heap.cc revision 407f702da4f867c074fc3c8c688b8f8c32279eff
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 <vector> 24#include <valgrind.h> 25 26#include "base/histogram-inl.h" 27#include "base/stl_util.h" 28#include "common_throws.h" 29#include "cutils/sched_policy.h" 30#include "debugger.h" 31#include "gc/accounting/atomic_stack.h" 32#include "gc/accounting/card_table-inl.h" 33#include "gc/accounting/heap_bitmap-inl.h" 34#include "gc/accounting/mod_union_table.h" 35#include "gc/accounting/mod_union_table-inl.h" 36#include "gc/accounting/remembered_set.h" 37#include "gc/accounting/space_bitmap-inl.h" 38#include "gc/collector/mark_sweep-inl.h" 39#include "gc/collector/partial_mark_sweep.h" 40#include "gc/collector/semi_space.h" 41#include "gc/collector/sticky_mark_sweep.h" 42#include "gc/space/bump_pointer_space.h" 43#include "gc/space/dlmalloc_space-inl.h" 44#include "gc/space/image_space.h" 45#include "gc/space/large_object_space.h" 46#include "gc/space/rosalloc_space-inl.h" 47#include "gc/space/space-inl.h" 48#include "gc/space/zygote_space.h" 49#include "entrypoints/quick/quick_alloc_entrypoints.h" 50#include "heap-inl.h" 51#include "image.h" 52#include "mirror/art_field-inl.h" 53#include "mirror/class-inl.h" 54#include "mirror/object.h" 55#include "mirror/object-inl.h" 56#include "mirror/object_array-inl.h" 57#include "mirror/reference-inl.h" 58#include "object_utils.h" 59#include "os.h" 60#include "reflection.h" 61#include "runtime.h" 62#include "ScopedLocalRef.h" 63#include "scoped_thread_state_change.h" 64#include "sirt_ref.h" 65#include "thread_list.h" 66#include "UniquePtr.h" 67#include "well_known_classes.h" 68 69namespace art { 70 71namespace gc { 72 73static constexpr bool kGCALotMode = false; 74static constexpr size_t kGcAlotInterval = KB; 75// Minimum amount of remaining bytes before a concurrent GC is triggered. 76static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 77static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 78 79Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 80 double target_utilization, size_t capacity, const std::string& image_file_name, 81 CollectorType post_zygote_collector_type, CollectorType background_collector_type, 82 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 83 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 84 bool ignore_max_footprint, bool use_tlab, bool verify_pre_gc_heap, 85 bool verify_post_gc_heap, bool verify_pre_gc_rosalloc, 86 bool verify_post_gc_rosalloc) 87 : non_moving_space_(nullptr), 88 rosalloc_space_(nullptr), 89 dlmalloc_space_(nullptr), 90 main_space_(nullptr), 91 collector_type_(kCollectorTypeNone), 92 post_zygote_collector_type_(post_zygote_collector_type), 93 background_collector_type_(background_collector_type), 94 desired_collector_type_(collector_type_), 95 heap_trim_request_lock_(nullptr), 96 last_trim_time_(0), 97 heap_transition_target_time_(0), 98 heap_trim_request_pending_(false), 99 parallel_gc_threads_(parallel_gc_threads), 100 conc_gc_threads_(conc_gc_threads), 101 low_memory_mode_(low_memory_mode), 102 long_pause_log_threshold_(long_pause_log_threshold), 103 long_gc_log_threshold_(long_gc_log_threshold), 104 ignore_max_footprint_(ignore_max_footprint), 105 have_zygote_space_(false), 106 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 107 collector_type_running_(kCollectorTypeNone), 108 last_gc_type_(collector::kGcTypeNone), 109 next_gc_type_(collector::kGcTypePartial), 110 capacity_(capacity), 111 growth_limit_(growth_limit), 112 max_allowed_footprint_(initial_size), 113 native_footprint_gc_watermark_(initial_size), 114 native_footprint_limit_(2 * initial_size), 115 native_need_to_run_finalization_(false), 116 // Initially assume we perceive jank in case the process state is never updated. 117 process_state_(kProcessStateJankPerceptible), 118 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 119 total_bytes_freed_ever_(0), 120 total_objects_freed_ever_(0), 121 num_bytes_allocated_(0), 122 native_bytes_allocated_(0), 123 gc_memory_overhead_(0), 124 verify_missing_card_marks_(false), 125 verify_system_weaks_(false), 126 verify_pre_gc_heap_(verify_pre_gc_heap), 127 verify_post_gc_heap_(verify_post_gc_heap), 128 verify_mod_union_table_(false), 129 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 130 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 131 allocation_rate_(0), 132 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 133 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 134 * verification is enabled, we limit the size of allocation stacks to speed up their 135 * searching. 136 */ 137 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 138 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 139 current_allocator_(kAllocatorTypeDlMalloc), 140 current_non_moving_allocator_(kAllocatorTypeNonMoving), 141 bump_pointer_space_(nullptr), 142 temp_space_(nullptr), 143 min_free_(min_free), 144 max_free_(max_free), 145 target_utilization_(target_utilization), 146 total_wait_time_(0), 147 total_allocation_time_(0), 148 verify_object_mode_(kVerifyObjectModeDisabled), 149 disable_moving_gc_count_(0), 150 running_on_valgrind_(RUNNING_ON_VALGRIND > 0), 151 use_tlab_(use_tlab) { 152 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 153 LOG(INFO) << "Heap() entering"; 154 } 155 const bool is_zygote = Runtime::Current()->IsZygote(); 156 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 157 // entrypoints. 158 if (!is_zygote) { 159 desired_collector_type_ = post_zygote_collector_type_; 160 large_object_threshold_ = kDefaultLargeObjectThreshold; 161 } else { 162 if (kMovingCollector) { 163 // We are the zygote, use bump pointer allocation + semi space collector. 164 bool generational = post_zygote_collector_type_ == kCollectorTypeGSS; 165 desired_collector_type_ = generational ? kCollectorTypeGSS : kCollectorTypeSS; 166 } else { 167 desired_collector_type_ = post_zygote_collector_type_; 168 } 169 } 170 ChangeCollector(desired_collector_type_); 171 172 live_bitmap_.reset(new accounting::HeapBitmap(this)); 173 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 174 // Requested begin for the alloc space, to follow the mapped image and oat files 175 byte* requested_alloc_space_begin = nullptr; 176 if (!image_file_name.empty()) { 177 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str()); 178 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 179 AddSpace(image_space); 180 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 181 // isn't going to get in the middle 182 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 183 CHECK_GT(oat_file_end_addr, image_space->End()); 184 if (oat_file_end_addr > requested_alloc_space_begin) { 185 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 186 } 187 } 188 MemMap* malloc_space_mem_map = nullptr; 189 const char* malloc_space_name = is_zygote ? "zygote space" : "alloc space"; 190 if (is_zygote) { 191 // Allocate a single mem map that is split into the malloc space 192 // and the post zygote non-moving space to put them adjacent. 193 size_t post_zygote_non_moving_space_size = 64 * MB; 194 size_t non_moving_spaces_size = capacity + post_zygote_non_moving_space_size; 195 std::string error_str; 196 malloc_space_mem_map = MemMap::MapAnonymous(malloc_space_name, requested_alloc_space_begin, 197 non_moving_spaces_size, PROT_READ | PROT_WRITE, 198 true, &error_str); 199 CHECK(malloc_space_mem_map != nullptr) << error_str; 200 post_zygote_non_moving_space_mem_map_.reset(malloc_space_mem_map->RemapAtEnd( 201 malloc_space_mem_map->Begin() + capacity, "post zygote non-moving space", 202 PROT_READ | PROT_WRITE, &error_str)); 203 CHECK(post_zygote_non_moving_space_mem_map_.get() != nullptr) << error_str; 204 VLOG(heap) << "malloc space mem map : " << malloc_space_mem_map; 205 VLOG(heap) << "post zygote non-moving space mem map : " 206 << post_zygote_non_moving_space_mem_map_.get(); 207 } else { 208 // Allocate a mem map for the malloc space. 209 std::string error_str; 210 malloc_space_mem_map = MemMap::MapAnonymous(malloc_space_name, requested_alloc_space_begin, 211 capacity, PROT_READ | PROT_WRITE, true, &error_str); 212 CHECK(malloc_space_mem_map != nullptr) << error_str; 213 VLOG(heap) << "malloc space mem map : " << malloc_space_mem_map; 214 } 215 CHECK(malloc_space_mem_map != nullptr); 216 space::MallocSpace* malloc_space; 217 if (kUseRosAlloc) { 218 malloc_space = space::RosAllocSpace::CreateFromMemMap(malloc_space_mem_map, malloc_space_name, 219 kDefaultStartingSize, initial_size, 220 growth_limit, capacity, low_memory_mode_); 221 CHECK(malloc_space != nullptr) << "Failed to create rosalloc space"; 222 } else { 223 malloc_space = space::DlMallocSpace::CreateFromMemMap(malloc_space_mem_map, malloc_space_name, 224 kDefaultStartingSize, initial_size, 225 growth_limit, capacity); 226 CHECK(malloc_space != nullptr) << "Failed to create dlmalloc space"; 227 } 228 VLOG(heap) << "malloc_space : " << malloc_space; 229 if (kMovingCollector) { 230 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 231 // TODO: Having 3+ spaces as big as the large heap size can cause virtual memory fragmentation 232 // issues. 233 const size_t bump_pointer_space_size = std::min(malloc_space->Capacity(), 128 * MB); 234 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space", 235 bump_pointer_space_size, nullptr); 236 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 237 AddSpace(bump_pointer_space_); 238 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", bump_pointer_space_size, 239 nullptr); 240 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 241 AddSpace(temp_space_); 242 VLOG(heap) << "bump_pointer_space : " << bump_pointer_space_; 243 VLOG(heap) << "temp_space : " << temp_space_; 244 } 245 non_moving_space_ = malloc_space; 246 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 247 AddSpace(malloc_space); 248 249 // Allocate the large object space. 250 constexpr bool kUseFreeListSpaceForLOS = false; 251 if (kUseFreeListSpaceForLOS) { 252 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity); 253 } else { 254 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 255 } 256 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 257 AddSpace(large_object_space_); 258 259 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 260 CHECK(!continuous_spaces_.empty()); 261 262 // Relies on the spaces being sorted. 263 byte* heap_begin = continuous_spaces_.front()->Begin(); 264 byte* heap_end = continuous_spaces_.back()->Limit(); 265 if (is_zygote) { 266 CHECK(post_zygote_non_moving_space_mem_map_.get() != nullptr); 267 heap_begin = std::min(post_zygote_non_moving_space_mem_map_->Begin(), heap_begin); 268 heap_end = std::max(post_zygote_non_moving_space_mem_map_->End(), heap_end); 269 } 270 size_t heap_capacity = heap_end - heap_begin; 271 272 // Allocate the card table. 273 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 274 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 275 276 // Card cache for now since it makes it easier for us to update the references to the copying 277 // spaces. 278 accounting::ModUnionTable* mod_union_table = 279 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 280 GetImageSpace()); 281 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 282 AddModUnionTable(mod_union_table); 283 284 if (collector::SemiSpace::kUseRememberedSet) { 285 accounting::RememberedSet* non_moving_space_rem_set = 286 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 287 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 288 AddRememberedSet(non_moving_space_rem_set); 289 } 290 291 // TODO: Count objects in the image space here. 292 num_bytes_allocated_ = 0; 293 294 // Default mark stack size in bytes. 295 static const size_t default_mark_stack_size = 64 * KB; 296 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", default_mark_stack_size)); 297 allocation_stack_.reset(accounting::ObjectStack::Create("allocation stack", 298 max_allocation_stack_size_)); 299 live_stack_.reset(accounting::ObjectStack::Create("live stack", 300 max_allocation_stack_size_)); 301 302 // It's still too early to take a lock because there are no threads yet, but we can create locks 303 // now. We don't create it earlier to make it clear that you can't use locks during heap 304 // initialization. 305 gc_complete_lock_ = new Mutex("GC complete lock"); 306 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 307 *gc_complete_lock_)); 308 heap_trim_request_lock_ = new Mutex("Heap trim request lock"); 309 last_gc_size_ = GetBytesAllocated(); 310 311 if (ignore_max_footprint_) { 312 SetIdealFootprint(std::numeric_limits<size_t>::max()); 313 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 314 } 315 CHECK_NE(max_allowed_footprint_, 0U); 316 317 // Create our garbage collectors. 318 for (size_t i = 0; i < 2; ++i) { 319 const bool concurrent = i != 0; 320 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 321 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 322 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 323 } 324 if (kMovingCollector) { 325 // TODO: Clean this up. 326 bool generational = post_zygote_collector_type_ == kCollectorTypeGSS; 327 semi_space_collector_ = new collector::SemiSpace(this, generational); 328 garbage_collectors_.push_back(semi_space_collector_); 329 } 330 331 if (running_on_valgrind_) { 332 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 333 } 334 335 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 336 LOG(INFO) << "Heap() exiting"; 337 } 338} 339 340void Heap::ChangeAllocator(AllocatorType allocator) { 341 if (current_allocator_ != allocator) { 342 // These two allocators are only used internally and don't have any entrypoints. 343 CHECK_NE(allocator, kAllocatorTypeLOS); 344 CHECK_NE(allocator, kAllocatorTypeNonMoving); 345 current_allocator_ = allocator; 346 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 347 SetQuickAllocEntryPointsAllocator(current_allocator_); 348 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 349 } 350} 351 352void Heap::DisableCompaction() { 353 if (IsCompactingGC(post_zygote_collector_type_)) { 354 post_zygote_collector_type_ = kCollectorTypeCMS; 355 } 356 if (IsCompactingGC(background_collector_type_)) { 357 background_collector_type_ = post_zygote_collector_type_; 358 } 359 TransitionCollector(post_zygote_collector_type_); 360} 361 362std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 363 if (!IsValidContinuousSpaceObjectAddress(klass)) { 364 return StringPrintf("<non heap address klass %p>", klass); 365 } 366 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 367 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 368 std::string result("["); 369 result += SafeGetClassDescriptor(component_type); 370 return result; 371 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 372 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 373 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 374 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 375 } else { 376 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 377 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 378 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 379 } 380 const DexFile* dex_file = dex_cache->GetDexFile(); 381 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 382 if (class_def_idx == DexFile::kDexNoIndex16) { 383 return "<class def not found>"; 384 } 385 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 386 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 387 return dex_file->GetTypeDescriptor(type_id); 388 } 389} 390 391std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 392 if (obj == nullptr) { 393 return "null"; 394 } 395 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 396 if (klass == nullptr) { 397 return "(class=null)"; 398 } 399 std::string result(SafeGetClassDescriptor(klass)); 400 if (obj->IsClass()) { 401 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 402 } 403 return result; 404} 405 406void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 407 if (obj == nullptr) { 408 stream << "(obj=null)"; 409 return; 410 } 411 if (IsAligned<kObjectAlignment>(obj)) { 412 space::Space* space = nullptr; 413 // Don't use find space since it only finds spaces which actually contain objects instead of 414 // spaces which may contain objects (e.g. cleared bump pointer spaces). 415 for (const auto& cur_space : continuous_spaces_) { 416 if (cur_space->HasAddress(obj)) { 417 space = cur_space; 418 break; 419 } 420 } 421 if (space == nullptr) { 422 if (allocator_mem_map_.get() == nullptr || !allocator_mem_map_->HasAddress(obj)) { 423 stream << "obj " << obj << " not a valid heap address"; 424 return; 425 } else if (allocator_mem_map_.get() != nullptr) { 426 allocator_mem_map_->Protect(PROT_READ | PROT_WRITE); 427 } 428 } 429 // Unprotect all the spaces. 430 for (const auto& space : continuous_spaces_) { 431 mprotect(space->Begin(), space->Capacity(), PROT_READ | PROT_WRITE); 432 } 433 stream << "Object " << obj; 434 if (space != nullptr) { 435 stream << " in space " << *space; 436 } 437 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 438 stream << "\nclass=" << klass; 439 if (klass != nullptr) { 440 stream << " type= " << SafePrettyTypeOf(obj); 441 } 442 // Re-protect the address we faulted on. 443 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 444 } 445} 446 447bool Heap::IsCompilingBoot() const { 448 for (const auto& space : continuous_spaces_) { 449 if (space->IsImageSpace() || space->IsZygoteSpace()) { 450 return false; 451 } 452 } 453 return true; 454} 455 456bool Heap::HasImageSpace() const { 457 for (const auto& space : continuous_spaces_) { 458 if (space->IsImageSpace()) { 459 return true; 460 } 461 } 462 return false; 463} 464 465void Heap::IncrementDisableMovingGC(Thread* self) { 466 // Need to do this holding the lock to prevent races where the GC is about to run / running when 467 // we attempt to disable it. 468 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 469 MutexLock mu(self, *gc_complete_lock_); 470 ++disable_moving_gc_count_; 471 if (IsCompactingGC(collector_type_running_)) { 472 WaitForGcToCompleteLocked(self); 473 } 474} 475 476void Heap::DecrementDisableMovingGC(Thread* self) { 477 MutexLock mu(self, *gc_complete_lock_); 478 CHECK_GE(disable_moving_gc_count_, 0U); 479 --disable_moving_gc_count_; 480} 481 482void Heap::UpdateProcessState(ProcessState process_state) { 483 if (process_state_ != process_state) { 484 process_state_ = process_state; 485 if (process_state_ == kProcessStateJankPerceptible) { 486 // Transition back to foreground right away to prevent jank. 487 RequestCollectorTransition(post_zygote_collector_type_, 0); 488 } else { 489 // Don't delay for debug builds since we may want to stress test the GC. 490 RequestCollectorTransition(background_collector_type_, kIsDebugBuild ? 0 : 491 kCollectorTransitionWait); 492 } 493 } 494} 495 496void Heap::CreateThreadPool() { 497 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 498 if (num_threads != 0) { 499 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 500 } 501} 502 503void Heap::VisitObjects(ObjectCallback callback, void* arg) { 504 Thread* self = Thread::Current(); 505 // GCs can move objects, so don't allow this. 506 const char* old_cause = self->StartAssertNoThreadSuspension("Visiting objects"); 507 if (bump_pointer_space_ != nullptr) { 508 // Visit objects in bump pointer space. 509 bump_pointer_space_->Walk(callback, arg); 510 } 511 // TODO: Switch to standard begin and end to use ranged a based loop. 512 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 513 it < end; ++it) { 514 mirror::Object* obj = *it; 515 if (obj != nullptr && obj->GetClass() != nullptr) { 516 // Avoid the race condition caused by the object not yet being written into the allocation 517 // stack or the class not yet being written in the object. Or, if kUseThreadLocalAllocationStack, 518 // there can be nulls on the allocation stack. 519 callback(obj, arg); 520 } 521 } 522 GetLiveBitmap()->Walk(callback, arg); 523 self->EndAssertNoThreadSuspension(old_cause); 524} 525 526void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 527 space::ContinuousSpace* space1 = rosalloc_space_ != nullptr ? rosalloc_space_ : non_moving_space_; 528 space::ContinuousSpace* space2 = dlmalloc_space_ != nullptr ? dlmalloc_space_ : non_moving_space_; 529 // This is just logic to handle a case of either not having a rosalloc or dlmalloc space. 530 // TODO: Generalize this to n bitmaps? 531 if (space1 == nullptr) { 532 DCHECK(space2 != nullptr); 533 space1 = space2; 534 } 535 if (space2 == nullptr) { 536 DCHECK(space1 != nullptr); 537 space2 = space1; 538 } 539 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 540 large_object_space_->GetLiveObjects(), stack); 541} 542 543void Heap::DeleteThreadPool() { 544 thread_pool_.reset(nullptr); 545} 546 547void Heap::AddSpace(space::Space* space, bool set_as_default) { 548 DCHECK(space != nullptr); 549 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 550 if (space->IsContinuousSpace()) { 551 DCHECK(!space->IsDiscontinuousSpace()); 552 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 553 // Continuous spaces don't necessarily have bitmaps. 554 accounting::SpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 555 accounting::SpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 556 if (live_bitmap != nullptr) { 557 DCHECK(mark_bitmap != nullptr); 558 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 559 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 560 } 561 continuous_spaces_.push_back(continuous_space); 562 if (set_as_default) { 563 if (continuous_space->IsDlMallocSpace()) { 564 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 565 } else if (continuous_space->IsRosAllocSpace()) { 566 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 567 } 568 } 569 // Ensure that spaces remain sorted in increasing order of start address. 570 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 571 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 572 return a->Begin() < b->Begin(); 573 }); 574 } else { 575 DCHECK(space->IsDiscontinuousSpace()); 576 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 577 DCHECK(discontinuous_space->GetLiveObjects() != nullptr); 578 live_bitmap_->AddDiscontinuousObjectSet(discontinuous_space->GetLiveObjects()); 579 DCHECK(discontinuous_space->GetMarkObjects() != nullptr); 580 mark_bitmap_->AddDiscontinuousObjectSet(discontinuous_space->GetMarkObjects()); 581 discontinuous_spaces_.push_back(discontinuous_space); 582 } 583 if (space->IsAllocSpace()) { 584 alloc_spaces_.push_back(space->AsAllocSpace()); 585 } 586} 587 588void Heap::RemoveSpace(space::Space* space) { 589 DCHECK(space != nullptr); 590 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 591 if (space->IsContinuousSpace()) { 592 DCHECK(!space->IsDiscontinuousSpace()); 593 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 594 // Continuous spaces don't necessarily have bitmaps. 595 accounting::SpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 596 accounting::SpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 597 if (live_bitmap != nullptr) { 598 DCHECK(mark_bitmap != nullptr); 599 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 600 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 601 } 602 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 603 DCHECK(it != continuous_spaces_.end()); 604 continuous_spaces_.erase(it); 605 if (continuous_space == dlmalloc_space_) { 606 dlmalloc_space_ = nullptr; 607 } else if (continuous_space == rosalloc_space_) { 608 rosalloc_space_ = nullptr; 609 } 610 if (continuous_space == main_space_) { 611 main_space_ = nullptr; 612 } 613 } else { 614 DCHECK(space->IsDiscontinuousSpace()); 615 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 616 DCHECK(discontinuous_space->GetLiveObjects() != nullptr); 617 live_bitmap_->RemoveDiscontinuousObjectSet(discontinuous_space->GetLiveObjects()); 618 DCHECK(discontinuous_space->GetMarkObjects() != nullptr); 619 mark_bitmap_->RemoveDiscontinuousObjectSet(discontinuous_space->GetMarkObjects()); 620 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 621 discontinuous_space); 622 DCHECK(it != discontinuous_spaces_.end()); 623 discontinuous_spaces_.erase(it); 624 } 625 if (space->IsAllocSpace()) { 626 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 627 DCHECK(it != alloc_spaces_.end()); 628 alloc_spaces_.erase(it); 629 } 630} 631 632void Heap::RegisterGCAllocation(size_t bytes) { 633 if (this != nullptr) { 634 gc_memory_overhead_.FetchAndAdd(bytes); 635 } 636} 637 638void Heap::RegisterGCDeAllocation(size_t bytes) { 639 if (this != nullptr) { 640 gc_memory_overhead_.FetchAndSub(bytes); 641 } 642} 643 644void Heap::DumpGcPerformanceInfo(std::ostream& os) { 645 // Dump cumulative timings. 646 os << "Dumping cumulative Gc timings\n"; 647 uint64_t total_duration = 0; 648 649 // Dump cumulative loggers for each GC type. 650 uint64_t total_paused_time = 0; 651 for (const auto& collector : garbage_collectors_) { 652 CumulativeLogger& logger = collector->GetCumulativeTimings(); 653 if (logger.GetTotalNs() != 0) { 654 os << Dumpable<CumulativeLogger>(logger); 655 const uint64_t total_ns = logger.GetTotalNs(); 656 const uint64_t total_pause_ns = collector->GetTotalPausedTimeNs(); 657 double seconds = NsToMs(logger.GetTotalNs()) / 1000.0; 658 const uint64_t freed_bytes = collector->GetTotalFreedBytes(); 659 const uint64_t freed_objects = collector->GetTotalFreedObjects(); 660 Histogram<uint64_t>::CumulativeData cumulative_data; 661 collector->GetPauseHistogram().CreateHistogram(&cumulative_data); 662 collector->GetPauseHistogram().PrintConfidenceIntervals(os, 0.99, cumulative_data); 663 os << collector->GetName() << " total time: " << PrettyDuration(total_ns) << "\n" 664 << collector->GetName() << " freed: " << freed_objects 665 << " objects with total size " << PrettySize(freed_bytes) << "\n" 666 << collector->GetName() << " throughput: " << freed_objects / seconds << "/s / " 667 << PrettySize(freed_bytes / seconds) << "/s\n"; 668 total_duration += total_ns; 669 total_paused_time += total_pause_ns; 670 } 671 } 672 uint64_t allocation_time = static_cast<uint64_t>(total_allocation_time_) * kTimeAdjust; 673 if (total_duration != 0) { 674 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 675 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 676 os << "Mean GC size throughput: " 677 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 678 os << "Mean GC object throughput: " 679 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 680 } 681 size_t total_objects_allocated = GetObjectsAllocatedEver(); 682 os << "Total number of allocations: " << total_objects_allocated << "\n"; 683 size_t total_bytes_allocated = GetBytesAllocatedEver(); 684 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 685 if (kMeasureAllocationTime) { 686 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 687 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 688 << "\n"; 689 } 690 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 691 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_) << "\n"; 692 os << "Approximate GC data structures memory overhead: " << gc_memory_overhead_; 693} 694 695Heap::~Heap() { 696 VLOG(heap) << "Starting ~Heap()"; 697 STLDeleteElements(&garbage_collectors_); 698 // If we don't reset then the mark stack complains in its destructor. 699 allocation_stack_->Reset(); 700 live_stack_->Reset(); 701 STLDeleteValues(&mod_union_tables_); 702 STLDeleteElements(&continuous_spaces_); 703 STLDeleteElements(&discontinuous_spaces_); 704 delete gc_complete_lock_; 705 VLOG(heap) << "Finished ~Heap()"; 706} 707 708space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 709 bool fail_ok) const { 710 for (const auto& space : continuous_spaces_) { 711 if (space->Contains(obj)) { 712 return space; 713 } 714 } 715 if (!fail_ok) { 716 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 717 } 718 return NULL; 719} 720 721space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 722 bool fail_ok) const { 723 for (const auto& space : discontinuous_spaces_) { 724 if (space->Contains(obj)) { 725 return space; 726 } 727 } 728 if (!fail_ok) { 729 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 730 } 731 return NULL; 732} 733 734space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 735 space::Space* result = FindContinuousSpaceFromObject(obj, true); 736 if (result != NULL) { 737 return result; 738 } 739 return FindDiscontinuousSpaceFromObject(obj, true); 740} 741 742struct SoftReferenceArgs { 743 IsMarkedCallback* is_marked_callback_; 744 MarkObjectCallback* mark_callback_; 745 void* arg_; 746}; 747 748mirror::Object* Heap::PreserveSoftReferenceCallback(mirror::Object* obj, void* arg) { 749 SoftReferenceArgs* args = reinterpret_cast<SoftReferenceArgs*>(arg); 750 // TODO: Not preserve all soft references. 751 return args->mark_callback_(obj, args->arg_); 752} 753 754void Heap::ProcessSoftReferences(TimingLogger& timings, bool clear_soft, 755 IsMarkedCallback* is_marked_callback, 756 MarkObjectCallback* mark_object_callback, 757 ProcessMarkStackCallback* process_mark_stack_callback, void* arg) { 758 // Unless required to clear soft references with white references, preserve some white referents. 759 if (!clear_soft) { 760 // Don't clear for sticky GC. 761 SoftReferenceArgs soft_reference_args; 762 soft_reference_args.is_marked_callback_ = is_marked_callback; 763 soft_reference_args.mark_callback_ = mark_object_callback; 764 soft_reference_args.arg_ = arg; 765 // References with a marked referent are removed from the list. 766 soft_reference_queue_.PreserveSomeSoftReferences(&PreserveSoftReferenceCallback, 767 &soft_reference_args); 768 process_mark_stack_callback(arg); 769 } 770} 771 772// Process reference class instances and schedule finalizations. 773void Heap::ProcessReferences(TimingLogger& timings, bool clear_soft, 774 IsMarkedCallback* is_marked_callback, 775 MarkObjectCallback* mark_object_callback, 776 ProcessMarkStackCallback* process_mark_stack_callback, void* arg) { 777 timings.StartSplit("(Paused)ProcessReferences"); 778 ProcessSoftReferences(timings, clear_soft, is_marked_callback, mark_object_callback, 779 process_mark_stack_callback, arg); 780 // Clear all remaining soft and weak references with white referents. 781 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 782 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 783 timings.EndSplit(); 784 // Preserve all white objects with finalize methods and schedule them for finalization. 785 timings.StartSplit("(Paused)EnqueueFinalizerReferences"); 786 finalizer_reference_queue_.EnqueueFinalizerReferences(cleared_references_, is_marked_callback, 787 mark_object_callback, arg); 788 process_mark_stack_callback(arg); 789 timings.EndSplit(); 790 timings.StartSplit("(Paused)ProcessReferences"); 791 // Clear all f-reachable soft and weak references with white referents. 792 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 793 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 794 // Clear all phantom references with white referents. 795 phantom_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 796 // At this point all reference queues other than the cleared references should be empty. 797 DCHECK(soft_reference_queue_.IsEmpty()); 798 DCHECK(weak_reference_queue_.IsEmpty()); 799 DCHECK(finalizer_reference_queue_.IsEmpty()); 800 DCHECK(phantom_reference_queue_.IsEmpty()); 801 timings.EndSplit(); 802} 803 804// Process the "referent" field in a java.lang.ref.Reference. If the referent has not yet been 805// marked, put it on the appropriate list in the heap for later processing. 806void Heap::DelayReferenceReferent(mirror::Class* klass, mirror::Reference* ref, 807 IsMarkedCallback is_marked_callback, void* arg) { 808 DCHECK_EQ(klass, ref->GetClass()); 809 mirror::Object* referent = ref->GetReferent(); 810 if (referent != nullptr) { 811 mirror::Object* forward_address = is_marked_callback(referent, arg); 812 // Null means that the object is not currently marked. 813 if (forward_address == nullptr) { 814 Thread* self = Thread::Current(); 815 // TODO: Remove these locks, and use atomic stacks for storing references? 816 // We need to check that the references haven't already been enqueued since we can end up 817 // scanning the same reference multiple times due to dirty cards. 818 if (klass->IsSoftReferenceClass()) { 819 soft_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 820 } else if (klass->IsWeakReferenceClass()) { 821 weak_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 822 } else if (klass->IsFinalizerReferenceClass()) { 823 finalizer_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 824 } else if (klass->IsPhantomReferenceClass()) { 825 phantom_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 826 } else { 827 LOG(FATAL) << "Invalid reference type " << PrettyClass(klass) << " " << std::hex 828 << klass->GetAccessFlags(); 829 } 830 } else if (referent != forward_address) { 831 // Referent is already marked and we need to update it. 832 ref->SetReferent<false>(forward_address); 833 } 834 } 835} 836 837space::ImageSpace* Heap::GetImageSpace() const { 838 for (const auto& space : continuous_spaces_) { 839 if (space->IsImageSpace()) { 840 return space->AsImageSpace(); 841 } 842 } 843 return NULL; 844} 845 846static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) { 847 size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start); 848 if (used_bytes < chunk_size) { 849 size_t chunk_free_bytes = chunk_size - used_bytes; 850 size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg); 851 max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes); 852 } 853} 854 855void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, bool large_object_allocation) { 856 std::ostringstream oss; 857 size_t total_bytes_free = GetFreeMemory(); 858 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 859 << " free bytes"; 860 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 861 if (!large_object_allocation && total_bytes_free >= byte_count) { 862 size_t max_contiguous_allocation = 0; 863 for (const auto& space : continuous_spaces_) { 864 if (space->IsMallocSpace()) { 865 // To allow the Walk/InspectAll() to exclusively-lock the mutator 866 // lock, temporarily release the shared access to the mutator 867 // lock here by transitioning to the suspended state. 868 Locks::mutator_lock_->AssertSharedHeld(self); 869 self->TransitionFromRunnableToSuspended(kSuspended); 870 space->AsMallocSpace()->Walk(MSpaceChunkCallback, &max_contiguous_allocation); 871 self->TransitionFromSuspendedToRunnable(); 872 Locks::mutator_lock_->AssertSharedHeld(self); 873 } 874 } 875 oss << "; failed due to fragmentation (largest possible contiguous allocation " 876 << max_contiguous_allocation << " bytes)"; 877 } 878 self->ThrowOutOfMemoryError(oss.str().c_str()); 879} 880 881void Heap::DoPendingTransitionOrTrim() { 882 Thread* self = Thread::Current(); 883 CollectorType desired_collector_type; 884 // Wait until we reach the desired transition time. 885 while (true) { 886 uint64_t wait_time; 887 { 888 MutexLock mu(self, *heap_trim_request_lock_); 889 desired_collector_type = desired_collector_type_; 890 uint64_t current_time = NanoTime(); 891 if (current_time >= heap_transition_target_time_) { 892 break; 893 } 894 wait_time = heap_transition_target_time_ - current_time; 895 } 896 ScopedThreadStateChange tsc(self, kSleeping); 897 usleep(wait_time / 1000); // Usleep takes microseconds. 898 } 899 // Transition the collector if the desired collector type is not the same as the current 900 // collector type. 901 TransitionCollector(desired_collector_type); 902 // Do a heap trim if it is needed. 903 Trim(); 904} 905 906void Heap::Trim() { 907 Thread* self = Thread::Current(); 908 { 909 MutexLock mu(self, *heap_trim_request_lock_); 910 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 911 return; 912 } 913 last_trim_time_ = NanoTime(); 914 heap_trim_request_pending_ = false; 915 } 916 { 917 // Need to do this before acquiring the locks since we don't want to get suspended while 918 // holding any locks. 919 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 920 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 921 // trimming. 922 MutexLock mu(self, *gc_complete_lock_); 923 // Ensure there is only one GC at a time. 924 WaitForGcToCompleteLocked(self); 925 collector_type_running_ = kCollectorTypeHeapTrim; 926 } 927 uint64_t start_ns = NanoTime(); 928 // Trim the managed spaces. 929 uint64_t total_alloc_space_allocated = 0; 930 uint64_t total_alloc_space_size = 0; 931 uint64_t managed_reclaimed = 0; 932 for (const auto& space : continuous_spaces_) { 933 if (space->IsMallocSpace()) { 934 gc::space::MallocSpace* alloc_space = space->AsMallocSpace(); 935 total_alloc_space_size += alloc_space->Size(); 936 managed_reclaimed += alloc_space->Trim(); 937 } 938 } 939 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated() - 940 bump_pointer_space_->Size(); 941 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 942 static_cast<float>(total_alloc_space_size); 943 uint64_t gc_heap_end_ns = NanoTime(); 944 // We never move things in the native heap, so we can finish the GC at this point. 945 FinishGC(self, collector::kGcTypeNone); 946 // Trim the native heap. 947 dlmalloc_trim(0); 948 size_t native_reclaimed = 0; 949 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 950 uint64_t end_ns = NanoTime(); 951 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 952 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 953 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 954 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 955 << "%."; 956} 957 958bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 959 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 960 // taking the lock. 961 if (obj == nullptr) { 962 return true; 963 } 964 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 965} 966 967bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 968 return FindContinuousSpaceFromObject(obj, true) != nullptr; 969} 970 971bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 972 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 973 return false; 974 } 975 for (const auto& space : continuous_spaces_) { 976 if (space->HasAddress(obj)) { 977 return true; 978 } 979 } 980 return false; 981} 982 983bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 984 bool search_live_stack, bool sorted) { 985 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 986 return false; 987 } 988 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 989 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 990 if (obj == klass) { 991 // This case happens for java.lang.Class. 992 return true; 993 } 994 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 995 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 996 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 997 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 998 return temp_space_->Contains(obj); 999 } 1000 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1001 space::DiscontinuousSpace* d_space = NULL; 1002 if (c_space != nullptr) { 1003 if (c_space->GetLiveBitmap()->Test(obj)) { 1004 return true; 1005 } 1006 } else { 1007 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1008 if (d_space != nullptr) { 1009 if (d_space->GetLiveObjects()->Test(obj)) { 1010 return true; 1011 } 1012 } 1013 } 1014 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1015 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1016 if (i > 0) { 1017 NanoSleep(MsToNs(10)); 1018 } 1019 if (search_allocation_stack) { 1020 if (sorted) { 1021 if (allocation_stack_->ContainsSorted(obj)) { 1022 return true; 1023 } 1024 } else if (allocation_stack_->Contains(obj)) { 1025 return true; 1026 } 1027 } 1028 1029 if (search_live_stack) { 1030 if (sorted) { 1031 if (live_stack_->ContainsSorted(obj)) { 1032 return true; 1033 } 1034 } else if (live_stack_->Contains(obj)) { 1035 return true; 1036 } 1037 } 1038 } 1039 // We need to check the bitmaps again since there is a race where we mark something as live and 1040 // then clear the stack containing it. 1041 if (c_space != nullptr) { 1042 if (c_space->GetLiveBitmap()->Test(obj)) { 1043 return true; 1044 } 1045 } else { 1046 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1047 if (d_space != nullptr && d_space->GetLiveObjects()->Test(obj)) { 1048 return true; 1049 } 1050 } 1051 return false; 1052} 1053 1054void Heap::DumpSpaces(std::ostream& stream) { 1055 for (const auto& space : continuous_spaces_) { 1056 accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1057 accounting::SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1058 stream << space << " " << *space << "\n"; 1059 if (live_bitmap != nullptr) { 1060 stream << live_bitmap << " " << *live_bitmap << "\n"; 1061 } 1062 if (mark_bitmap != nullptr) { 1063 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1064 } 1065 } 1066 for (const auto& space : discontinuous_spaces_) { 1067 stream << space << " " << *space << "\n"; 1068 } 1069} 1070 1071void Heap::VerifyObjectBody(mirror::Object* obj) { 1072 if (this == nullptr && verify_object_mode_ == kVerifyObjectModeDisabled) { 1073 return; 1074 } 1075 // Ignore early dawn of the universe verifications. 1076 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.Load()) < 10 * KB)) { 1077 return; 1078 } 1079 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1080 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>( 1081 mirror::Object::ClassOffset(), false); 1082 CHECK(c != nullptr) << "Null class in object " << obj; 1083 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1084 CHECK(VerifyClassClass(c)); 1085 1086 if (verify_object_mode_ > kVerifyObjectModeFast) { 1087 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1088 if (!IsLiveObjectLocked(obj)) { 1089 DumpSpaces(); 1090 LOG(FATAL) << "Object is dead: " << obj; 1091 } 1092 } 1093} 1094 1095void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1096 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1097} 1098 1099void Heap::VerifyHeap() { 1100 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1101 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1102} 1103 1104void Heap::RecordFree(ssize_t freed_objects, ssize_t freed_bytes) { 1105 // Use signed comparison since freed bytes can be negative when background compaction foreground 1106 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1107 // free list backed space typically increasing memory footprint due to padding and binning. 1108 DCHECK_LE(freed_bytes, static_cast<ssize_t>(num_bytes_allocated_.Load())); 1109 DCHECK_GE(freed_objects, 0); 1110 num_bytes_allocated_.FetchAndSub(freed_bytes); 1111 if (Runtime::Current()->HasStatsEnabled()) { 1112 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1113 thread_stats->freed_objects += freed_objects; 1114 thread_stats->freed_bytes += freed_bytes; 1115 // TODO: Do this concurrently. 1116 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1117 global_stats->freed_objects += freed_objects; 1118 global_stats->freed_bytes += freed_bytes; 1119 } 1120} 1121 1122mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1123 size_t alloc_size, size_t* bytes_allocated, 1124 size_t* usable_size, 1125 mirror::Class** klass) { 1126 mirror::Object* ptr = nullptr; 1127 bool was_default_allocator = allocator == GetCurrentAllocator(); 1128 DCHECK(klass != nullptr); 1129 SirtRef<mirror::Class> sirt_klass(self, *klass); 1130 // The allocation failed. If the GC is running, block until it completes, and then retry the 1131 // allocation. 1132 collector::GcType last_gc = WaitForGcToComplete(self); 1133 if (last_gc != collector::kGcTypeNone) { 1134 // If we were the default allocator but the allocator changed while we were suspended, 1135 // abort the allocation. 1136 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1137 *klass = sirt_klass.get(); 1138 return nullptr; 1139 } 1140 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1141 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1142 } 1143 1144 // Loop through our different Gc types and try to Gc until we get enough free memory. 1145 for (collector::GcType gc_type : gc_plan_) { 1146 if (ptr != nullptr) { 1147 break; 1148 } 1149 // Attempt to run the collector, if we succeed, re-try the allocation. 1150 bool gc_ran = 1151 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1152 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1153 *klass = sirt_klass.get(); 1154 return nullptr; 1155 } 1156 if (gc_ran) { 1157 // Did we free sufficient memory for the allocation to succeed? 1158 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1159 } 1160 } 1161 // Allocations have failed after GCs; this is an exceptional state. 1162 if (ptr == nullptr) { 1163 // Try harder, growing the heap if necessary. 1164 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1165 } 1166 if (ptr == nullptr) { 1167 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1168 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1169 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1170 // OOME. 1171 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1172 << " allocation"; 1173 // TODO: Run finalization, but this may cause more allocations to occur. 1174 // We don't need a WaitForGcToComplete here either. 1175 DCHECK(!gc_plan_.empty()); 1176 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1177 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1178 *klass = sirt_klass.get(); 1179 return nullptr; 1180 } 1181 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1182 if (ptr == nullptr) { 1183 ThrowOutOfMemoryError(self, alloc_size, false); 1184 } 1185 } 1186 *klass = sirt_klass.get(); 1187 return ptr; 1188} 1189 1190void Heap::SetTargetHeapUtilization(float target) { 1191 DCHECK_GT(target, 0.0f); // asserted in Java code 1192 DCHECK_LT(target, 1.0f); 1193 target_utilization_ = target; 1194} 1195 1196size_t Heap::GetObjectsAllocated() const { 1197 size_t total = 0; 1198 for (space::AllocSpace* space : alloc_spaces_) { 1199 total += space->GetObjectsAllocated(); 1200 } 1201 return total; 1202} 1203 1204size_t Heap::GetObjectsAllocatedEver() const { 1205 return GetObjectsFreedEver() + GetObjectsAllocated(); 1206} 1207 1208size_t Heap::GetBytesAllocatedEver() const { 1209 return GetBytesFreedEver() + GetBytesAllocated(); 1210} 1211 1212class InstanceCounter { 1213 public: 1214 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1215 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1216 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1217 } 1218 static void Callback(mirror::Object* obj, void* arg) 1219 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1220 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1221 mirror::Class* instance_class = obj->GetClass(); 1222 CHECK(instance_class != nullptr); 1223 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1224 if (instance_counter->use_is_assignable_from_) { 1225 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1226 ++instance_counter->counts_[i]; 1227 } 1228 } else if (instance_class == instance_counter->classes_[i]) { 1229 ++instance_counter->counts_[i]; 1230 } 1231 } 1232 } 1233 1234 private: 1235 const std::vector<mirror::Class*>& classes_; 1236 bool use_is_assignable_from_; 1237 uint64_t* const counts_; 1238 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1239}; 1240 1241void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1242 uint64_t* counts) { 1243 // Can't do any GC in this function since this may move classes. 1244 Thread* self = Thread::Current(); 1245 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1246 InstanceCounter counter(classes, use_is_assignable_from, counts); 1247 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1248 VisitObjects(InstanceCounter::Callback, &counter); 1249 self->EndAssertNoThreadSuspension(old_cause); 1250} 1251 1252class InstanceCollector { 1253 public: 1254 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1255 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1256 : class_(c), max_count_(max_count), instances_(instances) { 1257 } 1258 static void Callback(mirror::Object* obj, void* arg) 1259 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1260 DCHECK(arg != nullptr); 1261 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1262 mirror::Class* instance_class = obj->GetClass(); 1263 if (instance_class == instance_collector->class_) { 1264 if (instance_collector->max_count_ == 0 || 1265 instance_collector->instances_.size() < instance_collector->max_count_) { 1266 instance_collector->instances_.push_back(obj); 1267 } 1268 } 1269 } 1270 1271 private: 1272 mirror::Class* class_; 1273 uint32_t max_count_; 1274 std::vector<mirror::Object*>& instances_; 1275 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1276}; 1277 1278void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1279 std::vector<mirror::Object*>& instances) { 1280 // Can't do any GC in this function since this may move classes. 1281 Thread* self = Thread::Current(); 1282 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1283 InstanceCollector collector(c, max_count, instances); 1284 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1285 VisitObjects(&InstanceCollector::Callback, &collector); 1286 self->EndAssertNoThreadSuspension(old_cause); 1287} 1288 1289class ReferringObjectsFinder { 1290 public: 1291 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1292 std::vector<mirror::Object*>& referring_objects) 1293 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1294 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1295 } 1296 1297 static void Callback(mirror::Object* obj, void* arg) 1298 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1299 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1300 } 1301 1302 // For bitmap Visit. 1303 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1304 // annotalysis on visitors. 1305 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1306 o->VisitReferences<true>(*this); 1307 } 1308 1309 // For MarkSweep::VisitObjectReferences. 1310 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1311 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1312 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset, false); 1313 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1314 referring_objects_.push_back(obj); 1315 } 1316 } 1317 1318 private: 1319 mirror::Object* object_; 1320 uint32_t max_count_; 1321 std::vector<mirror::Object*>& referring_objects_; 1322 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1323}; 1324 1325void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1326 std::vector<mirror::Object*>& referring_objects) { 1327 // Can't do any GC in this function since this may move the object o. 1328 Thread* self = Thread::Current(); 1329 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1330 ReferringObjectsFinder finder(o, max_count, referring_objects); 1331 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1332 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1333 self->EndAssertNoThreadSuspension(old_cause); 1334} 1335 1336void Heap::CollectGarbage(bool clear_soft_references) { 1337 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1338 // last GC will not have necessarily been cleared. 1339 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1340} 1341 1342void Heap::TransitionCollector(CollectorType collector_type) { 1343 if (collector_type == collector_type_) { 1344 return; 1345 } 1346 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1347 << " -> " << static_cast<int>(collector_type); 1348 uint64_t start_time = NanoTime(); 1349 uint32_t before_size = GetTotalMemory(); 1350 uint32_t before_allocated = num_bytes_allocated_.Load(); 1351 ThreadList* tl = Runtime::Current()->GetThreadList(); 1352 Thread* self = Thread::Current(); 1353 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1354 Locks::mutator_lock_->AssertNotHeld(self); 1355 const bool copying_transition = 1356 IsCompactingGC(background_collector_type_) || IsCompactingGC(post_zygote_collector_type_); 1357 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1358 // compacting_gc_disable_count_, this should rarely occurs). 1359 for (;;) { 1360 { 1361 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1362 MutexLock mu(self, *gc_complete_lock_); 1363 // Ensure there is only one GC at a time. 1364 WaitForGcToCompleteLocked(self); 1365 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1366 if (!copying_transition || disable_moving_gc_count_ == 0) { 1367 // TODO: Not hard code in semi-space collector? 1368 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1369 break; 1370 } 1371 } 1372 usleep(1000); 1373 } 1374 tl->SuspendAll(); 1375 PreGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1376 switch (collector_type) { 1377 case kCollectorTypeSS: 1378 // Fall-through. 1379 case kCollectorTypeGSS: { 1380 mprotect(temp_space_->Begin(), temp_space_->Capacity(), PROT_READ | PROT_WRITE); 1381 CHECK(main_space_ != nullptr); 1382 Compact(temp_space_, main_space_); 1383 DCHECK(allocator_mem_map_.get() == nullptr); 1384 allocator_mem_map_.reset(main_space_->ReleaseMemMap()); 1385 madvise(main_space_->Begin(), main_space_->Size(), MADV_DONTNEED); 1386 // RemoveSpace does not delete the removed space. 1387 space::Space* old_space = main_space_; 1388 RemoveSpace(old_space); 1389 delete old_space; 1390 break; 1391 } 1392 case kCollectorTypeMS: 1393 // Fall through. 1394 case kCollectorTypeCMS: { 1395 if (IsCompactingGC(collector_type_)) { 1396 // TODO: Use mem-map from temp space? 1397 MemMap* mem_map = allocator_mem_map_.release(); 1398 CHECK(mem_map != nullptr); 1399 size_t starting_size = kDefaultStartingSize; 1400 size_t initial_size = kDefaultInitialSize; 1401 mprotect(mem_map->Begin(), initial_size, PROT_READ | PROT_WRITE); 1402 CHECK(main_space_ == nullptr); 1403 if (kUseRosAlloc) { 1404 main_space_ = 1405 space::RosAllocSpace::CreateFromMemMap(mem_map, "alloc space", starting_size, 1406 initial_size, mem_map->Size(), 1407 mem_map->Size(), low_memory_mode_); 1408 } else { 1409 main_space_ = 1410 space::DlMallocSpace::CreateFromMemMap(mem_map, "alloc space", starting_size, 1411 initial_size, mem_map->Size(), 1412 mem_map->Size()); 1413 } 1414 main_space_->SetFootprintLimit(main_space_->Capacity()); 1415 AddSpace(main_space_); 1416 Compact(main_space_, bump_pointer_space_); 1417 } 1418 break; 1419 } 1420 default: { 1421 LOG(FATAL) << "Attempted to transition to invalid collector type"; 1422 break; 1423 } 1424 } 1425 ChangeCollector(collector_type); 1426 PostGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1427 tl->ResumeAll(); 1428 // Can't call into java code with all threads suspended. 1429 EnqueueClearedReferences(); 1430 uint64_t duration = NanoTime() - start_time; 1431 GrowForUtilization(collector::kGcTypeFull, duration); 1432 FinishGC(self, collector::kGcTypeFull); 1433 int32_t after_size = GetTotalMemory(); 1434 int32_t delta_size = before_size - after_size; 1435 int32_t after_allocated = num_bytes_allocated_.Load(); 1436 int32_t delta_allocated = before_allocated - after_allocated; 1437 const std::string saved_bytes_str = 1438 delta_size < 0 ? "-" + PrettySize(-delta_size) : PrettySize(delta_size); 1439 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1440 << PrettyDuration(duration) << " " << PrettySize(before_size) << "->" 1441 << PrettySize(after_size) << " from " << PrettySize(delta_allocated) << " to " 1442 << PrettySize(delta_size) << " saved"; 1443} 1444 1445void Heap::ChangeCollector(CollectorType collector_type) { 1446 // TODO: Only do this with all mutators suspended to avoid races. 1447 if (collector_type != collector_type_) { 1448 collector_type_ = collector_type; 1449 gc_plan_.clear(); 1450 switch (collector_type_) { 1451 case kCollectorTypeSS: // Fall-through. 1452 case kCollectorTypeGSS: { 1453 gc_plan_.push_back(collector::kGcTypeFull); 1454 if (use_tlab_) { 1455 ChangeAllocator(kAllocatorTypeTLAB); 1456 } else { 1457 ChangeAllocator(kAllocatorTypeBumpPointer); 1458 } 1459 break; 1460 } 1461 case kCollectorTypeMS: { 1462 gc_plan_.push_back(collector::kGcTypeSticky); 1463 gc_plan_.push_back(collector::kGcTypePartial); 1464 gc_plan_.push_back(collector::kGcTypeFull); 1465 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1466 break; 1467 } 1468 case kCollectorTypeCMS: { 1469 gc_plan_.push_back(collector::kGcTypeSticky); 1470 gc_plan_.push_back(collector::kGcTypePartial); 1471 gc_plan_.push_back(collector::kGcTypeFull); 1472 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1473 break; 1474 } 1475 default: { 1476 LOG(FATAL) << "Unimplemented"; 1477 } 1478 } 1479 if (IsGcConcurrent()) { 1480 concurrent_start_bytes_ = 1481 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1482 } else { 1483 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1484 } 1485 } 1486} 1487 1488// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1489class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1490 public: 1491 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1492 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1493 } 1494 1495 void BuildBins(space::ContinuousSpace* space) { 1496 bin_live_bitmap_ = space->GetLiveBitmap(); 1497 bin_mark_bitmap_ = space->GetMarkBitmap(); 1498 BinContext context; 1499 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1500 context.collector_ = this; 1501 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1502 // Note: This requires traversing the space in increasing order of object addresses. 1503 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1504 // Add the last bin which spans after the last object to the end of the space. 1505 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1506 } 1507 1508 private: 1509 struct BinContext { 1510 uintptr_t prev_; // The end of the previous object. 1511 ZygoteCompactingCollector* collector_; 1512 }; 1513 // Maps from bin sizes to locations. 1514 std::multimap<size_t, uintptr_t> bins_; 1515 // Live bitmap of the space which contains the bins. 1516 accounting::SpaceBitmap* bin_live_bitmap_; 1517 // Mark bitmap of the space which contains the bins. 1518 accounting::SpaceBitmap* bin_mark_bitmap_; 1519 1520 static void Callback(mirror::Object* obj, void* arg) 1521 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1522 DCHECK(arg != nullptr); 1523 BinContext* context = reinterpret_cast<BinContext*>(arg); 1524 ZygoteCompactingCollector* collector = context->collector_; 1525 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1526 size_t bin_size = object_addr - context->prev_; 1527 // Add the bin consisting of the end of the previous object to the start of the current object. 1528 collector->AddBin(bin_size, context->prev_); 1529 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1530 } 1531 1532 void AddBin(size_t size, uintptr_t position) { 1533 if (size != 0) { 1534 bins_.insert(std::make_pair(size, position)); 1535 } 1536 } 1537 1538 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1539 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1540 // allocator. 1541 return false; 1542 } 1543 1544 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1545 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1546 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1547 mirror::Object* forward_address; 1548 // Find the smallest bin which we can move obj in. 1549 auto it = bins_.lower_bound(object_size); 1550 if (it == bins_.end()) { 1551 // No available space in the bins, place it in the target space instead (grows the zygote 1552 // space). 1553 size_t bytes_allocated; 1554 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1555 if (to_space_live_bitmap_ != nullptr) { 1556 to_space_live_bitmap_->Set(forward_address); 1557 } else { 1558 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1559 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1560 } 1561 } else { 1562 size_t size = it->first; 1563 uintptr_t pos = it->second; 1564 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1565 forward_address = reinterpret_cast<mirror::Object*>(pos); 1566 // Set the live and mark bits so that sweeping system weaks works properly. 1567 bin_live_bitmap_->Set(forward_address); 1568 bin_mark_bitmap_->Set(forward_address); 1569 DCHECK_GE(size, object_size); 1570 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1571 } 1572 // Copy the object over to its new location. 1573 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1574 if (kUseBrooksPointer) { 1575 obj->AssertSelfBrooksPointer(); 1576 DCHECK_EQ(forward_address->GetBrooksPointer(), obj); 1577 forward_address->SetBrooksPointer(forward_address); 1578 forward_address->AssertSelfBrooksPointer(); 1579 } 1580 return forward_address; 1581 } 1582}; 1583 1584void Heap::UnBindBitmaps() { 1585 for (const auto& space : GetContinuousSpaces()) { 1586 if (space->IsContinuousMemMapAllocSpace()) { 1587 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1588 if (alloc_space->HasBoundBitmaps()) { 1589 alloc_space->UnBindBitmaps(); 1590 } 1591 } 1592 } 1593} 1594 1595void Heap::PreZygoteFork() { 1596 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1597 static Mutex zygote_creation_lock_("zygote creation lock", kZygoteCreationLock); 1598 Thread* self = Thread::Current(); 1599 MutexLock mu(self, zygote_creation_lock_); 1600 // Try to see if we have any Zygote spaces. 1601 if (have_zygote_space_) { 1602 return; 1603 } 1604 VLOG(heap) << "Starting PreZygoteFork"; 1605 // Trim the pages at the end of the non moving space. 1606 non_moving_space_->Trim(); 1607 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1608 // Change the collector to the post zygote one. 1609 ChangeCollector(post_zygote_collector_type_); 1610 // TODO: Delete bump_pointer_space_ and temp_pointer_space_? 1611 if (semi_space_collector_ != nullptr) { 1612 // Temporarily disable rosalloc verification because the zygote 1613 // compaction will mess up the rosalloc internal metadata. 1614 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1615 ZygoteCompactingCollector zygote_collector(this); 1616 zygote_collector.BuildBins(non_moving_space_); 1617 // Create a new bump pointer space which we will compact into. 1618 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1619 non_moving_space_->Limit()); 1620 // Compact the bump pointer space to a new zygote bump pointer space. 1621 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1622 zygote_collector.SetFromSpace(bump_pointer_space_); 1623 zygote_collector.SetToSpace(&target_space); 1624 zygote_collector.Run(kGcCauseCollectorTransition, false); 1625 CHECK(temp_space_->IsEmpty()); 1626 total_objects_freed_ever_ += semi_space_collector_->GetFreedObjects(); 1627 total_bytes_freed_ever_ += semi_space_collector_->GetFreedBytes(); 1628 // Update the end and write out image. 1629 non_moving_space_->SetEnd(target_space.End()); 1630 non_moving_space_->SetLimit(target_space.Limit()); 1631 VLOG(heap) << "Zygote size " << non_moving_space_->Size() << " bytes"; 1632 } 1633 // Save the old space so that we can remove it after we complete creating the zygote space. 1634 space::MallocSpace* old_alloc_space = non_moving_space_; 1635 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1636 // the remaining available space. 1637 // Remove the old space before creating the zygote space since creating the zygote space sets 1638 // the old alloc space's bitmaps to nullptr. 1639 RemoveSpace(old_alloc_space); 1640 if (collector::SemiSpace::kUseRememberedSet) { 1641 // Sanity bound check. 1642 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1643 // Remove the remembered set for the now zygote space (the old 1644 // non-moving space). Note now that we have compacted objects into 1645 // the zygote space, the data in the remembered set is no longer 1646 // needed. The zygote space will instead have a mod-union table 1647 // from this point on. 1648 RemoveRememberedSet(old_alloc_space); 1649 } 1650 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1651 low_memory_mode_, 1652 &main_space_); 1653 delete old_alloc_space; 1654 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1655 AddSpace(zygote_space, false); 1656 CHECK(main_space_ != nullptr); 1657 if (main_space_->IsRosAllocSpace()) { 1658 rosalloc_space_ = main_space_->AsRosAllocSpace(); 1659 } else if (main_space_->IsDlMallocSpace()) { 1660 dlmalloc_space_ = main_space_->AsDlMallocSpace(); 1661 } 1662 main_space_->SetFootprintLimit(main_space_->Capacity()); 1663 AddSpace(main_space_); 1664 have_zygote_space_ = true; 1665 // Enable large object space allocations. 1666 large_object_threshold_ = kDefaultLargeObjectThreshold; 1667 // Create the zygote space mod union table. 1668 accounting::ModUnionTable* mod_union_table = 1669 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1670 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1671 AddModUnionTable(mod_union_table); 1672 if (collector::SemiSpace::kUseRememberedSet) { 1673 // Add a new remembered set for the new main space. 1674 accounting::RememberedSet* main_space_rem_set = 1675 new accounting::RememberedSet("Main space remembered set", this, main_space_); 1676 CHECK(main_space_rem_set != nullptr) << "Failed to create main space remembered set"; 1677 AddRememberedSet(main_space_rem_set); 1678 } 1679 // Can't use RosAlloc for non moving space due to thread local buffers. 1680 // TODO: Non limited space for non-movable objects? 1681 MemMap* mem_map = post_zygote_non_moving_space_mem_map_.release(); 1682 space::MallocSpace* new_non_moving_space = 1683 space::DlMallocSpace::CreateFromMemMap(mem_map, "Non moving dlmalloc space", kPageSize, 1684 2 * MB, mem_map->Size(), mem_map->Size()); 1685 AddSpace(new_non_moving_space, false); 1686 CHECK(new_non_moving_space != nullptr) << "Failed to create new non-moving space"; 1687 new_non_moving_space->SetFootprintLimit(new_non_moving_space->Capacity()); 1688 non_moving_space_ = new_non_moving_space; 1689 if (collector::SemiSpace::kUseRememberedSet) { 1690 // Add a new remembered set for the post-zygote non-moving space. 1691 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1692 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1693 non_moving_space_); 1694 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1695 << "Failed to create post-zygote non-moving space remembered set"; 1696 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1697 } 1698} 1699 1700void Heap::FlushAllocStack() { 1701 MarkAllocStackAsLive(allocation_stack_.get()); 1702 allocation_stack_->Reset(); 1703} 1704 1705void Heap::MarkAllocStack(accounting::SpaceBitmap* bitmap1, 1706 accounting::SpaceBitmap* bitmap2, 1707 accounting::ObjectSet* large_objects, 1708 accounting::ObjectStack* stack) { 1709 DCHECK(bitmap1 != nullptr); 1710 DCHECK(bitmap2 != nullptr); 1711 mirror::Object** limit = stack->End(); 1712 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1713 const mirror::Object* obj = *it; 1714 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1715 if (bitmap1->HasAddress(obj)) { 1716 bitmap1->Set(obj); 1717 } else if (bitmap2->HasAddress(obj)) { 1718 bitmap2->Set(obj); 1719 } else { 1720 large_objects->Set(obj); 1721 } 1722 } 1723 } 1724} 1725 1726void Heap::SwapSemiSpaces() { 1727 // Swap the spaces so we allocate into the space which we just evacuated. 1728 std::swap(bump_pointer_space_, temp_space_); 1729 bump_pointer_space_->Clear(); 1730} 1731 1732void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1733 space::ContinuousMemMapAllocSpace* source_space) { 1734 CHECK(kMovingCollector); 1735 CHECK_NE(target_space, source_space) << "In-place compaction currently unsupported"; 1736 if (target_space != source_space) { 1737 semi_space_collector_->SetFromSpace(source_space); 1738 semi_space_collector_->SetToSpace(target_space); 1739 semi_space_collector_->Run(kGcCauseCollectorTransition, false); 1740 } 1741} 1742 1743collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1744 bool clear_soft_references) { 1745 Thread* self = Thread::Current(); 1746 Runtime* runtime = Runtime::Current(); 1747 // If the heap can't run the GC, silently fail and return that no GC was run. 1748 switch (gc_type) { 1749 case collector::kGcTypePartial: { 1750 if (!have_zygote_space_) { 1751 return collector::kGcTypeNone; 1752 } 1753 break; 1754 } 1755 default: { 1756 // Other GC types don't have any special cases which makes them not runnable. The main case 1757 // here is full GC. 1758 } 1759 } 1760 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1761 Locks::mutator_lock_->AssertNotHeld(self); 1762 if (self->IsHandlingStackOverflow()) { 1763 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 1764 } 1765 bool compacting_gc; 1766 { 1767 gc_complete_lock_->AssertNotHeld(self); 1768 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1769 MutexLock mu(self, *gc_complete_lock_); 1770 // Ensure there is only one GC at a time. 1771 WaitForGcToCompleteLocked(self); 1772 compacting_gc = IsCompactingGC(collector_type_); 1773 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 1774 if (compacting_gc && disable_moving_gc_count_ != 0) { 1775 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 1776 return collector::kGcTypeNone; 1777 } 1778 collector_type_running_ = collector_type_; 1779 } 1780 1781 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 1782 ++runtime->GetStats()->gc_for_alloc_count; 1783 ++self->GetStats()->gc_for_alloc_count; 1784 } 1785 uint64_t gc_start_time_ns = NanoTime(); 1786 uint64_t gc_start_size = GetBytesAllocated(); 1787 // Approximate allocation rate in bytes / second. 1788 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 1789 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 1790 if (LIKELY(ms_delta != 0)) { 1791 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 1792 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 1793 } 1794 1795 DCHECK_LT(gc_type, collector::kGcTypeMax); 1796 DCHECK_NE(gc_type, collector::kGcTypeNone); 1797 1798 collector::GarbageCollector* collector = nullptr; 1799 // TODO: Clean this up. 1800 if (compacting_gc) { 1801 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 1802 current_allocator_ == kAllocatorTypeTLAB); 1803 gc_type = semi_space_collector_->GetGcType(); 1804 CHECK(temp_space_->IsEmpty()); 1805 semi_space_collector_->SetFromSpace(bump_pointer_space_); 1806 semi_space_collector_->SetToSpace(temp_space_); 1807 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1808 collector = semi_space_collector_; 1809 gc_type = collector::kGcTypeFull; 1810 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 1811 current_allocator_ == kAllocatorTypeDlMalloc) { 1812 for (const auto& cur_collector : garbage_collectors_) { 1813 if (cur_collector->GetCollectorType() == collector_type_ && 1814 cur_collector->GetGcType() == gc_type) { 1815 collector = cur_collector; 1816 break; 1817 } 1818 } 1819 } else { 1820 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 1821 } 1822 CHECK(collector != nullptr) 1823 << "Could not find garbage collector with collector_type=" 1824 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 1825 ATRACE_BEGIN(StringPrintf("%s %s GC", PrettyCause(gc_cause), collector->GetName()).c_str()); 1826 if (!clear_soft_references) { 1827 clear_soft_references = gc_type != collector::kGcTypeSticky; // TODO: GSS? 1828 } 1829 collector->Run(gc_cause, clear_soft_references || Runtime::Current()->IsZygote()); 1830 total_objects_freed_ever_ += collector->GetFreedObjects(); 1831 total_bytes_freed_ever_ += collector->GetFreedBytes(); 1832 RequestHeapTrim(); 1833 // Enqueue cleared references. 1834 EnqueueClearedReferences(); 1835 // Grow the heap so that we know when to perform the next GC. 1836 GrowForUtilization(gc_type, collector->GetDurationNs()); 1837 if (CareAboutPauseTimes()) { 1838 const size_t duration = collector->GetDurationNs(); 1839 std::vector<uint64_t> pauses = collector->GetPauseTimes(); 1840 // GC for alloc pauses the allocating thread, so consider it as a pause. 1841 bool was_slow = duration > long_gc_log_threshold_ || 1842 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 1843 if (!was_slow) { 1844 for (uint64_t pause : pauses) { 1845 was_slow = was_slow || pause > long_pause_log_threshold_; 1846 } 1847 } 1848 if (was_slow) { 1849 const size_t percent_free = GetPercentFree(); 1850 const size_t current_heap_size = GetBytesAllocated(); 1851 const size_t total_memory = GetTotalMemory(); 1852 std::ostringstream pause_string; 1853 for (size_t i = 0; i < pauses.size(); ++i) { 1854 pause_string << PrettyDuration((pauses[i] / 1000) * 1000) 1855 << ((i != pauses.size() - 1) ? ", " : ""); 1856 } 1857 LOG(INFO) << gc_cause << " " << collector->GetName() 1858 << " GC freed " << collector->GetFreedObjects() << "(" 1859 << PrettySize(collector->GetFreedBytes()) << ") AllocSpace objects, " 1860 << collector->GetFreedLargeObjects() << "(" 1861 << PrettySize(collector->GetFreedLargeObjectBytes()) << ") LOS objects, " 1862 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 1863 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 1864 << " total " << PrettyDuration((duration / 1000) * 1000); 1865 if (VLOG_IS_ON(heap)) { 1866 LOG(INFO) << Dumpable<TimingLogger>(collector->GetTimings()); 1867 } 1868 } 1869 } 1870 FinishGC(self, gc_type); 1871 ATRACE_END(); 1872 1873 // Inform DDMS that a GC completed. 1874 Dbg::GcDidFinish(); 1875 return gc_type; 1876} 1877 1878void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 1879 MutexLock mu(self, *gc_complete_lock_); 1880 collector_type_running_ = kCollectorTypeNone; 1881 if (gc_type != collector::kGcTypeNone) { 1882 last_gc_type_ = gc_type; 1883 } 1884 // Wake anyone who may have been waiting for the GC to complete. 1885 gc_complete_cond_->Broadcast(self); 1886} 1887 1888static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 1889 RootType /*root_type*/) { 1890 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 1891 if (*root == obj) { 1892 LOG(INFO) << "Object " << obj << " is a root"; 1893 } 1894} 1895 1896class ScanVisitor { 1897 public: 1898 void operator()(const mirror::Object* obj) const { 1899 LOG(ERROR) << "Would have rescanned object " << obj; 1900 } 1901}; 1902 1903// Verify a reference from an object. 1904class VerifyReferenceVisitor { 1905 public: 1906 explicit VerifyReferenceVisitor(Heap* heap) 1907 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 1908 : heap_(heap), failed_(false) {} 1909 1910 bool Failed() const { 1911 return failed_; 1912 } 1913 1914 void operator()(mirror::Class* klass, mirror::Reference* ref) const 1915 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1916 this->operator()(ref, mirror::Reference::ReferentOffset(), false); 1917 } 1918 1919 void operator()(mirror::Object* obj, MemberOffset offset, bool /* static */) const 1920 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1921 this->operator()(obj, obj->GetFieldObject<mirror::Object>(offset, false), offset); 1922 } 1923 1924 // TODO: Fix the no thread safety analysis. 1925 void operator()(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 1926 NO_THREAD_SAFETY_ANALYSIS { 1927 if (ref == nullptr || IsLive(ref)) { 1928 // Verify that the reference is live. 1929 return; 1930 } 1931 if (!failed_) { 1932 // Print message on only on first failure to prevent spam. 1933 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 1934 failed_ = true; 1935 } 1936 if (obj != nullptr) { 1937 accounting::CardTable* card_table = heap_->GetCardTable(); 1938 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 1939 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 1940 byte* card_addr = card_table->CardFromAddr(obj); 1941 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 1942 << offset << "\n card value = " << static_cast<int>(*card_addr); 1943 if (heap_->IsValidObjectAddress(obj->GetClass())) { 1944 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 1945 } else { 1946 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 1947 } 1948 1949 // Attmept to find the class inside of the recently freed objects. 1950 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 1951 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 1952 space::MallocSpace* space = ref_space->AsMallocSpace(); 1953 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 1954 if (ref_class != nullptr) { 1955 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 1956 << PrettyClass(ref_class); 1957 } else { 1958 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 1959 } 1960 } 1961 1962 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 1963 ref->GetClass()->IsClass()) { 1964 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 1965 } else { 1966 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 1967 << ") is not a valid heap address"; 1968 } 1969 1970 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 1971 void* cover_begin = card_table->AddrFromCard(card_addr); 1972 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 1973 accounting::CardTable::kCardSize); 1974 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 1975 << "-" << cover_end; 1976 accounting::SpaceBitmap* bitmap = heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 1977 1978 if (bitmap == nullptr) { 1979 LOG(ERROR) << "Object " << obj << " has no bitmap"; 1980 if (!VerifyClassClass(obj->GetClass())) { 1981 LOG(ERROR) << "Object " << obj << " failed class verification!"; 1982 } 1983 } else { 1984 // Print out how the object is live. 1985 if (bitmap->Test(obj)) { 1986 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 1987 } 1988 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 1989 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 1990 } 1991 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 1992 LOG(ERROR) << "Object " << obj << " found in live stack"; 1993 } 1994 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 1995 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 1996 } 1997 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 1998 LOG(ERROR) << "Ref " << ref << " found in live stack"; 1999 } 2000 // Attempt to see if the card table missed the reference. 2001 ScanVisitor scan_visitor; 2002 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 2003 card_table->Scan(bitmap, byte_cover_begin, 2004 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2005 } 2006 2007 // Search to see if any of the roots reference our object. 2008 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2009 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2010 2011 // Search to see if any of the roots reference our reference. 2012 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2013 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2014 } else { 2015 LOG(ERROR) << "Root " << ref << " is dead with type " << PrettyTypeOf(ref); 2016 } 2017 } 2018 2019 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2020 return heap_->IsLiveObjectLocked(obj, true, false, true); 2021 } 2022 2023 static void VerifyRoots(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2024 RootType /*root_type*/) { 2025 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2026 (*visitor)(nullptr, *root, MemberOffset(0)); 2027 } 2028 2029 private: 2030 Heap* const heap_; 2031 mutable bool failed_; 2032}; 2033 2034// Verify all references within an object, for use with HeapBitmap::Visit. 2035class VerifyObjectVisitor { 2036 public: 2037 explicit VerifyObjectVisitor(Heap* heap) : heap_(heap), failed_(false) {} 2038 2039 void operator()(mirror::Object* obj) const 2040 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2041 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2042 // be live or else how did we find it in the live bitmap? 2043 VerifyReferenceVisitor visitor(heap_); 2044 // The class doesn't count as a reference but we should verify it anyways. 2045 obj->VisitReferences<true>(visitor, visitor); 2046 failed_ = failed_ || visitor.Failed(); 2047 } 2048 2049 static void VisitCallback(mirror::Object* obj, void* arg) 2050 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2051 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2052 visitor->operator()(obj); 2053 } 2054 2055 bool Failed() const { 2056 return failed_; 2057 } 2058 2059 private: 2060 Heap* const heap_; 2061 mutable bool failed_; 2062}; 2063 2064// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2065bool Heap::VerifyHeapReferences() { 2066 Thread* self = Thread::Current(); 2067 Locks::mutator_lock_->AssertExclusiveHeld(self); 2068 // Lets sort our allocation stacks so that we can efficiently binary search them. 2069 allocation_stack_->Sort(); 2070 live_stack_->Sort(); 2071 // Since we sorted the allocation stack content, need to revoke all 2072 // thread-local allocation stacks. 2073 RevokeAllThreadLocalAllocationStacks(self); 2074 VerifyObjectVisitor visitor(this); 2075 // Verify objects in the allocation stack since these will be objects which were: 2076 // 1. Allocated prior to the GC (pre GC verification). 2077 // 2. Allocated during the GC (pre sweep GC verification). 2078 // We don't want to verify the objects in the live stack since they themselves may be 2079 // pointing to dead objects if they are not reachable. 2080 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2081 // Verify the roots: 2082 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRoots, &visitor); 2083 if (visitor.Failed()) { 2084 // Dump mod-union tables. 2085 for (const auto& table_pair : mod_union_tables_) { 2086 accounting::ModUnionTable* mod_union_table = table_pair.second; 2087 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2088 } 2089 // Dump remembered sets. 2090 for (const auto& table_pair : remembered_sets_) { 2091 accounting::RememberedSet* remembered_set = table_pair.second; 2092 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2093 } 2094 DumpSpaces(); 2095 return false; 2096 } 2097 return true; 2098} 2099 2100class VerifyReferenceCardVisitor { 2101 public: 2102 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2103 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2104 Locks::heap_bitmap_lock_) 2105 : heap_(heap), failed_(failed) { 2106 } 2107 2108 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2109 // annotalysis on visitors. 2110 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2111 NO_THREAD_SAFETY_ANALYSIS { 2112 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset, false); 2113 // Filter out class references since changing an object's class does not mark the card as dirty. 2114 // Also handles large objects, since the only reference they hold is a class reference. 2115 if (ref != nullptr && !ref->IsClass()) { 2116 accounting::CardTable* card_table = heap_->GetCardTable(); 2117 // If the object is not dirty and it is referencing something in the live stack other than 2118 // class, then it must be on a dirty card. 2119 if (!card_table->AddrIsInCardTable(obj)) { 2120 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2121 *failed_ = true; 2122 } else if (!card_table->IsDirty(obj)) { 2123 // TODO: Check mod-union tables. 2124 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2125 // kCardDirty - 1 if it didnt get touched since we aged it. 2126 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2127 if (live_stack->ContainsSorted(ref)) { 2128 if (live_stack->ContainsSorted(obj)) { 2129 LOG(ERROR) << "Object " << obj << " found in live stack"; 2130 } 2131 if (heap_->GetLiveBitmap()->Test(obj)) { 2132 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2133 } 2134 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2135 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2136 2137 // Print which field of the object is dead. 2138 if (!obj->IsObjectArray()) { 2139 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2140 CHECK(klass != NULL); 2141 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2142 : klass->GetIFields(); 2143 CHECK(fields != NULL); 2144 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2145 mirror::ArtField* cur = fields->Get(i); 2146 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2147 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2148 << PrettyField(cur); 2149 break; 2150 } 2151 } 2152 } else { 2153 mirror::ObjectArray<mirror::Object>* object_array = 2154 obj->AsObjectArray<mirror::Object>(); 2155 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2156 if (object_array->Get(i) == ref) { 2157 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2158 } 2159 } 2160 } 2161 2162 *failed_ = true; 2163 } 2164 } 2165 } 2166 } 2167 2168 private: 2169 Heap* const heap_; 2170 bool* const failed_; 2171}; 2172 2173class VerifyLiveStackReferences { 2174 public: 2175 explicit VerifyLiveStackReferences(Heap* heap) 2176 : heap_(heap), 2177 failed_(false) {} 2178 2179 void operator()(mirror::Object* obj) const 2180 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2181 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2182 obj->VisitReferences<true>(visitor); 2183 } 2184 2185 bool Failed() const { 2186 return failed_; 2187 } 2188 2189 private: 2190 Heap* const heap_; 2191 bool failed_; 2192}; 2193 2194bool Heap::VerifyMissingCardMarks() { 2195 Thread* self = Thread::Current(); 2196 Locks::mutator_lock_->AssertExclusiveHeld(self); 2197 2198 // We need to sort the live stack since we binary search it. 2199 live_stack_->Sort(); 2200 // Since we sorted the allocation stack content, need to revoke all 2201 // thread-local allocation stacks. 2202 RevokeAllThreadLocalAllocationStacks(self); 2203 VerifyLiveStackReferences visitor(this); 2204 GetLiveBitmap()->Visit(visitor); 2205 2206 // We can verify objects in the live stack since none of these should reference dead objects. 2207 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2208 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2209 visitor(*it); 2210 } 2211 } 2212 2213 if (visitor.Failed()) { 2214 DumpSpaces(); 2215 return false; 2216 } 2217 return true; 2218} 2219 2220void Heap::SwapStacks(Thread* self) { 2221 if (kUseThreadLocalAllocationStack) { 2222 live_stack_->AssertAllZero(); 2223 } 2224 allocation_stack_.swap(live_stack_); 2225} 2226 2227void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2228 // This must be called only during the pause. 2229 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2230 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2231 MutexLock mu2(self, *Locks::thread_list_lock_); 2232 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2233 for (Thread* t : thread_list) { 2234 t->RevokeThreadLocalAllocationStack(); 2235 } 2236} 2237 2238void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2239 if (kIsDebugBuild) { 2240 if (bump_pointer_space_ != nullptr) { 2241 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2242 } 2243 } 2244} 2245 2246accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2247 auto it = mod_union_tables_.find(space); 2248 if (it == mod_union_tables_.end()) { 2249 return nullptr; 2250 } 2251 return it->second; 2252} 2253 2254accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2255 auto it = remembered_sets_.find(space); 2256 if (it == remembered_sets_.end()) { 2257 return nullptr; 2258 } 2259 return it->second; 2260} 2261 2262void Heap::ProcessCards(TimingLogger& timings, bool use_rem_sets) { 2263 // Clear cards and keep track of cards cleared in the mod-union table. 2264 for (const auto& space : continuous_spaces_) { 2265 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2266 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2267 if (table != nullptr) { 2268 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2269 "ImageModUnionClearCards"; 2270 TimingLogger::ScopedSplit split(name, &timings); 2271 table->ClearCards(); 2272 } else if (use_rem_sets && rem_set != nullptr) { 2273 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2274 << static_cast<int>(collector_type_); 2275 TimingLogger::ScopedSplit split("AllocSpaceRemSetClearCards", &timings); 2276 rem_set->ClearCards(); 2277 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2278 TimingLogger::ScopedSplit split("AllocSpaceClearCards", &timings); 2279 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2280 // were dirty before the GC started. 2281 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2282 // -> clean(cleaning thread). 2283 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2284 // roots and then we scan / update mod union tables after. We will always scan either card. 2285 // If we end up with the non aged card, we scan it it in the pause. 2286 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), VoidFunctor()); 2287 } 2288 } 2289} 2290 2291static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2292} 2293 2294void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2295 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 2296 Thread* self = Thread::Current(); 2297 2298 if (verify_pre_gc_heap_) { 2299 thread_list->SuspendAll(); 2300 { 2301 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2302 if (!VerifyHeapReferences()) { 2303 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed"; 2304 } 2305 } 2306 thread_list->ResumeAll(); 2307 } 2308 2309 // Check that all objects which reference things in the live stack are on dirty cards. 2310 if (verify_missing_card_marks_) { 2311 thread_list->SuspendAll(); 2312 { 2313 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2314 SwapStacks(self); 2315 // Sort the live stack so that we can quickly binary search it later. 2316 if (!VerifyMissingCardMarks()) { 2317 LOG(FATAL) << "Pre " << gc->GetName() << " missing card mark verification failed"; 2318 } 2319 SwapStacks(self); 2320 } 2321 thread_list->ResumeAll(); 2322 } 2323 2324 if (verify_mod_union_table_) { 2325 thread_list->SuspendAll(); 2326 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2327 for (const auto& table_pair : mod_union_tables_) { 2328 accounting::ModUnionTable* mod_union_table = table_pair.second; 2329 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2330 mod_union_table->Verify(); 2331 } 2332 thread_list->ResumeAll(); 2333 } 2334} 2335 2336void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2337 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2338 // reachable objects. 2339 if (verify_post_gc_heap_) { 2340 Thread* self = Thread::Current(); 2341 CHECK_NE(self->GetState(), kRunnable); 2342 { 2343 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2344 // Swapping bound bitmaps does nothing. 2345 gc->SwapBitmaps(); 2346 if (!VerifyHeapReferences()) { 2347 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed"; 2348 } 2349 gc->SwapBitmaps(); 2350 } 2351 } 2352} 2353 2354void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2355 if (verify_system_weaks_) { 2356 Thread* self = Thread::Current(); 2357 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2358 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2359 mark_sweep->VerifySystemWeaks(); 2360 } 2361} 2362 2363void Heap::PreGcRosAllocVerification(TimingLogger* timings) { 2364 if (verify_pre_gc_rosalloc_) { 2365 TimingLogger::ScopedSplit split("PreGcRosAllocVerification", timings); 2366 for (const auto& space : continuous_spaces_) { 2367 if (space->IsRosAllocSpace()) { 2368 VLOG(heap) << "PreGcRosAllocVerification : " << space->GetName(); 2369 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2370 rosalloc_space->Verify(); 2371 } 2372 } 2373 } 2374} 2375 2376void Heap::PostGcRosAllocVerification(TimingLogger* timings) { 2377 if (verify_post_gc_rosalloc_) { 2378 TimingLogger::ScopedSplit split("PostGcRosAllocVerification", timings); 2379 for (const auto& space : continuous_spaces_) { 2380 if (space->IsRosAllocSpace()) { 2381 VLOG(heap) << "PostGcRosAllocVerification : " << space->GetName(); 2382 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2383 rosalloc_space->Verify(); 2384 } 2385 } 2386 } 2387} 2388 2389collector::GcType Heap::WaitForGcToComplete(Thread* self) { 2390 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2391 MutexLock mu(self, *gc_complete_lock_); 2392 return WaitForGcToCompleteLocked(self); 2393} 2394 2395collector::GcType Heap::WaitForGcToCompleteLocked(Thread* self) { 2396 collector::GcType last_gc_type = collector::kGcTypeNone; 2397 uint64_t wait_start = NanoTime(); 2398 while (collector_type_running_ != kCollectorTypeNone) { 2399 ATRACE_BEGIN("GC: Wait For Completion"); 2400 // We must wait, change thread state then sleep on gc_complete_cond_; 2401 gc_complete_cond_->Wait(self); 2402 last_gc_type = last_gc_type_; 2403 ATRACE_END(); 2404 } 2405 uint64_t wait_time = NanoTime() - wait_start; 2406 total_wait_time_ += wait_time; 2407 if (wait_time > long_pause_log_threshold_) { 2408 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time); 2409 } 2410 return last_gc_type; 2411} 2412 2413void Heap::DumpForSigQuit(std::ostream& os) { 2414 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2415 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2416 DumpGcPerformanceInfo(os); 2417} 2418 2419size_t Heap::GetPercentFree() { 2420 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / GetTotalMemory()); 2421} 2422 2423void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2424 if (max_allowed_footprint > GetMaxMemory()) { 2425 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2426 << PrettySize(GetMaxMemory()); 2427 max_allowed_footprint = GetMaxMemory(); 2428 } 2429 max_allowed_footprint_ = max_allowed_footprint; 2430} 2431 2432bool Heap::IsMovableObject(const mirror::Object* obj) const { 2433 if (kMovingCollector) { 2434 DCHECK(!IsInTempSpace(obj)); 2435 if (bump_pointer_space_->HasAddress(obj)) { 2436 return true; 2437 } 2438 // TODO: Refactor this logic into the space itself? 2439 // Objects in the main space are only copied during background -> foreground transitions or 2440 // visa versa. 2441 if (main_space_ != nullptr && main_space_->HasAddress(obj) && 2442 (IsCompactingGC(background_collector_type_) || 2443 IsCompactingGC(post_zygote_collector_type_))) { 2444 return true; 2445 } 2446 } 2447 return false; 2448} 2449 2450bool Heap::IsInTempSpace(const mirror::Object* obj) const { 2451 if (temp_space_->HasAddress(obj) && !temp_space_->Contains(obj)) { 2452 return true; 2453 } 2454 return false; 2455} 2456 2457void Heap::UpdateMaxNativeFootprint() { 2458 size_t native_size = native_bytes_allocated_; 2459 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2460 size_t target_size = native_size / GetTargetHeapUtilization(); 2461 if (target_size > native_size + max_free_) { 2462 target_size = native_size + max_free_; 2463 } else if (target_size < native_size + min_free_) { 2464 target_size = native_size + min_free_; 2465 } 2466 native_footprint_gc_watermark_ = target_size; 2467 native_footprint_limit_ = 2 * target_size - native_size; 2468} 2469 2470void Heap::GrowForUtilization(collector::GcType gc_type, uint64_t gc_duration) { 2471 // We know what our utilization is at this moment. 2472 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2473 const size_t bytes_allocated = GetBytesAllocated(); 2474 last_gc_size_ = bytes_allocated; 2475 last_gc_time_ns_ = NanoTime(); 2476 size_t target_size; 2477 if (gc_type != collector::kGcTypeSticky) { 2478 // Grow the heap for non sticky GC. 2479 target_size = bytes_allocated / GetTargetHeapUtilization(); 2480 if (target_size > bytes_allocated + max_free_) { 2481 target_size = bytes_allocated + max_free_; 2482 } else if (target_size < bytes_allocated + min_free_) { 2483 target_size = bytes_allocated + min_free_; 2484 } 2485 native_need_to_run_finalization_ = true; 2486 next_gc_type_ = collector::kGcTypeSticky; 2487 } else { 2488 // Based on how close the current heap size is to the target size, decide 2489 // whether or not to do a partial or sticky GC next. 2490 if (bytes_allocated + min_free_ <= max_allowed_footprint_) { 2491 next_gc_type_ = collector::kGcTypeSticky; 2492 } else { 2493 next_gc_type_ = have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2494 } 2495 // If we have freed enough memory, shrink the heap back down. 2496 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2497 target_size = bytes_allocated + max_free_; 2498 } else { 2499 target_size = std::max(bytes_allocated, max_allowed_footprint_); 2500 } 2501 } 2502 if (!ignore_max_footprint_) { 2503 SetIdealFootprint(target_size); 2504 if (IsGcConcurrent()) { 2505 // Calculate when to perform the next ConcurrentGC. 2506 // Calculate the estimated GC duration. 2507 const double gc_duration_seconds = NsToMs(gc_duration) / 1000.0; 2508 // Estimate how many remaining bytes we will have when we need to start the next GC. 2509 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2510 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2511 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2512 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2513 // A never going to happen situation that from the estimated allocation rate we will exceed 2514 // the applications entire footprint with the given estimated allocation rate. Schedule 2515 // another GC nearly straight away. 2516 remaining_bytes = kMinConcurrentRemainingBytes; 2517 } 2518 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2519 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2520 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2521 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2522 // right away. 2523 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, bytes_allocated); 2524 } 2525 } 2526} 2527 2528void Heap::ClearGrowthLimit() { 2529 growth_limit_ = capacity_; 2530 non_moving_space_->ClearGrowthLimit(); 2531} 2532 2533void Heap::AddFinalizerReference(Thread* self, mirror::Object* object) { 2534 ScopedObjectAccess soa(self); 2535 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(object)); 2536 jvalue args[1]; 2537 args[0].l = arg.get(); 2538 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2539} 2540 2541void Heap::EnqueueClearedReferences() { 2542 Thread* self = Thread::Current(); 2543 Locks::mutator_lock_->AssertNotHeld(self); 2544 if (!cleared_references_.IsEmpty()) { 2545 // When a runtime isn't started there are no reference queues to care about so ignore. 2546 if (LIKELY(Runtime::Current()->IsStarted())) { 2547 ScopedObjectAccess soa(self); 2548 ScopedLocalRef<jobject> arg(self->GetJniEnv(), 2549 soa.AddLocalReference<jobject>(cleared_references_.GetList())); 2550 jvalue args[1]; 2551 args[0].l = arg.get(); 2552 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_ReferenceQueue_add, args); 2553 } 2554 cleared_references_.Clear(); 2555 } 2556} 2557 2558void Heap::RequestConcurrentGC(Thread* self) { 2559 // Make sure that we can do a concurrent GC. 2560 Runtime* runtime = Runtime::Current(); 2561 if (runtime == NULL || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2562 self->IsHandlingStackOverflow()) { 2563 return; 2564 } 2565 // We already have a request pending, no reason to start more until we update 2566 // concurrent_start_bytes_. 2567 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2568 JNIEnv* env = self->GetJniEnv(); 2569 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2570 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2571 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2572 WellKnownClasses::java_lang_Daemons_requestGC); 2573 CHECK(!env->ExceptionCheck()); 2574} 2575 2576void Heap::ConcurrentGC(Thread* self) { 2577 if (Runtime::Current()->IsShuttingDown(self)) { 2578 return; 2579 } 2580 // Wait for any GCs currently running to finish. 2581 if (WaitForGcToComplete(self) == collector::kGcTypeNone) { 2582 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2583 // instead. E.g. can't do partial, so do full instead. 2584 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2585 collector::kGcTypeNone) { 2586 for (collector::GcType gc_type : gc_plan_) { 2587 // Attempt to run the collector, if we succeed, we are done. 2588 if (gc_type > next_gc_type_ && 2589 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2590 break; 2591 } 2592 } 2593 } 2594 } 2595} 2596 2597void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2598 Thread* self = Thread::Current(); 2599 { 2600 MutexLock mu(self, *heap_trim_request_lock_); 2601 if (desired_collector_type_ == desired_collector_type) { 2602 return; 2603 } 2604 heap_transition_target_time_ = std::max(heap_transition_target_time_, NanoTime() + delta_time); 2605 desired_collector_type_ = desired_collector_type; 2606 } 2607 SignalHeapTrimDaemon(self); 2608} 2609 2610void Heap::RequestHeapTrim() { 2611 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2612 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2613 // a space it will hold its lock and can become a cause of jank. 2614 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2615 // forking. 2616 2617 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2618 // because that only marks object heads, so a large array looks like lots of empty space. We 2619 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2620 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2621 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2622 // not how much use we're making of those pages. 2623 2624 Thread* self = Thread::Current(); 2625 Runtime* runtime = Runtime::Current(); 2626 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2627 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2628 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2629 // as we don't hold the lock while requesting the trim). 2630 return; 2631 } 2632 2633 // Request a heap trim only if we do not currently care about pause times. 2634 if (!CareAboutPauseTimes()) { 2635 { 2636 MutexLock mu(self, *heap_trim_request_lock_); 2637 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2638 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2639 // just yet. 2640 return; 2641 } 2642 heap_trim_request_pending_ = true; 2643 } 2644 // Notify the daemon thread which will actually do the heap trim. 2645 SignalHeapTrimDaemon(self); 2646 } 2647} 2648 2649void Heap::SignalHeapTrimDaemon(Thread* self) { 2650 JNIEnv* env = self->GetJniEnv(); 2651 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2652 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2653 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2654 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2655 CHECK(!env->ExceptionCheck()); 2656} 2657 2658void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2659 if (rosalloc_space_ != nullptr) { 2660 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2661 } 2662 if (bump_pointer_space_ != nullptr) { 2663 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2664 } 2665} 2666 2667void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 2668 if (rosalloc_space_ != nullptr) { 2669 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2670 } 2671} 2672 2673void Heap::RevokeAllThreadLocalBuffers() { 2674 if (rosalloc_space_ != nullptr) { 2675 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2676 } 2677 if (bump_pointer_space_ != nullptr) { 2678 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 2679 } 2680} 2681 2682bool Heap::IsGCRequestPending() const { 2683 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 2684} 2685 2686void Heap::RunFinalization(JNIEnv* env) { 2687 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 2688 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 2689 CHECK(WellKnownClasses::java_lang_System != nullptr); 2690 WellKnownClasses::java_lang_System_runFinalization = 2691 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 2692 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 2693 } 2694 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 2695 WellKnownClasses::java_lang_System_runFinalization); 2696} 2697 2698void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 2699 Thread* self = ThreadForEnv(env); 2700 if (native_need_to_run_finalization_) { 2701 RunFinalization(env); 2702 UpdateMaxNativeFootprint(); 2703 native_need_to_run_finalization_ = false; 2704 } 2705 // Total number of native bytes allocated. 2706 native_bytes_allocated_.FetchAndAdd(bytes); 2707 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_gc_watermark_) { 2708 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 2709 collector::kGcTypeFull; 2710 2711 // The second watermark is higher than the gc watermark. If you hit this it means you are 2712 // allocating native objects faster than the GC can keep up with. 2713 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2714 if (WaitForGcToComplete(self) != collector::kGcTypeNone) { 2715 // Just finished a GC, attempt to run finalizers. 2716 RunFinalization(env); 2717 CHECK(!env->ExceptionCheck()); 2718 } 2719 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 2720 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2721 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 2722 RunFinalization(env); 2723 native_need_to_run_finalization_ = false; 2724 CHECK(!env->ExceptionCheck()); 2725 } 2726 // We have just run finalizers, update the native watermark since it is very likely that 2727 // finalizers released native managed allocations. 2728 UpdateMaxNativeFootprint(); 2729 } else if (!IsGCRequestPending()) { 2730 if (IsGcConcurrent()) { 2731 RequestConcurrentGC(self); 2732 } else { 2733 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false); 2734 } 2735 } 2736 } 2737} 2738 2739void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 2740 int expected_size, new_size; 2741 do { 2742 expected_size = native_bytes_allocated_.Load(); 2743 new_size = expected_size - bytes; 2744 if (UNLIKELY(new_size < 0)) { 2745 ScopedObjectAccess soa(env); 2746 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 2747 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 2748 "registered as allocated", bytes, expected_size).c_str()); 2749 break; 2750 } 2751 } while (!native_bytes_allocated_.CompareAndSwap(expected_size, new_size)); 2752} 2753 2754size_t Heap::GetTotalMemory() const { 2755 size_t ret = 0; 2756 for (const auto& space : continuous_spaces_) { 2757 // Currently don't include the image space. 2758 if (!space->IsImageSpace()) { 2759 ret += space->Size(); 2760 } 2761 } 2762 for (const auto& space : discontinuous_spaces_) { 2763 if (space->IsLargeObjectSpace()) { 2764 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 2765 } 2766 } 2767 return ret; 2768} 2769 2770void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 2771 DCHECK(mod_union_table != nullptr); 2772 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 2773} 2774 2775void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 2776 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 2777 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 2778 strlen(ClassHelper(c).GetDescriptor()) == 0); 2779 CHECK_GE(byte_count, sizeof(mirror::Object)); 2780} 2781 2782void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 2783 CHECK(remembered_set != nullptr); 2784 space::Space* space = remembered_set->GetSpace(); 2785 CHECK(space != nullptr); 2786 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2787 remembered_sets_.Put(space, remembered_set); 2788 CHECK(remembered_sets_.find(space) != remembered_sets_.end()); 2789} 2790 2791void Heap::RemoveRememberedSet(space::Space* space) { 2792 CHECK(space != nullptr); 2793 auto it = remembered_sets_.find(space); 2794 CHECK(it != remembered_sets_.end()); 2795 remembered_sets_.erase(it); 2796 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2797} 2798 2799} // namespace gc 2800} // namespace art 2801