Elliott Hughes | 2faa5f1 | 2012-01-30 14:42:07 -0800 | [diff] [blame] | 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 | */ |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 16 | |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 17 | #include "mark_sweep.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 18 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 19 | #include <functional> |
| 20 | #include <numeric> |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 21 | #include <climits> |
| 22 | #include <vector> |
| 23 | |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 24 | #include "barrier.h" |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 25 | #include "card_table.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 26 | #include "class_loader.h" |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 27 | #include "dex_cache.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 28 | #include "heap.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 29 | #include "indirect_reference_table.h" |
| 30 | #include "intern_table.h" |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 31 | #include "jni_internal.h" |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 32 | #include "large_object_space.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 33 | #include "logging.h" |
| 34 | #include "macros.h" |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 35 | #include "monitor.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 36 | #include "object.h" |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 37 | #include "runtime.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 38 | #include "space.h" |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 39 | #include "timing_logger.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 40 | #include "thread.h" |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 41 | #include "thread_list.h" |
Ian Rogers | 0825427 | 2012-10-23 17:49:23 -0700 | [diff] [blame] | 42 | #include "verifier/method_verifier.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 43 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 44 | namespace art { |
| 45 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 46 | // Performance options. |
| 47 | static const bool kParallelMarkStack = true; |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 48 | static const bool kDisableFinger = kParallelMarkStack; |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 49 | static const bool kUseMarkStackPrefetch = true; |
| 50 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 51 | // Profiling and information flags. |
| 52 | static const bool kCountClassesMarked = false; |
| 53 | static const bool kProfileLargeObjects = false; |
| 54 | static const bool kMeasureOverhead = false; |
| 55 | static const bool kCountTasks = false; |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 56 | static const bool kCountJavaLangRefs = false; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 57 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 58 | class SetFingerVisitor { |
| 59 | public: |
| 60 | SetFingerVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 61 | |
| 62 | } |
| 63 | |
| 64 | void operator ()(void* finger) const { |
| 65 | mark_sweep_->SetFinger(reinterpret_cast<Object*>(finger)); |
| 66 | } |
| 67 | |
| 68 | private: |
| 69 | MarkSweep* const mark_sweep_; |
| 70 | }; |
| 71 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 72 | std::string MarkSweep::GetName() const { |
| 73 | std::ostringstream ss; |
| 74 | ss << (IsConcurrent() ? "Concurrent" : "") << GetGcType(); |
| 75 | return ss.str(); |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 76 | } |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 77 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 78 | void MarkSweep::ImmuneSpace(ContinuousSpace* space) { |
| 79 | // Bind live to mark bitmap if necessary. |
| 80 | if (space->GetLiveBitmap() != space->GetMarkBitmap()) { |
| 81 | BindLiveToMarkBitmap(space); |
| 82 | } |
| 83 | |
| 84 | // Add the space to the immune region. |
| 85 | if (immune_begin_ == NULL) { |
| 86 | DCHECK(immune_end_ == NULL); |
| 87 | SetImmuneRange(reinterpret_cast<Object*>(space->Begin()), |
| 88 | reinterpret_cast<Object*>(space->End())); |
| 89 | } else { |
| 90 | const Spaces& spaces = GetHeap()->GetSpaces(); |
| 91 | const ContinuousSpace* prev_space = NULL; |
| 92 | // Find out if the previous space is immune. |
| 93 | // TODO: C++0x |
| 94 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 95 | if (*it == space) { |
| 96 | break; |
| 97 | } |
| 98 | prev_space = *it; |
| 99 | } |
| 100 | |
| 101 | // If previous space was immune, then extend the immune region. |
| 102 | if (prev_space != NULL && |
| 103 | immune_begin_ <= reinterpret_cast<Object*>(prev_space->Begin()) && |
| 104 | immune_end_ >= reinterpret_cast<Object*>(prev_space->End())) { |
| 105 | immune_begin_ = std::min(reinterpret_cast<Object*>(space->Begin()), immune_begin_); |
| 106 | immune_end_ = std::max(reinterpret_cast<Object*>(space->End()), immune_end_); |
| 107 | } |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | // Bind the live bits to the mark bits of bitmaps based on the gc type. |
| 112 | void MarkSweep::BindBitmaps() { |
| 113 | Spaces& spaces = GetHeap()->GetSpaces(); |
| 114 | WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); |
| 115 | |
| 116 | // Mark all of the spaces we never collect as immune. |
| 117 | for (Spaces::iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 118 | ContinuousSpace* space = *it; |
| 119 | if (space->GetGcRetentionPolicy() == kGcRetentionPolicyNeverCollect) { |
| 120 | ImmuneSpace(space); |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | MarkSweep::MarkSweep(Heap* heap, bool is_concurrent) |
| 126 | : GarbageCollector(heap), |
| 127 | gc_barrier_(new Barrier(0)), |
| 128 | large_object_lock_("large object lock"), |
| 129 | mark_stack_expand_lock_("mark stack expand lock"), |
| 130 | timings_(GetName(), true), |
| 131 | cumulative_timings_(GetName(), true), |
| 132 | is_concurrent_(is_concurrent) { |
| 133 | cumulative_timings_.SetName(GetName()); |
| 134 | ResetCumulativeStatistics(); |
| 135 | } |
| 136 | |
| 137 | void MarkSweep::InitializePhase() { |
| 138 | mark_stack_ = GetHeap()->mark_stack_.get(); |
| 139 | DCHECK(mark_stack_ != NULL); |
| 140 | finger_ = NULL; |
| 141 | SetImmuneRange(NULL, NULL); |
| 142 | soft_reference_list_ = NULL; |
| 143 | weak_reference_list_ = NULL; |
| 144 | finalizer_reference_list_ = NULL; |
| 145 | phantom_reference_list_ = NULL; |
| 146 | cleared_reference_list_ = NULL; |
| 147 | freed_bytes_ = 0; |
| 148 | freed_objects_ = 0; |
| 149 | class_count_ = 0; |
| 150 | array_count_ = 0; |
| 151 | other_count_ = 0; |
| 152 | large_object_test_ = 0; |
| 153 | large_object_mark_ = 0; |
| 154 | classes_marked_ = 0; |
| 155 | overhead_time_ = 0; |
| 156 | work_chunks_created_ = 0; |
| 157 | work_chunks_deleted_ = 0; |
| 158 | reference_count_ = 0; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 159 | java_lang_Class_ = Class::GetJavaLangClass(); |
| 160 | CHECK(java_lang_Class_ != NULL); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 161 | FindDefaultMarkBitmap(); |
Mathieu Chartier | 9ebae1f | 2012-10-15 17:38:16 -0700 | [diff] [blame] | 162 | // Mark any concurrent roots as dirty since we need to scan them at least once during this GC. |
| 163 | Runtime::Current()->DirtyRoots(); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 164 | timings_.Reset(); |
| 165 | // Do any pre GC verification. |
| 166 | heap_->PreGcVerification(this); |
| 167 | } |
| 168 | |
| 169 | void MarkSweep::ProcessReferences(Thread* self) { |
Mathieu Chartier | 8e56c7e | 2012-11-20 13:25:50 -0800 | [diff] [blame^] | 170 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 171 | ProcessReferences(&soft_reference_list_, clear_soft_references_, &weak_reference_list_, |
| 172 | &finalizer_reference_list_, &phantom_reference_list_); |
| 173 | timings_.AddSplit("ProcessReferences"); |
| 174 | } |
| 175 | |
| 176 | bool MarkSweep::HandleDirtyObjectsPhase() { |
| 177 | Thread* self = Thread::Current(); |
| 178 | ObjectStack* allocation_stack = GetHeap()->allocation_stack_.get(); |
| 179 | Locks::mutator_lock_->AssertExclusiveHeld(self); |
| 180 | |
| 181 | { |
| 182 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 183 | |
| 184 | // Re-mark root set. |
| 185 | ReMarkRoots(); |
| 186 | timings_.AddSplit("ReMarkRoots"); |
| 187 | |
| 188 | // Scan dirty objects, this is only required if we are not doing concurrent GC. |
| 189 | RecursiveMarkDirtyObjects(); |
| 190 | } |
| 191 | |
| 192 | ProcessReferences(self); |
| 193 | |
| 194 | // Only need to do this if we have the card mark verification on, and only during concurrent GC. |
| 195 | if (GetHeap()->verify_missing_card_marks_) { |
| 196 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 197 | // This second sweep makes sure that we don't have any objects in the live stack which point to |
| 198 | // freed objects. These cause problems since their references may be previously freed objects. |
| 199 | SweepArray(timings_, allocation_stack, false); |
| 200 | } else { |
| 201 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 202 | // We only sweep over the live stack, and the live stack should not intersect with the |
| 203 | // allocation stack, so it should be safe to UnMark anything in the allocation stack as live. |
| 204 | heap_->UnMarkAllocStack(GetHeap()->alloc_space_->GetMarkBitmap(), |
| 205 | GetHeap()->large_object_space_->GetMarkObjects(), |
| 206 | allocation_stack); |
| 207 | timings_.AddSplit("UnMarkAllocStack"); |
| 208 | } |
| 209 | return true; |
| 210 | } |
| 211 | |
| 212 | bool MarkSweep::IsConcurrent() const { |
| 213 | return is_concurrent_; |
| 214 | } |
| 215 | |
| 216 | void MarkSweep::MarkingPhase() { |
| 217 | Heap* heap = GetHeap(); |
| 218 | Thread* self = Thread::Current(); |
| 219 | |
| 220 | BindBitmaps(); |
| 221 | FindDefaultMarkBitmap(); |
| 222 | timings_.AddSplit("BindBitmaps"); |
| 223 | |
| 224 | // Process dirty cards and add dirty cards to mod union tables. |
| 225 | heap->ProcessCards(timings_); |
| 226 | |
| 227 | // Need to do this before the checkpoint since we don't want any threads to add references to |
| 228 | // the live stack during the recursive mark. |
| 229 | heap->SwapStacks(); |
| 230 | timings_.AddSplit("SwapStacks"); |
| 231 | |
| 232 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 233 | if (Locks::mutator_lock_->IsExclusiveHeld(self)) { |
| 234 | // If we exclusively hold the mutator lock, all threads must be suspended. |
| 235 | MarkRoots(); |
| 236 | timings_.AddSplit("MarkConcurrentRoots"); |
| 237 | } else { |
| 238 | MarkRootsCheckpoint(); |
| 239 | timings_.AddSplit("MarkRootsCheckpoint"); |
| 240 | MarkNonThreadRoots(); |
| 241 | timings_.AddSplit("MarkNonThreadRoots"); |
| 242 | } |
| 243 | MarkConcurrentRoots(); |
| 244 | timings_.AddSplit("MarkConcurrentRoots"); |
| 245 | |
| 246 | heap->UpdateAndMarkModUnion(this, timings_, GetGcType()); |
| 247 | MarkReachableObjects(); |
| 248 | } |
| 249 | |
| 250 | void MarkSweep::MarkReachableObjects() { |
| 251 | // Mark everything allocated since the last as GC live so that we can sweep concurrently, |
| 252 | // knowing that new allocations won't be marked as live. |
| 253 | ObjectStack* live_stack = heap_->GetLiveStack(); |
| 254 | heap_->MarkAllocStack(heap_->alloc_space_->GetLiveBitmap(), |
| 255 | heap_->large_object_space_->GetLiveObjects(), |
| 256 | live_stack); |
| 257 | live_stack->Reset(); |
| 258 | timings_.AddSplit("MarkStackAsLive"); |
| 259 | // Recursively mark all the non-image bits set in the mark bitmap. |
| 260 | RecursiveMark(); |
| 261 | DisableFinger(); |
| 262 | } |
| 263 | |
| 264 | void MarkSweep::ReclaimPhase() { |
| 265 | Thread* self = Thread::Current(); |
| 266 | |
| 267 | if (!IsConcurrent()) { |
| 268 | ProcessReferences(self); |
| 269 | } |
| 270 | |
| 271 | // Before freeing anything, lets verify the heap. |
| 272 | if (kIsDebugBuild) { |
| 273 | ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 274 | VerifyImageRoots(); |
| 275 | } |
| 276 | heap_->PreSweepingGcVerification(this); |
| 277 | |
| 278 | { |
| 279 | WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); |
| 280 | |
| 281 | // Reclaim unmarked objects. |
| 282 | Sweep(timings_, false); |
| 283 | |
| 284 | // Swap the live and mark bitmaps for each space which we modified space. This is an |
| 285 | // optimization that enables us to not clear live bits inside of the sweep. Only swaps unbound |
| 286 | // bitmaps. |
| 287 | SwapBitmaps(); |
| 288 | timings_.AddSplit("SwapBitmaps"); |
| 289 | |
| 290 | // Unbind the live and mark bitmaps. |
| 291 | UnBindBitmaps(); |
| 292 | } |
| 293 | |
| 294 | heap_->GrowForUtilization(); |
| 295 | timings_.AddSplit("GrowForUtilization"); |
| 296 | } |
| 297 | |
| 298 | void MarkSweep::SwapBitmaps() { |
| 299 | // Swap the live and mark bitmaps for each alloc space. This is needed since sweep re-swaps |
| 300 | // these bitmaps. The bitmap swapping is an optimization so that we do not need to clear the live |
| 301 | // bits of dead objects in the live bitmap. |
| 302 | const GcType gc_type = GetGcType(); |
| 303 | // TODO: C++0x |
| 304 | Spaces& spaces = heap_->GetSpaces(); |
| 305 | for (Spaces::iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 306 | ContinuousSpace* space = *it; |
| 307 | // We never allocate into zygote spaces. |
| 308 | if (space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect || |
| 309 | (gc_type == kGcTypeFull && |
| 310 | space->GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect)) { |
| 311 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 312 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 313 | if (live_bitmap != mark_bitmap) { |
| 314 | heap_->GetLiveBitmap()->ReplaceBitmap(live_bitmap, mark_bitmap); |
| 315 | heap_->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap); |
| 316 | space->AsAllocSpace()->SwapBitmaps(); |
| 317 | } |
| 318 | } |
| 319 | } |
| 320 | SwapLargeObjects(); |
| 321 | } |
| 322 | |
| 323 | void MarkSweep::SwapLargeObjects() { |
| 324 | LargeObjectSpace* large_object_space = heap_->GetLargeObjectsSpace(); |
| 325 | large_object_space->SwapBitmaps(); |
| 326 | heap_->GetLiveBitmap()->SetLargeObjects(large_object_space->GetLiveObjects()); |
| 327 | heap_->GetMarkBitmap()->SetLargeObjects(large_object_space->GetMarkObjects()); |
| 328 | } |
| 329 | |
| 330 | void MarkSweep::SetImmuneRange(Object* begin, Object* end) { |
| 331 | immune_begin_ = begin; |
| 332 | immune_end_ = end; |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 333 | } |
| 334 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 335 | void MarkSweep::FindDefaultMarkBitmap() { |
| 336 | const Spaces& spaces = heap_->GetSpaces(); |
| 337 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 338 | if ((*it)->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect) { |
| 339 | current_mark_bitmap_ = (*it)->GetMarkBitmap(); |
| 340 | CHECK(current_mark_bitmap_ != NULL); |
| 341 | return; |
| 342 | } |
| 343 | } |
| 344 | GetHeap()->DumpSpaces(); |
| 345 | LOG(FATAL) << "Could not find a default mark bitmap"; |
| 346 | } |
| 347 | |
Mathieu Chartier | ac86a7c | 2012-11-12 15:03:16 -0800 | [diff] [blame] | 348 | void MarkSweep::ExpandMarkStack() { |
| 349 | // Rare case, no need to have Thread::Current be a parameter. |
| 350 | MutexLock mu(Thread::Current(), mark_stack_expand_lock_); |
| 351 | if (UNLIKELY(mark_stack_->Size() < mark_stack_->Capacity())) { |
| 352 | // Someone else acquired the lock and expanded the mark stack before us. |
| 353 | return; |
| 354 | } |
| 355 | std::vector<Object*> temp; |
| 356 | temp.insert(temp.begin(), mark_stack_->Begin(), mark_stack_->End()); |
| 357 | mark_stack_->Resize(mark_stack_->Capacity() * 2); |
| 358 | for (size_t i = 0; i < temp.size(); ++i) { |
| 359 | mark_stack_->PushBack(temp[i]); |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | inline void MarkSweep::MarkObjectNonNullParallel(const Object* obj, bool check_finger) { |
| 364 | DCHECK(obj != NULL); |
| 365 | if (MarkObjectParallel(obj)) { |
| 366 | if (kDisableFinger || (check_finger && obj < finger_)) { |
| 367 | while (UNLIKELY(!mark_stack_->AtomicPushBack(const_cast<Object*>(obj)))) { |
| 368 | // Only reason a push can fail is that the mark stack is full. |
| 369 | ExpandMarkStack(); |
| 370 | } |
| 371 | } |
| 372 | } |
| 373 | } |
| 374 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 375 | inline void MarkSweep::MarkObjectNonNull(const Object* obj, bool check_finger) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 376 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 377 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 378 | if (obj >= immune_begin_ && obj < immune_end_) { |
| 379 | DCHECK(IsMarked(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 380 | return; |
| 381 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 382 | |
| 383 | // Try to take advantage of locality of references within a space, failing this find the space |
| 384 | // the hard way. |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 385 | SpaceBitmap* object_bitmap = current_mark_bitmap_; |
| 386 | if (UNLIKELY(!object_bitmap->HasAddress(obj))) { |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 387 | SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetSpaceBitmap(obj); |
| 388 | if (new_bitmap != NULL) { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 389 | object_bitmap = new_bitmap; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 390 | } else { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 391 | MarkLargeObject(obj); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 392 | return; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 393 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 394 | } |
| 395 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 396 | // This object was not previously marked. |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 397 | if (!object_bitmap->Test(obj)) { |
| 398 | object_bitmap->Set(obj); |
| 399 | if (kDisableFinger || (check_finger && obj < finger_)) { |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 400 | // Do we need to expand the mark stack? |
| 401 | if (UNLIKELY(mark_stack_->Size() >= mark_stack_->Capacity())) { |
Mathieu Chartier | ac86a7c | 2012-11-12 15:03:16 -0800 | [diff] [blame] | 402 | ExpandMarkStack(); |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 403 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 404 | // The object must be pushed on to the mark stack. |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 405 | mark_stack_->PushBack(const_cast<Object*>(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 406 | } |
| 407 | } |
| 408 | } |
| 409 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 410 | // Rare case, probably not worth inlining since it will increase instruction cache miss rate. |
| 411 | bool MarkSweep::MarkLargeObject(const Object* obj) { |
| 412 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 413 | SpaceSetMap* large_objects = large_object_space->GetMarkObjects(); |
| 414 | if (kProfileLargeObjects) { |
| 415 | ++large_object_test_; |
| 416 | } |
| 417 | if (UNLIKELY(!large_objects->Test(obj))) { |
| 418 | if (!large_object_space->Contains(obj)) { |
| 419 | LOG(ERROR) << "Tried to mark " << obj << " not contained by any spaces"; |
| 420 | LOG(ERROR) << "Attempting see if it's a bad root"; |
| 421 | VerifyRoots(); |
| 422 | LOG(FATAL) << "Can't mark bad root"; |
| 423 | } |
| 424 | if (kProfileLargeObjects) { |
| 425 | ++large_object_mark_; |
| 426 | } |
| 427 | large_objects->Set(obj); |
| 428 | // Don't need to check finger since large objects never have any object references. |
| 429 | return true; |
| 430 | } |
| 431 | return false; |
| 432 | } |
| 433 | |
| 434 | inline bool MarkSweep::MarkObjectParallel(const Object* obj) { |
| 435 | DCHECK(obj != NULL); |
| 436 | |
| 437 | if (obj >= immune_begin_ && obj < immune_end_) { |
| 438 | DCHECK(IsMarked(obj)); |
| 439 | return false; |
| 440 | } |
| 441 | |
| 442 | // Try to take advantage of locality of references within a space, failing this find the space |
| 443 | // the hard way. |
| 444 | SpaceBitmap* object_bitmap = current_mark_bitmap_; |
| 445 | if (UNLIKELY(!object_bitmap->HasAddress(obj))) { |
| 446 | SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetSpaceBitmap(obj); |
| 447 | if (new_bitmap != NULL) { |
| 448 | object_bitmap = new_bitmap; |
| 449 | } else { |
| 450 | // TODO: Remove the Thread::Current here? |
| 451 | // TODO: Convert this to some kind of atomic marking? |
| 452 | MutexLock mu(Thread::Current(), large_object_lock_); |
| 453 | return MarkLargeObject(obj); |
| 454 | } |
| 455 | } |
| 456 | |
| 457 | // Return true if the object was not previously marked. |
| 458 | return !object_bitmap->AtomicTestAndSet(obj); |
| 459 | } |
| 460 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 461 | // Used to mark objects when recursing. Recursion is done by moving |
| 462 | // the finger across the bitmaps in address order and marking child |
| 463 | // objects. Any newly-marked objects whose addresses are lower than |
| 464 | // the finger won't be visited by the bitmap scan, so those objects |
| 465 | // need to be added to the mark stack. |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 466 | void MarkSweep::MarkObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 467 | if (obj != NULL) { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 468 | MarkObjectNonNull(obj, true); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 469 | } |
| 470 | } |
| 471 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 472 | void MarkSweep::MarkRoot(const Object* obj) { |
| 473 | if (obj != NULL) { |
| 474 | MarkObjectNonNull(obj, false); |
| 475 | } |
| 476 | } |
| 477 | |
Mathieu Chartier | ac86a7c | 2012-11-12 15:03:16 -0800 | [diff] [blame] | 478 | void MarkSweep::MarkRootParallelCallback(const Object* root, void* arg) { |
| 479 | DCHECK(root != NULL); |
| 480 | DCHECK(arg != NULL); |
| 481 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| 482 | mark_sweep->MarkObjectNonNullParallel(root, false); |
| 483 | } |
| 484 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 485 | void MarkSweep::MarkObjectCallback(const Object* root, void* arg) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 486 | DCHECK(root != NULL); |
| 487 | DCHECK(arg != NULL); |
| 488 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 489 | mark_sweep->MarkObjectNonNull(root, false); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 490 | } |
| 491 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 492 | void MarkSweep::ReMarkObjectVisitor(const Object* root, void* arg) { |
| 493 | DCHECK(root != NULL); |
| 494 | DCHECK(arg != NULL); |
| 495 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 496 | mark_sweep->MarkObjectNonNull(root, true); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 497 | } |
| 498 | |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 499 | void MarkSweep::VerifyRootCallback(const Object* root, void* arg, size_t vreg, |
Ian Rogers | 40e3bac | 2012-11-20 00:09:14 -0800 | [diff] [blame] | 500 | const StackVisitor* visitor) { |
| 501 | reinterpret_cast<MarkSweep*>(arg)->VerifyRoot(root, vreg, visitor); |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 502 | } |
| 503 | |
Ian Rogers | 40e3bac | 2012-11-20 00:09:14 -0800 | [diff] [blame] | 504 | void MarkSweep::VerifyRoot(const Object* root, size_t vreg, const StackVisitor* visitor) { |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 505 | // See if the root is on any space bitmap. |
Mathieu Chartier | 128c52c | 2012-10-16 14:12:41 -0700 | [diff] [blame] | 506 | if (GetHeap()->GetLiveBitmap()->GetSpaceBitmap(root) == NULL) { |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 507 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | 4202b74 | 2012-10-17 17:51:25 -0700 | [diff] [blame] | 508 | if (!large_object_space->Contains(root)) { |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 509 | LOG(ERROR) << "Found invalid root: " << root; |
Ian Rogers | 40e3bac | 2012-11-20 00:09:14 -0800 | [diff] [blame] | 510 | if (visitor != NULL) { |
| 511 | LOG(ERROR) << visitor->DescribeLocation() << " in VReg: " << vreg; |
Mathieu Chartier | 6f1c949 | 2012-10-15 12:08:41 -0700 | [diff] [blame] | 512 | } |
| 513 | } |
| 514 | } |
| 515 | } |
| 516 | |
| 517 | void MarkSweep::VerifyRoots() { |
| 518 | Runtime::Current()->GetThreadList()->VerifyRoots(VerifyRootCallback, this); |
| 519 | } |
| 520 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 521 | // Marks all objects in the root set. |
| 522 | void MarkSweep::MarkRoots() { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 523 | Runtime::Current()->VisitNonConcurrentRoots(MarkObjectCallback, this); |
Mathieu Chartier | 9ebae1f | 2012-10-15 17:38:16 -0700 | [diff] [blame] | 524 | } |
| 525 | |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 526 | void MarkSweep::MarkNonThreadRoots() { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 527 | Runtime::Current()->VisitNonThreadRoots(MarkObjectCallback, this); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 528 | } |
| 529 | |
Mathieu Chartier | 9ebae1f | 2012-10-15 17:38:16 -0700 | [diff] [blame] | 530 | void MarkSweep::MarkConcurrentRoots() { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 531 | Runtime::Current()->VisitConcurrentRoots(MarkObjectCallback, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 532 | } |
| 533 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 534 | class CheckObjectVisitor { |
| 535 | public: |
| 536 | CheckObjectVisitor(MarkSweep* const mark_sweep) |
| 537 | : mark_sweep_(mark_sweep) { |
| 538 | |
| 539 | } |
| 540 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 541 | void operator ()(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) const |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 542 | NO_THREAD_SAFETY_ANALYSIS { |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 543 | if (kDebugLocking) { |
| 544 | Locks::heap_bitmap_lock_->AssertSharedHeld(Thread::Current()); |
| 545 | } |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 546 | mark_sweep_->CheckReference(obj, ref, offset, is_static); |
| 547 | } |
| 548 | |
| 549 | private: |
| 550 | MarkSweep* const mark_sweep_; |
| 551 | }; |
| 552 | |
| 553 | void MarkSweep::CheckObject(const Object* obj) { |
| 554 | DCHECK(obj != NULL); |
| 555 | CheckObjectVisitor visitor(this); |
| 556 | VisitObjectReferences(obj, visitor); |
| 557 | } |
| 558 | |
| 559 | void MarkSweep::VerifyImageRootVisitor(Object* root, void* arg) { |
| 560 | DCHECK(root != NULL); |
| 561 | DCHECK(arg != NULL); |
| 562 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 563 | DCHECK(mark_sweep->heap_->GetMarkBitmap()->Test(root)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 564 | mark_sweep->CheckObject(root); |
| 565 | } |
| 566 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 567 | void MarkSweep::BindLiveToMarkBitmap(ContinuousSpace* space) { |
| 568 | CHECK(space->IsAllocSpace()); |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 569 | DlMallocSpace* alloc_space = space->AsAllocSpace(); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 570 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 571 | SpaceBitmap* mark_bitmap = alloc_space->mark_bitmap_.release(); |
| 572 | GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap); |
| 573 | alloc_space->temp_bitmap_.reset(mark_bitmap); |
| 574 | alloc_space->mark_bitmap_.reset(live_bitmap); |
| 575 | } |
| 576 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 577 | class ScanObjectVisitor { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 578 | public: |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 579 | ScanObjectVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 580 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 581 | } |
| 582 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 583 | // TODO: Fixme when anotatalysis works with visitors. |
| 584 | void operator ()(const Object* obj) const NO_THREAD_SAFETY_ANALYSIS { |
| 585 | if (kDebugLocking) { |
| 586 | Locks::mutator_lock_->AssertSharedHeld(Thread::Current()); |
| 587 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
| 588 | } |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 589 | mark_sweep_->ScanObject(obj); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 590 | } |
| 591 | |
| 592 | private: |
| 593 | MarkSweep* const mark_sweep_; |
| 594 | }; |
| 595 | |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 596 | void MarkSweep::ScanGrayObjects(byte minimum_age) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 597 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 598 | CardTable* card_table = heap_->GetCardTable(); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 599 | ScanObjectVisitor visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 600 | SetFingerVisitor finger_visitor(this); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 601 | // TODO: C++ 0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 602 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 603 | ContinuousSpace* space = *it; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 604 | byte* begin = space->Begin(); |
| 605 | byte* end = space->End(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 606 | // Image spaces are handled properly since live == marked for them. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 607 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 608 | card_table->Scan(mark_bitmap, begin, end, visitor, VoidFunctor(), minimum_age); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 609 | } |
| 610 | } |
| 611 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 612 | class CheckBitmapVisitor { |
| 613 | public: |
| 614 | CheckBitmapVisitor(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { |
| 615 | |
| 616 | } |
| 617 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 618 | void operator ()(const Object* obj) const |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 619 | NO_THREAD_SAFETY_ANALYSIS { |
| 620 | if (kDebugLocking) { |
| 621 | Locks::heap_bitmap_lock_->AssertSharedHeld(Thread::Current()); |
| 622 | } |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 623 | DCHECK(obj != NULL); |
| 624 | mark_sweep_->CheckObject(obj); |
| 625 | } |
| 626 | |
| 627 | private: |
| 628 | MarkSweep* mark_sweep_; |
| 629 | }; |
| 630 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 631 | void MarkSweep::VerifyImageRoots() { |
| 632 | // Verify roots ensures that all the references inside the image space point |
| 633 | // objects which are either in the image space or marked objects in the alloc |
| 634 | // space |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 635 | CheckBitmapVisitor visitor(this); |
| 636 | const Spaces& spaces = heap_->GetSpaces(); |
| 637 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 638 | if ((*it)->IsImageSpace()) { |
| 639 | ImageSpace* space = (*it)->AsImageSpace(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 640 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 641 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 642 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 643 | DCHECK(live_bitmap != NULL); |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 644 | live_bitmap->VisitMarkedRange(begin, end, visitor, VoidFunctor()); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 645 | } |
| 646 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 647 | } |
| 648 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 649 | // Populates the mark stack based on the set of marked objects and |
| 650 | // recursively marks until the mark stack is emptied. |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 651 | void MarkSweep::RecursiveMark() { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 652 | // RecursiveMark will build the lists of known instances of the Reference classes. |
| 653 | // See DelayReferenceReferent for details. |
| 654 | CHECK(soft_reference_list_ == NULL); |
| 655 | CHECK(weak_reference_list_ == NULL); |
| 656 | CHECK(finalizer_reference_list_ == NULL); |
| 657 | CHECK(phantom_reference_list_ == NULL); |
| 658 | CHECK(cleared_reference_list_ == NULL); |
| 659 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 660 | const bool partial = GetGcType() == kGcTypePartial; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 661 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 662 | SetFingerVisitor set_finger_visitor(this); |
| 663 | ScanObjectVisitor scan_visitor(this); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 664 | if (!kDisableFinger) { |
| 665 | finger_ = NULL; |
| 666 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 667 | ContinuousSpace* space = *it; |
| 668 | if ((space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect) || |
| 669 | (!partial && space->GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect) |
| 670 | ) { |
| 671 | current_mark_bitmap_ = space->GetMarkBitmap(); |
| 672 | if (current_mark_bitmap_ == NULL) { |
| 673 | GetHeap()->DumpSpaces(); |
| 674 | LOG(FATAL) << "invalid bitmap"; |
| 675 | } |
| 676 | // This function does not handle heap end increasing, so we must use the space end. |
| 677 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 678 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 679 | current_mark_bitmap_->VisitMarkedRange(begin, end, scan_visitor, set_finger_visitor); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 680 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 681 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 682 | } |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 683 | DisableFinger(); |
| 684 | timings_.AddSplit("RecursiveMark"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 685 | ProcessMarkStack(); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 686 | timings_.AddSplit("ProcessMarkStack"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 687 | } |
| 688 | |
| 689 | bool MarkSweep::IsMarkedCallback(const Object* object, void* arg) { |
| 690 | return |
| 691 | reinterpret_cast<MarkSweep*>(arg)->IsMarked(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 692 | !reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object); |
| 693 | } |
| 694 | |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 695 | void MarkSweep::RecursiveMarkDirtyObjects(byte minimum_age) { |
| 696 | ScanGrayObjects(minimum_age); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 697 | timings_.AddSplit("ScanGrayObjects"); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 698 | ProcessMarkStack(); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 699 | timings_.AddSplit("ProcessMarkStack"); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 700 | } |
| 701 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 702 | void MarkSweep::ReMarkRoots() { |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 703 | Runtime::Current()->VisitRoots(ReMarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 704 | } |
| 705 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 706 | void MarkSweep::SweepJniWeakGlobals(Heap::IsMarkedTester is_marked, void* arg) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 707 | JavaVMExt* vm = Runtime::Current()->GetJavaVM(); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 708 | MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 709 | IndirectReferenceTable* table = &vm->weak_globals; |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 710 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 711 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 712 | const Object** entry = *it; |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 713 | if (!is_marked(*entry, arg)) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 714 | *entry = kClearedJniWeakGlobal; |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 719 | struct ArrayMarkedCheck { |
| 720 | ObjectStack* live_stack; |
| 721 | MarkSweep* mark_sweep; |
| 722 | }; |
| 723 | |
| 724 | // Either marked or not live. |
| 725 | bool MarkSweep::IsMarkedArrayCallback(const Object* object, void* arg) { |
| 726 | ArrayMarkedCheck* array_check = reinterpret_cast<ArrayMarkedCheck*>(arg); |
| 727 | if (array_check->mark_sweep->IsMarked(object)) { |
| 728 | return true; |
| 729 | } |
| 730 | ObjectStack* live_stack = array_check->live_stack; |
| 731 | return std::find(live_stack->Begin(), live_stack->End(), object) == live_stack->End(); |
| 732 | } |
| 733 | |
| 734 | void MarkSweep::SweepSystemWeaksArray(ObjectStack* allocations) { |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 735 | Runtime* runtime = Runtime::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 736 | // The callbacks check |
| 737 | // !is_marked where is_marked is the callback but we want |
| 738 | // !IsMarked && IsLive |
| 739 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 740 | // Or for swapped (IsLive || !IsMarked). |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 741 | |
| 742 | ArrayMarkedCheck visitor; |
| 743 | visitor.live_stack = allocations; |
| 744 | visitor.mark_sweep = this; |
| 745 | runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedArrayCallback, &visitor); |
| 746 | runtime->GetMonitorList()->SweepMonitorList(IsMarkedArrayCallback, &visitor); |
| 747 | SweepJniWeakGlobals(IsMarkedArrayCallback, &visitor); |
| 748 | } |
| 749 | |
| 750 | void MarkSweep::SweepSystemWeaks() { |
| 751 | Runtime* runtime = Runtime::Current(); |
| 752 | // The callbacks check |
| 753 | // !is_marked where is_marked is the callback but we want |
| 754 | // !IsMarked && IsLive |
| 755 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 756 | // Or for swapped (IsLive || !IsMarked). |
| 757 | runtime->GetInternTable()->SweepInternTableWeaks(IsMarkedCallback, this); |
| 758 | runtime->GetMonitorList()->SweepMonitorList(IsMarkedCallback, this); |
| 759 | SweepJniWeakGlobals(IsMarkedCallback, this); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 760 | } |
| 761 | |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 762 | bool MarkSweep::VerifyIsLiveCallback(const Object* obj, void* arg) { |
| 763 | reinterpret_cast<MarkSweep*>(arg)->VerifyIsLive(obj); |
| 764 | // We don't actually want to sweep the object, so lets return "marked" |
| 765 | return true; |
| 766 | } |
| 767 | |
| 768 | void MarkSweep::VerifyIsLive(const Object* obj) { |
| 769 | Heap* heap = GetHeap(); |
| 770 | if (!heap->GetLiveBitmap()->Test(obj)) { |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 771 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 772 | if (!large_object_space->GetLiveObjects()->Test(obj)) { |
| 773 | if (std::find(heap->allocation_stack_->Begin(), heap->allocation_stack_->End(), obj) == |
| 774 | heap->allocation_stack_->End()) { |
| 775 | // Object not found! |
| 776 | heap->DumpSpaces(); |
| 777 | LOG(FATAL) << "Found dead object " << obj; |
| 778 | } |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 779 | } |
| 780 | } |
| 781 | } |
| 782 | |
| 783 | void MarkSweep::VerifySystemWeaks() { |
| 784 | Runtime* runtime = Runtime::Current(); |
| 785 | // Verify system weaks, uses a special IsMarked callback which always returns true. |
| 786 | runtime->GetInternTable()->SweepInternTableWeaks(VerifyIsLiveCallback, this); |
| 787 | runtime->GetMonitorList()->SweepMonitorList(VerifyIsLiveCallback, this); |
| 788 | |
| 789 | JavaVMExt* vm = runtime->GetJavaVM(); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 790 | MutexLock mu(Thread::Current(), vm->weak_globals_lock); |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 791 | IndirectReferenceTable* table = &vm->weak_globals; |
| 792 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
| 793 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 794 | const Object** entry = *it; |
| 795 | VerifyIsLive(*entry); |
| 796 | } |
| 797 | } |
| 798 | |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 799 | struct SweepCallbackContext { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 800 | MarkSweep* mark_sweep; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 801 | AllocSpace* space; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 802 | Thread* self; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 803 | }; |
| 804 | |
Mathieu Chartier | 0e4627e | 2012-10-23 16:13:36 -0700 | [diff] [blame] | 805 | class CheckpointMarkThreadRoots : public Closure { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 806 | public: |
| 807 | CheckpointMarkThreadRoots(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { |
| 808 | |
| 809 | } |
| 810 | |
| 811 | virtual void Run(Thread* thread) NO_THREAD_SAFETY_ANALYSIS { |
| 812 | // Note: self is not necessarily equal to thread since thread may be suspended. |
| 813 | Thread* self = Thread::Current(); |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 814 | CHECK(thread == self || thread->IsSuspended() || thread->GetState() == kWaitingPerformingGc) |
| 815 | << thread->GetState() << " thread " << thread << " self " << self; |
Mathieu Chartier | ac86a7c | 2012-11-12 15:03:16 -0800 | [diff] [blame] | 816 | thread->VisitRoots(MarkSweep::MarkRootParallelCallback, mark_sweep_); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 817 | mark_sweep_->GetBarrier().Pass(self); |
| 818 | } |
| 819 | |
| 820 | private: |
| 821 | MarkSweep* mark_sweep_; |
| 822 | }; |
| 823 | |
| 824 | Barrier& MarkSweep::GetBarrier() { |
| 825 | return *gc_barrier_; |
| 826 | } |
| 827 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 828 | const TimingLogger& MarkSweep::GetTimings() const { |
| 829 | return timings_; |
| 830 | } |
| 831 | |
| 832 | const CumulativeLogger& MarkSweep::GetCumulativeTimings() const { |
| 833 | return cumulative_timings_; |
| 834 | } |
| 835 | |
| 836 | void MarkSweep::ResetCumulativeStatistics() { |
| 837 | cumulative_timings_.Reset(); |
| 838 | total_time_ = 0; |
| 839 | total_paused_time_ = 0; |
| 840 | total_freed_objects_ = 0; |
| 841 | total_freed_bytes_ = 0; |
| 842 | } |
| 843 | |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 844 | void MarkSweep::MarkRootsCheckpoint() { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 845 | CheckpointMarkThreadRoots check_point(this); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 846 | ThreadList* thread_list = Runtime::Current()->GetThreadList(); |
| 847 | // Increment the count of the barrier. If all of the checkpoints have already been finished then |
| 848 | // will hit 0 and continue. Otherwise we are still waiting for some checkpoints, so the counter |
| 849 | // will go positive and we will unblock when it hits zero. |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 850 | gc_barrier_->Increment(Thread::Current(), thread_list->RunCheckpoint(&check_point)); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 851 | } |
| 852 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 853 | void MarkSweep::SweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 854 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 855 | MarkSweep* mark_sweep = context->mark_sweep; |
| 856 | Heap* heap = mark_sweep->GetHeap(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 857 | AllocSpace* space = context->space; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 858 | Thread* self = context->self; |
| 859 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(self); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 860 | // Use a bulk free, that merges consecutive objects before freeing or free per object? |
| 861 | // Documentation suggests better free performance with merging, but this may be at the expensive |
| 862 | // of allocation. |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 863 | size_t freed_objects = num_ptrs; |
| 864 | // AllocSpace::FreeList clears the value in ptrs, so perform after clearing the live bit |
| 865 | size_t freed_bytes = space->FreeList(self, num_ptrs, ptrs); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 866 | heap->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 867 | mark_sweep->freed_objects_ += freed_objects; |
| 868 | mark_sweep->freed_bytes_ += freed_bytes; |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 869 | } |
| 870 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 871 | void MarkSweep::ZygoteSweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 872 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 873 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(context->self); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 874 | Heap* heap = context->mark_sweep->GetHeap(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 875 | // We don't free any actual memory to avoid dirtying the shared zygote pages. |
| 876 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 877 | Object* obj = static_cast<Object*>(ptrs[i]); |
| 878 | heap->GetLiveBitmap()->Clear(obj); |
| 879 | heap->GetCardTable()->MarkCard(obj); |
| 880 | } |
| 881 | } |
| 882 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 883 | void MarkSweep::SweepArray(TimingLogger& logger, ObjectStack* allocations, bool swap_bitmaps) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 884 | size_t freed_bytes = 0; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 885 | DlMallocSpace* space = heap_->GetAllocSpace(); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 886 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 887 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 888 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 889 | SweepSystemWeaksArray(allocations); |
| 890 | logger.AddSplit("SweepSystemWeaks"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 891 | |
| 892 | // Newly allocated objects MUST be in the alloc space and those are the only objects which we are |
| 893 | // going to free. |
| 894 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 895 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 896 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 897 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 898 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 899 | if (swap_bitmaps) { |
| 900 | std::swap(live_bitmap, mark_bitmap); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 901 | std::swap(large_live_objects, large_mark_objects); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 902 | } |
| 903 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 904 | size_t freed_large_objects = 0; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 905 | size_t count = allocations->Size(); |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 906 | Object** objects = const_cast<Object**>(allocations->Begin()); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 907 | Object** out = objects; |
| 908 | |
| 909 | // Empty the allocation stack. |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 910 | Thread* self = Thread::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 911 | for (size_t i = 0;i < count;++i) { |
| 912 | Object* obj = objects[i]; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 913 | // There should only be objects in the AllocSpace/LargeObjectSpace in the allocation stack. |
| 914 | if (LIKELY(mark_bitmap->HasAddress(obj))) { |
| 915 | if (!mark_bitmap->Test(obj)) { |
| 916 | // Don't bother un-marking since we clear the mark bitmap anyways. |
| 917 | *(out++) = obj; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 918 | } |
| 919 | } else if (!large_mark_objects->Test(obj)) { |
| 920 | ++freed_large_objects; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 921 | freed_bytes += large_object_space->Free(self, obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 922 | } |
| 923 | } |
| 924 | logger.AddSplit("Process allocation stack"); |
| 925 | |
| 926 | size_t freed_objects = out - objects; |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 927 | freed_bytes += space->FreeList(self, freed_objects, objects); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 928 | VLOG(heap) << "Freed " << freed_objects << "/" << count |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 929 | << " objects with size " << PrettySize(freed_bytes); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 930 | heap_->RecordFree(freed_objects + freed_large_objects, freed_bytes); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 931 | freed_objects_ += freed_objects; |
| 932 | freed_bytes_ += freed_bytes; |
| 933 | logger.AddSplit("FreeList"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 934 | allocations->Reset(); |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 935 | logger.AddSplit("ResetStack"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 936 | } |
| 937 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 938 | void MarkSweep::Sweep(TimingLogger& timings, bool swap_bitmaps) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 939 | DCHECK(mark_stack_->IsEmpty()); |
| 940 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 941 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 942 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 943 | SweepSystemWeaks(); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 944 | timings.AddSplit("SweepSystemWeaks"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 945 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 946 | const bool partial = GetGcType() == kGcTypePartial; |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 947 | const Spaces& spaces = heap_->GetSpaces(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 948 | SweepCallbackContext scc; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 949 | scc.mark_sweep = this; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 950 | scc.self = Thread::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 951 | // TODO: C++0x auto |
| 952 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 953 | ContinuousSpace* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 954 | if ( |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 955 | space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect || |
| 956 | (!partial && space->GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect) |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 957 | ) { |
| 958 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 959 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 960 | scc.space = space->AsAllocSpace(); |
| 961 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 962 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | fd678be | 2012-08-30 14:50:54 -0700 | [diff] [blame] | 963 | if (swap_bitmaps) { |
| 964 | std::swap(live_bitmap, mark_bitmap); |
| 965 | } |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 966 | if (space->GetGcRetentionPolicy() == kGcRetentionPolicyAlwaysCollect) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 967 | // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 968 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 969 | &SweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 970 | } else { |
| 971 | // Zygote sweep takes care of dirtying cards and clearing live bits, does not free actual memory. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 972 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 973 | &ZygoteSweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 974 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 975 | } |
| 976 | } |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 977 | timings.AddSplit("Sweep"); |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 978 | |
| 979 | SweepLargeObjects(swap_bitmaps); |
| 980 | timings.AddSplit("SweepLargeObjects"); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 981 | } |
| 982 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 983 | void MarkSweep::SweepLargeObjects(bool swap_bitmaps) { |
| 984 | // Sweep large objects |
| 985 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 986 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 987 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
| 988 | if (swap_bitmaps) { |
| 989 | std::swap(large_live_objects, large_mark_objects); |
| 990 | } |
| 991 | SpaceSetMap::Objects& live_objects = large_live_objects->GetObjects(); |
| 992 | // O(n*log(n)) but hopefully there are not too many large objects. |
| 993 | size_t freed_objects = 0; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 994 | size_t freed_bytes = 0; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 995 | // TODO: C++0x |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 996 | Thread* self = Thread::Current(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 997 | for (SpaceSetMap::Objects::iterator it = live_objects.begin(); it != live_objects.end(); ++it) { |
| 998 | if (!large_mark_objects->Test(*it)) { |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 999 | freed_bytes += large_object_space->Free(self, const_cast<Object*>(*it)); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1000 | ++freed_objects; |
| 1001 | } |
| 1002 | } |
| 1003 | freed_objects_ += freed_objects; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 1004 | freed_bytes_ += freed_bytes; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1005 | // Large objects don't count towards bytes_allocated. |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 1006 | GetHeap()->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1007 | } |
| 1008 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 1009 | void MarkSweep::CheckReference(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) { |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1010 | const Spaces& spaces = heap_->GetSpaces(); |
| 1011 | // TODO: C++0x auto |
| 1012 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
| 1013 | if ((*cur)->IsAllocSpace() && (*cur)->Contains(ref)) { |
| 1014 | DCHECK(IsMarked(obj)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 1015 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1016 | bool is_marked = IsMarked(ref); |
| 1017 | if (!is_marked) { |
| 1018 | LOG(INFO) << **cur; |
| 1019 | LOG(WARNING) << (is_static ? "Static ref'" : "Instance ref'") << PrettyTypeOf(ref) |
| 1020 | << "' (" << reinterpret_cast<const void*>(ref) << ") in '" << PrettyTypeOf(obj) |
| 1021 | << "' (" << reinterpret_cast<const void*>(obj) << ") at offset " |
| 1022 | << reinterpret_cast<void*>(offset.Int32Value()) << " wasn't marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 1023 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1024 | const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
| 1025 | DCHECK(klass != NULL); |
| 1026 | const ObjectArray<Field>* fields = is_static ? klass->GetSFields() : klass->GetIFields(); |
| 1027 | DCHECK(fields != NULL); |
| 1028 | bool found = false; |
| 1029 | for (int32_t i = 0; i < fields->GetLength(); ++i) { |
| 1030 | const Field* cur = fields->Get(i); |
| 1031 | if (cur->GetOffset().Int32Value() == offset.Int32Value()) { |
| 1032 | LOG(WARNING) << "Field referencing the alloc space was " << PrettyField(cur); |
| 1033 | found = true; |
| 1034 | break; |
| 1035 | } |
| 1036 | } |
| 1037 | if (!found) { |
| 1038 | LOG(WARNING) << "Could not find field in object alloc space with offset " << offset.Int32Value(); |
| 1039 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 1040 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1041 | bool obj_marked = heap_->GetCardTable()->IsDirty(obj); |
| 1042 | if (!obj_marked) { |
| 1043 | LOG(WARNING) << "Object '" << PrettyTypeOf(obj) << "' " |
| 1044 | << "(" << reinterpret_cast<const void*>(obj) << ") contains references to " |
| 1045 | << "the alloc space, but wasn't card marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 1046 | } |
| 1047 | } |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 1048 | } |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1049 | break; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 1050 | } |
| 1051 | } |
| 1052 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1053 | // Process the "referent" field in a java.lang.ref.Reference. If the |
| 1054 | // referent has not yet been marked, put it on the appropriate list in |
| 1055 | // the gcHeap for later processing. |
| 1056 | void MarkSweep::DelayReferenceReferent(Object* obj) { |
| 1057 | DCHECK(obj != NULL); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 1058 | Class* klass = obj->GetClass(); |
| 1059 | DCHECK(klass != NULL); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1060 | DCHECK(klass->IsReferenceClass()); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1061 | Object* pending = obj->GetFieldObject<Object*>(heap_->GetReferencePendingNextOffset(), false); |
| 1062 | Object* referent = heap_->GetReferenceReferent(obj); |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1063 | if (kCountJavaLangRefs) { |
| 1064 | ++reference_count_; |
| 1065 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1066 | if (pending == NULL && referent != NULL && !IsMarked(referent)) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 1067 | Object** list = NULL; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1068 | if (klass->IsSoftReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1069 | list = &soft_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1070 | } else if (klass->IsWeakReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1071 | list = &weak_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1072 | } else if (klass->IsFinalizerReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1073 | list = &finalizer_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1074 | } else if (klass->IsPhantomReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1075 | list = &phantom_reference_list_; |
| 1076 | } |
Brian Carlstrom | 0796af0 | 2011-10-12 14:31:45 -0700 | [diff] [blame] | 1077 | DCHECK(list != NULL) << PrettyClass(klass) << " " << std::hex << klass->GetAccessFlags(); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1078 | // TODO: One lock per list? |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1079 | heap_->EnqueuePendingReference(obj, list); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1080 | } |
| 1081 | } |
| 1082 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1083 | void MarkSweep::ScanRoot(const Object* obj) { |
| 1084 | ScanObject(obj); |
| 1085 | } |
| 1086 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1087 | class MarkObjectVisitor { |
| 1088 | public: |
| 1089 | MarkObjectVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 1090 | } |
| 1091 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 1092 | // TODO: Fixme when anotatalysis works with visitors. |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1093 | void operator ()(const Object* /* obj */, const Object* ref, const MemberOffset& /* offset */, |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 1094 | bool /* is_static */) const |
| 1095 | NO_THREAD_SAFETY_ANALYSIS { |
| 1096 | if (kDebugLocking) { |
| 1097 | Locks::mutator_lock_->AssertSharedHeld(Thread::Current()); |
| 1098 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
| 1099 | } |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1100 | mark_sweep_->MarkObject(ref); |
| 1101 | } |
| 1102 | |
| 1103 | private: |
| 1104 | MarkSweep* const mark_sweep_; |
| 1105 | }; |
| 1106 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1107 | // Scans an object reference. Determines the type of the reference |
| 1108 | // and dispatches to a specialized scanning routine. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 1109 | void MarkSweep::ScanObject(const Object* obj) { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1110 | MarkObjectVisitor visitor(this); |
| 1111 | ScanObjectVisit(obj, visitor); |
| 1112 | } |
| 1113 | |
| 1114 | class MarkStackChunk : public Task { |
| 1115 | public: |
| 1116 | MarkStackChunk(ThreadPool* thread_pool, MarkSweep* mark_sweep, Object** begin, Object** end) |
| 1117 | : mark_sweep_(mark_sweep), |
| 1118 | thread_pool_(thread_pool), |
| 1119 | index_(0), |
| 1120 | length_(0), |
| 1121 | output_(NULL) { |
| 1122 | length_ = end - begin; |
| 1123 | if (begin != end) { |
| 1124 | // Cost not significant since we only do this for the initial set of mark stack chunks. |
| 1125 | memcpy(data_, begin, length_ * sizeof(*begin)); |
| 1126 | } |
| 1127 | if (kCountTasks) { |
| 1128 | ++mark_sweep_->work_chunks_created_; |
| 1129 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1130 | } |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1131 | |
| 1132 | ~MarkStackChunk() { |
| 1133 | DCHECK(output_ == NULL || output_->length_ == 0); |
| 1134 | DCHECK_GE(index_, length_); |
| 1135 | delete output_; |
| 1136 | if (kCountTasks) { |
| 1137 | ++mark_sweep_->work_chunks_deleted_; |
| 1138 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1139 | } |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1140 | |
| 1141 | MarkSweep* const mark_sweep_; |
| 1142 | ThreadPool* const thread_pool_; |
| 1143 | static const size_t max_size = 1 * KB; |
| 1144 | // Index of which object we are scanning. Only needs to be atomic if we are doing work stealing. |
| 1145 | size_t index_; |
| 1146 | // Input / output mark stack. We add newly marked references to data_ until length reaches |
| 1147 | // max_size. This is an optimization so that less tasks are created. |
| 1148 | // TODO: Investigate using a bounded buffer FIFO. |
| 1149 | Object* data_[max_size]; |
| 1150 | // How many elements in data_ we need to scan. |
| 1151 | size_t length_; |
| 1152 | // Output block, newly marked references get added to the ouput block so that another thread can |
| 1153 | // scan them. |
| 1154 | MarkStackChunk* output_; |
| 1155 | |
| 1156 | class MarkObjectParallelVisitor { |
| 1157 | public: |
| 1158 | MarkObjectParallelVisitor(MarkStackChunk* chunk_task) : chunk_task_(chunk_task) { |
| 1159 | |
| 1160 | } |
| 1161 | |
| 1162 | void operator ()(const Object* /* obj */, const Object* ref, |
| 1163 | const MemberOffset& /* offset */, bool /* is_static */) const { |
| 1164 | if (ref != NULL && chunk_task_->mark_sweep_->MarkObjectParallel(ref)) { |
| 1165 | chunk_task_->MarkStackPush(ref); |
| 1166 | } |
| 1167 | } |
| 1168 | |
| 1169 | private: |
| 1170 | MarkStackChunk* const chunk_task_; |
| 1171 | }; |
| 1172 | |
| 1173 | // Push an object into the block. |
| 1174 | // Don't need to use atomic ++ since we only one thread is writing to an output block at any |
| 1175 | // given time. |
| 1176 | void Push(Object* obj) { |
| 1177 | data_[length_++] = obj; |
| 1178 | } |
| 1179 | |
| 1180 | void MarkStackPush(const Object* obj) { |
| 1181 | if (static_cast<size_t>(length_) < max_size) { |
| 1182 | Push(const_cast<Object*>(obj)); |
| 1183 | } else { |
| 1184 | // Internal buffer is full, push to a new buffer instead. |
| 1185 | if (UNLIKELY(output_ == NULL)) { |
| 1186 | AllocateOutputChunk(); |
| 1187 | } else if (UNLIKELY(static_cast<size_t>(output_->length_) == max_size)) { |
| 1188 | // Output block is full, queue it up for processing and obtain a new block. |
| 1189 | EnqueueOutput(); |
| 1190 | AllocateOutputChunk(); |
| 1191 | } |
| 1192 | output_->Push(const_cast<Object*>(obj)); |
| 1193 | } |
| 1194 | } |
| 1195 | |
| 1196 | void ScanObject(Object* obj) { |
| 1197 | mark_sweep_->ScanObjectVisit(obj, MarkObjectParallelVisitor(this)); |
| 1198 | } |
| 1199 | |
| 1200 | void EnqueueOutput() { |
| 1201 | if (output_ != NULL) { |
| 1202 | uint64_t start = 0; |
| 1203 | if (kMeasureOverhead) { |
| 1204 | start = NanoTime(); |
| 1205 | } |
| 1206 | thread_pool_->AddTask(Thread::Current(), output_); |
| 1207 | output_ = NULL; |
| 1208 | if (kMeasureOverhead) { |
| 1209 | mark_sweep_->overhead_time_ += NanoTime() - start; |
| 1210 | } |
| 1211 | } |
| 1212 | } |
| 1213 | |
| 1214 | void AllocateOutputChunk() { |
| 1215 | uint64_t start = 0; |
| 1216 | if (kMeasureOverhead) { |
| 1217 | start = NanoTime(); |
| 1218 | } |
| 1219 | output_ = new MarkStackChunk(thread_pool_, mark_sweep_, NULL, NULL); |
| 1220 | if (kMeasureOverhead) { |
| 1221 | mark_sweep_->overhead_time_ += NanoTime() - start; |
| 1222 | } |
| 1223 | } |
| 1224 | |
| 1225 | void Finalize() { |
| 1226 | EnqueueOutput(); |
| 1227 | delete this; |
| 1228 | } |
| 1229 | |
| 1230 | // Scans all of the objects |
| 1231 | virtual void Run(Thread* self) { |
| 1232 | int index; |
| 1233 | while ((index = index_++) < length_) { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1234 | if (kUseMarkStackPrefetch) { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1235 | static const size_t prefetch_look_ahead = 1; |
| 1236 | __builtin_prefetch(data_[std::min(index + prefetch_look_ahead, length_ - 1)]); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1237 | } |
| 1238 | Object* obj = data_[index]; |
| 1239 | DCHECK(obj != NULL); |
| 1240 | ScanObject(obj); |
| 1241 | } |
| 1242 | } |
| 1243 | }; |
| 1244 | |
| 1245 | void MarkSweep::ProcessMarkStackParallel() { |
| 1246 | CHECK(kDisableFinger) << "parallel mark stack processing cannot work when finger is enabled"; |
| 1247 | Thread* self = Thread::Current(); |
| 1248 | ThreadPool* thread_pool = GetHeap()->GetThreadPool(); |
| 1249 | // Split the current mark stack up into work tasks. |
| 1250 | const size_t num_threads = thread_pool->GetThreadCount(); |
| 1251 | const size_t stack_size = mark_stack_->Size(); |
| 1252 | const size_t chunk_size = |
| 1253 | std::min((stack_size + num_threads - 1) / num_threads, |
| 1254 | static_cast<size_t>(MarkStackChunk::max_size)); |
| 1255 | size_t index = 0; |
| 1256 | for (size_t i = 0; i < num_threads || index < stack_size; ++i) { |
| 1257 | Object** begin = &mark_stack_->Begin()[std::min(stack_size, index)]; |
| 1258 | Object** end = &mark_stack_->Begin()[std::min(stack_size, index + chunk_size)]; |
| 1259 | index += chunk_size; |
| 1260 | thread_pool->AddTask(self, new MarkStackChunk(thread_pool, this, begin, end)); |
| 1261 | } |
| 1262 | thread_pool->StartWorkers(self); |
| 1263 | mark_stack_->Reset(); |
| 1264 | thread_pool->Wait(self, true); |
| 1265 | //LOG(INFO) << "Idle wait time " << PrettyDuration(thread_pool->GetWaitTime()); |
| 1266 | CHECK_EQ(work_chunks_created_, work_chunks_deleted_) << " some of the work chunks were leaked"; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1267 | } |
| 1268 | |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 1269 | // Scan anything that's on the mark stack. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1270 | void MarkSweep::ProcessMarkStack() { |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1271 | ThreadPool* thread_pool = GetHeap()->GetThreadPool(); |
| 1272 | if (kParallelMarkStack && thread_pool != NULL && thread_pool->GetThreadCount() > 0) { |
| 1273 | ProcessMarkStackParallel(); |
| 1274 | return; |
| 1275 | } |
| 1276 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 1277 | if (kUseMarkStackPrefetch) { |
| 1278 | const size_t fifo_size = 4; |
| 1279 | const size_t fifo_mask = fifo_size - 1; |
| 1280 | const Object* fifo[fifo_size]; |
| 1281 | for (size_t i = 0;i < fifo_size;++i) { |
| 1282 | fifo[i] = NULL; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1283 | } |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 1284 | size_t fifo_pos = 0; |
| 1285 | size_t fifo_count = 0; |
| 1286 | for (;;) { |
| 1287 | const Object* obj = fifo[fifo_pos & fifo_mask]; |
| 1288 | if (obj != NULL) { |
| 1289 | ScanObject(obj); |
| 1290 | fifo[fifo_pos & fifo_mask] = NULL; |
| 1291 | --fifo_count; |
| 1292 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1293 | |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 1294 | if (!mark_stack_->IsEmpty()) { |
| 1295 | const Object* obj = mark_stack_->PopBack(); |
| 1296 | DCHECK(obj != NULL); |
| 1297 | fifo[fifo_pos & fifo_mask] = obj; |
| 1298 | __builtin_prefetch(obj); |
| 1299 | fifo_count++; |
| 1300 | } |
| 1301 | fifo_pos++; |
| 1302 | |
| 1303 | if (!fifo_count) { |
| 1304 | CHECK(mark_stack_->IsEmpty()) << mark_stack_->Size(); |
| 1305 | break; |
| 1306 | } |
| 1307 | } |
| 1308 | } else { |
| 1309 | while (!mark_stack_->IsEmpty()) { |
| 1310 | const Object* obj = mark_stack_->PopBack(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1311 | DCHECK(obj != NULL); |
Mathieu Chartier | d8195f1 | 2012-10-05 12:21:28 -0700 | [diff] [blame] | 1312 | ScanObject(obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1313 | } |
| 1314 | } |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1315 | } |
| 1316 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1317 | // Walks the reference list marking any references subject to the |
| 1318 | // reference clearing policy. References with a black referent are |
| 1319 | // removed from the list. References with white referents biased |
| 1320 | // toward saving are blackened and also removed from the list. |
| 1321 | void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| 1322 | DCHECK(list != NULL); |
| 1323 | Object* clear = NULL; |
| 1324 | size_t counter = 0; |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 1325 | |
| 1326 | DCHECK(mark_stack_->IsEmpty()); |
| 1327 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1328 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1329 | Object* ref = heap_->DequeuePendingReference(list); |
| 1330 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1331 | if (referent == NULL) { |
| 1332 | // Referent was cleared by the user during marking. |
| 1333 | continue; |
| 1334 | } |
| 1335 | bool is_marked = IsMarked(referent); |
| 1336 | if (!is_marked && ((++counter) & 1)) { |
| 1337 | // Referent is white and biased toward saving, mark it. |
| 1338 | MarkObject(referent); |
| 1339 | is_marked = true; |
| 1340 | } |
| 1341 | if (!is_marked) { |
| 1342 | // Referent is white, queue it for clearing. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1343 | heap_->EnqueuePendingReference(ref, &clear); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1344 | } |
| 1345 | } |
| 1346 | *list = clear; |
| 1347 | // Restart the mark with the newly black references added to the |
| 1348 | // root set. |
| 1349 | ProcessMarkStack(); |
| 1350 | } |
| 1351 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1352 | inline bool MarkSweep::IsMarked(const Object* object) const |
| 1353 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { |
| 1354 | if (object >= immune_begin_ && object < immune_end_) { |
| 1355 | return true; |
| 1356 | } |
| 1357 | DCHECK(current_mark_bitmap_ != NULL); |
| 1358 | if (current_mark_bitmap_->HasAddress(object)) { |
| 1359 | return current_mark_bitmap_->Test(object); |
| 1360 | } |
| 1361 | return heap_->GetMarkBitmap()->Test(object); |
| 1362 | } |
| 1363 | |
| 1364 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1365 | // Unlink the reference list clearing references objects with white |
| 1366 | // referents. Cleared references registered to a reference queue are |
| 1367 | // scheduled for appending by the heap worker thread. |
| 1368 | void MarkSweep::ClearWhiteReferences(Object** list) { |
| 1369 | DCHECK(list != NULL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1370 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1371 | Object* ref = heap_->DequeuePendingReference(list); |
| 1372 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1373 | if (referent != NULL && !IsMarked(referent)) { |
| 1374 | // Referent is white, clear it. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1375 | heap_->ClearReferenceReferent(ref); |
| 1376 | if (heap_->IsEnqueuable(ref)) { |
| 1377 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1378 | } |
| 1379 | } |
| 1380 | } |
| 1381 | DCHECK(*list == NULL); |
| 1382 | } |
| 1383 | |
| 1384 | // Enqueues finalizer references with white referents. White |
| 1385 | // referents are blackened, moved to the zombie field, and the |
| 1386 | // referent field is cleared. |
| 1387 | void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| 1388 | DCHECK(list != NULL); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1389 | MemberOffset zombie_offset = heap_->GetFinalizerReferenceZombieOffset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1390 | bool has_enqueued = false; |
| 1391 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1392 | Object* ref = heap_->DequeuePendingReference(list); |
| 1393 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1394 | if (referent != NULL && !IsMarked(referent)) { |
| 1395 | MarkObject(referent); |
| 1396 | // If the referent is non-null the reference must queuable. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1397 | DCHECK(heap_->IsEnqueuable(ref)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 1398 | ref->SetFieldObject(zombie_offset, referent, false); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 1399 | heap_->ClearReferenceReferent(ref); |
| 1400 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1401 | has_enqueued = true; |
| 1402 | } |
| 1403 | } |
| 1404 | if (has_enqueued) { |
| 1405 | ProcessMarkStack(); |
| 1406 | } |
| 1407 | DCHECK(*list == NULL); |
| 1408 | } |
| 1409 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 1410 | // Process reference class instances and schedule finalizations. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1411 | void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| 1412 | Object** weak_references, |
| 1413 | Object** finalizer_references, |
| 1414 | Object** phantom_references) { |
| 1415 | DCHECK(soft_references != NULL); |
| 1416 | DCHECK(weak_references != NULL); |
| 1417 | DCHECK(finalizer_references != NULL); |
| 1418 | DCHECK(phantom_references != NULL); |
| 1419 | |
| 1420 | // Unless we are in the zygote or required to clear soft references |
| 1421 | // with white references, preserve some white referents. |
Ian Rogers | 2945e24 | 2012-06-03 14:45:16 -0700 | [diff] [blame] | 1422 | if (!clear_soft && !Runtime::Current()->IsZygote()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1423 | PreserveSomeSoftReferences(soft_references); |
| 1424 | } |
| 1425 | |
| 1426 | // Clear all remaining soft and weak references with white |
| 1427 | // referents. |
| 1428 | ClearWhiteReferences(soft_references); |
| 1429 | ClearWhiteReferences(weak_references); |
| 1430 | |
| 1431 | // Preserve all white objects with finalize methods and schedule |
| 1432 | // them for finalization. |
| 1433 | EnqueueFinalizerReferences(finalizer_references); |
| 1434 | |
| 1435 | // Clear all f-reachable soft and weak references with white |
| 1436 | // referents. |
| 1437 | ClearWhiteReferences(soft_references); |
| 1438 | ClearWhiteReferences(weak_references); |
| 1439 | |
| 1440 | // Clear all phantom references with white referents. |
| 1441 | ClearWhiteReferences(phantom_references); |
| 1442 | |
| 1443 | // At this point all reference lists should be empty. |
| 1444 | DCHECK(*soft_references == NULL); |
| 1445 | DCHECK(*weak_references == NULL); |
| 1446 | DCHECK(*finalizer_references == NULL); |
| 1447 | DCHECK(*phantom_references == NULL); |
| 1448 | } |
| 1449 | |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1450 | void MarkSweep::UnBindBitmaps() { |
| 1451 | const Spaces& spaces = heap_->GetSpaces(); |
| 1452 | // TODO: C++0x auto |
| 1453 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 1454 | Space* space = *it; |
| 1455 | if (space->IsAllocSpace()) { |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 1456 | DlMallocSpace* alloc_space = space->AsAllocSpace(); |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1457 | if (alloc_space->temp_bitmap_.get() != NULL) { |
| 1458 | // At this point, the temp_bitmap holds our old mark bitmap. |
| 1459 | SpaceBitmap* new_bitmap = alloc_space->temp_bitmap_.release(); |
| 1460 | GetHeap()->GetMarkBitmap()->ReplaceBitmap(alloc_space->mark_bitmap_.get(), new_bitmap); |
| 1461 | CHECK_EQ(alloc_space->mark_bitmap_.release(), alloc_space->live_bitmap_.get()); |
| 1462 | alloc_space->mark_bitmap_.reset(new_bitmap); |
| 1463 | DCHECK(alloc_space->temp_bitmap_.get() == NULL); |
| 1464 | } |
| 1465 | } |
| 1466 | } |
| 1467 | } |
| 1468 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 1469 | void MarkSweep::FinishPhase() { |
| 1470 | // Can't enqueue referneces if we hold the mutator lock. |
| 1471 | Object* cleared_references = GetClearedReferences(); |
| 1472 | heap_->EnqueueClearedReferences(&cleared_references); |
| 1473 | |
| 1474 | heap_->PostGcVerification(this); |
| 1475 | |
| 1476 | // Update the cumulative statistics |
| 1477 | total_time_ += GetDuration(); |
| 1478 | total_paused_time_ += std::accumulate(GetPauseTimes().begin(), GetPauseTimes().end(), 0, |
| 1479 | std::plus<uint64_t>()); |
| 1480 | total_freed_objects_ += GetFreedObjects(); |
| 1481 | total_freed_bytes_ += GetFreedBytes(); |
| 1482 | |
| 1483 | // Ensure that the mark stack is empty. |
| 1484 | CHECK(mark_stack_->IsEmpty()); |
| 1485 | |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1486 | if (kCountScannedTypes) { |
| 1487 | VLOG(gc) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_ |
| 1488 | << " other=" << other_count_; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1489 | } |
| 1490 | |
| 1491 | if (kCountTasks) { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1492 | VLOG(gc) << "Total number of work chunks allocated: " << work_chunks_created_; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1493 | } |
| 1494 | |
| 1495 | if (kMeasureOverhead) { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1496 | VLOG(gc) << "Overhead time " << PrettyDuration(overhead_time_); |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1497 | } |
| 1498 | |
| 1499 | if (kProfileLargeObjects) { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1500 | VLOG(gc) << "Large objects tested " << large_object_test_ << " marked " << large_object_mark_; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1501 | } |
| 1502 | |
| 1503 | if (kCountClassesMarked) { |
Mathieu Chartier | d22d548 | 2012-11-06 17:14:12 -0800 | [diff] [blame] | 1504 | VLOG(gc) << "Classes marked " << classes_marked_; |
| 1505 | } |
| 1506 | |
| 1507 | if (kCountJavaLangRefs) { |
| 1508 | VLOG(gc) << "References scanned " << reference_count_; |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1509 | } |
| 1510 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 1511 | // Update the cumulative loggers. |
| 1512 | cumulative_timings_.Start(); |
| 1513 | cumulative_timings_.AddLogger(timings_); |
| 1514 | cumulative_timings_.End(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1515 | |
Mathieu Chartier | 02b6a78 | 2012-10-26 13:51:26 -0700 | [diff] [blame] | 1516 | // Clear all of the spaces' mark bitmaps. |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1517 | const Spaces& spaces = heap_->GetSpaces(); |
| 1518 | // TODO: C++0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 1519 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 7469ebf | 2012-09-24 16:28:36 -0700 | [diff] [blame] | 1520 | ContinuousSpace* space = *it; |
| 1521 | if (space->GetGcRetentionPolicy() != kGcRetentionPolicyNeverCollect) { |
| 1522 | space->GetMarkBitmap()->Clear(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 1523 | } |
| 1524 | } |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 1525 | mark_stack_->Reset(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1526 | |
| 1527 | // Reset the marked large objects. |
| 1528 | LargeObjectSpace* large_objects = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 1529 | large_objects->GetMarkObjects()->Clear(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1530 | } |
| 1531 | |
Mathieu Chartier | 2b82db4 | 2012-11-14 17:29:05 -0800 | [diff] [blame] | 1532 | MarkSweep::~MarkSweep() { |
| 1533 | |
| 1534 | } |
| 1535 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1536 | } // namespace art |