 1376 } 1377 } 1378 1379 // Loop through our different Gc types and try to Gc until we get enough free memory. 1380 for (collector::GcType gc_type : gc_plan_) { 1381 if (gc_type == tried_type) { 1382 continue; 1383 } 1384 // Attempt to run the collector, if we succeed, re-try the allocation. 1385 const bool plan_gc_ran = 1386 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1387 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1388 return nullptr; 1389 } 1390 if (plan_gc_ran) { 1391 // Did we free sufficient memory for the allocation to succeed? 1392 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1393 usable_size); 1394 if (ptr != nullptr) { 1395 return ptr; 1396 } 1397 } 1398 } 1399 // Allocations have failed after GCs; this is an exceptional state. 1400 // Try harder, growing the heap if necessary. 1401 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1402 usable_size); 1403 if (ptr != nullptr) { 1404 return ptr; 1405 } 1406 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1407 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1408 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1409 // OOME. 1410 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1411 << " allocation"; 1412 // TODO: Run finalization, but this may cause more allocations to occur. 1413 // We don't need a WaitForGcToComplete here either. 1414 DCHECK(!gc_plan_.empty()); 1415 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1416 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1417 return nullptr; 1418 } 1419 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1420 if (ptr == nullptr) { 1421 const uint64_t current_time = NanoTime(); 1422 switch (allocator) { 1423 case kAllocatorTypeRosAlloc: 1424 // Fall-through. 1425 case kAllocatorTypeDlMalloc: { 1426 if (use_homogeneous_space_compaction_for_oom_ && 1427 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1428 min_interval_homogeneous_space_compaction_by_oom_) { 1429 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1430 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1431 switch (result) { 1432 case HomogeneousSpaceCompactResult::kSuccess: 1433 // If the allocation succeeded, we delayed an oom. 1434 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1435 usable_size); 1436 if (ptr != nullptr) { 1437 count_delayed_oom_++; 1438 } 1439 break; 1440 case HomogeneousSpaceCompactResult::kErrorReject: 1441 // Reject due to disabled moving GC. 1442 break; 1443 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1444 // Throw OOM by default. 1445 break; 1446 default: { 1447 UNIMPLEMENTED(FATAL) << "homogeneous space compaction result: " 1448 << static_cast<size_t>(result); 1449 UNREACHABLE(); 1450 } 1451 } 1452 // Always print that we ran homogeneous space compation since this can cause jank. 1453 VLOG(heap) << "Ran heap homogeneous space compaction, " 1454 << " requested defragmentation " 1455 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1456 << " performed defragmentation " 1457 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1458 << " ignored homogeneous space compaction " 1459 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1460 << " delayed count = " 1461 << count_delayed_oom_.LoadSequentiallyConsistent(); 1462 } 1463 break; 1464 } 1465 case kAllocatorTypeNonMoving: { 1466 // Try to transition the heap if the allocation failure was due to the space being full. 1467 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1468 // If we aren't out of memory then the OOM was probably from the non moving space being 1469 // full. Attempt to disable compaction and turn the main space into a non moving space. 1470 DisableMovingGc(); 1471 // If we are still a moving GC then something must have caused the transition to fail. 1472 if (IsMovingGc(collector_type_)) { 1473 MutexLock mu(self, *gc_complete_lock_); 1474 // If we couldn't disable moving GC, just throw OOME and return null. 1475 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1476 << disable_moving_gc_count_; 1477 } else { 1478 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1479 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1480 usable_size); 1481 } 1482 } 1483 break; 1484 } 1485 default: { 1486 // Do nothing for others allocators. 1487 } 1488 } 1489 } 1490 // If the allocation hasn't succeeded by this point, throw an OOM error. 1491 if (ptr == nullptr) { 1492 ThrowOutOfMemoryError(self, alloc_size, allocator); 1493 } 1494 return ptr; 1495} 1496 1497void Heap::SetTargetHeapUtilization(float target) { 1498 DCHECK_GT(target, 0.0f); // asserted in Java code 1499 DCHECK_LT(target, 1.0f); 1500 target_utilization_ = target; 1501} 1502 1503size_t Heap::GetObjectsAllocated() const { 1504 size_t total = 0; 1505 for (space::AllocSpace* space : alloc_spaces_) { 1506 total += space->GetObjectsAllocated(); 1507 } 1508 return total; 1509} 1510 1511uint64_t Heap::GetObjectsAllocatedEver() const { 1512 return GetObjectsFreedEver() + GetObjectsAllocated(); 1513} 1514 1515uint64_t Heap::GetBytesAllocatedEver() const { 1516 return GetBytesFreedEver() + GetBytesAllocated(); 1517} 1518 1519class InstanceCounter { 1520 public: 1521 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1522 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1523 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1524 } 1525 static void Callback(mirror::Object* obj, void* arg) 1526 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1527 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1528 mirror::Class* instance_class = obj->GetClass(); 1529 CHECK(instance_class != nullptr); 1530 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1531 if (instance_counter->use_is_assignable_from_) { 1532 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1533 ++instance_counter->counts_[i]; 1534 } 1535 } else if (instance_class == instance_counter->classes_[i]) { 1536 ++instance_counter->counts_[i]; 1537 } 1538 } 1539 } 1540 1541 private: 1542 const std::vector<mirror::Class*>& classes_; 1543 bool use_is_assignable_from_; 1544 uint64_t* const counts_; 1545 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1546}; 1547 1548void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1549 uint64_t* counts) { 1550 InstanceCounter counter(classes, use_is_assignable_from, counts); 1551 VisitObjects(InstanceCounter::Callback, &counter); 1552} 1553 1554class InstanceCollector { 1555 public: 1556 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1557 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1558 : class_(c), max_count_(max_count), instances_(instances) { 1559 } 1560 static void Callback(mirror::Object* obj, void* arg) 1561 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1562 DCHECK(arg != nullptr); 1563 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1564 if (obj->GetClass() == instance_collector->class_) { 1565 if (instance_collector->max_count_ == 0 || 1566 instance_collector->instances_.size() < instance_collector->max_count_) { 1567 instance_collector->instances_.push_back(obj); 1568 } 1569 } 1570 } 1571 1572 private: 1573 const mirror::Class* const class_; 1574 const uint32_t max_count_; 1575 std::vector<mirror::Object*>& instances_; 1576 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1577}; 1578 1579void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1580 std::vector<mirror::Object*>& instances) { 1581 InstanceCollector collector(c, max_count, instances); 1582 VisitObjects(&InstanceCollector::Callback, &collector); 1583} 1584 1585class ReferringObjectsFinder { 1586 public: 1587 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1588 std::vector<mirror::Object*>& referring_objects) 1589 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1590 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1591 } 1592 1593 static void Callback(mirror::Object* obj, void* arg) 1594 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1595 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1596 } 1597 1598 // For bitmap Visit. 1599 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1600 // annotalysis on visitors. 1601 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1602 o->VisitReferences<true>(*this, VoidFunctor()); 1603 } 1604 1605 // For Object::VisitReferences. 1606 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1607 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1608 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1609 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1610 referring_objects_.push_back(obj); 1611 } 1612 } 1613 1614 private: 1615 const mirror::Object* const object_; 1616 const uint32_t max_count_; 1617 std::vector<mirror::Object*>& referring_objects_; 1618 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1619}; 1620 1621void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1622 std::vector<mirror::Object*>& referring_objects) { 1623 ReferringObjectsFinder finder(o, max_count, referring_objects); 1624 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1625} 1626 1627void Heap::CollectGarbage(bool clear_soft_references) { 1628 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1629 // last GC will not have necessarily been cleared. 1630 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1631} 1632 1633HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1634 Thread* self = Thread::Current(); 1635 // Inc requested homogeneous space compaction. 1636 count_requested_homogeneous_space_compaction_++; 1637 // Store performed homogeneous space compaction at a new request arrival. 1638 ThreadList* tl = Runtime::Current()->GetThreadList(); 1639 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1640 Locks::mutator_lock_->AssertNotHeld(self); 1641 { 1642 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1643 MutexLock mu(self, *gc_complete_lock_); 1644 // Ensure there is only one GC at a time. 1645 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1646 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1647 // is non zero. 1648 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1649 // exit. 1650 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1651 !main_space_->CanMoveObjects()) { 1652 return HomogeneousSpaceCompactResult::kErrorReject; 1653 } 1654 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1655 } 1656 if (Runtime::Current()->IsShuttingDown(self)) { 1657 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1658 // cause objects to get finalized. 1659 FinishGC(self, collector::kGcTypeNone); 1660 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1661 } 1662 // Suspend all threads. 1663 tl->SuspendAll(); 1664 uint64_t start_time = NanoTime(); 1665 // Launch compaction. 1666 space::MallocSpace* to_space = main_space_backup_.release(); 1667 space::MallocSpace* from_space = main_space_; 1668 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1669 const uint64_t space_size_before_compaction = from_space->Size(); 1670 AddSpace(to_space); 1671 // Make sure that we will have enough room to copy. 1672 CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit()); 1673 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1674 const uint64_t space_size_after_compaction = to_space->Size(); 1675 main_space_ = to_space; 1676 main_space_backup_.reset(from_space); 1677 RemoveSpace(from_space); 1678 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1679 // Update performed homogeneous space compaction count. 1680 count_performed_homogeneous_space_compaction_++; 1681 // Print statics log and resume all threads. 1682 uint64_t duration = NanoTime() - start_time; 1683 VLOG(heap) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1684 << PrettySize(space_size_before_compaction) << " -> " 1685 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1686 << std::fixed << static_cast<double>(space_size_after_compaction) / 1687 static_cast<double>(space_size_before_compaction); 1688 tl->ResumeAll(); 1689 // Finish GC. 1690 reference_processor_.EnqueueClearedReferences(self); 1691 GrowForUtilization(semi_space_collector_); 1692 FinishGC(self, collector::kGcTypeFull); 1693 return HomogeneousSpaceCompactResult::kSuccess; 1694} 1695 1696void Heap::TransitionCollector(CollectorType collector_type) { 1697 if (collector_type == collector_type_) { 1698 return; 1699 } 1700 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1701 << " -> " << static_cast<int>(collector_type); 1702 uint64_t start_time = NanoTime(); 1703 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1704 Runtime* const runtime = Runtime::Current(); 1705 ThreadList* const tl = runtime->GetThreadList(); 1706 Thread* const self = Thread::Current(); 1707 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1708 Locks::mutator_lock_->AssertNotHeld(self); 1709 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1710 // compacting_gc_disable_count_, this should rarely occurs). 1711 for (;;) { 1712 { 1713 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1714 MutexLock mu(self, *gc_complete_lock_); 1715 // Ensure there is only one GC at a time. 1716 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1717 // Currently we only need a heap transition if we switch from a moving collector to a 1718 // non-moving one, or visa versa. 1719 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1720 // If someone else beat us to it and changed the collector before we could, exit. 1721 // This is safe to do before the suspend all since we set the collector_type_running_ before 1722 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1723 // then it would get blocked on WaitForGcToCompleteLocked. 1724 if (collector_type == collector_type_) { 1725 return; 1726 } 1727 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1728 if (!copying_transition || disable_moving_gc_count_ == 0) { 1729 // TODO: Not hard code in semi-space collector? 1730 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1731 break; 1732 } 1733 } 1734 usleep(1000); 1735 } 1736 if (runtime->IsShuttingDown(self)) { 1737 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1738 // cause objects to get finalized. 1739 FinishGC(self, collector::kGcTypeNone); 1740 return; 1741 } 1742 tl->SuspendAll(); 1743 switch (collector_type) { 1744 case kCollectorTypeSS: { 1745 if (!IsMovingGc(collector_type_)) { 1746 // Create the bump pointer space from the backup space. 1747 CHECK(main_space_backup_ != nullptr); 1748 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1749 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1750 // pointer space last transition it will be protected. 1751 CHECK(mem_map != nullptr); 1752 mem_map->Protect(PROT_READ | PROT_WRITE); 1753 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1754 mem_map.release()); 1755 AddSpace(bump_pointer_space_); 1756 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1757 // Use the now empty main space mem map for the bump pointer temp space. 1758 mem_map.reset(main_space_->ReleaseMemMap()); 1759 // Unset the pointers just in case. 1760 if (dlmalloc_space_ == main_space_) { 1761 dlmalloc_space_ = nullptr; 1762 } else if (rosalloc_space_ == main_space_) { 1763 rosalloc_space_ = nullptr; 1764 } 1765 // Remove the main space so that we don't try to trim it, this doens't work for debug 1766 // builds since RosAlloc attempts to read the magic number from a protected page. 1767 RemoveSpace(main_space_); 1768 RemoveRememberedSet(main_space_); 1769 delete main_space_; // Delete the space since it has been removed. 1770 main_space_ = nullptr; 1771 RemoveRememberedSet(main_space_backup_.get()); 1772 main_space_backup_.reset(nullptr); // Deletes the space. 1773 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1774 mem_map.release()); 1775 AddSpace(temp_space_); 1776 } 1777 break; 1778 } 1779 case kCollectorTypeMS: 1780 // Fall through. 1781 case kCollectorTypeCMS: { 1782 if (IsMovingGc(collector_type_)) { 1783 CHECK(temp_space_ != nullptr); 1784 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1785 RemoveSpace(temp_space_); 1786 temp_space_ = nullptr; 1787 mem_map->Protect(PROT_READ | PROT_WRITE); 1788 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, 1789 std::min(mem_map->Size(), growth_limit_), mem_map->Size()); 1790 mem_map.release(); 1791 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1792 AddSpace(main_space_); 1793 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1794 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1795 RemoveSpace(bump_pointer_space_); 1796 bump_pointer_space_ = nullptr; 1797 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1798 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1799 if (kIsDebugBuild && kUseRosAlloc) { 1800 mem_map->Protect(PROT_READ | PROT_WRITE); 1801 } 1802 main_space_backup_.reset(CreateMallocSpaceFromMemMap( 1803 mem_map.get(), kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1804 mem_map->Size(), name, true)); 1805 if (kIsDebugBuild && kUseRosAlloc) { 1806 mem_map->Protect(PROT_NONE); 1807 } 1808 mem_map.release(); 1809 } 1810 break; 1811 } 1812 default: { 1813 LOG(FATAL) << "Attempted to transition to invalid collector type " 1814 << static_cast<size_t>(collector_type); 1815 break; 1816 } 1817 } 1818 ChangeCollector(collector_type); 1819 tl->ResumeAll(); 1820 // Can't call into java code with all threads suspended. 1821 reference_processor_.EnqueueClearedReferences(self); 1822 uint64_t duration = NanoTime() - start_time; 1823 GrowForUtilization(semi_space_collector_); 1824 FinishGC(self, collector::kGcTypeFull); 1825 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1826 int32_t delta_allocated = before_allocated - after_allocated; 1827 std::string saved_str; 1828 if (delta_allocated >= 0) { 1829 saved_str = " saved at least " + PrettySize(delta_allocated); 1830 } else { 1831 saved_str = " expanded " + PrettySize(-delta_allocated); 1832 } 1833 VLOG(heap) << "Heap transition to " << process_state_ << " took " 1834 << PrettyDuration(duration) << saved_str; 1835} 1836 1837void Heap::ChangeCollector(CollectorType collector_type) { 1838 // TODO: Only do this with all mutators suspended to avoid races. 1839 if (collector_type != collector_type_) { 1840 if (collector_type == kCollectorTypeMC) { 1841 // Don't allow mark compact unless support is compiled in. 1842 CHECK(kMarkCompactSupport); 1843 } 1844 collector_type_ = collector_type; 1845 gc_plan_.clear(); 1846 switch (collector_type_) { 1847 case kCollectorTypeCC: { 1848 gc_plan_.push_back(collector::kGcTypeFull); 1849 if (use_tlab_) { 1850 ChangeAllocator(kAllocatorTypeRegionTLAB); 1851 } else { 1852 ChangeAllocator(kAllocatorTypeRegion); 1853 } 1854 break; 1855 } 1856 case kCollectorTypeMC: // Fall-through. 1857 case kCollectorTypeSS: // Fall-through. 1858 case kCollectorTypeGSS: { 1859 gc_plan_.push_back(collector::kGcTypeFull); 1860 if (use_tlab_) { 1861 ChangeAllocator(kAllocatorTypeTLAB); 1862 } else { 1863 ChangeAllocator(kAllocatorTypeBumpPointer); 1864 } 1865 break; 1866 } 1867 case kCollectorTypeMS: { 1868 gc_plan_.push_back(collector::kGcTypeSticky); 1869 gc_plan_.push_back(collector::kGcTypePartial); 1870 gc_plan_.push_back(collector::kGcTypeFull); 1871 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1872 break; 1873 } 1874 case kCollectorTypeCMS: { 1875 gc_plan_.push_back(collector::kGcTypeSticky); 1876 gc_plan_.push_back(collector::kGcTypePartial); 1877 gc_plan_.push_back(collector::kGcTypeFull); 1878 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1879 break; 1880 } 1881 default: { 1882 UNIMPLEMENTED(FATAL); 1883 UNREACHABLE(); 1884 } 1885 } 1886 if (IsGcConcurrent()) { 1887 concurrent_start_bytes_ = 1888 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1889 } else { 1890 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1891 } 1892 } 1893} 1894 1895// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1896class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1897 public: 1898 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1899 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1900 } 1901 1902 void BuildBins(space::ContinuousSpace* space) { 1903 bin_live_bitmap_ = space->GetLiveBitmap(); 1904 bin_mark_bitmap_ = space->GetMarkBitmap(); 1905 BinContext context; 1906 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1907 context.collector_ = this; 1908 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1909 // Note: This requires traversing the space in increasing order of object addresses. 1910 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1911 // Add the last bin which spans after the last object to the end of the space. 1912 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1913 } 1914 1915 private: 1916 struct BinContext { 1917 uintptr_t prev_; // The end of the previous object. 1918 ZygoteCompactingCollector* collector_; 1919 }; 1920 // Maps from bin sizes to locations. 1921 std::multimap<size_t, uintptr_t> bins_; 1922 // Live bitmap of the space which contains the bins. 1923 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1924 // Mark bitmap of the space which contains the bins. 1925 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1926 1927 static void Callback(mirror::Object* obj, void* arg) 1928 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1929 DCHECK(arg != nullptr); 1930 BinContext* context = reinterpret_cast<BinContext*>(arg); 1931 ZygoteCompactingCollector* collector = context->collector_; 1932 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1933 size_t bin_size = object_addr - context->prev_; 1934 // Add the bin consisting of the end of the previous object to the start of the current object. 1935 collector->AddBin(bin_size, context->prev_); 1936 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1937 } 1938 1939 void AddBin(size_t size, uintptr_t position) { 1940 if (size != 0) { 1941 bins_.insert(std::make_pair(size, position)); 1942 } 1943 } 1944 1945 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1946 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1947 // allocator. 1948 UNUSED(space); 1949 return false; 1950 } 1951 1952 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1953 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1954 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1955 mirror::Object* forward_address; 1956 // Find the smallest bin which we can move obj in. 1957 auto it = bins_.lower_bound(object_size); 1958 if (it == bins_.end()) { 1959 // No available space in the bins, place it in the target space instead (grows the zygote 1960 // space). 1961 size_t bytes_allocated; 1962 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1963 if (to_space_live_bitmap_ != nullptr) { 1964 to_space_live_bitmap_->Set(forward_address); 1965 } else { 1966 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1967 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1968 } 1969 } else { 1970 size_t size = it->first; 1971 uintptr_t pos = it->second; 1972 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1973 forward_address = reinterpret_cast<mirror::Object*>(pos); 1974 // Set the live and mark bits so that sweeping system weaks works properly. 1975 bin_live_bitmap_->Set(forward_address); 1976 bin_mark_bitmap_->Set(forward_address); 1977 DCHECK_GE(size, object_size); 1978 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1979 } 1980 // Copy the object over to its new location. 1981 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1982 if (kUseBakerOrBrooksReadBarrier) { 1983 obj->AssertReadBarrierPointer(); 1984 if (kUseBrooksReadBarrier) { 1985 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1986 forward_address->SetReadBarrierPointer(forward_address); 1987 } 1988 forward_address->AssertReadBarrierPointer(); 1989 } 1990 return forward_address; 1991 } 1992}; 1993 1994void Heap::UnBindBitmaps() { 1995 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1996 for (const auto& space : GetContinuousSpaces()) { 1997 if (space->IsContinuousMemMapAllocSpace()) { 1998 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1999 if (alloc_space->HasBoundBitmaps()) { 2000 alloc_space->UnBindBitmaps(); 2001 } 2002 } 2003 } 2004} 2005 2006void Heap::PreZygoteFork() { 2007 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 2008 Thread* self = Thread::Current(); 2009 MutexLock mu(self, zygote_creation_lock_); 2010 // Try to see if we have any Zygote spaces. 2011 if (HasZygoteSpace()) { 2012 LOG(WARNING) << __FUNCTION__ << " called when we already have a zygote space."; 2013 return; 2014 } 2015 Runtime::Current()->GetInternTable()->SwapPostZygoteWithPreZygote(); 2016 Runtime::Current()->GetClassLinker()->MoveClassTableToPreZygote(); 2017 VLOG(heap) << "Starting PreZygoteFork"; 2018 // Trim the pages at the end of the non moving space. 2019 non_moving_space_->Trim(); 2020 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 2021 // there. 2022 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2023 const bool same_space = non_moving_space_ == main_space_; 2024 if (kCompactZygote) { 2025 // Can't compact if the non moving space is the same as the main space. 2026 DCHECK(semi_space_collector_ != nullptr); 2027 // Temporarily disable rosalloc verification because the zygote 2028 // compaction will mess up the rosalloc internal metadata. 2029 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 2030 ZygoteCompactingCollector zygote_collector(this); 2031 zygote_collector.BuildBins(non_moving_space_); 2032 // Create a new bump pointer space which we will compact into. 2033 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 2034 non_moving_space_->Limit()); 2035 // Compact the bump pointer space to a new zygote bump pointer space. 2036 bool reset_main_space = false; 2037 if (IsMovingGc(collector_type_)) { 2038 if (collector_type_ == kCollectorTypeCC) { 2039 zygote_collector.SetFromSpace(region_space_); 2040 } else { 2041 zygote_collector.SetFromSpace(bump_pointer_space_); 2042 } 2043 } else { 2044 CHECK(main_space_ != nullptr); 2045 // Copy from the main space. 2046 zygote_collector.SetFromSpace(main_space_); 2047 reset_main_space = true; 2048 } 2049 zygote_collector.SetToSpace(&target_space); 2050 zygote_collector.SetSwapSemiSpaces(false); 2051 zygote_collector.Run(kGcCauseCollectorTransition, false); 2052 if (reset_main_space) { 2053 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2054 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 2055 MemMap* mem_map = main_space_->ReleaseMemMap(); 2056 RemoveSpace(main_space_); 2057 space::Space* old_main_space = main_space_; 2058 CreateMainMallocSpace(mem_map, kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 2059 mem_map->Size()); 2060 delete old_main_space; 2061 AddSpace(main_space_); 2062 } else { 2063 if (collector_type_ == kCollectorTypeCC) { 2064 region_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2065 } else { 2066 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2067 } 2068 } 2069 if (temp_space_ != nullptr) { 2070 CHECK(temp_space_->IsEmpty()); 2071 } 2072 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2073 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2074 // Update the end and write out image. 2075 non_moving_space_->SetEnd(target_space.End()); 2076 non_moving_space_->SetLimit(target_space.Limit()); 2077 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 2078 } 2079 // Change the collector to the post zygote one. 2080 ChangeCollector(foreground_collector_type_); 2081 // Save the old space so that we can remove it after we complete creating the zygote space. 2082 space::MallocSpace* old_alloc_space = non_moving_space_; 2083 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 2084 // the remaining available space. 2085 // Remove the old space before creating the zygote space since creating the zygote space sets 2086 // the old alloc space's bitmaps to nullptr. 2087 RemoveSpace(old_alloc_space); 2088 if (collector::SemiSpace::kUseRememberedSet) { 2089 // Sanity bound check. 2090 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 2091 // Remove the remembered set for the now zygote space (the old 2092 // non-moving space). Note now that we have compacted objects into 2093 // the zygote space, the data in the remembered set is no longer 2094 // needed. The zygote space will instead have a mod-union table 2095 // from this point on. 2096 RemoveRememberedSet(old_alloc_space); 2097 } 2098 // Remaining space becomes the new non moving space. 2099 zygote_space_ = old_alloc_space->CreateZygoteSpace(kNonMovingSpaceName, low_memory_mode_, 2100 &non_moving_space_); 2101 CHECK(!non_moving_space_->CanMoveObjects()); 2102 if (same_space) { 2103 main_space_ = non_moving_space_; 2104 SetSpaceAsDefault(main_space_); 2105 } 2106 delete old_alloc_space; 2107 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 2108 AddSpace(zygote_space_); 2109 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 2110 AddSpace(non_moving_space_); 2111 // Create the zygote space mod union table. 2112 accounting::ModUnionTable* mod_union_table = 2113 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 2114 zygote_space_); 2115 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 2116 // Set all the cards in the mod-union table since we don't know which objects contain references 2117 // to large objects. 2118 mod_union_table->SetCards(); 2119 AddModUnionTable(mod_union_table); 2120 if (collector::SemiSpace::kUseRememberedSet) { 2121 // Add a new remembered set for the post-zygote non-moving space. 2122 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 2123 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2124 non_moving_space_); 2125 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2126 << "Failed to create post-zygote non-moving space remembered set"; 2127 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2128 } 2129} 2130 2131void Heap::FlushAllocStack() { 2132 MarkAllocStackAsLive(allocation_stack_.get()); 2133 allocation_stack_->Reset(); 2134} 2135 2136void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2137 accounting::ContinuousSpaceBitmap* bitmap2, 2138 accounting::LargeObjectBitmap* large_objects, 2139 accounting::ObjectStack* stack) { 2140 DCHECK(bitmap1 != nullptr); 2141 DCHECK(bitmap2 != nullptr); 2142 mirror::Object** limit = stack->End(); 2143 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 2144 const mirror::Object* obj = *it; 2145 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2146 if (bitmap1->HasAddress(obj)) { 2147 bitmap1->Set(obj); 2148 } else if (bitmap2->HasAddress(obj)) { 2149 bitmap2->Set(obj); 2150 } else { 2151 DCHECK(large_objects != nullptr); 2152 large_objects->Set(obj); 2153 } 2154 } 2155 } 2156} 2157 2158void Heap::SwapSemiSpaces() { 2159 CHECK(bump_pointer_space_ != nullptr); 2160 CHECK(temp_space_ != nullptr); 2161 std::swap(bump_pointer_space_, temp_space_); 2162} 2163 2164void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2165 space::ContinuousMemMapAllocSpace* source_space, 2166 GcCause gc_cause) { 2167 CHECK(kMovingCollector); 2168 if (target_space != source_space) { 2169 // Don't swap spaces since this isn't a typical semi space collection. 2170 semi_space_collector_->SetSwapSemiSpaces(false); 2171 semi_space_collector_->SetFromSpace(source_space); 2172 semi_space_collector_->SetToSpace(target_space); 2173 semi_space_collector_->Run(gc_cause, false); 2174 } else { 2175 CHECK(target_space->IsBumpPointerSpace()) 2176 << "In-place compaction is only supported for bump pointer spaces"; 2177 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2178 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2179 } 2180} 2181 2182collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2183 bool clear_soft_references) { 2184 Thread* self = Thread::Current(); 2185 Runtime* runtime = Runtime::Current(); 2186 // If the heap can't run the GC, silently fail and return that no GC was run. 2187 switch (gc_type) { 2188 case collector::kGcTypePartial: { 2189 if (!HasZygoteSpace()) { 2190 return collector::kGcTypeNone; 2191 } 2192 break; 2193 } 2194 default: { 2195 // Other GC types don't have any special cases which makes them not runnable. The main case 2196 // here is full GC. 2197 } 2198 } 2199 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2200 Locks::mutator_lock_->AssertNotHeld(self); 2201 if (self->IsHandlingStackOverflow()) { 2202 // If we are throwing a stack overflow error we probably don't have enough remaining stack 2203 // space to run the GC. 2204 return collector::kGcTypeNone; 2205 } 2206 bool compacting_gc; 2207 { 2208 gc_complete_lock_->AssertNotHeld(self); 2209 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 2210 MutexLock mu(self, *gc_complete_lock_); 2211 // Ensure there is only one GC at a time. 2212 WaitForGcToCompleteLocked(gc_cause, self); 2213 compacting_gc = IsMovingGc(collector_type_); 2214 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2215 if (compacting_gc && disable_moving_gc_count_ != 0) { 2216 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2217 return collector::kGcTypeNone; 2218 } 2219 collector_type_running_ = collector_type_; 2220 } 2221 2222 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2223 ++runtime->GetStats()->gc_for_alloc_count; 2224 ++self->GetStats()->gc_for_alloc_count; 2225 } 2226 const uint64_t bytes_allocated_before_gc = GetBytesAllocated(); 2227 // Approximate heap size. 2228 ATRACE_INT("Heap size (KB)", bytes_allocated_before_gc / KB); 2229 2230 DCHECK_LT(gc_type, collector::kGcTypeMax); 2231 DCHECK_NE(gc_type, collector::kGcTypeNone); 2232 2233 collector::GarbageCollector* collector = nullptr; 2234 // TODO: Clean this up. 2235 if (compacting_gc) { 2236 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2237 current_allocator_ == kAllocatorTypeTLAB || 2238 current_allocator_ == kAllocatorTypeRegion || 2239 current_allocator_ == kAllocatorTypeRegionTLAB); 2240 switch (collector_type_) { 2241 case kCollectorTypeSS: 2242 // Fall-through. 2243 case kCollectorTypeGSS: 2244 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2245 semi_space_collector_->SetToSpace(temp_space_); 2246 semi_space_collector_->SetSwapSemiSpaces(true); 2247 collector = semi_space_collector_; 2248 break; 2249 case kCollectorTypeCC: 2250 concurrent_copying_collector_->SetRegionSpace(region_space_); 2251 collector = concurrent_copying_collector_; 2252 break; 2253 case kCollectorTypeMC: 2254 mark_compact_collector_->SetSpace(bump_pointer_space_); 2255 collector = mark_compact_collector_; 2256 break; 2257 default: 2258 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2259 } 2260 if (collector != mark_compact_collector_ && collector != concurrent_copying_collector_) { 2261 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2262 CHECK(temp_space_->IsEmpty()); 2263 } 2264 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2265 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2266 current_allocator_ == kAllocatorTypeDlMalloc) { 2267 collector = FindCollectorByGcType(gc_type); 2268 } else { 2269 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2270 } 2271 if (IsGcConcurrent()) { 2272 // Disable concurrent GC check so that we don't have spammy JNI requests. 2273 // This gets recalculated in GrowForUtilization. It is important that it is disabled / 2274 // calculated in the same thread so that there aren't any races that can cause it to become 2275 // permanantly disabled. b/17942071 2276 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2277 } 2278 CHECK(collector != nullptr) 2279 << "Could not find garbage collector with collector_type=" 2280 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2281 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2282 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2283 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2284 RequestTrim(self); 2285 // Enqueue cleared references. 2286 reference_processor_.EnqueueClearedReferences(self); 2287 // Grow the heap so that we know when to perform the next GC. 2288 GrowForUtilization(collector, bytes_allocated_before_gc); 2289 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2290 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2291 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2292 // (mutator time blocked >= long_pause_log_threshold_). 2293 bool log_gc = gc_cause == kGcCauseExplicit; 2294 if (!log_gc && CareAboutPauseTimes()) { 2295 // GC for alloc pauses the allocating thread, so consider it as a pause. 2296 log_gc = duration > long_gc_log_threshold_ || 2297 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2298 for (uint64_t pause : pause_times) { 2299 log_gc = log_gc || pause >= long_pause_log_threshold_; 2300 } 2301 } 2302 if (log_gc) { 2303 const size_t percent_free = GetPercentFree(); 2304 const size_t current_heap_size = GetBytesAllocated(); 2305 const size_t total_memory = GetTotalMemory(); 2306 std::ostringstream pause_string; 2307 for (size_t i = 0; i < pause_times.size(); ++i) { 2308 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2309 << ((i != pause_times.size() - 1) ? "," : ""); 2310 } 2311 LOG(INFO) << gc_cause << " " << collector->GetName() 2312 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2313 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2314 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2315 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2316 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2317 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2318 << " total " << PrettyDuration((duration / 1000) * 1000); 2319 VLOG(heap) << Dumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2320 } 2321 FinishGC(self, gc_type); 2322 // Inform DDMS that a GC completed. 2323 Dbg::GcDidFinish(); 2324 return gc_type; 2325} 2326 2327void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2328 MutexLock mu(self, *gc_complete_lock_); 2329 collector_type_running_ = kCollectorTypeNone; 2330 if (gc_type != collector::kGcTypeNone) { 2331 last_gc_type_ = gc_type; 2332 } 2333 // Wake anyone who may have been waiting for the GC to complete. 2334 gc_complete_cond_->Broadcast(self); 2335} 2336 2337static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, 2338 const RootInfo& /*root_info*/) { 2339 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2340 if (*root == obj) { 2341 LOG(INFO) << "Object " << obj << " is a root"; 2342 } 2343} 2344 2345class ScanVisitor { 2346 public: 2347 void operator()(const mirror::Object* obj) const { 2348 LOG(ERROR) << "Would have rescanned object " << obj; 2349 } 2350}; 2351 2352// Verify a reference from an object. 2353class VerifyReferenceVisitor { 2354 public: 2355 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2356 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2357 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2358 2359 size_t GetFailureCount() const { 2360 return fail_count_->LoadSequentiallyConsistent(); 2361 } 2362 2363 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2364 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2365 UNUSED(klass); 2366 if (verify_referent_) { 2367 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2368 } 2369 } 2370 2371 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2372 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2373 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2374 } 2375 2376 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2377 return heap_->IsLiveObjectLocked(obj, true, false, true); 2378 } 2379 2380 static void VerifyRootCallback(mirror::Object** root, void* arg, const RootInfo& root_info) 2381 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2382 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2383 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2384 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2385 << " thread_id= " << root_info.GetThreadId() << " root_type= " << root_info.GetType(); 2386 } 2387 } 2388 2389 private: 2390 // TODO: Fix the no thread safety analysis. 2391 // Returns false on failure. 2392 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2393 NO_THREAD_SAFETY_ANALYSIS { 2394 if (ref == nullptr || IsLive(ref)) { 2395 // Verify that the reference is live. 2396 return true; 2397 } 2398 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2399 // Print message on only on first failure to prevent spam. 2400 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2401 } 2402 if (obj != nullptr) { 2403 // Only do this part for non roots. 2404 accounting::CardTable* card_table = heap_->GetCardTable(); 2405 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2406 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2407 uint8_t* card_addr = card_table->CardFromAddr(obj); 2408 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2409 << offset << "\n card value = " << static_cast<int>(*card_addr); 2410 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2411 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2412 } else { 2413 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2414 } 2415 2416 // Attempt to find the class inside of the recently freed objects. 2417 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2418 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2419 space::MallocSpace* space = ref_space->AsMallocSpace(); 2420 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2421 if (ref_class != nullptr) { 2422 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2423 << PrettyClass(ref_class); 2424 } else { 2425 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2426 } 2427 } 2428 2429 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2430 ref->GetClass()->IsClass()) { 2431 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2432 } else { 2433 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2434 << ") is not a valid heap address"; 2435 } 2436 2437 card_table->CheckAddrIsInCardTable(reinterpret_cast<const uint8_t*>(obj)); 2438 void* cover_begin = card_table->AddrFromCard(card_addr); 2439 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2440 accounting::CardTable::kCardSize); 2441 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2442 << "-" << cover_end; 2443 accounting::ContinuousSpaceBitmap* bitmap = 2444 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2445 2446 if (bitmap == nullptr) { 2447 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2448 if (!VerifyClassClass(obj->GetClass())) { 2449 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2450 } 2451 } else { 2452 // Print out how the object is live. 2453 if (bitmap->Test(obj)) { 2454 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2455 } 2456 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2457 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2458 } 2459 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2460 LOG(ERROR) << "Object " << obj << " found in live stack"; 2461 } 2462 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2463 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2464 } 2465 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2466 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2467 } 2468 // Attempt to see if the card table missed the reference. 2469 ScanVisitor scan_visitor; 2470 uint8_t* byte_cover_begin = reinterpret_cast<uint8_t*>(card_table->AddrFromCard(card_addr)); 2471 card_table->Scan<false>(bitmap, byte_cover_begin, 2472 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2473 } 2474 2475 // Search to see if any of the roots reference our object. 2476 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2477 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2478 2479 // Search to see if any of the roots reference our reference. 2480 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2481 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2482 } 2483 return false; 2484 } 2485 2486 Heap* const heap_; 2487 Atomic<size_t>* const fail_count_; 2488 const bool verify_referent_; 2489}; 2490 2491// Verify all references within an object, for use with HeapBitmap::Visit. 2492class VerifyObjectVisitor { 2493 public: 2494 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2495 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2496 } 2497 2498 void operator()(mirror::Object* obj) const 2499 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2500 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2501 // be live or else how did we find it in the live bitmap? 2502 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2503 // The class doesn't count as a reference but we should verify it anyways. 2504 obj->VisitReferences<true>(visitor, visitor); 2505 } 2506 2507 static void VisitCallback(mirror::Object* obj, void* arg) 2508 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2509 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2510 visitor->operator()(obj); 2511 } 2512 2513 size_t GetFailureCount() const { 2514 return fail_count_->LoadSequentiallyConsistent(); 2515 } 2516 2517 private: 2518 Heap* const heap_; 2519 Atomic<size_t>* const fail_count_; 2520 const bool verify_referent_; 2521}; 2522 2523void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2524 // Slow path, the allocation stack push back must have already failed. 2525 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2526 do { 2527 // TODO: Add handle VerifyObject. 2528 StackHandleScope<1> hs(self); 2529 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2530 // Push our object into the reserve region of the allocaiton stack. This is only required due 2531 // to heap verification requiring that roots are live (either in the live bitmap or in the 2532 // allocation stack). 2533 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2534 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2535 } while (!allocation_stack_->AtomicPushBack(*obj)); 2536} 2537 2538void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2539 // Slow path, the allocation stack push back must have already failed. 2540 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2541 mirror::Object** start_address; 2542 mirror::Object** end_address; 2543 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2544 &end_address)) { 2545 // TODO: Add handle VerifyObject. 2546 StackHandleScope<1> hs(self); 2547 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2548 // Push our object into the reserve region of the allocaiton stack. This is only required due 2549 // to heap verification requiring that roots are live (either in the live bitmap or in the 2550 // allocation stack). 2551 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2552 // Push into the reserve allocation stack. 2553 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2554 } 2555 self->SetThreadLocalAllocationStack(start_address, end_address); 2556 // Retry on the new thread-local allocation stack. 2557 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2558} 2559 2560// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2561size_t Heap::VerifyHeapReferences(bool verify_referents) { 2562 Thread* self = Thread::Current(); 2563 Locks::mutator_lock_->AssertExclusiveHeld(self); 2564 // Lets sort our allocation stacks so that we can efficiently binary search them. 2565 allocation_stack_->Sort(); 2566 live_stack_->Sort(); 2567 // Since we sorted the allocation stack content, need to revoke all 2568 // thread-local allocation stacks. 2569 RevokeAllThreadLocalAllocationStacks(self); 2570 Atomic<size_t> fail_count_(0); 2571 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2572 // Verify objects in the allocation stack since these will be objects which were: 2573 // 1. Allocated prior to the GC (pre GC verification). 2574 // 2. Allocated during the GC (pre sweep GC verification). 2575 // We don't want to verify the objects in the live stack since they themselves may be 2576 // pointing to dead objects if they are not reachable. 2577 VisitObjectsPaused(VerifyObjectVisitor::VisitCallback, &visitor); 2578 // Verify the roots: 2579 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2580 if (visitor.GetFailureCount() > 0) { 2581 // Dump mod-union tables. 2582 for (const auto& table_pair : mod_union_tables_) { 2583 accounting::ModUnionTable* mod_union_table = table_pair.second; 2584 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2585 } 2586 // Dump remembered sets. 2587 for (const auto& table_pair : remembered_sets_) { 2588 accounting::RememberedSet* remembered_set = table_pair.second; 2589 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2590 } 2591 DumpSpaces(LOG(ERROR)); 2592 } 2593 return visitor.GetFailureCount(); 2594} 2595 2596class VerifyReferenceCardVisitor { 2597 public: 2598 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2599 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2600 Locks::heap_bitmap_lock_) 2601 : heap_(heap), failed_(failed) { 2602 } 2603 2604 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2605 // annotalysis on visitors. 2606 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2607 NO_THREAD_SAFETY_ANALYSIS { 2608 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2609 // Filter out class references since changing an object's class does not mark the card as dirty. 2610 // Also handles large objects, since the only reference they hold is a class reference. 2611 if (ref != nullptr && !ref->IsClass()) { 2612 accounting::CardTable* card_table = heap_->GetCardTable(); 2613 // If the object is not dirty and it is referencing something in the live stack other than 2614 // class, then it must be on a dirty card. 2615 if (!card_table->AddrIsInCardTable(obj)) { 2616 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2617 *failed_ = true; 2618 } else if (!card_table->IsDirty(obj)) { 2619 // TODO: Check mod-union tables. 2620 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2621 // kCardDirty - 1 if it didnt get touched since we aged it. 2622 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2623 if (live_stack->ContainsSorted(ref)) { 2624 if (live_stack->ContainsSorted(obj)) { 2625 LOG(ERROR) << "Object " << obj << " found in live stack"; 2626 } 2627 if (heap_->GetLiveBitmap()->Test(obj)) { 2628 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2629 } 2630 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2631 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2632 2633 // Print which field of the object is dead. 2634 if (!obj->IsObjectArray()) { 2635 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2636 CHECK(klass != NULL); 2637 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2638 : klass->GetIFields(); 2639 CHECK(fields != NULL); 2640 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2641 mirror::ArtField* cur = fields->Get(i); 2642 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2643 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2644 << PrettyField(cur); 2645 break; 2646 } 2647 } 2648 } else { 2649 mirror::ObjectArray<mirror::Object>* object_array = 2650 obj->AsObjectArray<mirror::Object>(); 2651 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2652 if (object_array->Get(i) == ref) { 2653 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2654 } 2655 } 2656 } 2657 2658 *failed_ = true; 2659 } 2660 } 2661 } 2662 } 2663 2664 private: 2665 Heap* const heap_; 2666 bool* const failed_; 2667}; 2668 2669class VerifyLiveStackReferences { 2670 public: 2671 explicit VerifyLiveStackReferences(Heap* heap) 2672 : heap_(heap), 2673 failed_(false) {} 2674 2675 void operator()(mirror::Object* obj) const 2676 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2677 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2678 obj->VisitReferences<true>(visitor, VoidFunctor()); 2679 } 2680 2681 bool Failed() const { 2682 return failed_; 2683 } 2684 2685 private: 2686 Heap* const heap_; 2687 bool failed_; 2688}; 2689 2690bool Heap::VerifyMissingCardMarks() { 2691 Thread* self = Thread::Current(); 2692 Locks::mutator_lock_->AssertExclusiveHeld(self); 2693 // We need to sort the live stack since we binary search it. 2694 live_stack_->Sort(); 2695 // Since we sorted the allocation stack content, need to revoke all 2696 // thread-local allocation stacks. 2697 RevokeAllThreadLocalAllocationStacks(self); 2698 VerifyLiveStackReferences visitor(this); 2699 GetLiveBitmap()->Visit(visitor); 2700 // We can verify objects in the live stack since none of these should reference dead objects. 2701 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2702 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2703 visitor(*it); 2704 } 2705 } 2706 return !visitor.Failed(); 2707} 2708 2709void Heap::SwapStacks(Thread* self) { 2710 UNUSED(self); 2711 if (kUseThreadLocalAllocationStack) { 2712 live_stack_->AssertAllZero(); 2713 } 2714 allocation_stack_.swap(live_stack_); 2715} 2716 2717void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2718 // This must be called only during the pause. 2719 DCHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2720 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2721 MutexLock mu2(self, *Locks::thread_list_lock_); 2722 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2723 for (Thread* t : thread_list) { 2724 t->RevokeThreadLocalAllocationStack(); 2725 } 2726} 2727 2728void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2729 if (kIsDebugBuild) { 2730 if (rosalloc_space_ != nullptr) { 2731 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2732 } 2733 if (bump_pointer_space_ != nullptr) { 2734 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2735 } 2736 } 2737} 2738 2739void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2740 if (kIsDebugBuild) { 2741 if (bump_pointer_space_ != nullptr) { 2742 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2743 } 2744 } 2745} 2746 2747accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2748 auto it = mod_union_tables_.find(space); 2749 if (it == mod_union_tables_.end()) { 2750 return nullptr; 2751 } 2752 return it->second; 2753} 2754 2755accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2756 auto it = remembered_sets_.find(space); 2757 if (it == remembered_sets_.end()) { 2758 return nullptr; 2759 } 2760 return it->second; 2761} 2762 2763void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2764 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2765 // Clear cards and keep track of cards cleared in the mod-union table. 2766 for (const auto& space : continuous_spaces_) { 2767 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2768 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2769 if (table != nullptr) { 2770 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2771 "ImageModUnionClearCards"; 2772 TimingLogger::ScopedTiming t2(name, timings); 2773 table->ClearCards(); 2774 } else if (use_rem_sets && rem_set != nullptr) { 2775 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2776 << static_cast<int>(collector_type_); 2777 TimingLogger::ScopedTiming t2("AllocSpaceRemSetClearCards", timings); 2778 rem_set->ClearCards(); 2779 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2780 TimingLogger::ScopedTiming t2("AllocSpaceClearCards", timings); 2781 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2782 // were dirty before the GC started. 2783 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2784 // -> clean(cleaning thread). 2785 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2786 // roots and then we scan / update mod union tables after. We will always scan either card. 2787 // If we end up with the non aged card, we scan it it in the pause. 2788 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2789 VoidFunctor()); 2790 } 2791 } 2792} 2793 2794static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2795} 2796 2797void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2798 Thread* const self = Thread::Current(); 2799 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2800 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2801 if (verify_pre_gc_heap_) { 2802 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyHeapReferences", timings); 2803 size_t failures = VerifyHeapReferences(); 2804 if (failures > 0) { 2805 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2806 << " failures"; 2807 } 2808 } 2809 // Check that all objects which reference things in the live stack are on dirty cards. 2810 if (verify_missing_card_marks_) { 2811 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyMissingCardMarks", timings); 2812 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2813 SwapStacks(self); 2814 // Sort the live stack so that we can quickly binary search it later. 2815 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2816 << " missing card mark verification failed\n" << DumpSpaces(); 2817 SwapStacks(self); 2818 } 2819 if (verify_mod_union_table_) { 2820 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyModUnionTables", timings); 2821 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2822 for (const auto& table_pair : mod_union_tables_) { 2823 accounting::ModUnionTable* mod_union_table = table_pair.second; 2824 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2825 mod_union_table->Verify(); 2826 } 2827 } 2828} 2829 2830void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2831 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2832 collector::GarbageCollector::ScopedPause pause(gc); 2833 PreGcVerificationPaused(gc); 2834 } 2835} 2836 2837void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2838 UNUSED(gc); 2839 // TODO: Add a new runtime option for this? 2840 if (verify_pre_gc_rosalloc_) { 2841 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2842 } 2843} 2844 2845void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2846 Thread* const self = Thread::Current(); 2847 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2848 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2849 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2850 // reachable objects. 2851 if (verify_pre_sweeping_heap_) { 2852 TimingLogger::ScopedTiming t2("(Paused)PostSweepingVerifyHeapReferences", timings); 2853 CHECK_NE(self->GetState(), kRunnable); 2854 { 2855 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2856 // Swapping bound bitmaps does nothing. 2857 gc->SwapBitmaps(); 2858 } 2859 // Pass in false since concurrent reference processing can mean that the reference referents 2860 // may point to dead objects at the point which PreSweepingGcVerification is called. 2861 size_t failures = VerifyHeapReferences(false); 2862 if (failures > 0) { 2863 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2864 << " failures"; 2865 } 2866 { 2867 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2868 gc->SwapBitmaps(); 2869 } 2870 } 2871 if (verify_pre_sweeping_rosalloc_) { 2872 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2873 } 2874} 2875 2876void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2877 // Only pause if we have to do some verification. 2878 Thread* const self = Thread::Current(); 2879 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2880 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2881 if (verify_system_weaks_) { 2882 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2883 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2884 mark_sweep->VerifySystemWeaks(); 2885 } 2886 if (verify_post_gc_rosalloc_) { 2887 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2888 } 2889 if (verify_post_gc_heap_) { 2890 TimingLogger::ScopedTiming t2("(Paused)PostGcVerifyHeapReferences", timings); 2891 size_t failures = VerifyHeapReferences(); 2892 if (failures > 0) { 2893 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2894 << " failures"; 2895 } 2896 } 2897} 2898 2899void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2900 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2901 collector::GarbageCollector::ScopedPause pause(gc); 2902 PostGcVerificationPaused(gc); 2903 } 2904} 2905 2906void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2907 TimingLogger::ScopedTiming t(name, timings); 2908 for (const auto& space : continuous_spaces_) { 2909 if (space->IsRosAllocSpace()) { 2910 VLOG(heap) << name << " : " << space->GetName(); 2911 space->AsRosAllocSpace()->Verify(); 2912 } 2913 } 2914} 2915 2916collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2917 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2918 MutexLock mu(self, *gc_complete_lock_); 2919 return WaitForGcToCompleteLocked(cause, self); 2920} 2921 2922collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2923 collector::GcType last_gc_type = collector::kGcTypeNone; 2924 uint64_t wait_start = NanoTime(); 2925 while (collector_type_running_ != kCollectorTypeNone) { 2926 ATRACE_BEGIN("GC: Wait For Completion"); 2927 // We must wait, change thread state then sleep on gc_complete_cond_; 2928 gc_complete_cond_->Wait(self); 2929 last_gc_type = last_gc_type_; 2930 ATRACE_END(); 2931 } 2932 uint64_t wait_time = NanoTime() - wait_start; 2933 total_wait_time_ += wait_time; 2934 if (wait_time > long_pause_log_threshold_) { 2935 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2936 << " for cause " << cause; 2937 } 2938 return last_gc_type; 2939} 2940 2941void Heap::DumpForSigQuit(std::ostream& os) { 2942 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2943 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2944 DumpGcPerformanceInfo(os); 2945} 2946 2947size_t Heap::GetPercentFree() { 2948 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2949} 2950 2951void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2952 if (max_allowed_footprint > GetMaxMemory()) { 2953 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2954 << PrettySize(GetMaxMemory()); 2955 max_allowed_footprint = GetMaxMemory(); 2956 } 2957 max_allowed_footprint_ = max_allowed_footprint; 2958} 2959 2960bool Heap::IsMovableObject(const mirror::Object* obj) const { 2961 if (kMovingCollector) { 2962 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2963 if (space != nullptr) { 2964 // TODO: Check large object? 2965 return space->CanMoveObjects(); 2966 } 2967 } 2968 return false; 2969} 2970 2971void Heap::UpdateMaxNativeFootprint() { 2972 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2973 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2974 size_t target_size = native_size / GetTargetHeapUtilization(); 2975 if (target_size > native_size + max_free_) { 2976 target_size = native_size + max_free_; 2977 } else if (target_size < native_size + min_free_) { 2978 target_size = native_size + min_free_; 2979 } 2980 native_footprint_gc_watermark_ = std::min(growth_limit_, target_size); 2981} 2982 2983collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2984 for (const auto& collector : garbage_collectors_) { 2985 if (collector->GetCollectorType() == collector_type_ && 2986 collector->GetGcType() == gc_type) { 2987 return collector; 2988 } 2989 } 2990 return nullptr; 2991} 2992 2993double Heap::HeapGrowthMultiplier() const { 2994 // If we don't care about pause times we are background, so return 1.0. 2995 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2996 return 1.0; 2997 } 2998 return foreground_heap_growth_multiplier_; 2999} 3000 3001void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran, 3002 uint64_t bytes_allocated_before_gc) { 3003 // We know what our utilization is at this moment. 3004 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 3005 const uint64_t bytes_allocated = GetBytesAllocated(); 3006 uint64_t target_size; 3007 collector::GcType gc_type = collector_ran->GetGcType(); 3008 const double multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 3009 // foreground. 3010 const uint64_t adjusted_min_free = static_cast<uint64_t>(min_free_ * multiplier); 3011 const uint64_t adjusted_max_free = static_cast<uint64_t>(max_free_ * multiplier); 3012 if (gc_type != collector::kGcTypeSticky) { 3013 // Grow the heap for non sticky GC. 3014 ssize_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 3015 CHECK_GE(delta, 0); 3016 target_size = bytes_allocated + delta * multiplier; 3017 target_size = std::min(target_size, bytes_allocated + adjusted_max_free); 3018 target_size = std::max(target_size, bytes_allocated + adjusted_min_free); 3019 native_need_to_run_finalization_ = true; 3020 next_gc_type_ = collector::kGcTypeSticky; 3021 } else { 3022 collector::GcType non_sticky_gc_type = 3023 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 3024 // Find what the next non sticky collector will be. 3025 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 3026 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 3027 // do another sticky collection next. 3028 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 3029 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 3030 // if the sticky GC throughput always remained >= the full/partial throughput. 3031 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 3032 non_sticky_collector->GetEstimatedMeanThroughput() && 3033 non_sticky_collector->NumberOfIterations() > 0 && 3034 bytes_allocated <= max_allowed_footprint_) { 3035 next_gc_type_ = collector::kGcTypeSticky; 3036 } else { 3037 next_gc_type_ = non_sticky_gc_type; 3038 } 3039 // If we have freed enough memory, shrink the heap back down. 3040 if (bytes_allocated + adjusted_max_free < max_allowed_footprint_) { 3041 target_size = bytes_allocated + adjusted_max_free; 3042 } else { 3043 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 3044 } 3045 } 3046 if (!ignore_max_footprint_) { 3047 SetIdealFootprint(target_size); 3048 if (IsGcConcurrent()) { 3049 const uint64_t freed_bytes = current_gc_iteration_.GetFreedBytes() + 3050 current_gc_iteration_.GetFreedLargeObjectBytes(); 3051 // Bytes allocated will shrink by freed_bytes after the GC runs, so if we want to figure out 3052 // how many bytes were allocated during the GC we need to add freed_bytes back on. 3053 CHECK_GE(bytes_allocated + freed_bytes, bytes_allocated_before_gc); 3054 const uint64_t bytes_allocated_during_gc = bytes_allocated + freed_bytes - 3055 bytes_allocated_before_gc; 3056 // Calculate when to perform the next ConcurrentGC. 3057 // Calculate the estimated GC duration. 3058 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 3059 // Estimate how many remaining bytes we will have when we need to start the next GC. 3060 size_t remaining_bytes = bytes_allocated_during_gc * gc_duration_seconds; 3061 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 3062 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 3063 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 3064 // A never going to happen situation that from the estimated allocation rate we will exceed 3065 // the applications entire footprint with the given estimated allocation rate. Schedule 3066 // another GC nearly straight away. 3067 remaining_bytes = kMinConcurrentRemainingBytes; 3068 } 3069 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 3070 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 3071 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 3072 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 3073 // right away. 3074 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 3075 static_cast<size_t>(bytes_allocated)); 3076 } 3077 } 3078} 3079 3080void Heap::ClampGrowthLimit() { 3081 capacity_ = growth_limit_; 3082 for (const auto& space : continuous_spaces_) { 3083 if (space->IsMallocSpace()) { 3084 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3085 malloc_space->ClampGrowthLimit(); 3086 } 3087 } 3088 // This space isn't added for performance reasons. 3089 if (main_space_backup_.get() != nullptr) { 3090 main_space_backup_->ClampGrowthLimit(); 3091 } 3092} 3093 3094void Heap::ClearGrowthLimit() { 3095 growth_limit_ = capacity_; 3096 for (const auto& space : continuous_spaces_) { 3097 if (space->IsMallocSpace()) { 3098 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3099 malloc_space->ClearGrowthLimit(); 3100 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 3101 } 3102 } 3103 // This space isn't added for performance reasons. 3104 if (main_space_backup_.get() != nullptr) { 3105 main_space_backup_->ClearGrowthLimit(); 3106 main_space_backup_->SetFootprintLimit(main_space_backup_->Capacity()); 3107 } 3108} 3109 3110void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 3111 ScopedObjectAccess soa(self); 3112 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 3113 jvalue args[1]; 3114 args[0].l = arg.get(); 3115 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 3116 // Restore object in case it gets moved. 3117 *object = soa.Decode<mirror::Object*>(arg.get()); 3118} 3119 3120void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 3121 StackHandleScope<1> hs(self); 3122 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 3123 RequestConcurrentGC(self); 3124} 3125 3126class Heap::ConcurrentGCTask : public HeapTask { 3127 public: 3128 explicit ConcurrentGCTask(uint64_t target_time) : HeapTask(target_time) { } 3129 virtual void Run(Thread* self) OVERRIDE { 3130 gc::Heap* heap = Runtime::Current()->GetHeap(); 3131 heap->ConcurrentGC(self); 3132 heap->ClearConcurrentGCRequest(); 3133 } 3134}; 3135 3136static bool CanAddHeapTask(Thread* self) LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_) { 3137 Runtime* runtime = Runtime::Current(); 3138 return runtime != nullptr && runtime->IsFinishedStarting() && !runtime->IsShuttingDown(self) && 3139 !self->IsHandlingStackOverflow(); 3140} 3141 3142void Heap::ClearConcurrentGCRequest() { 3143 concurrent_gc_pending_.StoreRelaxed(false); 3144} 3145 3146void Heap::RequestConcurrentGC(Thread* self) { 3147 if (CanAddHeapTask(self) && 3148 concurrent_gc_pending_.CompareExchangeStrongSequentiallyConsistent(false, true)) { 3149 task_processor_->AddTask(self, new ConcurrentGCTask(NanoTime())); // Start straight away. 3150 } 3151} 3152 3153void Heap::ConcurrentGC(Thread* self) { 3154 if (!Runtime::Current()->IsShuttingDown(self)) { 3155 // Wait for any GCs currently running to finish. 3156 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 3157 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 3158 // instead. E.g. can't do partial, so do full instead. 3159 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 3160 collector::kGcTypeNone) { 3161 for (collector::GcType gc_type : gc_plan_) { 3162 // Attempt to run the collector, if we succeed, we are done. 3163 if (gc_type > next_gc_type_ && 3164 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != 3165 collector::kGcTypeNone) { 3166 break; 3167 } 3168 } 3169 } 3170 } 3171 } 3172} 3173 3174class Heap::CollectorTransitionTask : public HeapTask { 3175 public: 3176 explicit CollectorTransitionTask(uint64_t target_time) : HeapTask(target_time) { } 3177 virtual void Run(Thread* self) OVERRIDE { 3178 gc::Heap* heap = Runtime::Current()->GetHeap(); 3179 heap->DoPendingCollectorTransition(); 3180 heap->ClearPendingCollectorTransition(self); 3181 } 3182}; 3183 3184void Heap::ClearPendingCollectorTransition(Thread* self) { 3185 MutexLock mu(self, *pending_task_lock_); 3186 pending_collector_transition_ = nullptr; 3187} 3188 3189void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 3190 Thread* self = Thread::Current(); 3191 desired_collector_type_ = desired_collector_type; 3192 if (desired_collector_type_ == collector_type_ || !CanAddHeapTask(self)) { 3193 return; 3194 } 3195 CollectorTransitionTask* added_task = nullptr; 3196 const uint64_t target_time = NanoTime() + delta_time; 3197 { 3198 MutexLock mu(self, *pending_task_lock_); 3199 // If we have an existing collector transition, update the targe time to be the new target. 3200 if (pending_collector_transition_ != nullptr) { 3201 task_processor_->UpdateTargetRunTime(self, pending_collector_transition_, target_time); 3202 return; 3203 } 3204 added_task = new CollectorTransitionTask(target_time); 3205 pending_collector_transition_ = added_task; 3206 } 3207 task_processor_->AddTask(self, added_task); 3208} 3209 3210class Heap::HeapTrimTask : public HeapTask { 3211 public: 3212 explicit HeapTrimTask(uint64_t delta_time) : HeapTask(NanoTime() + delta_time) { } 3213 virtual void Run(Thread* self) OVERRIDE { 3214 gc::Heap* heap = Runtime::Current()->GetHeap(); 3215 heap->Trim(self); 3216 heap->ClearPendingTrim(self); 3217 } 3218}; 3219 3220void Heap::ClearPendingTrim(Thread* self) { 3221 MutexLock mu(self, *pending_task_lock_); 3222 pending_heap_trim_ = nullptr; 3223} 3224 3225void Heap::RequestTrim(Thread* self) { 3226 if (!CanAddHeapTask(self)) { 3227 return; 3228 } 3229 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3230 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3231 // a space it will hold its lock and can become a cause of jank. 3232 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3233 // forking. 3234 3235 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3236 // because that only marks object heads, so a large array looks like lots of empty space. We 3237 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3238 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3239 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3240 // not how much use we're making of those pages. 3241 HeapTrimTask* added_task = nullptr; 3242 { 3243 MutexLock mu(self, *pending_task_lock_); 3244 if (pending_heap_trim_ != nullptr) { 3245 // Already have a heap trim request in task processor, ignore this request. 3246 return; 3247 } 3248 added_task = new HeapTrimTask(kHeapTrimWait); 3249 pending_heap_trim_ = added_task; 3250 } 3251 task_processor_->AddTask(self, added_task); 3252} 3253 3254void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3255 if (rosalloc_space_ != nullptr) { 3256 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3257 } 3258 if (bump_pointer_space_ != nullptr) { 3259 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 3260 } 3261 if (region_space_ != nullptr) { 3262 region_space_->RevokeThreadLocalBuffers(thread); 3263 } 3264} 3265 3266void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3267 if (rosalloc_space_ != nullptr) { 3268 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3269 } 3270} 3271 3272void Heap::RevokeAllThreadLocalBuffers() { 3273 if (rosalloc_space_ != nullptr) { 3274 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3275 } 3276 if (bump_pointer_space_ != nullptr) { 3277 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3278 } 3279 if (region_space_ != nullptr) { 3280 region_space_->RevokeAllThreadLocalBuffers(); 3281 } 3282} 3283 3284bool Heap::IsGCRequestPending() const { 3285 return concurrent_gc_pending_.LoadRelaxed(); 3286} 3287 3288void Heap::RunFinalization(JNIEnv* env) { 3289 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3290 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3291 CHECK(WellKnownClasses::java_lang_System != nullptr); 3292 WellKnownClasses::java_lang_System_runFinalization = 3293 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3294 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3295 } 3296 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3297 WellKnownClasses::java_lang_System_runFinalization); 3298} 3299 3300void Heap::RegisterNativeAllocation(JNIEnv* env, size_t bytes) { 3301 Thread* self = ThreadForEnv(env); 3302 if (native_need_to_run_finalization_) { 3303 RunFinalization(env); 3304 UpdateMaxNativeFootprint(); 3305 native_need_to_run_finalization_ = false; 3306 } 3307 // Total number of native bytes allocated. 3308 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3309 new_native_bytes_allocated += bytes; 3310 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3311 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3312 collector::kGcTypeFull; 3313 3314 // The second watermark is higher than the gc watermark. If you hit this it means you are 3315 // allocating native objects faster than the GC can keep up with. 3316 if (new_native_bytes_allocated > growth_limit_) { 3317 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3318 // Just finished a GC, attempt to run finalizers. 3319 RunFinalization(env); 3320 CHECK(!env->ExceptionCheck()); 3321 } 3322 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3323 if (new_native_bytes_allocated > growth_limit_) { 3324 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3325 RunFinalization(env); 3326 native_need_to_run_finalization_ = false; 3327 CHECK(!env->ExceptionCheck()); 3328 } 3329 // We have just run finalizers, update the native watermark since it is very likely that 3330 // finalizers released native managed allocations. 3331 UpdateMaxNativeFootprint(); 3332 } else if (!IsGCRequestPending()) { 3333 if (IsGcConcurrent()) { 3334 RequestConcurrentGC(self); 3335 } else { 3336 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3337 } 3338 } 3339 } 3340} 3341 3342void Heap::RegisterNativeFree(JNIEnv* env, size_t bytes) { 3343 size_t expected_size; 3344 do { 3345 expected_size = native_bytes_allocated_.LoadRelaxed(); 3346 if (UNLIKELY(bytes > expected_size)) { 3347 ScopedObjectAccess soa(env); 3348 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3349 StringPrintf("Attempted to free %zd native bytes with only %zd native bytes " 3350 "registered as allocated", bytes, expected_size).c_str()); 3351 break; 3352 } 3353 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, 3354 expected_size - bytes)); 3355} 3356 3357size_t Heap::GetTotalMemory() const { 3358 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3359} 3360 3361void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3362 DCHECK(mod_union_table != nullptr); 3363 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3364} 3365 3366void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3367 CHECK(c == nullptr || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3368 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3369 CHECK_GE(byte_count, sizeof(mirror::Object)); 3370} 3371 3372void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3373 CHECK(remembered_set != nullptr); 3374 space::Space* space = remembered_set->GetSpace(); 3375 CHECK(space != nullptr); 3376 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3377 remembered_sets_.Put(space, remembered_set); 3378 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3379} 3380 3381void Heap::RemoveRememberedSet(space::Space* space) { 3382 CHECK(space != nullptr); 3383 auto it = remembered_sets_.find(space); 3384 CHECK(it != remembered_sets_.end()); 3385 delete it->second; 3386 remembered_sets_.erase(it); 3387 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3388} 3389 3390void Heap::ClearMarkedObjects() { 3391 // Clear all of the spaces' mark bitmaps. 3392 for (const auto& space : GetContinuousSpaces()) { 3393 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3394 if (space->GetLiveBitmap() != mark_bitmap) { 3395 mark_bitmap->Clear(); 3396 } 3397 } 3398 // Clear the marked objects in the discontinous space object sets. 3399 for (const auto& space : GetDiscontinuousSpaces()) { 3400 space->GetMarkBitmap()->Clear(); 3401 } 3402} 3403 3404} // namespace gc 3405} // namespace art 3406