heap.cc revision 38e68e9978236db87c9008bbe47db80525d2fa16
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 concurrent_gc_(false), 92 collector_type_(kCollectorTypeNone), 93 post_zygote_collector_type_(post_zygote_collector_type), 94 background_collector_type_(background_collector_type), 95 desired_collector_type_(collector_type_), 96 heap_trim_request_lock_(nullptr), 97 last_trim_time_(0), 98 heap_transition_target_time_(0), 99 heap_trim_request_pending_(false), 100 parallel_gc_threads_(parallel_gc_threads), 101 conc_gc_threads_(conc_gc_threads), 102 low_memory_mode_(low_memory_mode), 103 long_pause_log_threshold_(long_pause_log_threshold), 104 long_gc_log_threshold_(long_gc_log_threshold), 105 ignore_max_footprint_(ignore_max_footprint), 106 have_zygote_space_(false), 107 large_object_threshold_(std::numeric_limits<size_t>::max()), // Starts out disabled. 108 collector_type_running_(kCollectorTypeNone), 109 last_gc_type_(collector::kGcTypeNone), 110 next_gc_type_(collector::kGcTypePartial), 111 capacity_(capacity), 112 growth_limit_(growth_limit), 113 max_allowed_footprint_(initial_size), 114 native_footprint_gc_watermark_(initial_size), 115 native_footprint_limit_(2 * initial_size), 116 native_need_to_run_finalization_(false), 117 // Initially assume we perceive jank in case the process state is never updated. 118 process_state_(kProcessStateJankPerceptible), 119 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 120 total_bytes_freed_ever_(0), 121 total_objects_freed_ever_(0), 122 num_bytes_allocated_(0), 123 native_bytes_allocated_(0), 124 gc_memory_overhead_(0), 125 verify_missing_card_marks_(false), 126 verify_system_weaks_(false), 127 verify_pre_gc_heap_(verify_pre_gc_heap), 128 verify_post_gc_heap_(verify_post_gc_heap), 129 verify_mod_union_table_(false), 130 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 131 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 132 allocation_rate_(0), 133 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 134 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 135 * verification is enabled, we limit the size of allocation stacks to speed up their 136 * searching. 137 */ 138 max_allocation_stack_size_(kGCALotMode ? kGcAlotInterval 139 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? KB : MB), 140 current_allocator_(kAllocatorTypeDlMalloc), 141 current_non_moving_allocator_(kAllocatorTypeNonMoving), 142 bump_pointer_space_(nullptr), 143 temp_space_(nullptr), 144 min_free_(min_free), 145 max_free_(max_free), 146 target_utilization_(target_utilization), 147 total_wait_time_(0), 148 total_allocation_time_(0), 149 verify_object_mode_(kVerifyObjectModeDisabled), 150 disable_moving_gc_count_(0), 151 running_on_valgrind_(RUNNING_ON_VALGRIND > 0), 152 use_tlab_(use_tlab) { 153 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 154 LOG(INFO) << "Heap() entering"; 155 } 156 const bool is_zygote = Runtime::Current()->IsZygote(); 157 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 158 // entrypoints. 159 if (!is_zygote) { 160 desired_collector_type_ = post_zygote_collector_type_; 161 large_object_threshold_ = kDefaultLargeObjectThreshold; 162 } else { 163 if (kMovingCollector) { 164 // We are the zygote, use bump pointer allocation + semi space collector. 165 bool generational = post_zygote_collector_type_ == kCollectorTypeGSS; 166 desired_collector_type_ = generational ? kCollectorTypeGSS : kCollectorTypeSS; 167 } else { 168 desired_collector_type_ = post_zygote_collector_type_; 169 } 170 } 171 ChangeCollector(desired_collector_type_); 172 173 live_bitmap_.reset(new accounting::HeapBitmap(this)); 174 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 175 // Requested begin for the alloc space, to follow the mapped image and oat files 176 byte* requested_alloc_space_begin = nullptr; 177 if (!image_file_name.empty()) { 178 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str()); 179 CHECK(image_space != nullptr) << "Failed to create space for " << image_file_name; 180 AddSpace(image_space); 181 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 182 // isn't going to get in the middle 183 byte* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 184 CHECK_GT(oat_file_end_addr, image_space->End()); 185 if (oat_file_end_addr > requested_alloc_space_begin) { 186 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 187 } 188 } 189 MemMap* malloc_space_mem_map = nullptr; 190 const char* malloc_space_name = is_zygote ? "zygote space" : "alloc space"; 191 if (is_zygote) { 192 // Allocate a single mem map that is split into the malloc space 193 // and the post zygote non-moving space to put them adjacent. 194 size_t post_zygote_non_moving_space_size = 64 * MB; 195 size_t non_moving_spaces_size = capacity + post_zygote_non_moving_space_size; 196 std::string error_str; 197 malloc_space_mem_map = MemMap::MapAnonymous(malloc_space_name, requested_alloc_space_begin, 198 non_moving_spaces_size, PROT_READ | PROT_WRITE, 199 true, &error_str); 200 CHECK(malloc_space_mem_map != nullptr) << error_str; 201 post_zygote_non_moving_space_mem_map_.reset(malloc_space_mem_map->RemapAtEnd( 202 malloc_space_mem_map->Begin() + capacity, "post zygote non-moving space", 203 PROT_READ | PROT_WRITE, &error_str)); 204 CHECK(post_zygote_non_moving_space_mem_map_.get() != nullptr) << error_str; 205 VLOG(heap) << "malloc space mem map : " << malloc_space_mem_map; 206 VLOG(heap) << "post zygote non-moving space mem map : " 207 << post_zygote_non_moving_space_mem_map_.get(); 208 } else { 209 // Allocate a mem map for the malloc space. 210 std::string error_str; 211 malloc_space_mem_map = MemMap::MapAnonymous(malloc_space_name, requested_alloc_space_begin, 212 capacity, PROT_READ | PROT_WRITE, true, &error_str); 213 CHECK(malloc_space_mem_map != nullptr) << error_str; 214 VLOG(heap) << "malloc space mem map : " << malloc_space_mem_map; 215 } 216 CHECK(malloc_space_mem_map != nullptr); 217 space::MallocSpace* malloc_space; 218 if (kUseRosAlloc) { 219 malloc_space = space::RosAllocSpace::CreateFromMemMap(malloc_space_mem_map, malloc_space_name, 220 kDefaultStartingSize, initial_size, 221 growth_limit, capacity, low_memory_mode_); 222 CHECK(malloc_space != nullptr) << "Failed to create rosalloc space"; 223 } else { 224 malloc_space = space::DlMallocSpace::CreateFromMemMap(malloc_space_mem_map, malloc_space_name, 225 kDefaultStartingSize, initial_size, 226 growth_limit, capacity); 227 CHECK(malloc_space != nullptr) << "Failed to create dlmalloc space"; 228 } 229 VLOG(heap) << "malloc_space : " << malloc_space; 230 if (kMovingCollector) { 231 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 232 // TODO: Having 3+ spaces as big as the large heap size can cause virtual memory fragmentation 233 // issues. 234 const size_t bump_pointer_space_size = std::min(malloc_space->Capacity(), 128 * MB); 235 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space", 236 bump_pointer_space_size, nullptr); 237 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 238 AddSpace(bump_pointer_space_); 239 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", bump_pointer_space_size, 240 nullptr); 241 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 242 AddSpace(temp_space_); 243 VLOG(heap) << "bump_pointer_space : " << bump_pointer_space_; 244 VLOG(heap) << "temp_space : " << temp_space_; 245 } 246 non_moving_space_ = malloc_space; 247 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 248 AddSpace(malloc_space); 249 250 // Allocate the large object space. 251 constexpr bool kUseFreeListSpaceForLOS = false; 252 if (kUseFreeListSpaceForLOS) { 253 large_object_space_ = space::FreeListSpace::Create("large object space", nullptr, capacity); 254 } else { 255 large_object_space_ = space::LargeObjectMapSpace::Create("large object space"); 256 } 257 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 258 AddSpace(large_object_space_); 259 260 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 261 CHECK(!continuous_spaces_.empty()); 262 263 // Relies on the spaces being sorted. 264 byte* heap_begin = continuous_spaces_.front()->Begin(); 265 byte* heap_end = continuous_spaces_.back()->Limit(); 266 if (is_zygote) { 267 CHECK(post_zygote_non_moving_space_mem_map_.get() != nullptr); 268 heap_begin = std::min(post_zygote_non_moving_space_mem_map_->Begin(), heap_begin); 269 heap_end = std::max(post_zygote_non_moving_space_mem_map_->End(), heap_end); 270 } 271 size_t heap_capacity = heap_end - heap_begin; 272 273 // Allocate the card table. 274 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 275 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 276 277 // Card cache for now since it makes it easier for us to update the references to the copying 278 // spaces. 279 accounting::ModUnionTable* mod_union_table = 280 new accounting::ModUnionTableCardCache("Image mod-union table", this, 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} 753 754// Process reference class instances and schedule finalizations. 755void Heap::ProcessReferences(TimingLogger& timings, bool clear_soft, 756 IsMarkedCallback* is_marked_callback, 757 MarkObjectCallback* mark_object_callback, 758 ProcessMarkStackCallback* process_mark_stack_callback, void* arg) { 759 // Unless we are in the zygote or required to clear soft references with white references, 760 // preserve some white referents. 761 if (!clear_soft && !Runtime::Current()->IsZygote()) { 762 SoftReferenceArgs soft_reference_args; 763 soft_reference_args.is_marked_callback_ = is_marked_callback; 764 soft_reference_args.mark_callback_ = mark_object_callback; 765 soft_reference_args.arg_ = arg; 766 soft_reference_queue_.PreserveSomeSoftReferences(&PreserveSoftReferenceCallback, 767 &soft_reference_args); 768 process_mark_stack_callback(arg); 769 } 770 timings.StartSplit("(Paused)ProcessReferences"); 771 // Clear all remaining soft and weak references with white referents. 772 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 773 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 774 timings.EndSplit(); 775 // Preserve all white objects with finalize methods and schedule them for finalization. 776 timings.StartSplit("(Paused)EnqueueFinalizerReferences"); 777 finalizer_reference_queue_.EnqueueFinalizerReferences(cleared_references_, is_marked_callback, 778 mark_object_callback, arg); 779 process_mark_stack_callback(arg); 780 timings.EndSplit(); 781 timings.StartSplit("(Paused)ProcessReferences"); 782 // Clear all f-reachable soft and weak references with white referents. 783 soft_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 784 weak_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 785 // Clear all phantom references with white referents. 786 phantom_reference_queue_.ClearWhiteReferences(cleared_references_, is_marked_callback, arg); 787 // At this point all reference queues other than the cleared references should be empty. 788 DCHECK(soft_reference_queue_.IsEmpty()); 789 DCHECK(weak_reference_queue_.IsEmpty()); 790 DCHECK(finalizer_reference_queue_.IsEmpty()); 791 DCHECK(phantom_reference_queue_.IsEmpty()); 792 timings.EndSplit(); 793} 794 795// Process the "referent" field in a java.lang.ref.Reference. If the referent has not yet been 796// marked, put it on the appropriate list in the heap for later processing. 797void Heap::DelayReferenceReferent(mirror::Class* klass, mirror::Reference* ref, 798 IsMarkedCallback is_marked_callback, void* arg) { 799 DCHECK_EQ(klass, ref->GetClass()); 800 mirror::Object* referent = ref->GetReferent(); 801 if (referent != nullptr) { 802 mirror::Object* forward_address = is_marked_callback(referent, arg); 803 // Null means that the object is not currently marked. 804 if (forward_address == nullptr) { 805 Thread* self = Thread::Current(); 806 // TODO: Remove these locks, and use atomic stacks for storing references? 807 // We need to check that the references haven't already been enqueued since we can end up 808 // scanning the same reference multiple times due to dirty cards. 809 if (klass->IsSoftReferenceClass()) { 810 soft_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 811 } else if (klass->IsWeakReferenceClass()) { 812 weak_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 813 } else if (klass->IsFinalizerReferenceClass()) { 814 finalizer_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 815 } else if (klass->IsPhantomReferenceClass()) { 816 phantom_reference_queue_.AtomicEnqueueIfNotEnqueued(self, ref); 817 } else { 818 LOG(FATAL) << "Invalid reference type " << PrettyClass(klass) << " " << std::hex 819 << klass->GetAccessFlags(); 820 } 821 } else if (referent != forward_address) { 822 // Referent is already marked and we need to update it. 823 ref->SetReferent<false>(forward_address); 824 } 825 } 826} 827 828space::ImageSpace* Heap::GetImageSpace() const { 829 for (const auto& space : continuous_spaces_) { 830 if (space->IsImageSpace()) { 831 return space->AsImageSpace(); 832 } 833 } 834 return NULL; 835} 836 837static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) { 838 size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start); 839 if (used_bytes < chunk_size) { 840 size_t chunk_free_bytes = chunk_size - used_bytes; 841 size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg); 842 max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes); 843 } 844} 845 846void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, bool large_object_allocation) { 847 std::ostringstream oss; 848 size_t total_bytes_free = GetFreeMemory(); 849 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 850 << " free bytes"; 851 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 852 if (!large_object_allocation && total_bytes_free >= byte_count) { 853 size_t max_contiguous_allocation = 0; 854 for (const auto& space : continuous_spaces_) { 855 if (space->IsMallocSpace()) { 856 // To allow the Walk/InspectAll() to exclusively-lock the mutator 857 // lock, temporarily release the shared access to the mutator 858 // lock here by transitioning to the suspended state. 859 Locks::mutator_lock_->AssertSharedHeld(self); 860 self->TransitionFromRunnableToSuspended(kSuspended); 861 space->AsMallocSpace()->Walk(MSpaceChunkCallback, &max_contiguous_allocation); 862 self->TransitionFromSuspendedToRunnable(); 863 Locks::mutator_lock_->AssertSharedHeld(self); 864 } 865 } 866 oss << "; failed due to fragmentation (largest possible contiguous allocation " 867 << max_contiguous_allocation << " bytes)"; 868 } 869 self->ThrowOutOfMemoryError(oss.str().c_str()); 870} 871 872void Heap::DoPendingTransitionOrTrim() { 873 Thread* self = Thread::Current(); 874 CollectorType desired_collector_type; 875 // Wait until we reach the desired transition time. 876 while (true) { 877 uint64_t wait_time; 878 { 879 MutexLock mu(self, *heap_trim_request_lock_); 880 desired_collector_type = desired_collector_type_; 881 uint64_t current_time = NanoTime(); 882 if (current_time >= heap_transition_target_time_) { 883 break; 884 } 885 wait_time = heap_transition_target_time_ - current_time; 886 } 887 ScopedThreadStateChange tsc(self, kSleeping); 888 usleep(wait_time / 1000); // Usleep takes microseconds. 889 } 890 // Transition the collector if the desired collector type is not the same as the current 891 // collector type. 892 TransitionCollector(desired_collector_type); 893 // Do a heap trim if it is needed. 894 Trim(); 895} 896 897void Heap::Trim() { 898 Thread* self = Thread::Current(); 899 { 900 MutexLock mu(self, *heap_trim_request_lock_); 901 if (!heap_trim_request_pending_ || last_trim_time_ + kHeapTrimWait >= NanoTime()) { 902 return; 903 } 904 last_trim_time_ = NanoTime(); 905 heap_trim_request_pending_ = false; 906 } 907 { 908 // Need to do this before acquiring the locks since we don't want to get suspended while 909 // holding any locks. 910 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 911 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 912 // trimming. 913 MutexLock mu(self, *gc_complete_lock_); 914 // Ensure there is only one GC at a time. 915 WaitForGcToCompleteLocked(self); 916 collector_type_running_ = kCollectorTypeHeapTrim; 917 } 918 uint64_t start_ns = NanoTime(); 919 // Trim the managed spaces. 920 uint64_t total_alloc_space_allocated = 0; 921 uint64_t total_alloc_space_size = 0; 922 uint64_t managed_reclaimed = 0; 923 for (const auto& space : continuous_spaces_) { 924 if (space->IsMallocSpace()) { 925 gc::space::MallocSpace* alloc_space = space->AsMallocSpace(); 926 total_alloc_space_size += alloc_space->Size(); 927 managed_reclaimed += alloc_space->Trim(); 928 } 929 } 930 total_alloc_space_allocated = GetBytesAllocated() - large_object_space_->GetBytesAllocated() - 931 bump_pointer_space_->Size(); 932 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 933 static_cast<float>(total_alloc_space_size); 934 uint64_t gc_heap_end_ns = NanoTime(); 935 // We never move things in the native heap, so we can finish the GC at this point. 936 FinishGC(self, collector::kGcTypeNone); 937 // Trim the native heap. 938 dlmalloc_trim(0); 939 size_t native_reclaimed = 0; 940 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 941 uint64_t end_ns = NanoTime(); 942 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 943 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 944 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 945 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 946 << "%."; 947} 948 949bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 950 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 951 // taking the lock. 952 if (obj == nullptr) { 953 return true; 954 } 955 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 956} 957 958bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 959 return FindContinuousSpaceFromObject(obj, true) != nullptr; 960} 961 962bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 963 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 964 return false; 965 } 966 for (const auto& space : continuous_spaces_) { 967 if (space->HasAddress(obj)) { 968 return true; 969 } 970 } 971 return false; 972} 973 974bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 975 bool search_live_stack, bool sorted) { 976 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 977 return false; 978 } 979 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 980 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 981 if (obj == klass) { 982 // This case happens for java.lang.Class. 983 return true; 984 } 985 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 986 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 987 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 988 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 989 return temp_space_->Contains(obj); 990 } 991 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 992 space::DiscontinuousSpace* d_space = NULL; 993 if (c_space != nullptr) { 994 if (c_space->GetLiveBitmap()->Test(obj)) { 995 return true; 996 } 997 } else { 998 d_space = FindDiscontinuousSpaceFromObject(obj, true); 999 if (d_space != nullptr) { 1000 if (d_space->GetLiveObjects()->Test(obj)) { 1001 return true; 1002 } 1003 } 1004 } 1005 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1006 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1007 if (i > 0) { 1008 NanoSleep(MsToNs(10)); 1009 } 1010 if (search_allocation_stack) { 1011 if (sorted) { 1012 if (allocation_stack_->ContainsSorted(const_cast<mirror::Object*>(obj))) { 1013 return true; 1014 } 1015 } else if (allocation_stack_->Contains(const_cast<mirror::Object*>(obj))) { 1016 return true; 1017 } 1018 } 1019 1020 if (search_live_stack) { 1021 if (sorted) { 1022 if (live_stack_->ContainsSorted(const_cast<mirror::Object*>(obj))) { 1023 return true; 1024 } 1025 } else if (live_stack_->Contains(const_cast<mirror::Object*>(obj))) { 1026 return true; 1027 } 1028 } 1029 } 1030 // We need to check the bitmaps again since there is a race where we mark something as live and 1031 // then clear the stack containing it. 1032 if (c_space != nullptr) { 1033 if (c_space->GetLiveBitmap()->Test(obj)) { 1034 return true; 1035 } 1036 } else { 1037 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1038 if (d_space != nullptr && d_space->GetLiveObjects()->Test(obj)) { 1039 return true; 1040 } 1041 } 1042 return false; 1043} 1044 1045void Heap::DumpSpaces(std::ostream& stream) { 1046 for (const auto& space : continuous_spaces_) { 1047 accounting::SpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1048 accounting::SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1049 stream << space << " " << *space << "\n"; 1050 if (live_bitmap != nullptr) { 1051 stream << live_bitmap << " " << *live_bitmap << "\n"; 1052 } 1053 if (mark_bitmap != nullptr) { 1054 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1055 } 1056 } 1057 for (const auto& space : discontinuous_spaces_) { 1058 stream << space << " " << *space << "\n"; 1059 } 1060} 1061 1062void Heap::VerifyObjectBody(mirror::Object* obj) { 1063 if (this == nullptr && verify_object_mode_ == kVerifyObjectModeDisabled) { 1064 return; 1065 } 1066 // Ignore early dawn of the universe verifications. 1067 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.Load()) < 10 * KB)) { 1068 return; 1069 } 1070 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1071 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>( 1072 mirror::Object::ClassOffset(), false); 1073 CHECK(c != nullptr) << "Null class in object " << obj; 1074 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1075 CHECK(VerifyClassClass(c)); 1076 1077 if (verify_object_mode_ > kVerifyObjectModeFast) { 1078 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1079 if (!IsLiveObjectLocked(obj)) { 1080 DumpSpaces(); 1081 LOG(FATAL) << "Object is dead: " << obj; 1082 } 1083 } 1084} 1085 1086void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1087 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1088} 1089 1090void Heap::VerifyHeap() { 1091 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1092 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1093} 1094 1095void Heap::RecordFree(size_t freed_objects, size_t freed_bytes) { 1096 DCHECK_LE(freed_bytes, num_bytes_allocated_.Load()); 1097 num_bytes_allocated_.FetchAndSub(freed_bytes); 1098 if (Runtime::Current()->HasStatsEnabled()) { 1099 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1100 thread_stats->freed_objects += freed_objects; 1101 thread_stats->freed_bytes += freed_bytes; 1102 // TODO: Do this concurrently. 1103 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1104 global_stats->freed_objects += freed_objects; 1105 global_stats->freed_bytes += freed_bytes; 1106 } 1107} 1108 1109mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1110 size_t alloc_size, size_t* bytes_allocated, 1111 size_t* usable_size, 1112 mirror::Class** klass) { 1113 mirror::Object* ptr = nullptr; 1114 bool was_default_allocator = allocator == GetCurrentAllocator(); 1115 DCHECK(klass != nullptr); 1116 SirtRef<mirror::Class> sirt_klass(self, *klass); 1117 // The allocation failed. If the GC is running, block until it completes, and then retry the 1118 // allocation. 1119 collector::GcType last_gc = WaitForGcToComplete(self); 1120 if (last_gc != collector::kGcTypeNone) { 1121 // If we were the default allocator but the allocator changed while we were suspended, 1122 // abort the allocation. 1123 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1124 *klass = sirt_klass.get(); 1125 return nullptr; 1126 } 1127 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1128 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1129 } 1130 1131 // Loop through our different Gc types and try to Gc until we get enough free memory. 1132 for (collector::GcType gc_type : gc_plan_) { 1133 if (ptr != nullptr) { 1134 break; 1135 } 1136 // Attempt to run the collector, if we succeed, re-try the allocation. 1137 bool gc_ran = 1138 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1139 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1140 *klass = sirt_klass.get(); 1141 return nullptr; 1142 } 1143 if (gc_ran) { 1144 // Did we free sufficient memory for the allocation to succeed? 1145 ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, usable_size); 1146 } 1147 } 1148 // Allocations have failed after GCs; this is an exceptional state. 1149 if (ptr == nullptr) { 1150 // Try harder, growing the heap if necessary. 1151 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1152 } 1153 if (ptr == nullptr) { 1154 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1155 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1156 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1157 // OOME. 1158 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1159 << " allocation"; 1160 // TODO: Run finalization, but this may cause more allocations to occur. 1161 // We don't need a WaitForGcToComplete here either. 1162 DCHECK(!gc_plan_.empty()); 1163 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1164 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1165 *klass = sirt_klass.get(); 1166 return nullptr; 1167 } 1168 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1169 if (ptr == nullptr) { 1170 ThrowOutOfMemoryError(self, alloc_size, false); 1171 } 1172 } 1173 *klass = sirt_klass.get(); 1174 return ptr; 1175} 1176 1177void Heap::SetTargetHeapUtilization(float target) { 1178 DCHECK_GT(target, 0.0f); // asserted in Java code 1179 DCHECK_LT(target, 1.0f); 1180 target_utilization_ = target; 1181} 1182 1183size_t Heap::GetObjectsAllocated() const { 1184 size_t total = 0; 1185 for (space::AllocSpace* space : alloc_spaces_) { 1186 total += space->GetObjectsAllocated(); 1187 } 1188 return total; 1189} 1190 1191size_t Heap::GetObjectsAllocatedEver() const { 1192 return GetObjectsFreedEver() + GetObjectsAllocated(); 1193} 1194 1195size_t Heap::GetBytesAllocatedEver() const { 1196 return GetBytesFreedEver() + GetBytesAllocated(); 1197} 1198 1199class InstanceCounter { 1200 public: 1201 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1202 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1203 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1204 } 1205 static void Callback(mirror::Object* obj, void* arg) 1206 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1207 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1208 mirror::Class* instance_class = obj->GetClass(); 1209 CHECK(instance_class != nullptr); 1210 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1211 if (instance_counter->use_is_assignable_from_) { 1212 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1213 ++instance_counter->counts_[i]; 1214 } 1215 } else if (instance_class == instance_counter->classes_[i]) { 1216 ++instance_counter->counts_[i]; 1217 } 1218 } 1219 } 1220 1221 private: 1222 const std::vector<mirror::Class*>& classes_; 1223 bool use_is_assignable_from_; 1224 uint64_t* const counts_; 1225 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1226}; 1227 1228void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1229 uint64_t* counts) { 1230 // Can't do any GC in this function since this may move classes. 1231 Thread* self = Thread::Current(); 1232 auto* old_cause = self->StartAssertNoThreadSuspension("CountInstances"); 1233 InstanceCounter counter(classes, use_is_assignable_from, counts); 1234 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1235 VisitObjects(InstanceCounter::Callback, &counter); 1236 self->EndAssertNoThreadSuspension(old_cause); 1237} 1238 1239class InstanceCollector { 1240 public: 1241 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1242 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1243 : class_(c), max_count_(max_count), instances_(instances) { 1244 } 1245 static void Callback(mirror::Object* obj, void* arg) 1246 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1247 DCHECK(arg != nullptr); 1248 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1249 mirror::Class* instance_class = obj->GetClass(); 1250 if (instance_class == instance_collector->class_) { 1251 if (instance_collector->max_count_ == 0 || 1252 instance_collector->instances_.size() < instance_collector->max_count_) { 1253 instance_collector->instances_.push_back(obj); 1254 } 1255 } 1256 } 1257 1258 private: 1259 mirror::Class* class_; 1260 uint32_t max_count_; 1261 std::vector<mirror::Object*>& instances_; 1262 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1263}; 1264 1265void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1266 std::vector<mirror::Object*>& instances) { 1267 // Can't do any GC in this function since this may move classes. 1268 Thread* self = Thread::Current(); 1269 auto* old_cause = self->StartAssertNoThreadSuspension("GetInstances"); 1270 InstanceCollector collector(c, max_count, instances); 1271 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1272 VisitObjects(&InstanceCollector::Callback, &collector); 1273 self->EndAssertNoThreadSuspension(old_cause); 1274} 1275 1276class ReferringObjectsFinder { 1277 public: 1278 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1279 std::vector<mirror::Object*>& referring_objects) 1280 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1281 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1282 } 1283 1284 static void Callback(mirror::Object* obj, void* arg) 1285 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1286 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1287 } 1288 1289 // For bitmap Visit. 1290 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1291 // annotalysis on visitors. 1292 void operator()(const mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1293 collector::MarkSweep::VisitObjectReferences(const_cast<mirror::Object*>(o), *this, true); 1294 } 1295 1296 // For MarkSweep::VisitObjectReferences. 1297 void operator()(mirror::Object* referrer, mirror::Object* object, 1298 const MemberOffset&, bool) const { 1299 if (object == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1300 referring_objects_.push_back(referrer); 1301 } 1302 } 1303 1304 private: 1305 mirror::Object* object_; 1306 uint32_t max_count_; 1307 std::vector<mirror::Object*>& referring_objects_; 1308 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1309}; 1310 1311void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1312 std::vector<mirror::Object*>& referring_objects) { 1313 // Can't do any GC in this function since this may move the object o. 1314 Thread* self = Thread::Current(); 1315 auto* old_cause = self->StartAssertNoThreadSuspension("GetReferringObjects"); 1316 ReferringObjectsFinder finder(o, max_count, referring_objects); 1317 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 1318 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1319 self->EndAssertNoThreadSuspension(old_cause); 1320} 1321 1322void Heap::CollectGarbage(bool clear_soft_references) { 1323 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1324 // last GC will not have necessarily been cleared. 1325 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1326} 1327 1328void Heap::TransitionCollector(CollectorType collector_type) { 1329 if (collector_type == collector_type_) { 1330 return; 1331 } 1332 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1333 << " -> " << static_cast<int>(collector_type); 1334 uint64_t start_time = NanoTime(); 1335 uint32_t before_size = GetTotalMemory(); 1336 uint32_t before_allocated = num_bytes_allocated_.Load(); 1337 ThreadList* tl = Runtime::Current()->GetThreadList(); 1338 Thread* self = Thread::Current(); 1339 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1340 Locks::mutator_lock_->AssertNotHeld(self); 1341 const bool copying_transition = 1342 IsCompactingGC(background_collector_type_) || IsCompactingGC(post_zygote_collector_type_); 1343 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1344 // compacting_gc_disable_count_, this should rarely occurs). 1345 for (;;) { 1346 { 1347 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1348 MutexLock mu(self, *gc_complete_lock_); 1349 // Ensure there is only one GC at a time. 1350 WaitForGcToCompleteLocked(self); 1351 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1352 if (!copying_transition || disable_moving_gc_count_ == 0) { 1353 // TODO: Not hard code in semi-space collector? 1354 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1355 break; 1356 } 1357 } 1358 usleep(1000); 1359 } 1360 tl->SuspendAll(); 1361 PreGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1362 switch (collector_type) { 1363 case kCollectorTypeSS: 1364 // Fall-through. 1365 case kCollectorTypeGSS: { 1366 mprotect(temp_space_->Begin(), temp_space_->Capacity(), PROT_READ | PROT_WRITE); 1367 CHECK(main_space_ != nullptr); 1368 Compact(temp_space_, main_space_); 1369 DCHECK(allocator_mem_map_.get() == nullptr); 1370 allocator_mem_map_.reset(main_space_->ReleaseMemMap()); 1371 madvise(main_space_->Begin(), main_space_->Size(), MADV_DONTNEED); 1372 // RemoveSpace does not delete the removed space. 1373 space::Space* old_space = main_space_; 1374 RemoveSpace(old_space); 1375 delete old_space; 1376 break; 1377 } 1378 case kCollectorTypeMS: 1379 // Fall through. 1380 case kCollectorTypeCMS: { 1381 if (IsCompactingGC(collector_type_)) { 1382 // TODO: Use mem-map from temp space? 1383 MemMap* mem_map = allocator_mem_map_.release(); 1384 CHECK(mem_map != nullptr); 1385 size_t starting_size = kDefaultStartingSize; 1386 size_t initial_size = kDefaultInitialSize; 1387 mprotect(mem_map->Begin(), initial_size, PROT_READ | PROT_WRITE); 1388 CHECK(main_space_ == nullptr); 1389 if (kUseRosAlloc) { 1390 main_space_ = 1391 space::RosAllocSpace::CreateFromMemMap(mem_map, "alloc space", starting_size, 1392 initial_size, mem_map->Size(), 1393 mem_map->Size(), low_memory_mode_); 1394 } else { 1395 main_space_ = 1396 space::DlMallocSpace::CreateFromMemMap(mem_map, "alloc space", starting_size, 1397 initial_size, mem_map->Size(), 1398 mem_map->Size()); 1399 } 1400 main_space_->SetFootprintLimit(main_space_->Capacity()); 1401 AddSpace(main_space_); 1402 Compact(main_space_, bump_pointer_space_); 1403 } 1404 break; 1405 } 1406 default: { 1407 LOG(FATAL) << "Attempted to transition to invalid collector type"; 1408 break; 1409 } 1410 } 1411 ChangeCollector(collector_type); 1412 PostGcRosAllocVerification(&semi_space_collector_->GetTimings()); 1413 tl->ResumeAll(); 1414 // Can't call into java code with all threads suspended. 1415 EnqueueClearedReferences(); 1416 uint64_t duration = NanoTime() - start_time; 1417 GrowForUtilization(collector::kGcTypeFull, duration); 1418 FinishGC(self, collector::kGcTypeFull); 1419 int32_t after_size = GetTotalMemory(); 1420 int32_t delta_size = before_size - after_size; 1421 int32_t after_allocated = num_bytes_allocated_.Load(); 1422 int32_t delta_allocated = before_allocated - after_allocated; 1423 const std::string saved_bytes_str = 1424 delta_size < 0 ? "-" + PrettySize(-delta_size) : PrettySize(delta_size); 1425 LOG(INFO) << "Heap transition to " << process_state_ << " took " 1426 << PrettyDuration(duration) << " " << PrettySize(before_size) << "->" 1427 << PrettySize(after_size) << " from " << PrettySize(delta_allocated) << " to " 1428 << PrettySize(delta_size) << " saved"; 1429} 1430 1431void Heap::ChangeCollector(CollectorType collector_type) { 1432 // TODO: Only do this with all mutators suspended to avoid races. 1433 if (collector_type != collector_type_) { 1434 collector_type_ = collector_type; 1435 gc_plan_.clear(); 1436 switch (collector_type_) { 1437 case kCollectorTypeSS: 1438 // Fall-through. 1439 case kCollectorTypeGSS: { 1440 concurrent_gc_ = false; 1441 gc_plan_.push_back(collector::kGcTypeFull); 1442 if (use_tlab_) { 1443 ChangeAllocator(kAllocatorTypeTLAB); 1444 } else { 1445 ChangeAllocator(kAllocatorTypeBumpPointer); 1446 } 1447 break; 1448 } 1449 case kCollectorTypeMS: { 1450 concurrent_gc_ = false; 1451 gc_plan_.push_back(collector::kGcTypeSticky); 1452 gc_plan_.push_back(collector::kGcTypePartial); 1453 gc_plan_.push_back(collector::kGcTypeFull); 1454 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1455 break; 1456 } 1457 case kCollectorTypeCMS: { 1458 concurrent_gc_ = true; 1459 gc_plan_.push_back(collector::kGcTypeSticky); 1460 gc_plan_.push_back(collector::kGcTypePartial); 1461 gc_plan_.push_back(collector::kGcTypeFull); 1462 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1463 break; 1464 } 1465 default: { 1466 LOG(FATAL) << "Unimplemented"; 1467 } 1468 } 1469 if (concurrent_gc_) { 1470 concurrent_start_bytes_ = 1471 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1472 } else { 1473 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1474 } 1475 } 1476} 1477 1478// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1479class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1480 public: 1481 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1482 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1483 } 1484 1485 void BuildBins(space::ContinuousSpace* space) { 1486 bin_live_bitmap_ = space->GetLiveBitmap(); 1487 bin_mark_bitmap_ = space->GetMarkBitmap(); 1488 BinContext context; 1489 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1490 context.collector_ = this; 1491 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1492 // Note: This requires traversing the space in increasing order of object addresses. 1493 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1494 // Add the last bin which spans after the last object to the end of the space. 1495 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1496 } 1497 1498 private: 1499 struct BinContext { 1500 uintptr_t prev_; // The end of the previous object. 1501 ZygoteCompactingCollector* collector_; 1502 }; 1503 // Maps from bin sizes to locations. 1504 std::multimap<size_t, uintptr_t> bins_; 1505 // Live bitmap of the space which contains the bins. 1506 accounting::SpaceBitmap* bin_live_bitmap_; 1507 // Mark bitmap of the space which contains the bins. 1508 accounting::SpaceBitmap* bin_mark_bitmap_; 1509 1510 static void Callback(mirror::Object* obj, void* arg) 1511 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1512 DCHECK(arg != nullptr); 1513 BinContext* context = reinterpret_cast<BinContext*>(arg); 1514 ZygoteCompactingCollector* collector = context->collector_; 1515 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1516 size_t bin_size = object_addr - context->prev_; 1517 // Add the bin consisting of the end of the previous object to the start of the current object. 1518 collector->AddBin(bin_size, context->prev_); 1519 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1520 } 1521 1522 void AddBin(size_t size, uintptr_t position) { 1523 if (size != 0) { 1524 bins_.insert(std::make_pair(size, position)); 1525 } 1526 } 1527 1528 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1529 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1530 // allocator. 1531 return false; 1532 } 1533 1534 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1535 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1536 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1537 mirror::Object* forward_address; 1538 // Find the smallest bin which we can move obj in. 1539 auto it = bins_.lower_bound(object_size); 1540 if (it == bins_.end()) { 1541 // No available space in the bins, place it in the target space instead (grows the zygote 1542 // space). 1543 size_t bytes_allocated; 1544 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1545 if (to_space_live_bitmap_ != nullptr) { 1546 to_space_live_bitmap_->Set(forward_address); 1547 } else { 1548 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1549 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1550 } 1551 } else { 1552 size_t size = it->first; 1553 uintptr_t pos = it->second; 1554 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1555 forward_address = reinterpret_cast<mirror::Object*>(pos); 1556 // Set the live and mark bits so that sweeping system weaks works properly. 1557 bin_live_bitmap_->Set(forward_address); 1558 bin_mark_bitmap_->Set(forward_address); 1559 DCHECK_GE(size, object_size); 1560 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1561 } 1562 // Copy the object over to its new location. 1563 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1564 if (kUseBrooksPointer) { 1565 obj->AssertSelfBrooksPointer(); 1566 DCHECK_EQ(forward_address->GetBrooksPointer(), obj); 1567 forward_address->SetBrooksPointer(forward_address); 1568 forward_address->AssertSelfBrooksPointer(); 1569 } 1570 return forward_address; 1571 } 1572}; 1573 1574void Heap::UnBindBitmaps() { 1575 for (const auto& space : GetContinuousSpaces()) { 1576 if (space->IsContinuousMemMapAllocSpace()) { 1577 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1578 if (alloc_space->HasBoundBitmaps()) { 1579 alloc_space->UnBindBitmaps(); 1580 } 1581 } 1582 } 1583} 1584 1585void Heap::PreZygoteFork() { 1586 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1587 static Mutex zygote_creation_lock_("zygote creation lock", kZygoteCreationLock); 1588 Thread* self = Thread::Current(); 1589 MutexLock mu(self, zygote_creation_lock_); 1590 // Try to see if we have any Zygote spaces. 1591 if (have_zygote_space_) { 1592 return; 1593 } 1594 VLOG(heap) << "Starting PreZygoteFork"; 1595 // Trim the pages at the end of the non moving space. 1596 non_moving_space_->Trim(); 1597 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1598 // Change the collector to the post zygote one. 1599 ChangeCollector(post_zygote_collector_type_); 1600 // TODO: Delete bump_pointer_space_ and temp_pointer_space_? 1601 if (semi_space_collector_ != nullptr) { 1602 // Temporarily disable rosalloc verification because the zygote 1603 // compaction will mess up the rosalloc internal metadata. 1604 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1605 ZygoteCompactingCollector zygote_collector(this); 1606 zygote_collector.BuildBins(non_moving_space_); 1607 // Create a new bump pointer space which we will compact into. 1608 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1609 non_moving_space_->Limit()); 1610 // Compact the bump pointer space to a new zygote bump pointer space. 1611 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1612 zygote_collector.SetFromSpace(bump_pointer_space_); 1613 zygote_collector.SetToSpace(&target_space); 1614 zygote_collector.Run(kGcCauseCollectorTransition, false); 1615 CHECK(temp_space_->IsEmpty()); 1616 total_objects_freed_ever_ += semi_space_collector_->GetFreedObjects(); 1617 total_bytes_freed_ever_ += semi_space_collector_->GetFreedBytes(); 1618 // Update the end and write out image. 1619 non_moving_space_->SetEnd(target_space.End()); 1620 non_moving_space_->SetLimit(target_space.Limit()); 1621 VLOG(heap) << "Zygote size " << non_moving_space_->Size() << " bytes"; 1622 } 1623 // Save the old space so that we can remove it after we complete creating the zygote space. 1624 space::MallocSpace* old_alloc_space = non_moving_space_; 1625 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 1626 // the remaining available space. 1627 // Remove the old space before creating the zygote space since creating the zygote space sets 1628 // the old alloc space's bitmaps to nullptr. 1629 RemoveSpace(old_alloc_space); 1630 if (collector::SemiSpace::kUseRememberedSet) { 1631 // Sanity bound check. 1632 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 1633 // Remove the remembered set for the now zygote space (the old 1634 // non-moving space). Note now that we have compacted objects into 1635 // the zygote space, the data in the remembered set is no longer 1636 // needed. The zygote space will instead have a mod-union table 1637 // from this point on. 1638 RemoveRememberedSet(old_alloc_space); 1639 } 1640 space::ZygoteSpace* zygote_space = old_alloc_space->CreateZygoteSpace("alloc space", 1641 low_memory_mode_, 1642 &main_space_); 1643 delete old_alloc_space; 1644 CHECK(zygote_space != nullptr) << "Failed creating zygote space"; 1645 AddSpace(zygote_space, false); 1646 CHECK(main_space_ != nullptr); 1647 if (main_space_->IsRosAllocSpace()) { 1648 rosalloc_space_ = main_space_->AsRosAllocSpace(); 1649 } else if (main_space_->IsDlMallocSpace()) { 1650 dlmalloc_space_ = main_space_->AsDlMallocSpace(); 1651 } 1652 main_space_->SetFootprintLimit(main_space_->Capacity()); 1653 AddSpace(main_space_); 1654 have_zygote_space_ = true; 1655 // Enable large object space allocations. 1656 large_object_threshold_ = kDefaultLargeObjectThreshold; 1657 // Create the zygote space mod union table. 1658 accounting::ModUnionTable* mod_union_table = 1659 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, zygote_space); 1660 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 1661 AddModUnionTable(mod_union_table); 1662 if (collector::SemiSpace::kUseRememberedSet) { 1663 // Add a new remembered set for the new main space. 1664 accounting::RememberedSet* main_space_rem_set = 1665 new accounting::RememberedSet("Main space remembered set", this, main_space_); 1666 CHECK(main_space_rem_set != nullptr) << "Failed to create main space remembered set"; 1667 AddRememberedSet(main_space_rem_set); 1668 } 1669 // Can't use RosAlloc for non moving space due to thread local buffers. 1670 // TODO: Non limited space for non-movable objects? 1671 MemMap* mem_map = post_zygote_non_moving_space_mem_map_.release(); 1672 space::MallocSpace* new_non_moving_space = 1673 space::DlMallocSpace::CreateFromMemMap(mem_map, "Non moving dlmalloc space", kPageSize, 1674 2 * MB, mem_map->Size(), mem_map->Size()); 1675 AddSpace(new_non_moving_space, false); 1676 CHECK(new_non_moving_space != nullptr) << "Failed to create new non-moving space"; 1677 new_non_moving_space->SetFootprintLimit(new_non_moving_space->Capacity()); 1678 non_moving_space_ = new_non_moving_space; 1679 if (collector::SemiSpace::kUseRememberedSet) { 1680 // Add a new remembered set for the post-zygote non-moving space. 1681 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 1682 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 1683 non_moving_space_); 1684 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 1685 << "Failed to create post-zygote non-moving space remembered set"; 1686 AddRememberedSet(post_zygote_non_moving_space_rem_set); 1687 } 1688} 1689 1690void Heap::FlushAllocStack() { 1691 MarkAllocStackAsLive(allocation_stack_.get()); 1692 allocation_stack_->Reset(); 1693} 1694 1695void Heap::MarkAllocStack(accounting::SpaceBitmap* bitmap1, 1696 accounting::SpaceBitmap* bitmap2, 1697 accounting::ObjectSet* large_objects, 1698 accounting::ObjectStack* stack) { 1699 DCHECK(bitmap1 != nullptr); 1700 DCHECK(bitmap2 != nullptr); 1701 mirror::Object** limit = stack->End(); 1702 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 1703 const mirror::Object* obj = *it; 1704 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 1705 if (bitmap1->HasAddress(obj)) { 1706 bitmap1->Set(obj); 1707 } else if (bitmap2->HasAddress(obj)) { 1708 bitmap2->Set(obj); 1709 } else { 1710 large_objects->Set(obj); 1711 } 1712 } 1713 } 1714} 1715 1716void Heap::SwapSemiSpaces() { 1717 // Swap the spaces so we allocate into the space which we just evacuated. 1718 std::swap(bump_pointer_space_, temp_space_); 1719 bump_pointer_space_->Clear(); 1720} 1721 1722void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 1723 space::ContinuousMemMapAllocSpace* source_space) { 1724 CHECK(kMovingCollector); 1725 CHECK_NE(target_space, source_space) << "In-place compaction currently unsupported"; 1726 if (target_space != source_space) { 1727 semi_space_collector_->SetFromSpace(source_space); 1728 semi_space_collector_->SetToSpace(target_space); 1729 semi_space_collector_->Run(kGcCauseCollectorTransition, false); 1730 } 1731} 1732 1733collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 1734 bool clear_soft_references) { 1735 Thread* self = Thread::Current(); 1736 Runtime* runtime = Runtime::Current(); 1737 // If the heap can't run the GC, silently fail and return that no GC was run. 1738 switch (gc_type) { 1739 case collector::kGcTypePartial: { 1740 if (!have_zygote_space_) { 1741 return collector::kGcTypeNone; 1742 } 1743 break; 1744 } 1745 default: { 1746 // Other GC types don't have any special cases which makes them not runnable. The main case 1747 // here is full GC. 1748 } 1749 } 1750 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1751 Locks::mutator_lock_->AssertNotHeld(self); 1752 if (self->IsHandlingStackOverflow()) { 1753 LOG(WARNING) << "Performing GC on a thread that is handling a stack overflow."; 1754 } 1755 bool compacting_gc; 1756 { 1757 gc_complete_lock_->AssertNotHeld(self); 1758 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1759 MutexLock mu(self, *gc_complete_lock_); 1760 // Ensure there is only one GC at a time. 1761 WaitForGcToCompleteLocked(self); 1762 compacting_gc = IsCompactingGC(collector_type_); 1763 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 1764 if (compacting_gc && disable_moving_gc_count_ != 0) { 1765 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 1766 return collector::kGcTypeNone; 1767 } 1768 collector_type_running_ = collector_type_; 1769 } 1770 1771 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 1772 ++runtime->GetStats()->gc_for_alloc_count; 1773 ++self->GetStats()->gc_for_alloc_count; 1774 } 1775 uint64_t gc_start_time_ns = NanoTime(); 1776 uint64_t gc_start_size = GetBytesAllocated(); 1777 // Approximate allocation rate in bytes / second. 1778 uint64_t ms_delta = NsToMs(gc_start_time_ns - last_gc_time_ns_); 1779 // Back to back GCs can cause 0 ms of wait time in between GC invocations. 1780 if (LIKELY(ms_delta != 0)) { 1781 allocation_rate_ = ((gc_start_size - last_gc_size_) * 1000) / ms_delta; 1782 VLOG(heap) << "Allocation rate: " << PrettySize(allocation_rate_) << "/s"; 1783 } 1784 1785 DCHECK_LT(gc_type, collector::kGcTypeMax); 1786 DCHECK_NE(gc_type, collector::kGcTypeNone); 1787 1788 collector::GarbageCollector* collector = nullptr; 1789 // TODO: Clean this up. 1790 if (compacting_gc) { 1791 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 1792 current_allocator_ == kAllocatorTypeTLAB); 1793 gc_type = semi_space_collector_->GetGcType(); 1794 CHECK(temp_space_->IsEmpty()); 1795 semi_space_collector_->SetFromSpace(bump_pointer_space_); 1796 semi_space_collector_->SetToSpace(temp_space_); 1797 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1798 collector = semi_space_collector_; 1799 gc_type = collector::kGcTypeFull; 1800 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 1801 current_allocator_ == kAllocatorTypeDlMalloc) { 1802 for (const auto& cur_collector : garbage_collectors_) { 1803 if (cur_collector->IsConcurrent() == concurrent_gc_ && 1804 cur_collector->GetGcType() == gc_type) { 1805 collector = cur_collector; 1806 break; 1807 } 1808 } 1809 } else { 1810 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 1811 } 1812 CHECK(collector != nullptr) 1813 << "Could not find garbage collector with concurrent=" << concurrent_gc_ 1814 << " and type=" << gc_type; 1815 ATRACE_BEGIN(StringPrintf("%s %s GC", PrettyCause(gc_cause), collector->GetName()).c_str()); 1816 collector->Run(gc_cause, clear_soft_references); 1817 total_objects_freed_ever_ += collector->GetFreedObjects(); 1818 total_bytes_freed_ever_ += collector->GetFreedBytes(); 1819 RequestHeapTrim(); 1820 // Enqueue cleared references. 1821 EnqueueClearedReferences(); 1822 // Grow the heap so that we know when to perform the next GC. 1823 GrowForUtilization(gc_type, collector->GetDurationNs()); 1824 if (CareAboutPauseTimes()) { 1825 const size_t duration = collector->GetDurationNs(); 1826 std::vector<uint64_t> pauses = collector->GetPauseTimes(); 1827 // GC for alloc pauses the allocating thread, so consider it as a pause. 1828 bool was_slow = duration > long_gc_log_threshold_ || 1829 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 1830 if (!was_slow) { 1831 for (uint64_t pause : pauses) { 1832 was_slow = was_slow || pause > long_pause_log_threshold_; 1833 } 1834 } 1835 if (was_slow) { 1836 const size_t percent_free = GetPercentFree(); 1837 const size_t current_heap_size = GetBytesAllocated(); 1838 const size_t total_memory = GetTotalMemory(); 1839 std::ostringstream pause_string; 1840 for (size_t i = 0; i < pauses.size(); ++i) { 1841 pause_string << PrettyDuration((pauses[i] / 1000) * 1000) 1842 << ((i != pauses.size() - 1) ? ", " : ""); 1843 } 1844 LOG(INFO) << gc_cause << " " << collector->GetName() 1845 << " GC freed " << collector->GetFreedObjects() << "(" 1846 << PrettySize(collector->GetFreedBytes()) << ") AllocSpace objects, " 1847 << collector->GetFreedLargeObjects() << "(" 1848 << PrettySize(collector->GetFreedLargeObjectBytes()) << ") LOS objects, " 1849 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 1850 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 1851 << " total " << PrettyDuration((duration / 1000) * 1000); 1852 if (VLOG_IS_ON(heap)) { 1853 LOG(INFO) << Dumpable<TimingLogger>(collector->GetTimings()); 1854 } 1855 } 1856 } 1857 FinishGC(self, gc_type); 1858 ATRACE_END(); 1859 1860 // Inform DDMS that a GC completed. 1861 Dbg::GcDidFinish(); 1862 return gc_type; 1863} 1864 1865void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 1866 MutexLock mu(self, *gc_complete_lock_); 1867 collector_type_running_ = kCollectorTypeNone; 1868 if (gc_type != collector::kGcTypeNone) { 1869 last_gc_type_ = gc_type; 1870 } 1871 // Wake anyone who may have been waiting for the GC to complete. 1872 gc_complete_cond_->Broadcast(self); 1873} 1874 1875static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 1876 RootType /*root_type*/) { 1877 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 1878 if (*root == obj) { 1879 LOG(INFO) << "Object " << obj << " is a root"; 1880 } 1881} 1882 1883class ScanVisitor { 1884 public: 1885 void operator()(const mirror::Object* obj) const { 1886 LOG(ERROR) << "Would have rescanned object " << obj; 1887 } 1888}; 1889 1890// Verify a reference from an object. 1891class VerifyReferenceVisitor { 1892 public: 1893 explicit VerifyReferenceVisitor(Heap* heap) 1894 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 1895 : heap_(heap), failed_(false) {} 1896 1897 bool Failed() const { 1898 return failed_; 1899 } 1900 1901 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for smarter 1902 // analysis on visitors. 1903 void operator()(mirror::Object* obj, mirror::Object* ref, 1904 const MemberOffset& offset, bool /* is_static */) const 1905 NO_THREAD_SAFETY_ANALYSIS { 1906 if (ref == nullptr || IsLive(ref)) { 1907 // Verify that the reference is live. 1908 return; 1909 } 1910 if (!failed_) { 1911 // Print message on only on first failure to prevent spam. 1912 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 1913 failed_ = true; 1914 } 1915 if (obj != nullptr) { 1916 accounting::CardTable* card_table = heap_->GetCardTable(); 1917 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 1918 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 1919 byte* card_addr = card_table->CardFromAddr(obj); 1920 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 1921 << offset << "\n card value = " << static_cast<int>(*card_addr); 1922 if (heap_->IsValidObjectAddress(obj->GetClass())) { 1923 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 1924 } else { 1925 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 1926 } 1927 1928 // Attmept to find the class inside of the recently freed objects. 1929 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 1930 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 1931 space::MallocSpace* space = ref_space->AsMallocSpace(); 1932 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 1933 if (ref_class != nullptr) { 1934 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 1935 << PrettyClass(ref_class); 1936 } else { 1937 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 1938 } 1939 } 1940 1941 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 1942 ref->GetClass()->IsClass()) { 1943 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 1944 } else { 1945 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 1946 << ") is not a valid heap address"; 1947 } 1948 1949 card_table->CheckAddrIsInCardTable(reinterpret_cast<const byte*>(obj)); 1950 void* cover_begin = card_table->AddrFromCard(card_addr); 1951 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 1952 accounting::CardTable::kCardSize); 1953 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 1954 << "-" << cover_end; 1955 accounting::SpaceBitmap* bitmap = heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 1956 1957 if (bitmap == nullptr) { 1958 LOG(ERROR) << "Object " << obj << " has no bitmap"; 1959 if (!VerifyClassClass(obj->GetClass())) { 1960 LOG(ERROR) << "Object " << obj << " failed class verification!"; 1961 } 1962 } else { 1963 // Print out how the object is live. 1964 if (bitmap->Test(obj)) { 1965 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 1966 } 1967 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 1968 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 1969 } 1970 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 1971 LOG(ERROR) << "Object " << obj << " found in live stack"; 1972 } 1973 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 1974 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 1975 } 1976 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 1977 LOG(ERROR) << "Ref " << ref << " found in live stack"; 1978 } 1979 // Attempt to see if the card table missed the reference. 1980 ScanVisitor scan_visitor; 1981 byte* byte_cover_begin = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 1982 card_table->Scan(bitmap, byte_cover_begin, 1983 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 1984 } 1985 1986 // Search to see if any of the roots reference our object. 1987 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 1988 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 1989 1990 // Search to see if any of the roots reference our reference. 1991 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 1992 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 1993 } else { 1994 LOG(ERROR) << "Root " << ref << " is dead with type " << PrettyTypeOf(ref); 1995 } 1996 } 1997 1998 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 1999 return heap_->IsLiveObjectLocked(obj, true, false, true); 2000 } 2001 2002 static void VerifyRoots(mirror::Object** root, void* arg, uint32_t /*thread_id*/, 2003 RootType /*root_type*/) { 2004 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2005 (*visitor)(nullptr, *root, MemberOffset(0), true); 2006 } 2007 2008 private: 2009 Heap* const heap_; 2010 mutable bool failed_; 2011}; 2012 2013// Verify all references within an object, for use with HeapBitmap::Visit. 2014class VerifyObjectVisitor { 2015 public: 2016 explicit VerifyObjectVisitor(Heap* heap) : heap_(heap), failed_(false) {} 2017 2018 void operator()(mirror::Object* obj) const 2019 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2020 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2021 // be live or else how did we find it in the live bitmap? 2022 VerifyReferenceVisitor visitor(heap_); 2023 // The class doesn't count as a reference but we should verify it anyways. 2024 collector::MarkSweep::VisitObjectReferences(obj, visitor, true); 2025 if (obj->IsReferenceInstance()) { 2026 mirror::Reference* ref = obj->AsReference(); 2027 visitor(obj, ref->GetReferent(), mirror::Reference::ReferentOffset(), false); 2028 } 2029 failed_ = failed_ || visitor.Failed(); 2030 } 2031 2032 static void VisitCallback(mirror::Object* obj, void* arg) 2033 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2034 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2035 visitor->operator()(obj); 2036 } 2037 2038 bool Failed() const { 2039 return failed_; 2040 } 2041 2042 private: 2043 Heap* const heap_; 2044 mutable bool failed_; 2045}; 2046 2047// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2048bool Heap::VerifyHeapReferences() { 2049 Thread* self = Thread::Current(); 2050 Locks::mutator_lock_->AssertExclusiveHeld(self); 2051 // Lets sort our allocation stacks so that we can efficiently binary search them. 2052 allocation_stack_->Sort(); 2053 live_stack_->Sort(); 2054 // Since we sorted the allocation stack content, need to revoke all 2055 // thread-local allocation stacks. 2056 RevokeAllThreadLocalAllocationStacks(self); 2057 VerifyObjectVisitor visitor(this); 2058 // Verify objects in the allocation stack since these will be objects which were: 2059 // 1. Allocated prior to the GC (pre GC verification). 2060 // 2. Allocated during the GC (pre sweep GC verification). 2061 // We don't want to verify the objects in the live stack since they themselves may be 2062 // pointing to dead objects if they are not reachable. 2063 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2064 // Verify the roots: 2065 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRoots, &visitor); 2066 if (visitor.Failed()) { 2067 // Dump mod-union tables. 2068 for (const auto& table_pair : mod_union_tables_) { 2069 accounting::ModUnionTable* mod_union_table = table_pair.second; 2070 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2071 } 2072 // Dump remembered sets. 2073 for (const auto& table_pair : remembered_sets_) { 2074 accounting::RememberedSet* remembered_set = table_pair.second; 2075 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2076 } 2077 DumpSpaces(); 2078 return false; 2079 } 2080 return true; 2081} 2082 2083class VerifyReferenceCardVisitor { 2084 public: 2085 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2086 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2087 Locks::heap_bitmap_lock_) 2088 : heap_(heap), failed_(failed) { 2089 } 2090 2091 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2092 // annotalysis on visitors. 2093 void operator()(mirror::Object* obj, mirror::Object* ref, const MemberOffset& offset, 2094 bool is_static) const NO_THREAD_SAFETY_ANALYSIS { 2095 // Filter out class references since changing an object's class does not mark the card as dirty. 2096 // Also handles large objects, since the only reference they hold is a class reference. 2097 if (ref != NULL && !ref->IsClass()) { 2098 accounting::CardTable* card_table = heap_->GetCardTable(); 2099 // If the object is not dirty and it is referencing something in the live stack other than 2100 // class, then it must be on a dirty card. 2101 if (!card_table->AddrIsInCardTable(obj)) { 2102 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2103 *failed_ = true; 2104 } else if (!card_table->IsDirty(obj)) { 2105 // TODO: Check mod-union tables. 2106 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2107 // kCardDirty - 1 if it didnt get touched since we aged it. 2108 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2109 if (live_stack->ContainsSorted(const_cast<mirror::Object*>(ref))) { 2110 if (live_stack->ContainsSorted(const_cast<mirror::Object*>(obj))) { 2111 LOG(ERROR) << "Object " << obj << " found in live stack"; 2112 } 2113 if (heap_->GetLiveBitmap()->Test(obj)) { 2114 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2115 } 2116 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2117 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2118 2119 // Print which field of the object is dead. 2120 if (!obj->IsObjectArray()) { 2121 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2122 CHECK(klass != NULL); 2123 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2124 : klass->GetIFields(); 2125 CHECK(fields != NULL); 2126 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2127 mirror::ArtField* cur = fields->Get(i); 2128 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2129 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2130 << PrettyField(cur); 2131 break; 2132 } 2133 } 2134 } else { 2135 mirror::ObjectArray<mirror::Object>* object_array = 2136 obj->AsObjectArray<mirror::Object>(); 2137 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2138 if (object_array->Get(i) == ref) { 2139 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2140 } 2141 } 2142 } 2143 2144 *failed_ = true; 2145 } 2146 } 2147 } 2148 } 2149 2150 private: 2151 Heap* const heap_; 2152 bool* const failed_; 2153}; 2154 2155class VerifyLiveStackReferences { 2156 public: 2157 explicit VerifyLiveStackReferences(Heap* heap) 2158 : heap_(heap), 2159 failed_(false) {} 2160 2161 void operator()(mirror::Object* obj) const 2162 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2163 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2164 collector::MarkSweep::VisitObjectReferences(const_cast<mirror::Object*>(obj), visitor, true); 2165 } 2166 2167 bool Failed() const { 2168 return failed_; 2169 } 2170 2171 private: 2172 Heap* const heap_; 2173 bool failed_; 2174}; 2175 2176bool Heap::VerifyMissingCardMarks() { 2177 Thread* self = Thread::Current(); 2178 Locks::mutator_lock_->AssertExclusiveHeld(self); 2179 2180 // We need to sort the live stack since we binary search it. 2181 live_stack_->Sort(); 2182 // Since we sorted the allocation stack content, need to revoke all 2183 // thread-local allocation stacks. 2184 RevokeAllThreadLocalAllocationStacks(self); 2185 VerifyLiveStackReferences visitor(this); 2186 GetLiveBitmap()->Visit(visitor); 2187 2188 // We can verify objects in the live stack since none of these should reference dead objects. 2189 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2190 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2191 visitor(*it); 2192 } 2193 } 2194 2195 if (visitor.Failed()) { 2196 DumpSpaces(); 2197 return false; 2198 } 2199 return true; 2200} 2201 2202void Heap::SwapStacks(Thread* self) { 2203 if (kUseThreadLocalAllocationStack) { 2204 live_stack_->AssertAllZero(); 2205 } 2206 allocation_stack_.swap(live_stack_); 2207} 2208 2209void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2210 // This must be called only during the pause. 2211 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2212 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2213 MutexLock mu2(self, *Locks::thread_list_lock_); 2214 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2215 for (Thread* t : thread_list) { 2216 t->RevokeThreadLocalAllocationStack(); 2217 } 2218} 2219 2220accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2221 auto it = mod_union_tables_.find(space); 2222 if (it == mod_union_tables_.end()) { 2223 return nullptr; 2224 } 2225 return it->second; 2226} 2227 2228accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2229 auto it = remembered_sets_.find(space); 2230 if (it == remembered_sets_.end()) { 2231 return nullptr; 2232 } 2233 return it->second; 2234} 2235 2236void Heap::ProcessCards(TimingLogger& timings, bool use_rem_sets) { 2237 // Clear cards and keep track of cards cleared in the mod-union table. 2238 for (const auto& space : continuous_spaces_) { 2239 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2240 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2241 if (table != nullptr) { 2242 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2243 "ImageModUnionClearCards"; 2244 TimingLogger::ScopedSplit split(name, &timings); 2245 table->ClearCards(); 2246 } else if (use_rem_sets && rem_set != nullptr) { 2247 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2248 << static_cast<int>(collector_type_); 2249 TimingLogger::ScopedSplit split("AllocSpaceRemSetClearCards", &timings); 2250 rem_set->ClearCards(); 2251 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2252 TimingLogger::ScopedSplit split("AllocSpaceClearCards", &timings); 2253 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2254 // were dirty before the GC started. 2255 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2256 // -> clean(cleaning thread). 2257 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2258 // roots and then we scan / update mod union tables after. We will always scan either card. 2259 // If we end up with the non aged card, we scan it it in the pause. 2260 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), VoidFunctor()); 2261 } 2262 } 2263} 2264 2265static mirror::Object* IdentityMarkObjectCallback(mirror::Object* obj, void*) { 2266 return obj; 2267} 2268 2269void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2270 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 2271 Thread* self = Thread::Current(); 2272 2273 if (verify_pre_gc_heap_) { 2274 thread_list->SuspendAll(); 2275 { 2276 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2277 if (!VerifyHeapReferences()) { 2278 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed"; 2279 } 2280 } 2281 thread_list->ResumeAll(); 2282 } 2283 2284 // Check that all objects which reference things in the live stack are on dirty cards. 2285 if (verify_missing_card_marks_) { 2286 thread_list->SuspendAll(); 2287 { 2288 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2289 SwapStacks(self); 2290 // Sort the live stack so that we can quickly binary search it later. 2291 if (!VerifyMissingCardMarks()) { 2292 LOG(FATAL) << "Pre " << gc->GetName() << " missing card mark verification failed"; 2293 } 2294 SwapStacks(self); 2295 } 2296 thread_list->ResumeAll(); 2297 } 2298 2299 if (verify_mod_union_table_) { 2300 thread_list->SuspendAll(); 2301 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2302 for (const auto& table_pair : mod_union_tables_) { 2303 accounting::ModUnionTable* mod_union_table = table_pair.second; 2304 mod_union_table->UpdateAndMarkReferences(IdentityMarkObjectCallback, nullptr); 2305 mod_union_table->Verify(); 2306 } 2307 thread_list->ResumeAll(); 2308 } 2309} 2310 2311void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2312 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2313 // reachable objects. 2314 if (verify_post_gc_heap_) { 2315 Thread* self = Thread::Current(); 2316 CHECK_NE(self->GetState(), kRunnable); 2317 { 2318 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2319 // Swapping bound bitmaps does nothing. 2320 gc->SwapBitmaps(); 2321 if (!VerifyHeapReferences()) { 2322 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed"; 2323 } 2324 gc->SwapBitmaps(); 2325 } 2326 } 2327} 2328 2329void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2330 if (verify_system_weaks_) { 2331 Thread* self = Thread::Current(); 2332 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2333 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2334 mark_sweep->VerifySystemWeaks(); 2335 } 2336} 2337 2338void Heap::PreGcRosAllocVerification(TimingLogger* timings) { 2339 if (verify_pre_gc_rosalloc_) { 2340 TimingLogger::ScopedSplit split("PreGcRosAllocVerification", timings); 2341 for (const auto& space : continuous_spaces_) { 2342 if (space->IsRosAllocSpace()) { 2343 VLOG(heap) << "PreGcRosAllocVerification : " << space->GetName(); 2344 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2345 rosalloc_space->Verify(); 2346 } 2347 } 2348 } 2349} 2350 2351void Heap::PostGcRosAllocVerification(TimingLogger* timings) { 2352 if (verify_post_gc_rosalloc_) { 2353 TimingLogger::ScopedSplit split("PostGcRosAllocVerification", timings); 2354 for (const auto& space : continuous_spaces_) { 2355 if (space->IsRosAllocSpace()) { 2356 VLOG(heap) << "PostGcRosAllocVerification : " << space->GetName(); 2357 space::RosAllocSpace* rosalloc_space = space->AsRosAllocSpace(); 2358 rosalloc_space->Verify(); 2359 } 2360 } 2361 } 2362} 2363 2364collector::GcType Heap::WaitForGcToComplete(Thread* self) { 2365 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2366 MutexLock mu(self, *gc_complete_lock_); 2367 return WaitForGcToCompleteLocked(self); 2368} 2369 2370collector::GcType Heap::WaitForGcToCompleteLocked(Thread* self) { 2371 collector::GcType last_gc_type = collector::kGcTypeNone; 2372 uint64_t wait_start = NanoTime(); 2373 while (collector_type_running_ != kCollectorTypeNone) { 2374 ATRACE_BEGIN("GC: Wait For Completion"); 2375 // We must wait, change thread state then sleep on gc_complete_cond_; 2376 gc_complete_cond_->Wait(self); 2377 last_gc_type = last_gc_type_; 2378 ATRACE_END(); 2379 } 2380 uint64_t wait_time = NanoTime() - wait_start; 2381 total_wait_time_ += wait_time; 2382 if (wait_time > long_pause_log_threshold_) { 2383 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time); 2384 } 2385 return last_gc_type; 2386} 2387 2388void Heap::DumpForSigQuit(std::ostream& os) { 2389 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2390 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2391 DumpGcPerformanceInfo(os); 2392} 2393 2394size_t Heap::GetPercentFree() { 2395 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / GetTotalMemory()); 2396} 2397 2398void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2399 if (max_allowed_footprint > GetMaxMemory()) { 2400 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2401 << PrettySize(GetMaxMemory()); 2402 max_allowed_footprint = GetMaxMemory(); 2403 } 2404 max_allowed_footprint_ = max_allowed_footprint; 2405} 2406 2407bool Heap::IsMovableObject(const mirror::Object* obj) const { 2408 if (kMovingCollector) { 2409 DCHECK(!IsInTempSpace(obj)); 2410 if (bump_pointer_space_->HasAddress(obj)) { 2411 return true; 2412 } 2413 // TODO: Refactor this logic into the space itself? 2414 // Objects in the main space are only copied during background -> foreground transitions or 2415 // visa versa. 2416 if (main_space_ != nullptr && main_space_->HasAddress(obj) && 2417 (IsCompactingGC(background_collector_type_) || 2418 IsCompactingGC(post_zygote_collector_type_))) { 2419 return true; 2420 } 2421 } 2422 return false; 2423} 2424 2425bool Heap::IsInTempSpace(const mirror::Object* obj) const { 2426 if (temp_space_->HasAddress(obj) && !temp_space_->Contains(obj)) { 2427 return true; 2428 } 2429 return false; 2430} 2431 2432void Heap::UpdateMaxNativeFootprint() { 2433 size_t native_size = native_bytes_allocated_; 2434 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2435 size_t target_size = native_size / GetTargetHeapUtilization(); 2436 if (target_size > native_size + max_free_) { 2437 target_size = native_size + max_free_; 2438 } else if (target_size < native_size + min_free_) { 2439 target_size = native_size + min_free_; 2440 } 2441 native_footprint_gc_watermark_ = target_size; 2442 native_footprint_limit_ = 2 * target_size - native_size; 2443} 2444 2445void Heap::GrowForUtilization(collector::GcType gc_type, uint64_t gc_duration) { 2446 // We know what our utilization is at this moment. 2447 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2448 const size_t bytes_allocated = GetBytesAllocated(); 2449 last_gc_size_ = bytes_allocated; 2450 last_gc_time_ns_ = NanoTime(); 2451 size_t target_size; 2452 if (gc_type != collector::kGcTypeSticky) { 2453 // Grow the heap for non sticky GC. 2454 target_size = bytes_allocated / GetTargetHeapUtilization(); 2455 if (target_size > bytes_allocated + max_free_) { 2456 target_size = bytes_allocated + max_free_; 2457 } else if (target_size < bytes_allocated + min_free_) { 2458 target_size = bytes_allocated + min_free_; 2459 } 2460 native_need_to_run_finalization_ = true; 2461 next_gc_type_ = collector::kGcTypeSticky; 2462 } else { 2463 // Based on how close the current heap size is to the target size, decide 2464 // whether or not to do a partial or sticky GC next. 2465 if (bytes_allocated + min_free_ <= max_allowed_footprint_) { 2466 next_gc_type_ = collector::kGcTypeSticky; 2467 } else { 2468 next_gc_type_ = have_zygote_space_ ? collector::kGcTypePartial : collector::kGcTypeFull; 2469 } 2470 // If we have freed enough memory, shrink the heap back down. 2471 if (bytes_allocated + max_free_ < max_allowed_footprint_) { 2472 target_size = bytes_allocated + max_free_; 2473 } else { 2474 target_size = std::max(bytes_allocated, max_allowed_footprint_); 2475 } 2476 } 2477 if (!ignore_max_footprint_) { 2478 SetIdealFootprint(target_size); 2479 if (concurrent_gc_) { 2480 // Calculate when to perform the next ConcurrentGC. 2481 // Calculate the estimated GC duration. 2482 const double gc_duration_seconds = NsToMs(gc_duration) / 1000.0; 2483 // Estimate how many remaining bytes we will have when we need to start the next GC. 2484 size_t remaining_bytes = allocation_rate_ * gc_duration_seconds; 2485 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2486 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2487 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2488 // A never going to happen situation that from the estimated allocation rate we will exceed 2489 // the applications entire footprint with the given estimated allocation rate. Schedule 2490 // another GC nearly straight away. 2491 remaining_bytes = kMinConcurrentRemainingBytes; 2492 } 2493 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2494 DCHECK_LE(max_allowed_footprint_, growth_limit_); 2495 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2496 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2497 // right away. 2498 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, bytes_allocated); 2499 } 2500 } 2501} 2502 2503void Heap::ClearGrowthLimit() { 2504 growth_limit_ = capacity_; 2505 non_moving_space_->ClearGrowthLimit(); 2506} 2507 2508void Heap::AddFinalizerReference(Thread* self, mirror::Object* object) { 2509 ScopedObjectAccess soa(self); 2510 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(object)); 2511 jvalue args[1]; 2512 args[0].l = arg.get(); 2513 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 2514} 2515 2516void Heap::EnqueueClearedReferences() { 2517 Thread* self = Thread::Current(); 2518 Locks::mutator_lock_->AssertNotHeld(self); 2519 if (!cleared_references_.IsEmpty()) { 2520 // When a runtime isn't started there are no reference queues to care about so ignore. 2521 if (LIKELY(Runtime::Current()->IsStarted())) { 2522 ScopedObjectAccess soa(self); 2523 ScopedLocalRef<jobject> arg(self->GetJniEnv(), 2524 soa.AddLocalReference<jobject>(cleared_references_.GetList())); 2525 jvalue args[1]; 2526 args[0].l = arg.get(); 2527 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_ReferenceQueue_add, args); 2528 } 2529 cleared_references_.Clear(); 2530 } 2531} 2532 2533void Heap::RequestConcurrentGC(Thread* self) { 2534 // Make sure that we can do a concurrent GC. 2535 Runtime* runtime = Runtime::Current(); 2536 if (runtime == NULL || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self) || 2537 self->IsHandlingStackOverflow()) { 2538 return; 2539 } 2540 // We already have a request pending, no reason to start more until we update 2541 // concurrent_start_bytes_. 2542 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2543 JNIEnv* env = self->GetJniEnv(); 2544 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2545 DCHECK(WellKnownClasses::java_lang_Daemons_requestGC != nullptr); 2546 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2547 WellKnownClasses::java_lang_Daemons_requestGC); 2548 CHECK(!env->ExceptionCheck()); 2549} 2550 2551void Heap::ConcurrentGC(Thread* self) { 2552 if (Runtime::Current()->IsShuttingDown(self)) { 2553 return; 2554 } 2555 // Wait for any GCs currently running to finish. 2556 if (WaitForGcToComplete(self) == collector::kGcTypeNone) { 2557 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 2558 // instead. E.g. can't do partial, so do full instead. 2559 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 2560 collector::kGcTypeNone) { 2561 for (collector::GcType gc_type : gc_plan_) { 2562 // Attempt to run the collector, if we succeed, we are done. 2563 if (gc_type > next_gc_type_ && 2564 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != collector::kGcTypeNone) { 2565 break; 2566 } 2567 } 2568 } 2569 } 2570} 2571 2572void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 2573 Thread* self = Thread::Current(); 2574 { 2575 MutexLock mu(self, *heap_trim_request_lock_); 2576 if (desired_collector_type_ == desired_collector_type) { 2577 return; 2578 } 2579 heap_transition_target_time_ = std::max(heap_transition_target_time_, NanoTime() + delta_time); 2580 desired_collector_type_ = desired_collector_type; 2581 } 2582 SignalHeapTrimDaemon(self); 2583} 2584 2585void Heap::RequestHeapTrim() { 2586 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 2587 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 2588 // a space it will hold its lock and can become a cause of jank. 2589 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 2590 // forking. 2591 2592 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 2593 // because that only marks object heads, so a large array looks like lots of empty space. We 2594 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 2595 // to utilization (which is probably inversely proportional to how much benefit we can expect). 2596 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 2597 // not how much use we're making of those pages. 2598 2599 Thread* self = Thread::Current(); 2600 Runtime* runtime = Runtime::Current(); 2601 if (runtime == nullptr || !runtime->IsFinishedStarting() || runtime->IsShuttingDown(self)) { 2602 // Heap trimming isn't supported without a Java runtime or Daemons (such as at dex2oat time) 2603 // Also: we do not wish to start a heap trim if the runtime is shutting down (a racy check 2604 // as we don't hold the lock while requesting the trim). 2605 return; 2606 } 2607 2608 // Request a heap trim only if we do not currently care about pause times. 2609 if (!CareAboutPauseTimes()) { 2610 { 2611 MutexLock mu(self, *heap_trim_request_lock_); 2612 if (last_trim_time_ + kHeapTrimWait >= NanoTime()) { 2613 // We have done a heap trim in the last kHeapTrimWait nanosecs, don't request another one 2614 // just yet. 2615 return; 2616 } 2617 heap_trim_request_pending_ = true; 2618 } 2619 // Notify the daemon thread which will actually do the heap trim. 2620 SignalHeapTrimDaemon(self); 2621 } 2622} 2623 2624void Heap::SignalHeapTrimDaemon(Thread* self) { 2625 JNIEnv* env = self->GetJniEnv(); 2626 DCHECK(WellKnownClasses::java_lang_Daemons != nullptr); 2627 DCHECK(WellKnownClasses::java_lang_Daemons_requestHeapTrim != nullptr); 2628 env->CallStaticVoidMethod(WellKnownClasses::java_lang_Daemons, 2629 WellKnownClasses::java_lang_Daemons_requestHeapTrim); 2630 CHECK(!env->ExceptionCheck()); 2631} 2632 2633void Heap::RevokeThreadLocalBuffers(Thread* thread) { 2634 if (rosalloc_space_ != nullptr) { 2635 rosalloc_space_->RevokeThreadLocalBuffers(thread); 2636 } 2637 if (bump_pointer_space_ != nullptr) { 2638 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 2639 } 2640} 2641 2642void Heap::RevokeAllThreadLocalBuffers() { 2643 if (rosalloc_space_ != nullptr) { 2644 rosalloc_space_->RevokeAllThreadLocalBuffers(); 2645 } 2646 if (bump_pointer_space_ != nullptr) { 2647 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 2648 } 2649} 2650 2651bool Heap::IsGCRequestPending() const { 2652 return concurrent_start_bytes_ != std::numeric_limits<size_t>::max(); 2653} 2654 2655void Heap::RunFinalization(JNIEnv* env) { 2656 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 2657 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 2658 CHECK(WellKnownClasses::java_lang_System != nullptr); 2659 WellKnownClasses::java_lang_System_runFinalization = 2660 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 2661 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 2662 } 2663 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 2664 WellKnownClasses::java_lang_System_runFinalization); 2665} 2666 2667void Heap::RegisterNativeAllocation(JNIEnv* env, int bytes) { 2668 Thread* self = ThreadForEnv(env); 2669 if (native_need_to_run_finalization_) { 2670 RunFinalization(env); 2671 UpdateMaxNativeFootprint(); 2672 native_need_to_run_finalization_ = false; 2673 } 2674 // Total number of native bytes allocated. 2675 native_bytes_allocated_.FetchAndAdd(bytes); 2676 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_gc_watermark_) { 2677 collector::GcType gc_type = have_zygote_space_ ? collector::kGcTypePartial : 2678 collector::kGcTypeFull; 2679 2680 // The second watermark is higher than the gc watermark. If you hit this it means you are 2681 // allocating native objects faster than the GC can keep up with. 2682 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2683 if (WaitForGcToComplete(self) != collector::kGcTypeNone) { 2684 // Just finished a GC, attempt to run finalizers. 2685 RunFinalization(env); 2686 CHECK(!env->ExceptionCheck()); 2687 } 2688 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 2689 if (static_cast<size_t>(native_bytes_allocated_) > native_footprint_limit_) { 2690 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 2691 RunFinalization(env); 2692 native_need_to_run_finalization_ = false; 2693 CHECK(!env->ExceptionCheck()); 2694 } 2695 // We have just run finalizers, update the native watermark since it is very likely that 2696 // finalizers released native managed allocations. 2697 UpdateMaxNativeFootprint(); 2698 } else if (!IsGCRequestPending()) { 2699 if (concurrent_gc_) { 2700 RequestConcurrentGC(self); 2701 } else { 2702 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false); 2703 } 2704 } 2705 } 2706} 2707 2708void Heap::RegisterNativeFree(JNIEnv* env, int bytes) { 2709 int expected_size, new_size; 2710 do { 2711 expected_size = native_bytes_allocated_.Load(); 2712 new_size = expected_size - bytes; 2713 if (UNLIKELY(new_size < 0)) { 2714 ScopedObjectAccess soa(env); 2715 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 2716 StringPrintf("Attempted to free %d native bytes with only %d native bytes " 2717 "registered as allocated", bytes, expected_size).c_str()); 2718 break; 2719 } 2720 } while (!native_bytes_allocated_.CompareAndSwap(expected_size, new_size)); 2721} 2722 2723size_t Heap::GetTotalMemory() const { 2724 size_t ret = 0; 2725 for (const auto& space : continuous_spaces_) { 2726 // Currently don't include the image space. 2727 if (!space->IsImageSpace()) { 2728 ret += space->Size(); 2729 } 2730 } 2731 for (const auto& space : discontinuous_spaces_) { 2732 if (space->IsLargeObjectSpace()) { 2733 ret += space->AsLargeObjectSpace()->GetBytesAllocated(); 2734 } 2735 } 2736 return ret; 2737} 2738 2739void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 2740 DCHECK(mod_union_table != nullptr); 2741 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 2742} 2743 2744void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 2745 CHECK(c == NULL || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 2746 (c->IsVariableSize() || c->GetObjectSize() == byte_count) || 2747 strlen(ClassHelper(c).GetDescriptor()) == 0); 2748 CHECK_GE(byte_count, sizeof(mirror::Object)); 2749} 2750 2751void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 2752 CHECK(remembered_set != nullptr); 2753 space::Space* space = remembered_set->GetSpace(); 2754 CHECK(space != nullptr); 2755 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2756 remembered_sets_.Put(space, remembered_set); 2757 CHECK(remembered_sets_.find(space) != remembered_sets_.end()); 2758} 2759 2760void Heap::RemoveRememberedSet(space::Space* space) { 2761 CHECK(space != nullptr); 2762 auto it = remembered_sets_.find(space); 2763 CHECK(it != remembered_sets_.end()); 2764 remembered_sets_.erase(it); 2765 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 2766} 2767 2768} // namespace gc 2769} // namespace art 2770