heap.cc revision 70a596d61f8cf5b6447326c46c3386e0fbd5bfb5
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/rosalloc_space-inl.h" 53#include "gc/space/space-inl.h" 54#include "gc/space/zygote_space.h" 55#include "entrypoints/quick/quick_alloc_entrypoints.h" 56#include "heap-inl.h" 57#include "image.h" 58#include "intern_table.h" 59#include "mirror/art_field-inl.h" 60#include "mirror/class-inl.h" 61#include "mirror/object.h" 62#include "mirror/object-inl.h" 63#include "mirror/object_array-inl.h" 64#include "mirror/reference-inl.h" 65#include "os.h" 66#include "reflection.h" 67#include "runtime.h" 68#include "ScopedLocalRef.h" 69#include "scoped_thread_state_change.h" 70#include "handle_scope-inl.h" 71#include "thread_list.h" 72#include "well_known_classes.h" 73 74namespace art { 75 76namespace gc { 77 78static constexpr size_t kCollectorTransitionStressIterations = 0; 79static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 80// Minimum amount of remaining bytes before a concurrent GC is triggered. 81static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 82static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 83// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 84// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 85// threads (lower pauses, use less memory bandwidth). 86static constexpr double kStickyGcThroughputAdjustment = 1.0; 87// Whether or not we compact the zygote in PreZygoteFork. 88static constexpr bool kCompactZygote = kMovingCollector; 89// How many reserve entries are at the end of the allocation stack, these are only needed if the 90// allocation stack overflows. 91static constexpr size_t kAllocationStackReserveSize = 1024; 92// Default mark stack size in bytes. 93static const size_t kDefaultMarkStackSize = 64 * KB; 94// Define space name. 95static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 96static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 97static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 98static const char* kNonMovingSpaceName = "non moving space"; 99static const char* kZygoteSpaceName = "zygote space"; 100static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 101static constexpr bool kGCALotMode = false; 102// GC alot mode uses a small allocation stack to stress test a lot of GC. 103static constexpr size_t kGcAlotAllocationStackSize = 4 * KB / 104 sizeof(mirror::HeapReference<mirror::Object>); 105// Verify objet has a small allocation stack size since searching the allocation stack is slow. 106static constexpr size_t kVerifyObjectAllocationStackSize = 16 * KB / 107 sizeof(mirror::HeapReference<mirror::Object>); 108static constexpr size_t kDefaultAllocationStackSize = 8 * MB / 109 sizeof(mirror::HeapReference<mirror::Object>); 110 111Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 112 double target_utilization, double foreground_heap_growth_multiplier, 113 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 114 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 115 CollectorType background_collector_type, 116 space::LargeObjectSpaceType large_object_space_type, size_t large_object_threshold, 117 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 118 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 119 bool ignore_max_footprint, bool use_tlab, 120 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 121 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 122 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 123 uint64_t min_interval_homogeneous_space_compaction_by_oom) 124 : non_moving_space_(nullptr), 125 rosalloc_space_(nullptr), 126 dlmalloc_space_(nullptr), 127 main_space_(nullptr), 128 collector_type_(kCollectorTypeNone), 129 foreground_collector_type_(foreground_collector_type), 130 background_collector_type_(background_collector_type), 131 desired_collector_type_(foreground_collector_type_), 132 heap_trim_request_lock_(nullptr), 133 last_trim_time_(0), 134 heap_transition_or_trim_target_time_(0), 135 heap_trim_request_pending_(false), 136 parallel_gc_threads_(parallel_gc_threads), 137 conc_gc_threads_(conc_gc_threads), 138 low_memory_mode_(low_memory_mode), 139 long_pause_log_threshold_(long_pause_log_threshold), 140 long_gc_log_threshold_(long_gc_log_threshold), 141 ignore_max_footprint_(ignore_max_footprint), 142 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 143 zygote_space_(nullptr), 144 large_object_threshold_(large_object_threshold), 145 gc_request_pending_(false), 146 collector_type_running_(kCollectorTypeNone), 147 last_gc_type_(collector::kGcTypeNone), 148 next_gc_type_(collector::kGcTypePartial), 149 capacity_(capacity), 150 growth_limit_(growth_limit), 151 max_allowed_footprint_(initial_size), 152 native_footprint_gc_watermark_(initial_size), 153 native_need_to_run_finalization_(false), 154 // Initially assume we perceive jank in case the process state is never updated. 155 process_state_(kProcessStateJankPerceptible), 156 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 157 total_bytes_freed_ever_(0), 158 total_objects_freed_ever_(0), 159 num_bytes_allocated_(0), 160 native_bytes_allocated_(0), 161 verify_missing_card_marks_(false), 162 verify_system_weaks_(false), 163 verify_pre_gc_heap_(verify_pre_gc_heap), 164 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 165 verify_post_gc_heap_(verify_post_gc_heap), 166 verify_mod_union_table_(false), 167 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 168 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 169 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 170 last_gc_time_ns_(NanoTime()), 171 allocation_rate_(0), 172 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 173 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 174 * verification is enabled, we limit the size of allocation stacks to speed up their 175 * searching. 176 */ 177 max_allocation_stack_size_(kGCALotMode ? kGcAlotAllocationStackSize 178 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? kVerifyObjectAllocationStackSize : 179 kDefaultAllocationStackSize), 180 current_allocator_(kAllocatorTypeDlMalloc), 181 current_non_moving_allocator_(kAllocatorTypeNonMoving), 182 bump_pointer_space_(nullptr), 183 temp_space_(nullptr), 184 min_free_(min_free), 185 max_free_(max_free), 186 target_utilization_(target_utilization), 187 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 188 total_wait_time_(0), 189 total_allocation_time_(0), 190 verify_object_mode_(kVerifyObjectModeDisabled), 191 disable_moving_gc_count_(0), 192 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 193 use_tlab_(use_tlab), 194 main_space_backup_(nullptr), 195 min_interval_homogeneous_space_compaction_by_oom_( 196 min_interval_homogeneous_space_compaction_by_oom), 197 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 198 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 199 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 200 LOG(INFO) << "Heap() entering"; 201 } 202 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 203 // entrypoints. 204 const bool is_zygote = Runtime::Current()->IsZygote(); 205 if (!is_zygote) { 206 // Background compaction is currently not supported for command line runs. 207 if (background_collector_type_ != foreground_collector_type_) { 208 VLOG(heap) << "Disabling background compaction for non zygote"; 209 background_collector_type_ = foreground_collector_type_; 210 } 211 } 212 ChangeCollector(desired_collector_type_); 213 live_bitmap_.reset(new accounting::HeapBitmap(this)); 214 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 215 // Requested begin for the alloc space, to follow the mapped image and oat files 216 uint8_t* requested_alloc_space_begin = nullptr; 217 if (!image_file_name.empty()) { 218 std::string error_msg; 219 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 220 image_instruction_set, 221 &error_msg); 222 if (image_space != nullptr) { 223 AddSpace(image_space); 224 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 225 // isn't going to get in the middle 226 uint8_t* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 227 CHECK_GT(oat_file_end_addr, image_space->End()); 228 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 229 } else { 230 LOG(WARNING) << "Could not create image space with image file '" << image_file_name << "'. " 231 << "Attempting to fall back to imageless running. Error was: " << error_msg; 232 } 233 } 234 /* 235 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 236 +- nonmoving space (non_moving_space_capacity)+- 237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 238 +-????????????????????????????????????????????+- 239 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 240 +-main alloc space / bump space 1 (capacity_) +- 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 242 +-????????????????????????????????????????????+- 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 244 +-main alloc space2 / bump space 2 (capacity_)+- 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 246 */ 247 // We don't have hspace compaction enabled with GSS. 248 if (foreground_collector_type_ == kCollectorTypeGSS) { 249 use_homogeneous_space_compaction_for_oom_ = false; 250 } 251 bool support_homogeneous_space_compaction = 252 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 253 use_homogeneous_space_compaction_for_oom_; 254 // We may use the same space the main space for the non moving space if we don't need to compact 255 // from the main space. 256 // This is not the case if we support homogeneous compaction or have a moving background 257 // collector type. 258 bool separate_non_moving_space = is_zygote || 259 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 260 IsMovingGc(background_collector_type_); 261 if (foreground_collector_type == kCollectorTypeGSS) { 262 separate_non_moving_space = false; 263 } 264 std::unique_ptr<MemMap> main_mem_map_1; 265 std::unique_ptr<MemMap> main_mem_map_2; 266 uint8_t* request_begin = requested_alloc_space_begin; 267 if (request_begin != nullptr && separate_non_moving_space) { 268 request_begin += non_moving_space_capacity; 269 } 270 std::string error_str; 271 std::unique_ptr<MemMap> non_moving_space_mem_map; 272 if (separate_non_moving_space) { 273 // If we are the zygote, the non moving space becomes the zygote space when we run 274 // PreZygoteFork the first time. In this case, call the map "zygote space" since we can't 275 // rename the mem map later. 276 const char* space_name = is_zygote ? kZygoteSpaceName: kNonMovingSpaceName; 277 // Reserve the non moving mem map before the other two since it needs to be at a specific 278 // address. 279 non_moving_space_mem_map.reset( 280 MemMap::MapAnonymous(space_name, requested_alloc_space_begin, 281 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str)); 282 CHECK(non_moving_space_mem_map != nullptr) << error_str; 283 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 284 request_begin = reinterpret_cast<uint8_t*>(300 * MB); 285 } 286 // Attempt to create 2 mem maps at or after the requested begin. 287 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 288 &error_str)); 289 CHECK(main_mem_map_1.get() != nullptr) << error_str; 290 if (support_homogeneous_space_compaction || 291 background_collector_type_ == kCollectorTypeSS || 292 foreground_collector_type_ == kCollectorTypeSS) { 293 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 294 capacity_, &error_str)); 295 CHECK(main_mem_map_2.get() != nullptr) << error_str; 296 } 297 // Create the non moving space first so that bitmaps don't take up the address range. 298 if (separate_non_moving_space) { 299 // Non moving space is always dlmalloc since we currently don't have support for multiple 300 // active rosalloc spaces. 301 const size_t size = non_moving_space_mem_map->Size(); 302 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 303 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 304 initial_size, size, size, false); 305 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 306 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 307 << requested_alloc_space_begin; 308 AddSpace(non_moving_space_); 309 } 310 // Create other spaces based on whether or not we have a moving GC. 311 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 312 // Create bump pointer spaces. 313 // We only to create the bump pointer if the foreground collector is a compacting GC. 314 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 315 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 316 main_mem_map_1.release()); 317 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 318 AddSpace(bump_pointer_space_); 319 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 320 main_mem_map_2.release()); 321 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 322 AddSpace(temp_space_); 323 CHECK(separate_non_moving_space); 324 } else { 325 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 326 CHECK(main_space_ != nullptr); 327 AddSpace(main_space_); 328 if (!separate_non_moving_space) { 329 non_moving_space_ = main_space_; 330 CHECK(!non_moving_space_->CanMoveObjects()); 331 } 332 if (foreground_collector_type_ == kCollectorTypeGSS) { 333 CHECK_EQ(foreground_collector_type_, background_collector_type_); 334 // Create bump pointer spaces instead of a backup space. 335 main_mem_map_2.release(); 336 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 337 kGSSBumpPointerSpaceCapacity, nullptr); 338 CHECK(bump_pointer_space_ != nullptr); 339 AddSpace(bump_pointer_space_); 340 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 341 kGSSBumpPointerSpaceCapacity, nullptr); 342 CHECK(temp_space_ != nullptr); 343 AddSpace(temp_space_); 344 } else if (main_mem_map_2.get() != nullptr) { 345 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 346 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 347 growth_limit_, capacity_, name, true)); 348 CHECK(main_space_backup_.get() != nullptr); 349 // Add the space so its accounted for in the heap_begin and heap_end. 350 AddSpace(main_space_backup_.get()); 351 } 352 } 353 CHECK(non_moving_space_ != nullptr); 354 CHECK(!non_moving_space_->CanMoveObjects()); 355 // Allocate the large object space. 356 if (large_object_space_type == space::kLargeObjectSpaceTypeFreeList) { 357 large_object_space_ = space::FreeListSpace::Create("free list large object space", nullptr, 358 capacity_); 359 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 360 } else if (large_object_space_type == space::kLargeObjectSpaceTypeMap) { 361 large_object_space_ = space::LargeObjectMapSpace::Create("mem map large object space"); 362 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 363 } else { 364 // Disable the large object space by making the cutoff excessively large. 365 large_object_threshold_ = std::numeric_limits<size_t>::max(); 366 large_object_space_ = nullptr; 367 } 368 if (large_object_space_ != nullptr) { 369 AddSpace(large_object_space_); 370 } 371 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 372 CHECK(!continuous_spaces_.empty()); 373 // Relies on the spaces being sorted. 374 uint8_t* heap_begin = continuous_spaces_.front()->Begin(); 375 uint8_t* heap_end = continuous_spaces_.back()->Limit(); 376 size_t heap_capacity = heap_end - heap_begin; 377 // Remove the main backup space since it slows down the GC to have unused extra spaces. 378 // TODO: Avoid needing to do this. 379 if (main_space_backup_.get() != nullptr) { 380 RemoveSpace(main_space_backup_.get()); 381 } 382 // Allocate the card table. 383 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 384 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 385 // Card cache for now since it makes it easier for us to update the references to the copying 386 // spaces. 387 accounting::ModUnionTable* mod_union_table = 388 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 389 GetImageSpace()); 390 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 391 AddModUnionTable(mod_union_table); 392 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 393 accounting::RememberedSet* non_moving_space_rem_set = 394 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 395 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 396 AddRememberedSet(non_moving_space_rem_set); 397 } 398 // TODO: Count objects in the image space here? 399 num_bytes_allocated_.StoreRelaxed(0); 400 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 401 kDefaultMarkStackSize)); 402 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 403 allocation_stack_.reset(accounting::ObjectStack::Create( 404 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 405 live_stack_.reset(accounting::ObjectStack::Create( 406 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 407 // It's still too early to take a lock because there are no threads yet, but we can create locks 408 // now. We don't create it earlier to make it clear that you can't use locks during heap 409 // initialization. 410 gc_complete_lock_ = new Mutex("GC complete lock"); 411 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 412 *gc_complete_lock_)); 413 gc_request_lock_ = new Mutex("GC request lock"); 414 gc_request_cond_.reset(new ConditionVariable("GC request condition variable", *gc_request_lock_)); 415 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 416 last_gc_size_ = GetBytesAllocated(); 417 if (ignore_max_footprint_) { 418 SetIdealFootprint(std::numeric_limits<size_t>::max()); 419 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 420 } 421 CHECK_NE(max_allowed_footprint_, 0U); 422 // Create our garbage collectors. 423 for (size_t i = 0; i < 2; ++i) { 424 const bool concurrent = i != 0; 425 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 426 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 427 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 428 } 429 if (kMovingCollector) { 430 // TODO: Clean this up. 431 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 432 semi_space_collector_ = new collector::SemiSpace(this, generational, 433 generational ? "generational" : ""); 434 garbage_collectors_.push_back(semi_space_collector_); 435 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 436 garbage_collectors_.push_back(concurrent_copying_collector_); 437 mark_compact_collector_ = new collector::MarkCompact(this); 438 garbage_collectors_.push_back(mark_compact_collector_); 439 } 440 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 441 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 442 // Check that there's no gap between the image space and the non moving space so that the 443 // immune region won't break (eg. due to a large object allocated in the gap). This is only 444 // required when we're the zygote or using GSS. 445 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 446 non_moving_space_->GetMemMap()); 447 if (!no_gap) { 448 MemMap::DumpMaps(LOG(ERROR)); 449 LOG(FATAL) << "There's a gap between the image space and the main space"; 450 } 451 } 452 if (running_on_valgrind_) { 453 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 454 } 455 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 456 LOG(INFO) << "Heap() exiting"; 457 } 458} 459 460MemMap* Heap::MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 461 size_t capacity, std::string* out_error_str) { 462 while (true) { 463 MemMap* map = MemMap::MapAnonymous(name, request_begin, capacity, 464 PROT_READ | PROT_WRITE, true, out_error_str); 465 if (map != nullptr || request_begin == nullptr) { 466 return map; 467 } 468 // Retry a second time with no specified request begin. 469 request_begin = nullptr; 470 } 471 return nullptr; 472} 473 474space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 475 size_t growth_limit, size_t capacity, 476 const char* name, bool can_move_objects) { 477 space::MallocSpace* malloc_space = nullptr; 478 if (kUseRosAlloc) { 479 // Create rosalloc space. 480 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 481 initial_size, growth_limit, capacity, 482 low_memory_mode_, can_move_objects); 483 } else { 484 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 485 initial_size, growth_limit, capacity, 486 can_move_objects); 487 } 488 if (collector::SemiSpace::kUseRememberedSet) { 489 accounting::RememberedSet* rem_set = 490 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 491 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 492 AddRememberedSet(rem_set); 493 } 494 CHECK(malloc_space != nullptr) << "Failed to create " << name; 495 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 496 return malloc_space; 497} 498 499void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 500 size_t capacity) { 501 // Is background compaction is enabled? 502 bool can_move_objects = IsMovingGc(background_collector_type_) != 503 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 504 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 505 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 506 // from the main space to the zygote space. If background compaction is enabled, always pass in 507 // that we can move objets. 508 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 509 // After the zygote we want this to be false if we don't have background compaction enabled so 510 // that getting primitive array elements is faster. 511 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 512 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 513 } 514 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 515 RemoveRememberedSet(main_space_); 516 } 517 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 518 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 519 can_move_objects); 520 SetSpaceAsDefault(main_space_); 521 VLOG(heap) << "Created main space " << main_space_; 522} 523 524void Heap::ChangeAllocator(AllocatorType allocator) { 525 if (current_allocator_ != allocator) { 526 // These two allocators are only used internally and don't have any entrypoints. 527 CHECK_NE(allocator, kAllocatorTypeLOS); 528 CHECK_NE(allocator, kAllocatorTypeNonMoving); 529 current_allocator_ = allocator; 530 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 531 SetQuickAllocEntryPointsAllocator(current_allocator_); 532 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 533 } 534} 535 536void Heap::DisableMovingGc() { 537 if (IsMovingGc(foreground_collector_type_)) { 538 foreground_collector_type_ = kCollectorTypeCMS; 539 } 540 if (IsMovingGc(background_collector_type_)) { 541 background_collector_type_ = foreground_collector_type_; 542 } 543 TransitionCollector(foreground_collector_type_); 544 ThreadList* tl = Runtime::Current()->GetThreadList(); 545 Thread* self = Thread::Current(); 546 ScopedThreadStateChange tsc(self, kSuspended); 547 tl->SuspendAll(); 548 // Something may have caused the transition to fail. 549 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 550 CHECK(main_space_ != nullptr); 551 // The allocation stack may have non movable objects in it. We need to flush it since the GC 552 // can't only handle marking allocation stack objects of one non moving space and one main 553 // space. 554 { 555 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 556 FlushAllocStack(); 557 } 558 main_space_->DisableMovingObjects(); 559 non_moving_space_ = main_space_; 560 CHECK(!non_moving_space_->CanMoveObjects()); 561 } 562 tl->ResumeAll(); 563} 564 565std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 566 if (!IsValidContinuousSpaceObjectAddress(klass)) { 567 return StringPrintf("<non heap address klass %p>", klass); 568 } 569 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 570 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 571 std::string result("["); 572 result += SafeGetClassDescriptor(component_type); 573 return result; 574 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 575 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 576 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 577 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 578 } else { 579 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 580 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 581 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 582 } 583 const DexFile* dex_file = dex_cache->GetDexFile(); 584 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 585 if (class_def_idx == DexFile::kDexNoIndex16) { 586 return "<class def not found>"; 587 } 588 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 589 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 590 return dex_file->GetTypeDescriptor(type_id); 591 } 592} 593 594std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 595 if (obj == nullptr) { 596 return "null"; 597 } 598 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 599 if (klass == nullptr) { 600 return "(class=null)"; 601 } 602 std::string result(SafeGetClassDescriptor(klass)); 603 if (obj->IsClass()) { 604 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 605 } 606 return result; 607} 608 609void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 610 if (obj == nullptr) { 611 stream << "(obj=null)"; 612 return; 613 } 614 if (IsAligned<kObjectAlignment>(obj)) { 615 space::Space* space = nullptr; 616 // Don't use find space since it only finds spaces which actually contain objects instead of 617 // spaces which may contain objects (e.g. cleared bump pointer spaces). 618 for (const auto& cur_space : continuous_spaces_) { 619 if (cur_space->HasAddress(obj)) { 620 space = cur_space; 621 break; 622 } 623 } 624 // Unprotect all the spaces. 625 for (const auto& con_space : continuous_spaces_) { 626 mprotect(con_space->Begin(), con_space->Capacity(), PROT_READ | PROT_WRITE); 627 } 628 stream << "Object " << obj; 629 if (space != nullptr) { 630 stream << " in space " << *space; 631 } 632 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 633 stream << "\nclass=" << klass; 634 if (klass != nullptr) { 635 stream << " type= " << SafePrettyTypeOf(obj); 636 } 637 // Re-protect the address we faulted on. 638 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 639 } 640} 641 642bool Heap::IsCompilingBoot() const { 643 if (!Runtime::Current()->IsCompiler()) { 644 return false; 645 } 646 for (const auto& space : continuous_spaces_) { 647 if (space->IsImageSpace() || space->IsZygoteSpace()) { 648 return false; 649 } 650 } 651 return true; 652} 653 654bool Heap::HasImageSpace() const { 655 for (const auto& space : continuous_spaces_) { 656 if (space->IsImageSpace()) { 657 return true; 658 } 659 } 660 return false; 661} 662 663void Heap::IncrementDisableMovingGC(Thread* self) { 664 // Need to do this holding the lock to prevent races where the GC is about to run / running when 665 // we attempt to disable it. 666 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 667 MutexLock mu(self, *gc_complete_lock_); 668 ++disable_moving_gc_count_; 669 if (IsMovingGc(collector_type_running_)) { 670 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 671 } 672} 673 674void Heap::DecrementDisableMovingGC(Thread* self) { 675 MutexLock mu(self, *gc_complete_lock_); 676 CHECK_GE(disable_moving_gc_count_, 0U); 677 --disable_moving_gc_count_; 678} 679 680void Heap::UpdateProcessState(ProcessState process_state) { 681 if (process_state_ != process_state) { 682 process_state_ = process_state; 683 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 684 // Start at index 1 to avoid "is always false" warning. 685 // Have iteration 1 always transition the collector. 686 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 687 ? foreground_collector_type_ : background_collector_type_); 688 usleep(kCollectorTransitionStressWait); 689 } 690 if (process_state_ == kProcessStateJankPerceptible) { 691 // Transition back to foreground right away to prevent jank. 692 RequestCollectorTransition(foreground_collector_type_, 0); 693 } else { 694 // Don't delay for debug builds since we may want to stress test the GC. 695 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 696 // special handling which does a homogenous space compaction once but then doesn't transition 697 // the collector. 698 RequestCollectorTransition(background_collector_type_, 699 kIsDebugBuild ? 0 : kCollectorTransitionWait); 700 } 701 } 702} 703 704void Heap::CreateThreadPool() { 705 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 706 if (num_threads != 0) { 707 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 708 } 709} 710 711void Heap::VisitObjects(ObjectCallback callback, void* arg) { 712 // GCs can move objects, so don't allow this. 713 ScopedAssertNoThreadSuspension ants(Thread::Current(), "Visiting objects"); 714 if (bump_pointer_space_ != nullptr) { 715 // Visit objects in bump pointer space. 716 bump_pointer_space_->Walk(callback, arg); 717 } 718 // TODO: Switch to standard begin and end to use ranged a based loop. 719 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 720 it < end; ++it) { 721 mirror::Object* obj = *it; 722 if (obj != nullptr && obj->GetClass() != nullptr) { 723 // Avoid the race condition caused by the object not yet being written into the allocation 724 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 725 // there can be nulls on the allocation stack. 726 callback(obj, arg); 727 } 728 } 729 GetLiveBitmap()->Walk(callback, arg); 730} 731 732void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 733 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 734 space::ContinuousSpace* space2 = non_moving_space_; 735 // TODO: Generalize this to n bitmaps? 736 CHECK(space1 != nullptr); 737 CHECK(space2 != nullptr); 738 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 739 (large_object_space_ != nullptr ? large_object_space_->GetLiveBitmap() : nullptr), 740 stack); 741} 742 743void Heap::DeleteThreadPool() { 744 thread_pool_.reset(nullptr); 745} 746 747void Heap::AddSpace(space::Space* space) { 748 CHECK(space != nullptr); 749 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 750 if (space->IsContinuousSpace()) { 751 DCHECK(!space->IsDiscontinuousSpace()); 752 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 753 // Continuous spaces don't necessarily have bitmaps. 754 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 755 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 756 if (live_bitmap != nullptr) { 757 CHECK(mark_bitmap != nullptr); 758 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 759 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 760 } 761 continuous_spaces_.push_back(continuous_space); 762 // Ensure that spaces remain sorted in increasing order of start address. 763 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 764 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 765 return a->Begin() < b->Begin(); 766 }); 767 } else { 768 CHECK(space->IsDiscontinuousSpace()); 769 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 770 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 771 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 772 discontinuous_spaces_.push_back(discontinuous_space); 773 } 774 if (space->IsAllocSpace()) { 775 alloc_spaces_.push_back(space->AsAllocSpace()); 776 } 777} 778 779void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 780 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 781 if (continuous_space->IsDlMallocSpace()) { 782 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 783 } else if (continuous_space->IsRosAllocSpace()) { 784 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 785 } 786} 787 788void Heap::RemoveSpace(space::Space* space) { 789 DCHECK(space != nullptr); 790 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 791 if (space->IsContinuousSpace()) { 792 DCHECK(!space->IsDiscontinuousSpace()); 793 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 794 // Continuous spaces don't necessarily have bitmaps. 795 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 796 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 797 if (live_bitmap != nullptr) { 798 DCHECK(mark_bitmap != nullptr); 799 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 800 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 801 } 802 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 803 DCHECK(it != continuous_spaces_.end()); 804 continuous_spaces_.erase(it); 805 } else { 806 DCHECK(space->IsDiscontinuousSpace()); 807 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 808 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 809 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 810 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 811 discontinuous_space); 812 DCHECK(it != discontinuous_spaces_.end()); 813 discontinuous_spaces_.erase(it); 814 } 815 if (space->IsAllocSpace()) { 816 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 817 DCHECK(it != alloc_spaces_.end()); 818 alloc_spaces_.erase(it); 819 } 820} 821 822void Heap::DumpGcPerformanceInfo(std::ostream& os) { 823 // Dump cumulative timings. 824 os << "Dumping cumulative Gc timings\n"; 825 uint64_t total_duration = 0; 826 // Dump cumulative loggers for each GC type. 827 uint64_t total_paused_time = 0; 828 for (auto& collector : garbage_collectors_) { 829 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 830 total_paused_time += collector->GetTotalPausedTimeNs(); 831 collector->DumpPerformanceInfo(os); 832 collector->ResetMeasurements(); 833 } 834 uint64_t allocation_time = 835 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 836 if (total_duration != 0) { 837 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 838 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 839 os << "Mean GC size throughput: " 840 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 841 os << "Mean GC object throughput: " 842 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 843 } 844 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 845 os << "Total number of allocations " << total_objects_allocated << "\n"; 846 uint64_t total_bytes_allocated = GetBytesAllocatedEver(); 847 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 848 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 849 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 850 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 851 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 852 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 853 if (kMeasureAllocationTime) { 854 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 855 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 856 << "\n"; 857 } 858 if (HasZygoteSpace()) { 859 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 860 } 861 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 862 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_); 863 BaseMutex::DumpAll(os); 864} 865 866Heap::~Heap() { 867 VLOG(heap) << "Starting ~Heap()"; 868 STLDeleteElements(&garbage_collectors_); 869 // If we don't reset then the mark stack complains in its destructor. 870 allocation_stack_->Reset(); 871 live_stack_->Reset(); 872 STLDeleteValues(&mod_union_tables_); 873 STLDeleteValues(&remembered_sets_); 874 STLDeleteElements(&continuous_spaces_); 875 STLDeleteElements(&discontinuous_spaces_); 876 delete gc_complete_lock_; 877 delete gc_request_lock_; 878 delete heap_trim_request_lock_; 879 VLOG(heap) << "Finished ~Heap()"; 880} 881 882space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 883 bool fail_ok) const { 884 for (const auto& space : continuous_spaces_) { 885 if (space->Contains(obj)) { 886 return space; 887 } 888 } 889 if (!fail_ok) { 890 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 891 } 892 return NULL; 893} 894 895space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 896 bool fail_ok) const { 897 for (const auto& space : discontinuous_spaces_) { 898 if (space->Contains(obj)) { 899 return space; 900 } 901 } 902 if (!fail_ok) { 903 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 904 } 905 return NULL; 906} 907 908space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 909 space::Space* result = FindContinuousSpaceFromObject(obj, true); 910 if (result != NULL) { 911 return result; 912 } 913 return FindDiscontinuousSpaceFromObject(obj, fail_ok); 914} 915 916space::ImageSpace* Heap::GetImageSpace() const { 917 for (const auto& space : continuous_spaces_) { 918 if (space->IsImageSpace()) { 919 return space->AsImageSpace(); 920 } 921 } 922 return NULL; 923} 924 925void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 926 std::ostringstream oss; 927 size_t total_bytes_free = GetFreeMemory(); 928 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 929 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 930 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 931 if (total_bytes_free >= byte_count) { 932 space::AllocSpace* space = nullptr; 933 if (allocator_type == kAllocatorTypeNonMoving) { 934 space = non_moving_space_; 935 } else if (allocator_type == kAllocatorTypeRosAlloc || 936 allocator_type == kAllocatorTypeDlMalloc) { 937 space = main_space_; 938 } else if (allocator_type == kAllocatorTypeBumpPointer || 939 allocator_type == kAllocatorTypeTLAB) { 940 space = bump_pointer_space_; 941 } 942 if (space != nullptr) { 943 space->LogFragmentationAllocFailure(oss, byte_count); 944 } 945 } 946 self->ThrowOutOfMemoryError(oss.str().c_str()); 947} 948 949void Heap::DoPendingTransitionOrTrim() { 950 Thread* self = Thread::Current(); 951 CollectorType desired_collector_type; 952 // Wait until we reach the desired transition time. 953 while (true) { 954 uint64_t wait_time; 955 { 956 MutexLock mu(self, *heap_trim_request_lock_); 957 desired_collector_type = desired_collector_type_; 958 uint64_t current_time = NanoTime(); 959 if (current_time >= heap_transition_or_trim_target_time_) { 960 break; 961 } 962 wait_time = heap_transition_or_trim_target_time_ - current_time; 963 } 964 ScopedThreadStateChange tsc(self, kSleeping); 965 usleep(wait_time / 1000); // Usleep takes microseconds. 966 } 967 // Launch homogeneous space compaction if it is desired. 968 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 969 if (!CareAboutPauseTimes()) { 970 PerformHomogeneousSpaceCompact(); 971 } 972 // No need to Trim(). Homogeneous space compaction may free more virtual and physical memory. 973 desired_collector_type = collector_type_; 974 return; 975 } 976 // Transition the collector if the desired collector type is not the same as the current 977 // collector type. 978 TransitionCollector(desired_collector_type); 979 if (!CareAboutPauseTimes()) { 980 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 981 // about pauses. 982 Runtime* runtime = Runtime::Current(); 983 runtime->GetThreadList()->SuspendAll(); 984 uint64_t start_time = NanoTime(); 985 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 986 VLOG(heap) << "Deflating " << count << " monitors took " 987 << PrettyDuration(NanoTime() - start_time); 988 runtime->GetThreadList()->ResumeAll(); 989 } 990 // Do a heap trim if it is needed. 991 Trim(); 992} 993 994class TrimIndirectReferenceTableClosure : public Closure { 995 public: 996 explicit TrimIndirectReferenceTableClosure(Barrier* barrier) : barrier_(barrier) { 997 } 998 virtual void Run(Thread* thread) OVERRIDE NO_THREAD_SAFETY_ANALYSIS { 999 ATRACE_BEGIN("Trimming reference table"); 1000 thread->GetJniEnv()->locals.Trim(); 1001 ATRACE_END(); 1002 barrier_->Pass(Thread::Current()); 1003 } 1004 1005 private: 1006 Barrier* const barrier_; 1007}; 1008 1009 1010void Heap::Trim() { 1011 Thread* self = Thread::Current(); 1012 { 1013 MutexLock mu(self, *heap_trim_request_lock_); 1014 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 1015 return; 1016 } 1017 last_trim_time_ = NanoTime(); 1018 heap_trim_request_pending_ = false; 1019 } 1020 { 1021 // Need to do this before acquiring the locks since we don't want to get suspended while 1022 // holding any locks. 1023 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1024 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 1025 // trimming. 1026 MutexLock mu(self, *gc_complete_lock_); 1027 // Ensure there is only one GC at a time. 1028 WaitForGcToCompleteLocked(kGcCauseTrim, self); 1029 collector_type_running_ = kCollectorTypeHeapTrim; 1030 } 1031 // Trim reference tables. 1032 { 1033 ScopedObjectAccess soa(self); 1034 JavaVMExt* vm = soa.Vm(); 1035 // Trim globals indirect reference table. 1036 vm->TrimGlobals(); 1037 // Trim locals indirect reference tables. 1038 Barrier barrier(0); 1039 TrimIndirectReferenceTableClosure closure(&barrier); 1040 ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); 1041 size_t barrier_count = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure); 1042 barrier.Increment(self, barrier_count); 1043 } 1044 uint64_t start_ns = NanoTime(); 1045 // Trim the managed spaces. 1046 uint64_t total_alloc_space_allocated = 0; 1047 uint64_t total_alloc_space_size = 0; 1048 uint64_t managed_reclaimed = 0; 1049 for (const auto& space : continuous_spaces_) { 1050 if (space->IsMallocSpace()) { 1051 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1052 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1053 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1054 // for a long period of time. 1055 managed_reclaimed += malloc_space->Trim(); 1056 } 1057 total_alloc_space_size += malloc_space->Size(); 1058 } 1059 } 1060 total_alloc_space_allocated = GetBytesAllocated(); 1061 if (large_object_space_ != nullptr) { 1062 total_alloc_space_allocated -= large_object_space_->GetBytesAllocated(); 1063 } 1064 if (bump_pointer_space_ != nullptr) { 1065 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1066 } 1067 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1068 static_cast<float>(total_alloc_space_size); 1069 uint64_t gc_heap_end_ns = NanoTime(); 1070 // We never move things in the native heap, so we can finish the GC at this point. 1071 FinishGC(self, collector::kGcTypeNone); 1072 size_t native_reclaimed = 0; 1073 1074#ifdef HAVE_ANDROID_OS 1075 // Only trim the native heap if we don't care about pauses. 1076 if (!CareAboutPauseTimes()) { 1077#if defined(USE_DLMALLOC) 1078 // Trim the native heap. 1079 dlmalloc_trim(0); 1080 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1081#elif defined(USE_JEMALLOC) 1082 // Jemalloc does it's own internal trimming. 1083#else 1084 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1085#endif 1086 } 1087#endif // HAVE_ANDROID_OS 1088 uint64_t end_ns = NanoTime(); 1089 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1090 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1091 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1092 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1093 << "%."; 1094} 1095 1096bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1097 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1098 // taking the lock. 1099 if (obj == nullptr) { 1100 return true; 1101 } 1102 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1103} 1104 1105bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1106 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1107} 1108 1109bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1110 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1111 return false; 1112 } 1113 for (const auto& space : continuous_spaces_) { 1114 if (space->HasAddress(obj)) { 1115 return true; 1116 } 1117 } 1118 return false; 1119} 1120 1121bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1122 bool search_live_stack, bool sorted) { 1123 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1124 return false; 1125 } 1126 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1127 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1128 if (obj == klass) { 1129 // This case happens for java.lang.Class. 1130 return true; 1131 } 1132 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1133 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1134 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1135 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1136 return temp_space_->Contains(obj); 1137 } 1138 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1139 space::DiscontinuousSpace* d_space = nullptr; 1140 if (c_space != nullptr) { 1141 if (c_space->GetLiveBitmap()->Test(obj)) { 1142 return true; 1143 } 1144 } else { 1145 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1146 if (d_space != nullptr) { 1147 if (d_space->GetLiveBitmap()->Test(obj)) { 1148 return true; 1149 } 1150 } 1151 } 1152 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1153 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1154 if (i > 0) { 1155 NanoSleep(MsToNs(10)); 1156 } 1157 if (search_allocation_stack) { 1158 if (sorted) { 1159 if (allocation_stack_->ContainsSorted(obj)) { 1160 return true; 1161 } 1162 } else if (allocation_stack_->Contains(obj)) { 1163 return true; 1164 } 1165 } 1166 1167 if (search_live_stack) { 1168 if (sorted) { 1169 if (live_stack_->ContainsSorted(obj)) { 1170 return true; 1171 } 1172 } else if (live_stack_->Contains(obj)) { 1173 return true; 1174 } 1175 } 1176 } 1177 // We need to check the bitmaps again since there is a race where we mark something as live and 1178 // then clear the stack containing it. 1179 if (c_space != nullptr) { 1180 if (c_space->GetLiveBitmap()->Test(obj)) { 1181 return true; 1182 } 1183 } else { 1184 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1185 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1186 return true; 1187 } 1188 } 1189 return false; 1190} 1191 1192std::string Heap::DumpSpaces() const { 1193 std::ostringstream oss; 1194 DumpSpaces(oss); 1195 return oss.str(); 1196} 1197 1198void Heap::DumpSpaces(std::ostream& stream) const { 1199 for (const auto& space : continuous_spaces_) { 1200 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1201 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1202 stream << space << " " << *space << "\n"; 1203 if (live_bitmap != nullptr) { 1204 stream << live_bitmap << " " << *live_bitmap << "\n"; 1205 } 1206 if (mark_bitmap != nullptr) { 1207 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1208 } 1209 } 1210 for (const auto& space : discontinuous_spaces_) { 1211 stream << space << " " << *space << "\n"; 1212 } 1213} 1214 1215void Heap::VerifyObjectBody(mirror::Object* obj) { 1216 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1217 return; 1218 } 1219 1220 // Ignore early dawn of the universe verifications. 1221 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1222 return; 1223 } 1224 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1225 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1226 CHECK(c != nullptr) << "Null class in object " << obj; 1227 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1228 CHECK(VerifyClassClass(c)); 1229 1230 if (verify_object_mode_ > kVerifyObjectModeFast) { 1231 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1232 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1233 } 1234} 1235 1236void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1237 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1238} 1239 1240void Heap::VerifyHeap() { 1241 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1242 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1243} 1244 1245void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1246 // Use signed comparison since freed bytes can be negative when background compaction foreground 1247 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1248 // free list backed space typically increasing memory footprint due to padding and binning. 1249 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1250 // Note: This relies on 2s complement for handling negative freed_bytes. 1251 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1252 if (Runtime::Current()->HasStatsEnabled()) { 1253 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1254 thread_stats->freed_objects += freed_objects; 1255 thread_stats->freed_bytes += freed_bytes; 1256 // TODO: Do this concurrently. 1257 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1258 global_stats->freed_objects += freed_objects; 1259 global_stats->freed_bytes += freed_bytes; 1260 } 1261} 1262 1263space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1264 for (const auto& space : continuous_spaces_) { 1265 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1266 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1267 return space->AsContinuousSpace()->AsRosAllocSpace(); 1268 } 1269 } 1270 } 1271 return nullptr; 1272} 1273 1274mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1275 size_t alloc_size, size_t* bytes_allocated, 1276 size_t* usable_size, 1277 mirror::Class** klass) { 1278 bool was_default_allocator = allocator == GetCurrentAllocator(); 1279 // Make sure there is no pending exception since we may need to throw an OOME. 1280 self->AssertNoPendingException(); 1281 DCHECK(klass != nullptr); 1282 StackHandleScope<1> hs(self); 1283 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1284 klass = nullptr; // Invalidate for safety. 1285 // The allocation failed. If the GC is running, block until it completes, and then retry the 1286 // allocation. 1287 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1288 if (last_gc != collector::kGcTypeNone) { 1289 // If we were the default allocator but the allocator changed while we were suspended, 1290 // abort the allocation. 1291 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1292 return nullptr; 1293 } 1294 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1295 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1296 usable_size); 1297 if (ptr != nullptr) { 1298 return ptr; 1299 } 1300 } 1301 1302 collector::GcType tried_type = next_gc_type_; 1303 const bool gc_ran = 1304 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1305 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1306 return nullptr; 1307 } 1308 if (gc_ran) { 1309 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1310 usable_size); 1311 if (ptr != nullptr) { 1312 return ptr; 1313 } 1314 } 1315 1316 // Loop through our different Gc types and try to Gc until we get enough free memory. 1317 for (collector::GcType gc_type : gc_plan_) { 1318 if (gc_type == tried_type) { 1319 continue; 1320 } 1321 // Attempt to run the collector, if we succeed, re-try the allocation. 1322 const bool plan_gc_ran = 1323 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1324 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1325 return nullptr; 1326 } 1327 if (plan_gc_ran) { 1328 // Did we free sufficient memory for the allocation to succeed? 1329 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1330 usable_size); 1331 if (ptr != nullptr) { 1332 return ptr; 1333 } 1334 } 1335 } 1336 // Allocations have failed after GCs; this is an exceptional state. 1337 // Try harder, growing the heap if necessary. 1338 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1339 usable_size); 1340 if (ptr != nullptr) { 1341 return ptr; 1342 } 1343 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1344 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1345 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1346 // OOME. 1347 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1348 << " allocation"; 1349 // TODO: Run finalization, but this may cause more allocations to occur. 1350 // We don't need a WaitForGcToComplete here either. 1351 DCHECK(!gc_plan_.empty()); 1352 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1353 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1354 return nullptr; 1355 } 1356 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1357 if (ptr == nullptr) { 1358 const uint64_t current_time = NanoTime(); 1359 switch (allocator) { 1360 case kAllocatorTypeRosAlloc: 1361 // Fall-through. 1362 case kAllocatorTypeDlMalloc: { 1363 if (use_homogeneous_space_compaction_for_oom_ && 1364 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1365 min_interval_homogeneous_space_compaction_by_oom_) { 1366 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1367 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1368 switch (result) { 1369 case HomogeneousSpaceCompactResult::kSuccess: 1370 // If the allocation succeeded, we delayed an oom. 1371 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1372 usable_size); 1373 if (ptr != nullptr) { 1374 count_delayed_oom_++; 1375 } 1376 break; 1377 case HomogeneousSpaceCompactResult::kErrorReject: 1378 // Reject due to disabled moving GC. 1379 break; 1380 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1381 // Throw OOM by default. 1382 break; 1383 default: { 1384 UNIMPLEMENTED(FATAL) << "homogeneous space compaction result: " 1385 << static_cast<size_t>(result); 1386 UNREACHABLE(); 1387 } 1388 } 1389 // Always print that we ran homogeneous space compation since this can cause jank. 1390 VLOG(heap) << "Ran heap homogeneous space compaction, " 1391 << " requested defragmentation " 1392 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1393 << " performed defragmentation " 1394 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1395 << " ignored homogeneous space compaction " 1396 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1397 << " delayed count = " 1398 << count_delayed_oom_.LoadSequentiallyConsistent(); 1399 } 1400 break; 1401 } 1402 case kAllocatorTypeNonMoving: { 1403 // Try to transition the heap if the allocation failure was due to the space being full. 1404 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1405 // If we aren't out of memory then the OOM was probably from the non moving space being 1406 // full. Attempt to disable compaction and turn the main space into a non moving space. 1407 DisableMovingGc(); 1408 // If we are still a moving GC then something must have caused the transition to fail. 1409 if (IsMovingGc(collector_type_)) { 1410 MutexLock mu(self, *gc_complete_lock_); 1411 // If we couldn't disable moving GC, just throw OOME and return null. 1412 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1413 << disable_moving_gc_count_; 1414 } else { 1415 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1416 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1417 usable_size); 1418 } 1419 } 1420 break; 1421 } 1422 default: { 1423 // Do nothing for others allocators. 1424 } 1425 } 1426 } 1427 // If the allocation hasn't succeeded by this point, throw an OOM error. 1428 if (ptr == nullptr) { 1429 ThrowOutOfMemoryError(self, alloc_size, allocator); 1430 } 1431 return ptr; 1432} 1433 1434void Heap::SetTargetHeapUtilization(float target) { 1435 DCHECK_GT(target, 0.0f); // asserted in Java code 1436 DCHECK_LT(target, 1.0f); 1437 target_utilization_ = target; 1438} 1439 1440size_t Heap::GetObjectsAllocated() const { 1441 size_t total = 0; 1442 for (space::AllocSpace* space : alloc_spaces_) { 1443 total += space->GetObjectsAllocated(); 1444 } 1445 return total; 1446} 1447 1448uint64_t Heap::GetObjectsAllocatedEver() const { 1449 return GetObjectsFreedEver() + GetObjectsAllocated(); 1450} 1451 1452uint64_t Heap::GetBytesAllocatedEver() const { 1453 return GetBytesFreedEver() + GetBytesAllocated(); 1454} 1455 1456class InstanceCounter { 1457 public: 1458 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1459 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1460 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1461 } 1462 static void Callback(mirror::Object* obj, void* arg) 1463 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1464 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1465 mirror::Class* instance_class = obj->GetClass(); 1466 CHECK(instance_class != nullptr); 1467 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1468 if (instance_counter->use_is_assignable_from_) { 1469 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1470 ++instance_counter->counts_[i]; 1471 } 1472 } else if (instance_class == instance_counter->classes_[i]) { 1473 ++instance_counter->counts_[i]; 1474 } 1475 } 1476 } 1477 1478 private: 1479 const std::vector<mirror::Class*>& classes_; 1480 bool use_is_assignable_from_; 1481 uint64_t* const counts_; 1482 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1483}; 1484 1485void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1486 uint64_t* counts) { 1487 // Can't do any GC in this function since this may move classes. 1488 ScopedAssertNoThreadSuspension ants(Thread::Current(), "CountInstances"); 1489 InstanceCounter counter(classes, use_is_assignable_from, counts); 1490 ReaderMutexLock mu(ants.Self(), *Locks::heap_bitmap_lock_); 1491 VisitObjects(InstanceCounter::Callback, &counter); 1492} 1493 1494class InstanceCollector { 1495 public: 1496 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1497 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1498 : class_(c), max_count_(max_count), instances_(instances) { 1499 } 1500 static void Callback(mirror::Object* obj, void* arg) 1501 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1502 DCHECK(arg != nullptr); 1503 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1504 if (obj->GetClass() == instance_collector->class_) { 1505 if (instance_collector->max_count_ == 0 || 1506 instance_collector->instances_.size() < instance_collector->max_count_) { 1507 instance_collector->instances_.push_back(obj); 1508 } 1509 } 1510 } 1511 1512 private: 1513 const mirror::Class* const class_; 1514 const uint32_t max_count_; 1515 std::vector<mirror::Object*>& instances_; 1516 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1517}; 1518 1519void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1520 std::vector<mirror::Object*>& instances) { 1521 // Can't do any GC in this function since this may move classes. 1522 ScopedAssertNoThreadSuspension ants(Thread::Current(), "GetInstances"); 1523 InstanceCollector collector(c, max_count, instances); 1524 ReaderMutexLock mu(ants.Self(), *Locks::heap_bitmap_lock_); 1525 VisitObjects(&InstanceCollector::Callback, &collector); 1526} 1527 1528class ReferringObjectsFinder { 1529 public: 1530 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1531 std::vector<mirror::Object*>& referring_objects) 1532 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1533 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1534 } 1535 1536 static void Callback(mirror::Object* obj, void* arg) 1537 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1538 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1539 } 1540 1541 // For bitmap Visit. 1542 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1543 // annotalysis on visitors. 1544 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1545 o->VisitReferences<true>(*this, VoidFunctor()); 1546 } 1547 1548 // For Object::VisitReferences. 1549 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1550 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1551 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1552 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1553 referring_objects_.push_back(obj); 1554 } 1555 } 1556 1557 private: 1558 const mirror::Object* const object_; 1559 const uint32_t max_count_; 1560 std::vector<mirror::Object*>& referring_objects_; 1561 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1562}; 1563 1564void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1565 std::vector<mirror::Object*>& referring_objects) { 1566 // Can't do any GC in this function since this may move the object o. 1567 ScopedAssertNoThreadSuspension ants(Thread::Current(), "GetReferringObjects"); 1568 ReferringObjectsFinder finder(o, max_count, referring_objects); 1569 ReaderMutexLock mu(ants.Self(), *Locks::heap_bitmap_lock_); 1570 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1571} 1572 1573void Heap::CollectGarbage(bool clear_soft_references) { 1574 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1575 // last GC will not have necessarily been cleared. 1576 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1577} 1578 1579HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1580 Thread* self = Thread::Current(); 1581 // Inc requested homogeneous space compaction. 1582 count_requested_homogeneous_space_compaction_++; 1583 // Store performed homogeneous space compaction at a new request arrival. 1584 ThreadList* tl = Runtime::Current()->GetThreadList(); 1585 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1586 Locks::mutator_lock_->AssertNotHeld(self); 1587 { 1588 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1589 MutexLock mu(self, *gc_complete_lock_); 1590 // Ensure there is only one GC at a time. 1591 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1592 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1593 // is non zero. 1594 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1595 // exit. 1596 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1597 !main_space_->CanMoveObjects()) { 1598 return HomogeneousSpaceCompactResult::kErrorReject; 1599 } 1600 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1601 } 1602 if (Runtime::Current()->IsShuttingDown(self)) { 1603 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1604 // cause objects to get finalized. 1605 FinishGC(self, collector::kGcTypeNone); 1606 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1607 } 1608 // Suspend all threads. 1609 tl->SuspendAll(); 1610 uint64_t start_time = NanoTime(); 1611 // Launch compaction. 1612 space::MallocSpace* to_space = main_space_backup_.release(); 1613 space::MallocSpace* from_space = main_space_; 1614 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1615 const uint64_t space_size_before_compaction = from_space->Size(); 1616 AddSpace(to_space); 1617 // Make sure that we will have enough room to copy. 1618 CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit()); 1619 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1620 // Leave as prot read so that we can still run ROSAlloc verification on this space. 1621 from_space->GetMemMap()->Protect(PROT_READ); 1622 const uint64_t space_size_after_compaction = to_space->Size(); 1623 main_space_ = to_space; 1624 main_space_backup_.reset(from_space); 1625 RemoveSpace(from_space); 1626 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1627 // Update performed homogeneous space compaction count. 1628 count_performed_homogeneous_space_compaction_++; 1629 // Print statics log and resume all threads. 1630 uint64_t duration = NanoTime() - start_time; 1631 VLOG(heap) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1632 << PrettySize(space_size_before_compaction) << " -> " 1633 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1634 << std::fixed << static_cast<double>(space_size_after_compaction) / 1635 static_cast<double>(space_size_before_compaction); 1636 tl->ResumeAll(); 1637 // Finish GC. 1638 reference_processor_.EnqueueClearedReferences(self); 1639 GrowForUtilization(semi_space_collector_); 1640 FinishGC(self, collector::kGcTypeFull); 1641 return HomogeneousSpaceCompactResult::kSuccess; 1642} 1643 1644 1645void Heap::TransitionCollector(CollectorType collector_type) { 1646 if (collector_type == collector_type_) { 1647 return; 1648 } 1649 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1650 << " -> " << static_cast<int>(collector_type); 1651 uint64_t start_time = NanoTime(); 1652 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1653 Runtime* const runtime = Runtime::Current(); 1654 ThreadList* const tl = runtime->GetThreadList(); 1655 Thread* const self = Thread::Current(); 1656 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1657 Locks::mutator_lock_->AssertNotHeld(self); 1658 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1659 // compacting_gc_disable_count_, this should rarely occurs). 1660 for (;;) { 1661 { 1662 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1663 MutexLock mu(self, *gc_complete_lock_); 1664 // Ensure there is only one GC at a time. 1665 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1666 // Currently we only need a heap transition if we switch from a moving collector to a 1667 // non-moving one, or visa versa. 1668 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1669 // If someone else beat us to it and changed the collector before we could, exit. 1670 // This is safe to do before the suspend all since we set the collector_type_running_ before 1671 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1672 // then it would get blocked on WaitForGcToCompleteLocked. 1673 if (collector_type == collector_type_) { 1674 return; 1675 } 1676 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1677 if (!copying_transition || disable_moving_gc_count_ == 0) { 1678 // TODO: Not hard code in semi-space collector? 1679 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1680 break; 1681 } 1682 } 1683 usleep(1000); 1684 } 1685 if (runtime->IsShuttingDown(self)) { 1686 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1687 // cause objects to get finalized. 1688 FinishGC(self, collector::kGcTypeNone); 1689 return; 1690 } 1691 tl->SuspendAll(); 1692 switch (collector_type) { 1693 case kCollectorTypeSS: { 1694 if (!IsMovingGc(collector_type_)) { 1695 // Create the bump pointer space from the backup space. 1696 CHECK(main_space_backup_ != nullptr); 1697 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1698 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1699 // pointer space last transition it will be protected. 1700 CHECK(mem_map != nullptr); 1701 mem_map->Protect(PROT_READ | PROT_WRITE); 1702 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1703 mem_map.release()); 1704 AddSpace(bump_pointer_space_); 1705 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1706 // Use the now empty main space mem map for the bump pointer temp space. 1707 mem_map.reset(main_space_->ReleaseMemMap()); 1708 // Unset the pointers just in case. 1709 if (dlmalloc_space_ == main_space_) { 1710 dlmalloc_space_ = nullptr; 1711 } else if (rosalloc_space_ == main_space_) { 1712 rosalloc_space_ = nullptr; 1713 } 1714 // Remove the main space so that we don't try to trim it, this doens't work for debug 1715 // builds since RosAlloc attempts to read the magic number from a protected page. 1716 RemoveSpace(main_space_); 1717 RemoveRememberedSet(main_space_); 1718 delete main_space_; // Delete the space since it has been removed. 1719 main_space_ = nullptr; 1720 RemoveRememberedSet(main_space_backup_.get()); 1721 main_space_backup_.reset(nullptr); // Deletes the space. 1722 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1723 mem_map.release()); 1724 AddSpace(temp_space_); 1725 } 1726 break; 1727 } 1728 case kCollectorTypeMS: 1729 // Fall through. 1730 case kCollectorTypeCMS: { 1731 if (IsMovingGc(collector_type_)) { 1732 CHECK(temp_space_ != nullptr); 1733 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1734 RemoveSpace(temp_space_); 1735 temp_space_ = nullptr; 1736 mem_map->Protect(PROT_READ | PROT_WRITE); 1737 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, 1738 std::min(mem_map->Size(), growth_limit_), mem_map->Size()); 1739 mem_map.release(); 1740 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1741 AddSpace(main_space_); 1742 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1743 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1744 RemoveSpace(bump_pointer_space_); 1745 bump_pointer_space_ = nullptr; 1746 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1747 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1748 if (kIsDebugBuild && kUseRosAlloc) { 1749 mem_map->Protect(PROT_READ | PROT_WRITE); 1750 } 1751 main_space_backup_.reset(CreateMallocSpaceFromMemMap( 1752 mem_map.get(), kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1753 mem_map->Size(), name, true)); 1754 if (kIsDebugBuild && kUseRosAlloc) { 1755 mem_map->Protect(PROT_NONE); 1756 } 1757 mem_map.release(); 1758 } 1759 break; 1760 } 1761 default: { 1762 LOG(FATAL) << "Attempted to transition to invalid collector type " 1763 << static_cast<size_t>(collector_type); 1764 break; 1765 } 1766 } 1767 ChangeCollector(collector_type); 1768 tl->ResumeAll(); 1769 // Can't call into java code with all threads suspended. 1770 reference_processor_.EnqueueClearedReferences(self); 1771 uint64_t duration = NanoTime() - start_time; 1772 GrowForUtilization(semi_space_collector_); 1773 FinishGC(self, collector::kGcTypeFull); 1774 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1775 int32_t delta_allocated = before_allocated - after_allocated; 1776 std::string saved_str; 1777 if (delta_allocated >= 0) { 1778 saved_str = " saved at least " + PrettySize(delta_allocated); 1779 } else { 1780 saved_str = " expanded " + PrettySize(-delta_allocated); 1781 } 1782 VLOG(heap) << "Heap transition to " << process_state_ << " took " 1783 << PrettyDuration(duration) << saved_str; 1784} 1785 1786void Heap::ChangeCollector(CollectorType collector_type) { 1787 // TODO: Only do this with all mutators suspended to avoid races. 1788 if (collector_type != collector_type_) { 1789 if (collector_type == kCollectorTypeMC) { 1790 // Don't allow mark compact unless support is compiled in. 1791 CHECK(kMarkCompactSupport); 1792 } 1793 collector_type_ = collector_type; 1794 gc_plan_.clear(); 1795 switch (collector_type_) { 1796 case kCollectorTypeCC: // Fall-through. 1797 case kCollectorTypeMC: // Fall-through. 1798 case kCollectorTypeSS: // Fall-through. 1799 case kCollectorTypeGSS: { 1800 gc_plan_.push_back(collector::kGcTypeFull); 1801 if (use_tlab_) { 1802 ChangeAllocator(kAllocatorTypeTLAB); 1803 } else { 1804 ChangeAllocator(kAllocatorTypeBumpPointer); 1805 } 1806 break; 1807 } 1808 case kCollectorTypeMS: { 1809 gc_plan_.push_back(collector::kGcTypeSticky); 1810 gc_plan_.push_back(collector::kGcTypePartial); 1811 gc_plan_.push_back(collector::kGcTypeFull); 1812 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1813 break; 1814 } 1815 case kCollectorTypeCMS: { 1816 gc_plan_.push_back(collector::kGcTypeSticky); 1817 gc_plan_.push_back(collector::kGcTypePartial); 1818 gc_plan_.push_back(collector::kGcTypeFull); 1819 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1820 break; 1821 } 1822 default: { 1823 UNIMPLEMENTED(FATAL); 1824 UNREACHABLE(); 1825 } 1826 } 1827 if (IsGcConcurrent()) { 1828 concurrent_start_bytes_ = 1829 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1830 } else { 1831 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1832 } 1833 } 1834} 1835 1836// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1837class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1838 public: 1839 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1840 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1841 } 1842 1843 void BuildBins(space::ContinuousSpace* space) { 1844 bin_live_bitmap_ = space->GetLiveBitmap(); 1845 bin_mark_bitmap_ = space->GetMarkBitmap(); 1846 BinContext context; 1847 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1848 context.collector_ = this; 1849 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1850 // Note: This requires traversing the space in increasing order of object addresses. 1851 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1852 // Add the last bin which spans after the last object to the end of the space. 1853 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1854 } 1855 1856 private: 1857 struct BinContext { 1858 uintptr_t prev_; // The end of the previous object. 1859 ZygoteCompactingCollector* collector_; 1860 }; 1861 // Maps from bin sizes to locations. 1862 std::multimap<size_t, uintptr_t> bins_; 1863 // Live bitmap of the space which contains the bins. 1864 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1865 // Mark bitmap of the space which contains the bins. 1866 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1867 1868 static void Callback(mirror::Object* obj, void* arg) 1869 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1870 DCHECK(arg != nullptr); 1871 BinContext* context = reinterpret_cast<BinContext*>(arg); 1872 ZygoteCompactingCollector* collector = context->collector_; 1873 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1874 size_t bin_size = object_addr - context->prev_; 1875 // Add the bin consisting of the end of the previous object to the start of the current object. 1876 collector->AddBin(bin_size, context->prev_); 1877 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1878 } 1879 1880 void AddBin(size_t size, uintptr_t position) { 1881 if (size != 0) { 1882 bins_.insert(std::make_pair(size, position)); 1883 } 1884 } 1885 1886 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1887 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1888 // allocator. 1889 UNUSED(space); 1890 return false; 1891 } 1892 1893 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1894 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1895 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1896 mirror::Object* forward_address; 1897 // Find the smallest bin which we can move obj in. 1898 auto it = bins_.lower_bound(object_size); 1899 if (it == bins_.end()) { 1900 // No available space in the bins, place it in the target space instead (grows the zygote 1901 // space). 1902 size_t bytes_allocated; 1903 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1904 if (to_space_live_bitmap_ != nullptr) { 1905 to_space_live_bitmap_->Set(forward_address); 1906 } else { 1907 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1908 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1909 } 1910 } else { 1911 size_t size = it->first; 1912 uintptr_t pos = it->second; 1913 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1914 forward_address = reinterpret_cast<mirror::Object*>(pos); 1915 // Set the live and mark bits so that sweeping system weaks works properly. 1916 bin_live_bitmap_->Set(forward_address); 1917 bin_mark_bitmap_->Set(forward_address); 1918 DCHECK_GE(size, object_size); 1919 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1920 } 1921 // Copy the object over to its new location. 1922 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1923 if (kUseBakerOrBrooksReadBarrier) { 1924 obj->AssertReadBarrierPointer(); 1925 if (kUseBrooksReadBarrier) { 1926 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1927 forward_address->SetReadBarrierPointer(forward_address); 1928 } 1929 forward_address->AssertReadBarrierPointer(); 1930 } 1931 return forward_address; 1932 } 1933}; 1934 1935void Heap::UnBindBitmaps() { 1936 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1937 for (const auto& space : GetContinuousSpaces()) { 1938 if (space->IsContinuousMemMapAllocSpace()) { 1939 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1940 if (alloc_space->HasBoundBitmaps()) { 1941 alloc_space->UnBindBitmaps(); 1942 } 1943 } 1944 } 1945} 1946 1947void Heap::PreZygoteFork() { 1948 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1949 Thread* self = Thread::Current(); 1950 MutexLock mu(self, zygote_creation_lock_); 1951 // Try to see if we have any Zygote spaces. 1952 if (HasZygoteSpace()) { 1953 LOG(WARNING) << __FUNCTION__ << " called when we already have a zygote space."; 1954 return; 1955 } 1956 Runtime::Current()->GetInternTable()->SwapPostZygoteWithPreZygote(); 1957 Runtime::Current()->GetClassLinker()->MoveClassTableToPreZygote(); 1958 VLOG(heap) << "Starting PreZygoteFork"; 1959 // Trim the pages at the end of the non moving space. 1960 non_moving_space_->Trim(); 1961 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1962 // there. 1963 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1964 const bool same_space = non_moving_space_ == main_space_; 1965 if (kCompactZygote) { 1966 // Can't compact if the non moving space is the same as the main space. 1967 DCHECK(semi_space_collector_ != nullptr); 1968 // Temporarily disable rosalloc verification because the zygote 1969 // compaction will mess up the rosalloc internal metadata. 1970 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1971 ZygoteCompactingCollector zygote_collector(this); 1972 zygote_collector.BuildBins(non_moving_space_); 1973 // Create a new bump pointer space which we will compact into. 1974 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1975 non_moving_space_->Limit()); 1976 // Compact the bump pointer space to a new zygote bump pointer space. 1977 bool reset_main_space = false; 1978 if (IsMovingGc(collector_type_)) { 1979 zygote_collector.SetFromSpace(bump_pointer_space_); 1980 } else { 1981 CHECK(main_space_ != nullptr); 1982 // Copy from the main space. 1983 zygote_collector.SetFromSpace(main_space_); 1984 reset_main_space = true; 1985 } 1986 zygote_collector.SetToSpace(&target_space); 1987 zygote_collector.SetSwapSemiSpaces(false); 1988 zygote_collector.Run(kGcCauseCollectorTransition, false); 1989 if (reset_main_space) { 1990 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1991 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1992 MemMap* mem_map = main_space_->ReleaseMemMap(); 1993 RemoveSpace(main_space_); 1994 space::Space* old_main_space = main_space_; 1995 CreateMainMallocSpace(mem_map, kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1996 mem_map->Size()); 1997 delete old_main_space; 1998 AddSpace(main_space_); 1999 } else { 2000 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2001 } 2002 if (temp_space_ != nullptr) { 2003 CHECK(temp_space_->IsEmpty()); 2004 } 2005 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2006 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2007 // Update the end and write out image. 2008 non_moving_space_->SetEnd(target_space.End()); 2009 non_moving_space_->SetLimit(target_space.Limit()); 2010 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 2011 } 2012 // Change the collector to the post zygote one. 2013 ChangeCollector(foreground_collector_type_); 2014 // Save the old space so that we can remove it after we complete creating the zygote space. 2015 space::MallocSpace* old_alloc_space = non_moving_space_; 2016 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 2017 // the remaining available space. 2018 // Remove the old space before creating the zygote space since creating the zygote space sets 2019 // the old alloc space's bitmaps to nullptr. 2020 RemoveSpace(old_alloc_space); 2021 if (collector::SemiSpace::kUseRememberedSet) { 2022 // Sanity bound check. 2023 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 2024 // Remove the remembered set for the now zygote space (the old 2025 // non-moving space). Note now that we have compacted objects into 2026 // the zygote space, the data in the remembered set is no longer 2027 // needed. The zygote space will instead have a mod-union table 2028 // from this point on. 2029 RemoveRememberedSet(old_alloc_space); 2030 } 2031 // Remaining space becomes the new non moving space. 2032 zygote_space_ = old_alloc_space->CreateZygoteSpace(kNonMovingSpaceName, low_memory_mode_, 2033 &non_moving_space_); 2034 CHECK(!non_moving_space_->CanMoveObjects()); 2035 if (same_space) { 2036 main_space_ = non_moving_space_; 2037 SetSpaceAsDefault(main_space_); 2038 } 2039 delete old_alloc_space; 2040 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 2041 AddSpace(zygote_space_); 2042 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 2043 AddSpace(non_moving_space_); 2044 // Create the zygote space mod union table. 2045 accounting::ModUnionTable* mod_union_table = 2046 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 2047 zygote_space_); 2048 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 2049 // Set all the cards in the mod-union table since we don't know which objects contain references 2050 // to large objects. 2051 mod_union_table->SetCards(); 2052 AddModUnionTable(mod_union_table); 2053 if (collector::SemiSpace::kUseRememberedSet) { 2054 // Add a new remembered set for the post-zygote non-moving space. 2055 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 2056 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2057 non_moving_space_); 2058 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2059 << "Failed to create post-zygote non-moving space remembered set"; 2060 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2061 } 2062} 2063 2064void Heap::FlushAllocStack() { 2065 MarkAllocStackAsLive(allocation_stack_.get()); 2066 allocation_stack_->Reset(); 2067} 2068 2069void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2070 accounting::ContinuousSpaceBitmap* bitmap2, 2071 accounting::LargeObjectBitmap* large_objects, 2072 accounting::ObjectStack* stack) { 2073 DCHECK(bitmap1 != nullptr); 2074 DCHECK(bitmap2 != nullptr); 2075 mirror::Object** limit = stack->End(); 2076 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 2077 const mirror::Object* obj = *it; 2078 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2079 if (bitmap1->HasAddress(obj)) { 2080 bitmap1->Set(obj); 2081 } else if (bitmap2->HasAddress(obj)) { 2082 bitmap2->Set(obj); 2083 } else { 2084 DCHECK(large_objects != nullptr); 2085 large_objects->Set(obj); 2086 } 2087 } 2088 } 2089} 2090 2091void Heap::SwapSemiSpaces() { 2092 CHECK(bump_pointer_space_ != nullptr); 2093 CHECK(temp_space_ != nullptr); 2094 std::swap(bump_pointer_space_, temp_space_); 2095} 2096 2097void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2098 space::ContinuousMemMapAllocSpace* source_space, 2099 GcCause gc_cause) { 2100 CHECK(kMovingCollector); 2101 if (target_space != source_space) { 2102 // Don't swap spaces since this isn't a typical semi space collection. 2103 semi_space_collector_->SetSwapSemiSpaces(false); 2104 semi_space_collector_->SetFromSpace(source_space); 2105 semi_space_collector_->SetToSpace(target_space); 2106 semi_space_collector_->Run(gc_cause, false); 2107 } else { 2108 CHECK(target_space->IsBumpPointerSpace()) 2109 << "In-place compaction is only supported for bump pointer spaces"; 2110 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2111 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2112 } 2113} 2114 2115collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2116 bool clear_soft_references) { 2117 Thread* self = Thread::Current(); 2118 Runtime* runtime = Runtime::Current(); 2119 // If the heap can't run the GC, silently fail and return that no GC was run. 2120 switch (gc_type) { 2121 case collector::kGcTypePartial: { 2122 if (!HasZygoteSpace()) { 2123 return collector::kGcTypeNone; 2124 } 2125 break; 2126 } 2127 default: { 2128 // Other GC types don't have any special cases which makes them not runnable. The main case 2129 // here is full GC. 2130 } 2131 } 2132 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2133 Locks::mutator_lock_->AssertNotHeld(self); 2134 if (self->IsHandlingStackOverflow()) { 2135 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 2136 } 2137 bool compacting_gc; 2138 { 2139 gc_complete_lock_->AssertNotHeld(self); 2140 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 2141 MutexLock mu(self, *gc_complete_lock_); 2142 // Ensure there is only one GC at a time. 2143 WaitForGcToCompleteLocked(gc_cause, self); 2144 compacting_gc = IsMovingGc(collector_type_); 2145 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2146 if (compacting_gc && disable_moving_gc_count_ != 0) { 2147 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2148 return collector::kGcTypeNone; 2149 } 2150 collector_type_running_ = collector_type_; 2151 } 2152 2153 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2154 ++runtime->GetStats()->gc_for_alloc_count; 2155 ++self->GetStats()->gc_for_alloc_count; 2156 } 2157 uint64_t gc_start_time_ns = NanoTime(); 2158 uint64_t gc_start_size = GetBytesAllocated(); 2159 // Approximate allocation rate in bytes / second. 2160 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 2161 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 2162 if (LIKELY(ms_delta != 0)) { 2163 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 2164 ATRACE_INT("Allocation rate KB/s", allocation_rate_ / KB); 2165 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 2166 } 2167 2168 DCHECK_LT(gc_type, collector::kGcTypeMax); 2169 DCHECK_NE(gc_type, collector::kGcTypeNone); 2170 2171 collector::GarbageCollector* collector = nullptr; 2172 // TODO: Clean this up. 2173 if (compacting_gc) { 2174 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2175 current_allocator_ == kAllocatorTypeTLAB); 2176 switch (collector_type_) { 2177 case kCollectorTypeSS: 2178 // Fall-through. 2179 case kCollectorTypeGSS: 2180 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2181 semi_space_collector_->SetToSpace(temp_space_); 2182 semi_space_collector_->SetSwapSemiSpaces(true); 2183 collector = semi_space_collector_; 2184 break; 2185 case kCollectorTypeCC: 2186 collector = concurrent_copying_collector_; 2187 break; 2188 case kCollectorTypeMC: 2189 mark_compact_collector_->SetSpace(bump_pointer_space_); 2190 collector = mark_compact_collector_; 2191 break; 2192 default: 2193 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2194 } 2195 if (collector != mark_compact_collector_) { 2196 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2197 CHECK(temp_space_->IsEmpty()); 2198 } 2199 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2200 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2201 current_allocator_ == kAllocatorTypeDlMalloc) { 2202 collector = FindCollectorByGcType(gc_type); 2203 } else { 2204 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2205 } 2206 if (IsGcConcurrent()) { 2207 // Disable concurrent GC check so that we don't have spammy JNI requests. 2208 // This gets recalculated in GrowForUtilization. It is important that it is disabled / 2209 // calculated in the same thread so that there aren't any races that can cause it to become 2210 // permanantly disabled. b/17942071 2211 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2212 } 2213 CHECK(collector != nullptr) 2214 << "Could not find garbage collector with collector_type=" 2215 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2216 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2217 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2218 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2219 RequestHeapTrim(); 2220 // Enqueue cleared references. 2221 reference_processor_.EnqueueClearedReferences(self); 2222 // Grow the heap so that we know when to perform the next GC. 2223 GrowForUtilization(collector); 2224 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2225 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2226 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2227 // (mutator time blocked >= long_pause_log_threshold_). 2228 bool log_gc = gc_cause == kGcCauseExplicit; 2229 if (!log_gc && CareAboutPauseTimes()) { 2230 // GC for alloc pauses the allocating thread, so consider it as a pause. 2231 log_gc = duration > long_gc_log_threshold_ || 2232 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2233 for (uint64_t pause : pause_times) { 2234 log_gc = log_gc || pause >= long_pause_log_threshold_; 2235 } 2236 } 2237 if (log_gc) { 2238 const size_t percent_free = GetPercentFree(); 2239 const size_t current_heap_size = GetBytesAllocated(); 2240 const size_t total_memory = GetTotalMemory(); 2241 std::ostringstream pause_string; 2242 for (size_t i = 0; i < pause_times.size(); ++i) { 2243 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2244 << ((i != pause_times.size() - 1) ? "," : ""); 2245 } 2246 LOG(INFO) << gc_cause << " " << collector->GetName() 2247 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2248 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2249 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2250 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2251 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2252 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2253 << " total " << PrettyDuration((duration / 1000) * 1000); 2254 VLOG(heap) << Dumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2255 } 2256 FinishGC(self, gc_type); 2257 // Inform DDMS that a GC completed. 2258 Dbg::GcDidFinish(); 2259 return gc_type; 2260} 2261 2262void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2263 MutexLock mu(self, *gc_complete_lock_); 2264 collector_type_running_ = kCollectorTypeNone; 2265 if (gc_type != collector::kGcTypeNone) { 2266 last_gc_type_ = gc_type; 2267 } 2268 // Wake anyone who may have been waiting for the GC to complete. 2269 gc_complete_cond_->Broadcast(self); 2270} 2271 2272static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2273 RootType /*root_type*/) { 2274 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2275 if (*root == obj) { 2276 LOG(INFO) << "Object " << obj << " is a root"; 2277 } 2278} 2279 2280class ScanVisitor { 2281 public: 2282 void operator()(const mirror::Object* obj) const { 2283 LOG(ERROR) << "Would have rescanned object " << obj; 2284 } 2285}; 2286 2287// Verify a reference from an object. 2288class VerifyReferenceVisitor { 2289 public: 2290 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2291 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2292 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2293 2294 size_t GetFailureCount() const { 2295 return fail_count_->LoadSequentiallyConsistent(); 2296 } 2297 2298 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2299 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2300 UNUSED(klass); 2301 if (verify_referent_) { 2302 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2303 } 2304 } 2305 2306 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2307 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2308 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2309 } 2310 2311 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2312 return heap_->IsLiveObjectLocked(obj, true, false, true); 2313 } 2314 2315 static void VerifyRootCallback(mirror::Object** root, void* arg, uint32_t thread_id, 2316 RootType root_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2317 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2318 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2319 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2320 << " thread_id= " << thread_id << " root_type= " << root_type; 2321 } 2322 } 2323 2324 private: 2325 // TODO: Fix the no thread safety analysis. 2326 // Returns false on failure. 2327 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2328 NO_THREAD_SAFETY_ANALYSIS { 2329 if (ref == nullptr || IsLive(ref)) { 2330 // Verify that the reference is live. 2331 return true; 2332 } 2333 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2334 // Print message on only on first failure to prevent spam. 2335 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2336 } 2337 if (obj != nullptr) { 2338 // Only do this part for non roots. 2339 accounting::CardTable* card_table = heap_->GetCardTable(); 2340 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2341 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2342 uint8_t* card_addr = card_table->CardFromAddr(obj); 2343 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2344 << offset << "\n card value = " << static_cast<int>(*card_addr); 2345 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2346 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2347 } else { 2348 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2349 } 2350 2351 // Attempt to find the class inside of the recently freed objects. 2352 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2353 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2354 space::MallocSpace* space = ref_space->AsMallocSpace(); 2355 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2356 if (ref_class != nullptr) { 2357 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2358 << PrettyClass(ref_class); 2359 } else { 2360 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2361 } 2362 } 2363 2364 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2365 ref->GetClass()->IsClass()) { 2366 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2367 } else { 2368 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2369 << ") is not a valid heap address"; 2370 } 2371 2372 card_table->CheckAddrIsInCardTable(reinterpret_cast<const uint8_t*>(obj)); 2373 void* cover_begin = card_table->AddrFromCard(card_addr); 2374 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2375 accounting::CardTable::kCardSize); 2376 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2377 << "-" << cover_end; 2378 accounting::ContinuousSpaceBitmap* bitmap = 2379 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2380 2381 if (bitmap == nullptr) { 2382 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2383 if (!VerifyClassClass(obj->GetClass())) { 2384 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2385 } 2386 } else { 2387 // Print out how the object is live. 2388 if (bitmap->Test(obj)) { 2389 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2390 } 2391 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2392 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2393 } 2394 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2395 LOG(ERROR) << "Object " << obj << " found in live stack"; 2396 } 2397 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2398 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2399 } 2400 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2401 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2402 } 2403 // Attempt to see if the card table missed the reference. 2404 ScanVisitor scan_visitor; 2405 uint8_t* byte_cover_begin = reinterpret_cast<uint8_t*>(card_table->AddrFromCard(card_addr)); 2406 card_table->Scan(bitmap, byte_cover_begin, 2407 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2408 } 2409 2410 // Search to see if any of the roots reference our object. 2411 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2412 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2413 2414 // Search to see if any of the roots reference our reference. 2415 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2416 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2417 } 2418 return false; 2419 } 2420 2421 Heap* const heap_; 2422 Atomic<size_t>* const fail_count_; 2423 const bool verify_referent_; 2424}; 2425 2426// Verify all references within an object, for use with HeapBitmap::Visit. 2427class VerifyObjectVisitor { 2428 public: 2429 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2430 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2431 } 2432 2433 void operator()(mirror::Object* obj) const 2434 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2435 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2436 // be live or else how did we find it in the live bitmap? 2437 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2438 // The class doesn't count as a reference but we should verify it anyways. 2439 obj->VisitReferences<true>(visitor, visitor); 2440 } 2441 2442 static void VisitCallback(mirror::Object* obj, void* arg) 2443 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2444 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2445 visitor->operator()(obj); 2446 } 2447 2448 size_t GetFailureCount() const { 2449 return fail_count_->LoadSequentiallyConsistent(); 2450 } 2451 2452 private: 2453 Heap* const heap_; 2454 Atomic<size_t>* const fail_count_; 2455 const bool verify_referent_; 2456}; 2457 2458void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2459 // Slow path, the allocation stack push back must have already failed. 2460 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2461 do { 2462 // TODO: Add handle VerifyObject. 2463 StackHandleScope<1> hs(self); 2464 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2465 // Push our object into the reserve region of the allocaiton stack. This is only required due 2466 // to heap verification requiring that roots are live (either in the live bitmap or in the 2467 // allocation stack). 2468 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2469 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2470 } while (!allocation_stack_->AtomicPushBack(*obj)); 2471} 2472 2473void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2474 // Slow path, the allocation stack push back must have already failed. 2475 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2476 mirror::Object** start_address; 2477 mirror::Object** end_address; 2478 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2479 &end_address)) { 2480 // TODO: Add handle VerifyObject. 2481 StackHandleScope<1> hs(self); 2482 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2483 // Push our object into the reserve region of the allocaiton stack. This is only required due 2484 // to heap verification requiring that roots are live (either in the live bitmap or in the 2485 // allocation stack). 2486 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2487 // Push into the reserve allocation stack. 2488 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2489 } 2490 self->SetThreadLocalAllocationStack(start_address, end_address); 2491 // Retry on the new thread-local allocation stack. 2492 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2493} 2494 2495// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2496size_t Heap::VerifyHeapReferences(bool verify_referents) { 2497 Thread* self = Thread::Current(); 2498 Locks::mutator_lock_->AssertExclusiveHeld(self); 2499 // Lets sort our allocation stacks so that we can efficiently binary search them. 2500 allocation_stack_->Sort(); 2501 live_stack_->Sort(); 2502 // Since we sorted the allocation stack content, need to revoke all 2503 // thread-local allocation stacks. 2504 RevokeAllThreadLocalAllocationStacks(self); 2505 Atomic<size_t> fail_count_(0); 2506 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2507 // Verify objects in the allocation stack since these will be objects which were: 2508 // 1. Allocated prior to the GC (pre GC verification). 2509 // 2. Allocated during the GC (pre sweep GC verification). 2510 // We don't want to verify the objects in the live stack since they themselves may be 2511 // pointing to dead objects if they are not reachable. 2512 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2513 // Verify the roots: 2514 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2515 if (visitor.GetFailureCount() > 0) { 2516 // Dump mod-union tables. 2517 for (const auto& table_pair : mod_union_tables_) { 2518 accounting::ModUnionTable* mod_union_table = table_pair.second; 2519 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2520 } 2521 // Dump remembered sets. 2522 for (const auto& table_pair : remembered_sets_) { 2523 accounting::RememberedSet* remembered_set = table_pair.second; 2524 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2525 } 2526 DumpSpaces(LOG(ERROR)); 2527 } 2528 return visitor.GetFailureCount(); 2529} 2530 2531class VerifyReferenceCardVisitor { 2532 public: 2533 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2534 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2535 Locks::heap_bitmap_lock_) 2536 : heap_(heap), failed_(failed) { 2537 } 2538 2539 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2540 // annotalysis on visitors. 2541 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2542 NO_THREAD_SAFETY_ANALYSIS { 2543 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2544 // Filter out class references since changing an object's class does not mark the card as dirty. 2545 // Also handles large objects, since the only reference they hold is a class reference. 2546 if (ref != nullptr && !ref->IsClass()) { 2547 accounting::CardTable* card_table = heap_->GetCardTable(); 2548 // If the object is not dirty and it is referencing something in the live stack other than 2549 // class, then it must be on a dirty card. 2550 if (!card_table->AddrIsInCardTable(obj)) { 2551 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2552 *failed_ = true; 2553 } else if (!card_table->IsDirty(obj)) { 2554 // TODO: Check mod-union tables. 2555 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2556 // kCardDirty - 1 if it didnt get touched since we aged it. 2557 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2558 if (live_stack->ContainsSorted(ref)) { 2559 if (live_stack->ContainsSorted(obj)) { 2560 LOG(ERROR) << "Object " << obj << " found in live stack"; 2561 } 2562 if (heap_->GetLiveBitmap()->Test(obj)) { 2563 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2564 } 2565 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2566 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2567 2568 // Print which field of the object is dead. 2569 if (!obj->IsObjectArray()) { 2570 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2571 CHECK(klass != NULL); 2572 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2573 : klass->GetIFields(); 2574 CHECK(fields != NULL); 2575 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2576 mirror::ArtField* cur = fields->Get(i); 2577 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2578 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2579 << PrettyField(cur); 2580 break; 2581 } 2582 } 2583 } else { 2584 mirror::ObjectArray<mirror::Object>* object_array = 2585 obj->AsObjectArray<mirror::Object>(); 2586 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2587 if (object_array->Get(i) == ref) { 2588 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2589 } 2590 } 2591 } 2592 2593 *failed_ = true; 2594 } 2595 } 2596 } 2597 } 2598 2599 private: 2600 Heap* const heap_; 2601 bool* const failed_; 2602}; 2603 2604class VerifyLiveStackReferences { 2605 public: 2606 explicit VerifyLiveStackReferences(Heap* heap) 2607 : heap_(heap), 2608 failed_(false) {} 2609 2610 void operator()(mirror::Object* obj) const 2611 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2612 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2613 obj->VisitReferences<true>(visitor, VoidFunctor()); 2614 } 2615 2616 bool Failed() const { 2617 return failed_; 2618 } 2619 2620 private: 2621 Heap* const heap_; 2622 bool failed_; 2623}; 2624 2625bool Heap::VerifyMissingCardMarks() { 2626 Thread* self = Thread::Current(); 2627 Locks::mutator_lock_->AssertExclusiveHeld(self); 2628 // We need to sort the live stack since we binary search it. 2629 live_stack_->Sort(); 2630 // Since we sorted the allocation stack content, need to revoke all 2631 // thread-local allocation stacks. 2632 RevokeAllThreadLocalAllocationStacks(self); 2633 VerifyLiveStackReferences visitor(this); 2634 GetLiveBitmap()->Visit(visitor); 2635 // We can verify objects in the live stack since none of these should reference dead objects. 2636 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2637 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2638 visitor(*it); 2639 } 2640 } 2641 return !visitor.Failed(); 2642} 2643 2644void Heap::SwapStacks(Thread* self) { 2645 UNUSED(self); 2646 if (kUseThreadLocalAllocationStack) { 2647 live_stack_->AssertAllZero(); 2648 } 2649 allocation_stack_.swap(live_stack_); 2650} 2651 2652void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2653 // This must be called only during the pause. 2654 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2655 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2656 MutexLock mu2(self, *Locks::thread_list_lock_); 2657 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2658 for (Thread* t : thread_list) { 2659 t->RevokeThreadLocalAllocationStack(); 2660 } 2661} 2662 2663void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2664 if (kIsDebugBuild) { 2665 if (rosalloc_space_ != nullptr) { 2666 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2667 } 2668 if (bump_pointer_space_ != nullptr) { 2669 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2670 } 2671 } 2672} 2673 2674void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2675 if (kIsDebugBuild) { 2676 if (bump_pointer_space_ != nullptr) { 2677 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2678 } 2679 } 2680} 2681 2682accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2683 auto it = mod_union_tables_.find(space); 2684 if (it == mod_union_tables_.end()) { 2685 return nullptr; 2686 } 2687 return it->second; 2688} 2689 2690accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2691 auto it = remembered_sets_.find(space); 2692 if (it == remembered_sets_.end()) { 2693 return nullptr; 2694 } 2695 return it->second; 2696} 2697 2698void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2699 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2700 // Clear cards and keep track of cards cleared in the mod-union table. 2701 for (const auto& space : continuous_spaces_) { 2702 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2703 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2704 if (table != nullptr) { 2705 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2706 "ImageModUnionClearCards"; 2707 TimingLogger::ScopedTiming t2(name, timings); 2708 table->ClearCards(); 2709 } else if (use_rem_sets && rem_set != nullptr) { 2710 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2711 << static_cast<int>(collector_type_); 2712 TimingLogger::ScopedTiming t2("AllocSpaceRemSetClearCards", timings); 2713 rem_set->ClearCards(); 2714 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2715 TimingLogger::ScopedTiming t2("AllocSpaceClearCards", timings); 2716 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2717 // were dirty before the GC started. 2718 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2719 // -> clean(cleaning thread). 2720 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2721 // roots and then we scan / update mod union tables after. We will always scan either card. 2722 // If we end up with the non aged card, we scan it it in the pause. 2723 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2724 VoidFunctor()); 2725 } 2726 } 2727} 2728 2729static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2730} 2731 2732void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2733 Thread* const self = Thread::Current(); 2734 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2735 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2736 if (verify_pre_gc_heap_) { 2737 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyHeapReferences", timings); 2738 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2739 size_t failures = VerifyHeapReferences(); 2740 if (failures > 0) { 2741 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2742 << " failures"; 2743 } 2744 } 2745 // Check that all objects which reference things in the live stack are on dirty cards. 2746 if (verify_missing_card_marks_) { 2747 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyMissingCardMarks", timings); 2748 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2749 SwapStacks(self); 2750 // Sort the live stack so that we can quickly binary search it later. 2751 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2752 << " missing card mark verification failed\n" << DumpSpaces(); 2753 SwapStacks(self); 2754 } 2755 if (verify_mod_union_table_) { 2756 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyModUnionTables", timings); 2757 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2758 for (const auto& table_pair : mod_union_tables_) { 2759 accounting::ModUnionTable* mod_union_table = table_pair.second; 2760 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2761 mod_union_table->Verify(); 2762 } 2763 } 2764} 2765 2766void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2767 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2768 collector::GarbageCollector::ScopedPause pause(gc); 2769 PreGcVerificationPaused(gc); 2770 } 2771} 2772 2773void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2774 UNUSED(gc); 2775 // TODO: Add a new runtime option for this? 2776 if (verify_pre_gc_rosalloc_) { 2777 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2778 } 2779} 2780 2781void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2782 Thread* const self = Thread::Current(); 2783 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2784 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2785 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2786 // reachable objects. 2787 if (verify_pre_sweeping_heap_) { 2788 TimingLogger::ScopedTiming t2("(Paused)PostSweepingVerifyHeapReferences", timings); 2789 CHECK_NE(self->GetState(), kRunnable); 2790 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2791 // Swapping bound bitmaps does nothing. 2792 gc->SwapBitmaps(); 2793 // Pass in false since concurrent reference processing can mean that the reference referents 2794 // may point to dead objects at the point which PreSweepingGcVerification is called. 2795 size_t failures = VerifyHeapReferences(false); 2796 if (failures > 0) { 2797 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2798 << " failures"; 2799 } 2800 gc->SwapBitmaps(); 2801 } 2802 if (verify_pre_sweeping_rosalloc_) { 2803 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2804 } 2805} 2806 2807void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2808 // Only pause if we have to do some verification. 2809 Thread* const self = Thread::Current(); 2810 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2811 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2812 if (verify_system_weaks_) { 2813 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2814 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2815 mark_sweep->VerifySystemWeaks(); 2816 } 2817 if (verify_post_gc_rosalloc_) { 2818 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2819 } 2820 if (verify_post_gc_heap_) { 2821 TimingLogger::ScopedTiming t2("(Paused)PostGcVerifyHeapReferences", timings); 2822 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2823 size_t failures = VerifyHeapReferences(); 2824 if (failures > 0) { 2825 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2826 << " failures"; 2827 } 2828 } 2829} 2830 2831void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2832 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2833 collector::GarbageCollector::ScopedPause pause(gc); 2834 PostGcVerificationPaused(gc); 2835 } 2836} 2837 2838void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2839 TimingLogger::ScopedTiming t(name, timings); 2840 for (const auto& space : continuous_spaces_) { 2841 if (space->IsRosAllocSpace()) { 2842 VLOG(heap) << name << " : " << space->GetName(); 2843 space->AsRosAllocSpace()->Verify(); 2844 } 2845 } 2846} 2847 2848collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2849 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2850 MutexLock mu(self, *gc_complete_lock_); 2851 return WaitForGcToCompleteLocked(cause, self); 2852} 2853 2854collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2855 collector::GcType last_gc_type = collector::kGcTypeNone; 2856 uint64_t wait_start = NanoTime(); 2857 while (collector_type_running_ != kCollectorTypeNone) { 2858 ATRACE_BEGIN("GC: Wait For Completion"); 2859 // We must wait, change thread state then sleep on gc_complete_cond_; 2860 gc_complete_cond_->Wait(self); 2861 last_gc_type = last_gc_type_; 2862 ATRACE_END(); 2863 } 2864 uint64_t wait_time = NanoTime() - wait_start; 2865 total_wait_time_ += wait_time; 2866 if (wait_time > long_pause_log_threshold_) { 2867 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2868 << " for cause " << cause; 2869 } 2870 return last_gc_type; 2871} 2872 2873void Heap::DumpForSigQuit(std::ostream& os) { 2874 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2875 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2876 DumpGcPerformanceInfo(os); 2877} 2878 2879size_t Heap::GetPercentFree() { 2880 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2881} 2882 2883void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2884 if (max_allowed_footprint > GetMaxMemory()) { 2885 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2886 << PrettySize(GetMaxMemory()); 2887 max_allowed_footprint = GetMaxMemory(); 2888 } 2889 max_allowed_footprint_ = max_allowed_footprint; 2890} 2891 2892bool Heap::IsMovableObject(const mirror::Object* obj) const { 2893 if (kMovingCollector) { 2894 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2895 if (space != nullptr) { 2896 // TODO: Check large object? 2897 return space->CanMoveObjects(); 2898 } 2899 } 2900 return false; 2901} 2902 2903void Heap::UpdateMaxNativeFootprint() { 2904 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2905 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2906 size_t target_size = native_size / GetTargetHeapUtilization(); 2907 if (target_size > native_size + max_free_) { 2908 target_size = native_size + max_free_; 2909 } else if (target_size < native_size + min_free_) { 2910 target_size = native_size + min_free_; 2911 } 2912 native_footprint_gc_watermark_ = std::min(growth_limit_, target_size); 2913} 2914 2915collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2916 for (const auto& collector : garbage_collectors_) { 2917 if (collector->GetCollectorType() == collector_type_ && 2918 collector->GetGcType() == gc_type) { 2919 return collector; 2920 } 2921 } 2922 return nullptr; 2923} 2924 2925double Heap::HeapGrowthMultiplier() const { 2926 // If we don't care about pause times we are background, so return 1.0. 2927 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2928 return 1.0; 2929 } 2930 return foreground_heap_growth_multiplier_; 2931} 2932 2933void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran) { 2934 // We know what our utilization is at this moment. 2935 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2936 const uint64_t bytes_allocated = GetBytesAllocated(); 2937 last_gc_size_ = bytes_allocated; 2938 last_gc_time_ns_ = NanoTime(); 2939 uint64_t target_size; 2940 collector::GcType gc_type = collector_ran->GetGcType(); 2941 if (gc_type != collector::kGcTypeSticky) { 2942 // Grow the heap for non sticky GC. 2943 const float multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2944 // foreground. 2945 intptr_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2946 CHECK_GE(delta, 0); 2947 target_size = bytes_allocated + delta * multiplier; 2948 target_size = std::min(target_size, 2949 bytes_allocated + static_cast<uint64_t>(max_free_ * multiplier)); 2950 target_size = std::max(target_size, 2951 bytes_allocated + static_cast<uint64_t>(min_free_ * multiplier)); 2952 native_need_to_run_finalization_ = true; 2953 next_gc_type_ = collector::kGcTypeSticky; 2954 } else { 2955 collector::GcType non_sticky_gc_type = 2956 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 2957 // Find what the next non sticky collector will be. 2958 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2959 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2960 // do another sticky collection next. 2961 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2962 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2963 // if the sticky GC throughput always remained >= the full/partial throughput. 2964 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2965 non_sticky_collector->GetEstimatedMeanThroughput() && 2966 non_sticky_collector->NumberOfIterations() > 0 && 2967 bytes_allocated <= max_allowed_footprint_) { 2968 next_gc_type_ = collector::kGcTypeSticky; 2969 } else { 2970 next_gc_type_ = non_sticky_gc_type; 2971 } 2972 // If we have freed enough memory, shrink the heap back down. 2973 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2974 target_size = bytes_allocated + max_free_; 2975 } else { 2976 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2977 } 2978 } 2979 if (!ignore_max_footprint_) { 2980 SetIdealFootprint(target_size); 2981 if (IsGcConcurrent()) { 2982 // Calculate when to perform the next ConcurrentGC. 2983 // Calculate the estimated GC duration. 2984 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2985 // Estimate how many remaining bytes we will have when we need to start the next GC. 2986 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2987 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2988 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2989 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2990 // A never going to happen situation that from the estimated allocation rate we will exceed 2991 // the applications entire footprint with the given estimated allocation rate. Schedule 2992 // another GC nearly straight away. 2993 remaining_bytes = kMinConcurrentRemainingBytes; 2994 } 2995 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2996 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 2997 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2998 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2999 // right away. 3000 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 3001 static_cast<size_t>(bytes_allocated)); 3002 } 3003 } 3004} 3005 3006void Heap::ClearGrowthLimit() { 3007 growth_limit_ = capacity_; 3008 for (const auto& space : continuous_spaces_) { 3009 if (space->IsMallocSpace()) { 3010 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3011 malloc_space->ClearGrowthLimit(); 3012 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 3013 } 3014 } 3015 // This space isn't added for performance reasons. 3016 if (main_space_backup_.get() != nullptr) { 3017 main_space_backup_->ClearGrowthLimit(); 3018 main_space_backup_->SetFootprintLimit(main_space_backup_->Capacity()); 3019 } 3020} 3021 3022void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 3023 ScopedObjectAccess soa(self); 3024 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 3025 jvalue args[1]; 3026 args[0].l = arg.get(); 3027 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 3028 // Restore object in case it gets moved. 3029 *object = soa.Decode<mirror::Object*>(arg.get()); 3030} 3031 3032void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 3033 StackHandleScope<1> hs(self); 3034 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 3035 RequestConcurrentGC(self); 3036} 3037 3038void Heap::RequestConcurrentGC(Thread* self) { 3039 // Make sure that we can do a concurrent GC. 3040 Runtime* runtime = Runtime::Current(); 3041 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 3042 self->IsHandlingStackOverflow()) { 3043 return; 3044 } 3045 NotifyConcurrentGCRequest(self); 3046} 3047 3048void Heap::ConcurrentGC(Thread* self) { 3049 if (Runtime::Current()->IsShuttingDown(self)) { 3050 return; 3051 } 3052 // Wait for any GCs currently running to finish. 3053 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 3054 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 3055 // instead. E.g. can't do partial, so do full instead. 3056 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 3057 collector::kGcTypeNone) { 3058 for (collector::GcType gc_type : gc_plan_) { 3059 // Attempt to run the collector, if we succeed, we are done. 3060 if (gc_type > next_gc_type_ && 3061 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 3062 break; 3063 } 3064 } 3065 } 3066 } 3067} 3068 3069void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 3070 Thread* self = Thread::Current(); 3071 { 3072 MutexLock mu(self, *heap_trim_request_lock_); 3073 if (desired_collector_type_ == desired_collector_type) { 3074 return; 3075 } 3076 heap_transition_or_trim_target_time_ = 3077 std::max(heap_transition_or_trim_target_time_, NanoTime() + delta_time); 3078 desired_collector_type_ = desired_collector_type; 3079 } 3080 SignalHeapTrimDaemon(self); 3081} 3082 3083void Heap::RequestHeapTrim() { 3084 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3085 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3086 // a space it will hold its lock and can become a cause of jank. 3087 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3088 // forking. 3089 3090 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3091 // because that only marks object heads, so a large array looks like lots of empty space. We 3092 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3093 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3094 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3095 // not how much use we're making of those pages. 3096 3097 Thread* self = Thread::Current(); 3098 Runtime* runtime = Runtime::Current(); 3099 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 3100 runtime->IsZygote()) { 3101 // Ignore the request if we are the zygote to prevent app launching lag due to sleep in heap 3102 // trimmer daemon. b/17310019 3103 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 3104 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 3105 // as we don't hold the lock while requesting the trim). 3106 return; 3107 } 3108 { 3109 MutexLock mu(self, *heap_trim_request_lock_); 3110 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 3111 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 3112 // just yet. 3113 return; 3114 } 3115 heap_trim_request_pending_ = true; 3116 uint64_t current_time = NanoTime(); 3117 if (heap_transition_or_trim_target_time_ < current_time) { 3118 heap_transition_or_trim_target_time_ = current_time + kHeapTrimWait; 3119 } 3120 } 3121 // Notify the daemon thread which will actually do the heap trim. 3122 SignalHeapTrimDaemon(self); 3123} 3124 3125void Heap::SignalHeapTrimDaemon(Thread* self) { 3126 JNIEnv* env = self->GetJniEnv(); 3127 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 3128 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 3129 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 3130 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 3131 CHECK(!env->ExceptionCheck()); 3132} 3133 3134void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3135 if (rosalloc_space_ != nullptr) { 3136 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3137 } 3138 if (bump_pointer_space_ != nullptr) { 3139 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 3140 } 3141} 3142 3143void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3144 if (rosalloc_space_ != nullptr) { 3145 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3146 } 3147} 3148 3149void Heap::RevokeAllThreadLocalBuffers() { 3150 if (rosalloc_space_ != nullptr) { 3151 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3152 } 3153 if (bump_pointer_space_ != nullptr) { 3154 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3155 } 3156} 3157 3158bool Heap::IsGCRequestPending() const { 3159 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 3160} 3161 3162void Heap::RunFinalization(JNIEnv* env) { 3163 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3164 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3165 CHECK(WellKnownClasses::java_lang_System != nullptr); 3166 WellKnownClasses::java_lang_System_runFinalization = 3167 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3168 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3169 } 3170 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3171 WellKnownClasses::java_lang_System_runFinalization); 3172} 3173 3174void Heap::RegisterNativeAllocation(JNIEnv* env, size_t bytes) { 3175 Thread* self = ThreadForEnv(env); 3176 if (native_need_to_run_finalization_) { 3177 RunFinalization(env); 3178 UpdateMaxNativeFootprint(); 3179 native_need_to_run_finalization_ = false; 3180 } 3181 // Total number of native bytes allocated. 3182 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3183 new_native_bytes_allocated += bytes; 3184 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3185 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3186 collector::kGcTypeFull; 3187 3188 // The second watermark is higher than the gc watermark. If you hit this it means you are 3189 // allocating native objects faster than the GC can keep up with. 3190 if (new_native_bytes_allocated > growth_limit_) { 3191 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3192 // Just finished a GC, attempt to run finalizers. 3193 RunFinalization(env); 3194 CHECK(!env->ExceptionCheck()); 3195 } 3196 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3197 if (new_native_bytes_allocated > growth_limit_) { 3198 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3199 RunFinalization(env); 3200 native_need_to_run_finalization_ = false; 3201 CHECK(!env->ExceptionCheck()); 3202 } 3203 // We have just run finalizers, update the native watermark since it is very likely that 3204 // finalizers released native managed allocations. 3205 UpdateMaxNativeFootprint(); 3206 } else if (!IsGCRequestPending()) { 3207 if (IsGcConcurrent()) { 3208 RequestConcurrentGC(self); 3209 } else { 3210 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3211 } 3212 } 3213 } 3214} 3215 3216void Heap::RegisterNativeFree(JNIEnv* env, size_t bytes) { 3217 size_t expected_size; 3218 do { 3219 expected_size = native_bytes_allocated_.LoadRelaxed(); 3220 if (UNLIKELY(bytes > expected_size)) { 3221 ScopedObjectAccess soa(env); 3222 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3223 StringPrintf("Attempted to free %zd native bytes with only %zd native bytes " 3224 "registered as allocated", bytes, expected_size).c_str()); 3225 break; 3226 } 3227 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, 3228 expected_size - bytes)); 3229} 3230 3231size_t Heap::GetTotalMemory() const { 3232 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3233} 3234 3235void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3236 DCHECK(mod_union_table != nullptr); 3237 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3238} 3239 3240void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3241 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3242 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3243 CHECK_GE(byte_count, sizeof(mirror::Object)); 3244} 3245 3246void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3247 CHECK(remembered_set != nullptr); 3248 space::Space* space = remembered_set->GetSpace(); 3249 CHECK(space != nullptr); 3250 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3251 remembered_sets_.Put(space, remembered_set); 3252 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3253} 3254 3255void Heap::RemoveRememberedSet(space::Space* space) { 3256 CHECK(space != nullptr); 3257 auto it = remembered_sets_.find(space); 3258 CHECK(it != remembered_sets_.end()); 3259 delete it->second; 3260 remembered_sets_.erase(it); 3261 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3262} 3263 3264void Heap::ClearMarkedObjects() { 3265 // Clear all of the spaces' mark bitmaps. 3266 for (const auto& space : GetContinuousSpaces()) { 3267 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3268 if (space->GetLiveBitmap() != mark_bitmap) { 3269 mark_bitmap->Clear(); 3270 } 3271 } 3272 // Clear the marked objects in the discontinous space object sets. 3273 for (const auto& space : GetDiscontinuousSpaces()) { 3274 space->GetMarkBitmap()->Clear(); 3275 } 3276} 3277 3278void Heap::WaitForConcurrentGCRequest(Thread* self) { 3279 ScopedThreadStateChange tsc(self, kBlocked); 3280 MutexLock mu(self, *gc_request_lock_); 3281 while (!gc_request_pending_) { 3282 gc_request_cond_->Wait(self); 3283 } 3284 gc_request_pending_ = false; 3285} 3286 3287void Heap::NotifyConcurrentGCRequest(Thread* self) { 3288 ScopedThreadStateChange tsc(self, kBlocked); 3289 MutexLock mu(self, *gc_request_lock_); 3290 gc_request_pending_ = true; 3291 gc_request_cond_->Signal(self); 3292} 3293 3294} // namespace gc 3295} // namespace art 3296