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 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 19 | #include <climits> |
| 20 | #include <vector> |
| 21 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 22 | #include "card_table.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 23 | #include "class_loader.h" |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 24 | #include "dex_cache.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 25 | #include "heap.h" |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 26 | #include "indirect_reference_table.h" |
| 27 | #include "intern_table.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 28 | #include "logging.h" |
| 29 | #include "macros.h" |
| 30 | #include "mark_stack.h" |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 31 | #include "monitor.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 32 | #include "object.h" |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 33 | #include "runtime.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 34 | #include "space.h" |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 35 | #include "timing_logger.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 36 | #include "thread.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 37 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 38 | #define MARK_STACK_PREFETCH 1 |
| 39 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 40 | namespace art { |
| 41 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 42 | class SetFingerVisitor { |
| 43 | public: |
| 44 | SetFingerVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 45 | |
| 46 | } |
| 47 | |
| 48 | void operator ()(void* finger) const { |
| 49 | mark_sweep_->SetFinger(reinterpret_cast<Object*>(finger)); |
| 50 | } |
| 51 | |
| 52 | private: |
| 53 | MarkSweep* const mark_sweep_; |
| 54 | }; |
| 55 | |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 56 | MarkSweep::MarkSweep(MarkStack* mark_stack) |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 57 | : current_mark_bitmap_(NULL), |
| 58 | mark_stack_(mark_stack), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 59 | heap_(NULL), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 60 | finger_(NULL), |
| 61 | condemned_(NULL), |
| 62 | soft_reference_list_(NULL), |
| 63 | weak_reference_list_(NULL), |
| 64 | finalizer_reference_list_(NULL), |
| 65 | phantom_reference_list_(NULL), |
| 66 | cleared_reference_list_(NULL), |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 67 | freed_bytes_(0), freed_objects_(0), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 68 | class_count_(0), array_count_(0), other_count_(0) { |
| 69 | DCHECK(mark_stack_ != NULL); |
| 70 | } |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 71 | |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 72 | void MarkSweep::Init() { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 73 | heap_ = Runtime::Current()->GetHeap(); |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 74 | mark_stack_->Reset(); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 75 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 76 | const Spaces& spaces = heap_->GetSpaces(); |
| 77 | // TODO: C++0x auto |
| 78 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 79 | if (current_mark_bitmap_ == NULL || (*cur)->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT) { |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 80 | current_mark_bitmap_ = (*cur)->GetMarkBitmap(); |
| 81 | break; |
| 82 | } |
| 83 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 84 | if (current_mark_bitmap_ == NULL) { |
| 85 | GetHeap()->DumpSpaces(); |
| 86 | DCHECK(false) << "current_mark_bitmap_ == NULL"; |
| 87 | } |
buzbee | 0d966cf | 2011-09-08 17:34:58 -0700 | [diff] [blame] | 88 | // TODO: if concurrent, enable card marking in compiler |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 89 | // TODO: check that the mark bitmap is entirely clear. |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 90 | } |
| 91 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 92 | inline void MarkSweep::MarkObject0(const Object* obj, bool check_finger) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 93 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 94 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 95 | if (obj < condemned_) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 96 | // May later use condemned for the NULL check. |
| 97 | DCHECK(obj == NULL || IsMarked(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 98 | return; |
| 99 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 100 | |
| 101 | // Try to take advantage of locality of references within a space, failing this find the space |
| 102 | // the hard way. |
| 103 | if (!current_mark_bitmap_->HasAddress(obj)) { |
| 104 | current_mark_bitmap_ = heap_->GetMarkBitmap()->GetSpaceBitmap(obj); |
| 105 | #ifndef NDEBUG |
| 106 | if (current_mark_bitmap_ == NULL) { |
| 107 | LOG(WARNING) << obj; |
| 108 | GetHeap()->DumpSpaces(); |
| 109 | LOG(FATAL) << "space_bitmap == NULL"; |
| 110 | } |
| 111 | #endif |
| 112 | } |
| 113 | |
| 114 | bool is_marked = current_mark_bitmap_->Test(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 115 | // This object was not previously marked. |
| 116 | if (!is_marked) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 117 | current_mark_bitmap_->Set(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 118 | if (check_finger && obj < finger_) { |
| 119 | // The object must be pushed on to the mark stack. |
| 120 | mark_stack_->Push(obj); |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | // Used to mark objects when recursing. Recursion is done by moving |
| 126 | // the finger across the bitmaps in address order and marking child |
| 127 | // objects. Any newly-marked objects whose addresses are lower than |
| 128 | // the finger won't be visited by the bitmap scan, so those objects |
| 129 | // need to be added to the mark stack. |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 130 | void MarkSweep::MarkObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 131 | if (obj != NULL) { |
| 132 | MarkObject0(obj, true); |
| 133 | } |
| 134 | } |
| 135 | |
Elliott Hughes | cf4c6c4 | 2011-09-01 15:16:42 -0700 | [diff] [blame] | 136 | void MarkSweep::MarkObjectVisitor(const Object* root, void* arg) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 137 | DCHECK(root != NULL); |
| 138 | DCHECK(arg != NULL); |
| 139 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 140 | mark_sweep->MarkObject0(root, false); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 141 | } |
| 142 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 143 | void MarkSweep::ReMarkObjectVisitor(const Object* root, void* arg) { |
| 144 | DCHECK(root != NULL); |
| 145 | DCHECK(arg != NULL); |
| 146 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| 147 | mark_sweep->MarkObject0(root, true); |
| 148 | } |
| 149 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 150 | // Marks all objects in the root set. |
| 151 | void MarkSweep::MarkRoots() { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 152 | Runtime::Current()->VisitRoots(MarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 153 | } |
| 154 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 155 | class CheckObjectVisitor { |
| 156 | public: |
| 157 | CheckObjectVisitor(MarkSweep* const mark_sweep) |
| 158 | : mark_sweep_(mark_sweep) { |
| 159 | |
| 160 | } |
| 161 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 162 | void operator ()(const Object* obj, const Object* ref, MemberOffset offset, bool is_static) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 163 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 164 | Locks::mutator_lock_) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 165 | mark_sweep_->CheckReference(obj, ref, offset, is_static); |
| 166 | } |
| 167 | |
| 168 | private: |
| 169 | MarkSweep* const mark_sweep_; |
| 170 | }; |
| 171 | |
| 172 | void MarkSweep::CheckObject(const Object* obj) { |
| 173 | DCHECK(obj != NULL); |
| 174 | CheckObjectVisitor visitor(this); |
| 175 | VisitObjectReferences(obj, visitor); |
| 176 | } |
| 177 | |
| 178 | void MarkSweep::VerifyImageRootVisitor(Object* root, void* arg) { |
| 179 | DCHECK(root != NULL); |
| 180 | DCHECK(arg != NULL); |
| 181 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 182 | DCHECK(mark_sweep->heap_->GetMarkBitmap()->Test(root)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 183 | mark_sweep->CheckObject(root); |
| 184 | } |
| 185 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 186 | void MarkSweep::CopyMarkBits(Space* space) { |
| 187 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 188 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 189 | mark_bitmap->CopyFrom(live_bitmap); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 190 | } |
| 191 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 192 | class ScanImageRootVisitor { |
| 193 | public: |
| 194 | ScanImageRootVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 195 | } |
| 196 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 197 | void operator ()(const Object* root) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 198 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 199 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 200 | DCHECK(root != NULL); |
| 201 | mark_sweep_->ScanObject(root); |
| 202 | } |
| 203 | |
| 204 | private: |
| 205 | MarkSweep* const mark_sweep_; |
| 206 | }; |
| 207 | |
| 208 | // Marks all objects that are in images and have been touched by the mutator |
| 209 | void MarkSweep::ScanDirtyImageRoots() { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 210 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 211 | CardTable* card_table = heap_->GetCardTable(); |
| 212 | ScanImageRootVisitor image_root_visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 213 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 214 | Space* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 215 | if (space->IsImageSpace()) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 216 | card_table->Scan(space->GetLiveBitmap(), space->Begin(), space->End(), image_root_visitor, |
| 217 | IdentityFunctor()); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 218 | } |
| 219 | } |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 220 | } |
| 221 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 222 | void MarkSweep::ScanGrayObjects(bool update_finger) { |
| 223 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 224 | CardTable* card_table = heap_->GetCardTable(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 225 | ScanImageRootVisitor image_root_visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 226 | SetFingerVisitor finger_visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 227 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 228 | Space* space = *it; |
| 229 | byte* begin = space->Begin(); |
| 230 | byte* end = space->End(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 231 | // Image spaces are handled properly since live == marked for them. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 232 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 233 | if (update_finger) { |
| 234 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, finger_visitor); |
| 235 | } else { |
| 236 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, IdentityFunctor()); |
| 237 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 238 | } |
| 239 | } |
| 240 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 241 | class CheckBitmapVisitor { |
| 242 | public: |
| 243 | CheckBitmapVisitor(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { |
| 244 | |
| 245 | } |
| 246 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 247 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 248 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 249 | Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 250 | DCHECK(obj != NULL); |
| 251 | mark_sweep_->CheckObject(obj); |
| 252 | } |
| 253 | |
| 254 | private: |
| 255 | MarkSweep* mark_sweep_; |
| 256 | }; |
| 257 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 258 | void MarkSweep::VerifyImageRoots() { |
| 259 | // Verify roots ensures that all the references inside the image space point |
| 260 | // objects which are either in the image space or marked objects in the alloc |
| 261 | // space |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 262 | CheckBitmapVisitor visitor(this); |
| 263 | const Spaces& spaces = heap_->GetSpaces(); |
| 264 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 265 | const Space* space = *it; |
| 266 | if (space->IsImageSpace()) { |
| 267 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 268 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 269 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 270 | DCHECK(live_bitmap != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 271 | live_bitmap->VisitMarkedRange(begin, end, visitor, IdentityFunctor()); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 272 | } |
| 273 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 274 | } |
| 275 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 276 | class ScanObjectVisitor { |
| 277 | public: |
| 278 | ScanObjectVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 279 | |
| 280 | } |
| 281 | |
| 282 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 283 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 284 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 285 | mark_sweep_->ScanObject(obj); |
| 286 | } |
| 287 | |
| 288 | private: |
| 289 | MarkSweep* const mark_sweep_; |
| 290 | }; |
| 291 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 292 | // Populates the mark stack based on the set of marked objects and |
| 293 | // recursively marks until the mark stack is emptied. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 294 | void MarkSweep::RecursiveMark(bool partial, TimingLogger& timings) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 295 | // RecursiveMark will build the lists of known instances of the Reference classes. |
| 296 | // See DelayReferenceReferent for details. |
| 297 | CHECK(soft_reference_list_ == NULL); |
| 298 | CHECK(weak_reference_list_ == NULL); |
| 299 | CHECK(finalizer_reference_list_ == NULL); |
| 300 | CHECK(phantom_reference_list_ == NULL); |
| 301 | CHECK(cleared_reference_list_ == NULL); |
| 302 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 303 | const Spaces& spaces = heap_->GetSpaces(); |
| 304 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 305 | SetFingerVisitor set_finger_visitor(this); |
| 306 | ScanObjectVisitor scan_visitor(this); |
| 307 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 308 | Space* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 309 | if (space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT || |
| 310 | (!partial && space->GetGcRetentionPolicy() == GCRP_FULL_COLLECT) |
| 311 | ) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 312 | current_mark_bitmap_ = space->GetMarkBitmap(); |
| 313 | if (current_mark_bitmap_ == NULL) { |
| 314 | GetHeap()->DumpSpaces(); |
| 315 | DCHECK(false) << "invalid bitmap"; |
| 316 | } |
| 317 | // This function does not handle heap end increasing, so we must use the space end. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 318 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 319 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 320 | current_mark_bitmap_->VisitMarkedRange(begin, end, scan_visitor, set_finger_visitor); |
Mathieu Chartier | 7664f5c | 2012-06-08 18:15:32 -0700 | [diff] [blame] | 321 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 322 | } |
| 323 | finger_ = reinterpret_cast<Object*>(~0); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 324 | timings.AddSplit("RecursiveMark"); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 325 | // TODO: tune the frequency of emptying the mark stack |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 326 | ProcessMarkStack(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 327 | timings.AddSplit("ProcessMarkStack"); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 328 | } |
| 329 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 330 | void MarkSweep::RecursiveMarkCards(CardTable* card_table, const std::vector<byte*>& cards, |
| 331 | TimingLogger& timings) { |
| 332 | ScanImageRootVisitor image_root_visitor(this); |
| 333 | SetFingerVisitor finger_visitor(this); |
| 334 | for (size_t i = 0;i < cards.size();) { |
| 335 | Object* start_obj = reinterpret_cast<Object*>(card_table->AddrFromCard(cards[i])); |
| 336 | uintptr_t begin = reinterpret_cast<uintptr_t>(start_obj); |
| 337 | uintptr_t end = begin + GC_CARD_SIZE; |
| 338 | for (++i; reinterpret_cast<uintptr_t>(cards[i]) == end && i < cards.size(); ++i) { |
| 339 | end += GC_CARD_SIZE; |
| 340 | } |
| 341 | if (current_mark_bitmap_ == NULL || !current_mark_bitmap_->HasAddress(start_obj)) { |
| 342 | current_mark_bitmap_ = heap_->GetMarkBitmap()->GetSpaceBitmap(start_obj); |
| 343 | #ifndef NDEBUG |
| 344 | if (current_mark_bitmap_ == NULL) { |
| 345 | GetHeap()->DumpSpaces(); |
| 346 | DCHECK(false) << "Object " << reinterpret_cast<const void*>(start_obj); |
| 347 | } |
| 348 | #endif |
| 349 | } |
| 350 | current_mark_bitmap_->VisitMarkedRange(begin, end, image_root_visitor, finger_visitor); |
| 351 | } |
| 352 | timings.AddSplit("RecursiveMarkCards"); |
| 353 | ProcessMarkStack(); |
| 354 | timings.AddSplit("ProcessMarkStack"); |
| 355 | } |
| 356 | |
| 357 | bool MarkSweep::IsMarkedCallback(const Object* object, void* arg) { |
| 358 | return |
| 359 | reinterpret_cast<MarkSweep*>(arg)->IsMarked(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 360 | !reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object); |
| 361 | } |
| 362 | |
| 363 | bool MarkSweep::IsLiveCallback(const Object* object, void* arg) { |
| 364 | return |
| 365 | reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 366 | !reinterpret_cast<MarkSweep*>(arg)->IsMarked(object); |
| 367 | } |
| 368 | |
| 369 | void MarkSweep::RecursiveMarkDirtyObjects(bool update_finger) { |
| 370 | ScanGrayObjects(update_finger); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 371 | ProcessMarkStack(); |
| 372 | } |
| 373 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 374 | void MarkSweep::ReMarkRoots() { |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 375 | Runtime::Current()->VisitRoots(ReMarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 376 | } |
| 377 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 378 | void MarkSweep::SweepJniWeakGlobals(bool swap_bitmaps) { |
| 379 | HeapBitmap* live_bitmap = GetHeap()->GetLiveBitmap(); |
| 380 | HeapBitmap* mark_bitmap = GetHeap()->GetMarkBitmap(); |
| 381 | |
| 382 | if (swap_bitmaps) { |
| 383 | std::swap(live_bitmap, mark_bitmap); |
| 384 | } |
| 385 | |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 386 | JavaVMExt* vm = Runtime::Current()->GetJavaVM(); |
| 387 | MutexLock mu(vm->weak_globals_lock); |
| 388 | IndirectReferenceTable* table = &vm->weak_globals; |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 389 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 390 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 391 | const Object** entry = *it; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 392 | if (live_bitmap->Test(*entry) && !mark_bitmap->Test(*entry)) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 393 | *entry = kClearedJniWeakGlobal; |
| 394 | } |
| 395 | } |
| 396 | } |
| 397 | |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 398 | void MarkSweep::SweepSystemWeaks(bool swap_bitmaps) { |
| 399 | Runtime* runtime = Runtime::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 400 | // The callbacks check |
| 401 | // !is_marked where is_marked is the callback but we want |
| 402 | // !IsMarked && IsLive |
| 403 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 404 | // Or for swapped (IsLive || !IsMarked). |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 405 | runtime->GetInternTable()->SweepInternTableWeaks(swap_bitmaps ? IsLiveCallback : IsMarkedCallback, |
| 406 | this); |
| 407 | runtime->GetMonitorList()->SweepMonitorList(swap_bitmaps ? IsLiveCallback : IsMarkedCallback, |
| 408 | this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 409 | SweepJniWeakGlobals(swap_bitmaps); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 410 | } |
| 411 | |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame^] | 412 | bool MarkSweep::VerifyIsLiveCallback(const Object* obj, void* arg) { |
| 413 | reinterpret_cast<MarkSweep*>(arg)->VerifyIsLive(obj); |
| 414 | // We don't actually want to sweep the object, so lets return "marked" |
| 415 | return true; |
| 416 | } |
| 417 | |
| 418 | void MarkSweep::VerifyIsLive(const Object* obj) { |
| 419 | Heap* heap = GetHeap(); |
| 420 | if (!heap->GetLiveBitmap()->Test(obj)) { |
| 421 | if (std::find(heap->allocation_stack_->Begin(), heap->allocation_stack_->End(), obj) == |
| 422 | heap->allocation_stack_->End()) { |
| 423 | // Object not found! |
| 424 | heap->DumpSpaces(); |
| 425 | LOG(FATAL) << "Found dead object " << obj; |
| 426 | } |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | void MarkSweep::VerifySystemWeaks() { |
| 431 | Runtime* runtime = Runtime::Current(); |
| 432 | // Verify system weaks, uses a special IsMarked callback which always returns true. |
| 433 | runtime->GetInternTable()->SweepInternTableWeaks(VerifyIsLiveCallback, this); |
| 434 | runtime->GetMonitorList()->SweepMonitorList(VerifyIsLiveCallback, this); |
| 435 | |
| 436 | JavaVMExt* vm = runtime->GetJavaVM(); |
| 437 | MutexLock mu(vm->weak_globals_lock); |
| 438 | IndirectReferenceTable* table = &vm->weak_globals; |
| 439 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
| 440 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 441 | const Object** entry = *it; |
| 442 | VerifyIsLive(*entry); |
| 443 | } |
| 444 | } |
| 445 | |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 446 | struct SweepCallbackContext { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 447 | MarkSweep* mark_sweep; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 448 | AllocSpace* space; |
| 449 | }; |
| 450 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 451 | void MarkSweep::SweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 452 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(); |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 453 | |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 454 | size_t freed_objects = num_ptrs; |
| 455 | size_t freed_bytes = 0; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 456 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 457 | MarkSweep* mark_sweep = context->mark_sweep; |
| 458 | Heap* heap = mark_sweep->GetHeap(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 459 | AllocSpace* space = context->space; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 460 | // Use a bulk free, that merges consecutive objects before freeing or free per object? |
| 461 | // Documentation suggests better free performance with merging, but this may be at the expensive |
| 462 | // of allocation. |
| 463 | // TODO: investigate performance |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 464 | static const bool kUseFreeList = true; |
| 465 | if (kUseFreeList) { |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 466 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 467 | Object* obj = static_cast<Object*>(ptrs[i]); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 468 | freed_bytes += space->AllocationSize(obj); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 469 | } |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 470 | // AllocSpace::FreeList clears the value in ptrs, so perform after clearing the live bit |
| 471 | space->FreeList(num_ptrs, ptrs); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 472 | } else { |
| 473 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 474 | Object* obj = static_cast<Object*>(ptrs[i]); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 475 | freed_bytes += space->AllocationSize(obj); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 476 | space->Free(obj); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 477 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 478 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 479 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 480 | heap->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 481 | mark_sweep->freed_objects_ += freed_objects; |
| 482 | mark_sweep->freed_bytes_ += freed_bytes; |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 483 | } |
| 484 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 485 | void MarkSweep::ZygoteSweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 486 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 487 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 488 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 489 | Heap* heap = context->mark_sweep->GetHeap(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 490 | // We don't free any actual memory to avoid dirtying the shared zygote pages. |
| 491 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 492 | Object* obj = static_cast<Object*>(ptrs[i]); |
| 493 | heap->GetLiveBitmap()->Clear(obj); |
| 494 | heap->GetCardTable()->MarkCard(obj); |
| 495 | } |
| 496 | } |
| 497 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 498 | void MarkSweep::SweepArray(TimingLogger& logger, MarkStack* allocations, bool swap_bitmaps) { |
| 499 | size_t freed_bytes = 0; |
| 500 | AllocSpace* space = heap_->GetAllocSpace(); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 501 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 502 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 503 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
| 504 | // TODO: Fix when sweeping weaks works properly with mutators unpaused + allocation list. |
| 505 | // SweepSystemWeaks(swap_bitmaps); |
| 506 | |
| 507 | // Newly allocated objects MUST be in the alloc space and those are the only objects which we are |
| 508 | // going to free. |
| 509 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 510 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 511 | if (swap_bitmaps) { |
| 512 | std::swap(live_bitmap, mark_bitmap); |
| 513 | } |
| 514 | |
| 515 | size_t count = allocations->Size(); |
| 516 | Object** objects = allocations->Begin(); |
| 517 | Object** out = objects; |
| 518 | |
| 519 | // Empty the allocation stack. |
| 520 | for (size_t i = 0;i < count;++i) { |
| 521 | Object* obj = objects[i]; |
| 522 | // There should only be objects in the AllocSpace in the allocation stack. |
| 523 | DCHECK(space->Contains(obj)); |
| 524 | DCHECK(mark_bitmap->HasAddress(obj)); |
| 525 | // Mark as live in the live bitmap if and only if we are marked in the mark bitmap. |
| 526 | if (mark_bitmap->Test(obj)) { |
| 527 | live_bitmap->Set(obj); |
| 528 | } else { |
| 529 | // Due to bitmap swapping, a young object can end up being marked as live. |
| 530 | live_bitmap->Clear(obj); |
| 531 | // Don't bother un-marking since we clear the mark bitmap anyways. |
| 532 | *(out++) = obj; |
| 533 | size_t size = space->AllocationSize(obj); |
| 534 | freed_bytes += size; |
| 535 | } |
| 536 | } |
| 537 | logger.AddSplit("Process allocation stack"); |
| 538 | |
| 539 | size_t freed_objects = out - objects; |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 540 | VLOG(heap) << "Freed " << freed_objects << "/" << count |
| 541 | << " objects with size " << PrettySize(freed_bytes); |
| 542 | space->FreeList(freed_objects, objects); |
| 543 | heap_->RecordFree(freed_objects, freed_bytes); |
| 544 | freed_objects_ += freed_objects; |
| 545 | freed_bytes_ += freed_bytes; |
| 546 | logger.AddSplit("FreeList"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 547 | |
| 548 | allocations->Reset(); |
| 549 | logger.AddSplit("Reset stack"); |
| 550 | } |
| 551 | |
| 552 | void MarkSweep::Sweep(bool partial, bool swap_bitmaps) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 553 | DCHECK(mark_stack_->IsEmpty()); |
| 554 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 555 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 556 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
| 557 | // SweepSystemWeaks(swap_bitmaps); |
| 558 | |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 559 | const Spaces& spaces = heap_->GetSpaces(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 560 | SweepCallbackContext scc; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 561 | scc.mark_sweep = this; |
| 562 | // TODO: C++0x auto |
| 563 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 564 | Space* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 565 | if ( |
| 566 | space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT || |
| 567 | (!partial && space->GetGcRetentionPolicy() == GCRP_FULL_COLLECT) |
| 568 | ) { |
| 569 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 570 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 571 | scc.space = space->AsAllocSpace(); |
| 572 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 573 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | fd678be | 2012-08-30 14:50:54 -0700 | [diff] [blame] | 574 | if (swap_bitmaps) { |
| 575 | std::swap(live_bitmap, mark_bitmap); |
| 576 | } |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 577 | if (space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT) { |
| 578 | // 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] | 579 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 580 | &SweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 581 | } else { |
| 582 | // 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] | 583 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 584 | &ZygoteSweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 585 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 586 | } |
| 587 | } |
| 588 | } |
| 589 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 590 | // Scans instance fields. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 591 | inline void MarkSweep::ScanInstanceFields(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 592 | DCHECK(obj != NULL); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 593 | Class* klass = obj->GetClass(); |
| 594 | DCHECK(klass != NULL); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 595 | ScanFields(obj, klass->GetReferenceInstanceOffsets(), false); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 596 | } |
| 597 | |
| 598 | // Scans static storage on a Class. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 599 | inline void MarkSweep::ScanStaticFields(const Class* klass) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 600 | DCHECK(klass != NULL); |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 601 | ScanFields(klass, klass->GetReferenceStaticOffsets(), true); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 602 | } |
| 603 | |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 604 | inline void MarkSweep::ScanFields(const Object* obj, uint32_t ref_offsets, bool is_static) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 605 | if (ref_offsets != CLASS_WALK_SUPER) { |
| 606 | // Found a reference offset bitmap. Mark the specified offsets. |
| 607 | while (ref_offsets != 0) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 608 | const size_t right_shift = CLZ(ref_offsets); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 609 | MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift); |
| 610 | const Object* ref = obj->GetFieldObject<const Object*>(byte_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 611 | MarkObject(ref); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 612 | ref_offsets ^= CLASS_HIGH_BIT >> right_shift; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 613 | } |
| 614 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 615 | // There is no reference offset bitmap. In the non-static case, |
| 616 | // walk up the class inheritance hierarchy and find reference |
| 617 | // offsets the hard way. In the static case, just consider this |
| 618 | // class. |
| 619 | for (const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 620 | klass != NULL; |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 621 | klass = is_static ? NULL : klass->GetSuperClass()) { |
| 622 | size_t num_reference_fields = (is_static |
| 623 | ? klass->NumReferenceStaticFields() |
| 624 | : klass->NumReferenceInstanceFields()); |
| 625 | for (size_t i = 0; i < num_reference_fields; ++i) { |
| 626 | Field* field = (is_static |
| 627 | ? klass->GetStaticField(i) |
| 628 | : klass->GetInstanceField(i)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 629 | MemberOffset field_offset = field->GetOffset(); |
| 630 | const Object* ref = obj->GetFieldObject<const Object*>(field_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 631 | MarkObject(ref); |
| 632 | } |
| 633 | } |
| 634 | } |
| 635 | } |
| 636 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 637 | 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] | 638 | const Spaces& spaces = heap_->GetSpaces(); |
| 639 | // TODO: C++0x auto |
| 640 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
| 641 | if ((*cur)->IsAllocSpace() && (*cur)->Contains(ref)) { |
| 642 | DCHECK(IsMarked(obj)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 643 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 644 | bool is_marked = IsMarked(ref); |
| 645 | if (!is_marked) { |
| 646 | LOG(INFO) << **cur; |
| 647 | LOG(WARNING) << (is_static ? "Static ref'" : "Instance ref'") << PrettyTypeOf(ref) |
| 648 | << "' (" << reinterpret_cast<const void*>(ref) << ") in '" << PrettyTypeOf(obj) |
| 649 | << "' (" << reinterpret_cast<const void*>(obj) << ") at offset " |
| 650 | << reinterpret_cast<void*>(offset.Int32Value()) << " wasn't marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 651 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 652 | const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
| 653 | DCHECK(klass != NULL); |
| 654 | const ObjectArray<Field>* fields = is_static ? klass->GetSFields() : klass->GetIFields(); |
| 655 | DCHECK(fields != NULL); |
| 656 | bool found = false; |
| 657 | for (int32_t i = 0; i < fields->GetLength(); ++i) { |
| 658 | const Field* cur = fields->Get(i); |
| 659 | if (cur->GetOffset().Int32Value() == offset.Int32Value()) { |
| 660 | LOG(WARNING) << "Field referencing the alloc space was " << PrettyField(cur); |
| 661 | found = true; |
| 662 | break; |
| 663 | } |
| 664 | } |
| 665 | if (!found) { |
| 666 | LOG(WARNING) << "Could not find field in object alloc space with offset " << offset.Int32Value(); |
| 667 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 668 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 669 | bool obj_marked = heap_->GetCardTable()->IsDirty(obj); |
| 670 | if (!obj_marked) { |
| 671 | LOG(WARNING) << "Object '" << PrettyTypeOf(obj) << "' " |
| 672 | << "(" << reinterpret_cast<const void*>(obj) << ") contains references to " |
| 673 | << "the alloc space, but wasn't card marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 674 | } |
| 675 | } |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 676 | } |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 677 | break; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 678 | } |
| 679 | } |
| 680 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 681 | // Scans the header, static field references, and interface pointers |
| 682 | // of a class object. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 683 | inline void MarkSweep::ScanClass(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 684 | #ifndef NDEBUG |
| 685 | ++class_count_; |
| 686 | #endif |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 687 | ScanInstanceFields(obj); |
Brian Carlstrom | 40381fb | 2011-10-19 14:13:40 -0700 | [diff] [blame] | 688 | ScanStaticFields(obj->AsClass()); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 689 | } |
| 690 | |
| 691 | // Scans the header of all array objects. If the array object is |
| 692 | // specialized to a reference type, scans the array data as well. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 693 | inline void MarkSweep::ScanArray(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 694 | #ifndef NDEBUG |
| 695 | ++array_count_; |
| 696 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 697 | MarkObject(obj->GetClass()); |
| 698 | if (obj->IsObjectArray()) { |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 699 | const ObjectArray<Object>* array = obj->AsObjectArray<Object>(); |
Elliott Hughes | d8ddfd5 | 2011-08-15 14:32:53 -0700 | [diff] [blame] | 700 | for (int32_t i = 0; i < array->GetLength(); ++i) { |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 701 | const Object* element = array->GetWithoutChecks(i); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 702 | MarkObject(element); |
| 703 | } |
| 704 | } |
| 705 | } |
| 706 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 707 | // Process the "referent" field in a java.lang.ref.Reference. If the |
| 708 | // referent has not yet been marked, put it on the appropriate list in |
| 709 | // the gcHeap for later processing. |
| 710 | void MarkSweep::DelayReferenceReferent(Object* obj) { |
| 711 | DCHECK(obj != NULL); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 712 | Class* klass = obj->GetClass(); |
| 713 | DCHECK(klass != NULL); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 714 | DCHECK(klass->IsReferenceClass()); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 715 | Object* pending = obj->GetFieldObject<Object*>(heap_->GetReferencePendingNextOffset(), false); |
| 716 | Object* referent = heap_->GetReferenceReferent(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 717 | if (pending == NULL && referent != NULL && !IsMarked(referent)) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 718 | Object** list = NULL; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 719 | if (klass->IsSoftReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 720 | list = &soft_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 721 | } else if (klass->IsWeakReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 722 | list = &weak_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 723 | } else if (klass->IsFinalizerReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 724 | list = &finalizer_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 725 | } else if (klass->IsPhantomReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 726 | list = &phantom_reference_list_; |
| 727 | } |
Brian Carlstrom | 0796af0 | 2011-10-12 14:31:45 -0700 | [diff] [blame] | 728 | DCHECK(list != NULL) << PrettyClass(klass) << " " << std::hex << klass->GetAccessFlags(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 729 | heap_->EnqueuePendingReference(obj, list); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 730 | } |
| 731 | } |
| 732 | |
| 733 | // Scans the header and field references of a data object. If the |
| 734 | // scanned object is a reference subclass, it is scheduled for later |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 735 | // processing. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 736 | inline void MarkSweep::ScanOther(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 737 | #ifndef NDEBUG |
| 738 | ++other_count_; |
| 739 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 740 | ScanInstanceFields(obj); |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 741 | if (obj->GetClass()->IsReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 742 | DelayReferenceReferent(const_cast<Object*>(obj)); |
| 743 | } |
| 744 | } |
| 745 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 746 | void MarkSweep::ScanRoot(const Object* obj) { |
| 747 | ScanObject(obj); |
| 748 | } |
| 749 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 750 | // Scans an object reference. Determines the type of the reference |
| 751 | // and dispatches to a specialized scanning routine. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 752 | void MarkSweep::ScanObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 753 | DCHECK(obj != NULL); |
| 754 | DCHECK(obj->GetClass() != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 755 | #ifndef NDEBUG |
| 756 | if (!IsMarked(obj)) { |
| 757 | heap_->DumpSpaces(); |
| 758 | LOG(FATAL) << "Scanning unmarked object " << reinterpret_cast<const void*>(obj); |
| 759 | } |
| 760 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 761 | if (obj->IsClass()) { |
| 762 | ScanClass(obj); |
Brian Carlstrom | b63ec39 | 2011-08-27 17:38:27 -0700 | [diff] [blame] | 763 | } else if (obj->IsArrayInstance()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 764 | ScanArray(obj); |
| 765 | } else { |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 766 | ScanOther(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 767 | } |
| 768 | } |
| 769 | |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 770 | // Scan anything that's on the mark stack. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 771 | void MarkSweep::ProcessMarkStack() { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 772 | #if MARK_STACK_PREFETCH |
| 773 | const size_t fifo_size = 4; |
| 774 | const size_t fifo_mask = fifo_size - 1; |
| 775 | const Object* fifo[fifo_size]; |
| 776 | for (size_t i = 0;i < fifo_size;++i) { |
| 777 | fifo[i] = NULL; |
| 778 | } |
| 779 | size_t fifo_pos = 0; |
| 780 | size_t fifo_count = 0; |
| 781 | for (;;) { |
| 782 | const Object* obj = fifo[fifo_pos & fifo_mask]; |
| 783 | if (obj != NULL) { |
| 784 | ScanObject(obj); |
| 785 | fifo[fifo_pos & fifo_mask] = NULL; |
| 786 | --fifo_count; |
| 787 | } |
| 788 | |
| 789 | if (!mark_stack_->IsEmpty()) { |
| 790 | const Object* obj = mark_stack_->Pop(); |
| 791 | DCHECK(obj != NULL); |
| 792 | fifo[fifo_pos & fifo_mask] = obj; |
| 793 | __builtin_prefetch(obj); |
| 794 | fifo_count++; |
| 795 | } |
| 796 | fifo_pos++; |
| 797 | |
| 798 | if (!fifo_count) { |
| 799 | CHECK(mark_stack_->IsEmpty()) << mark_stack_->Size(); |
| 800 | break; |
| 801 | } |
| 802 | } |
| 803 | #else |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 804 | while (!mark_stack_->IsEmpty()) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 805 | const Object* obj = mark_stack_->Pop(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 806 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 807 | ScanObject(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 808 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 809 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 810 | } |
| 811 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 812 | // Walks the reference list marking any references subject to the |
| 813 | // reference clearing policy. References with a black referent are |
| 814 | // removed from the list. References with white referents biased |
| 815 | // toward saving are blackened and also removed from the list. |
| 816 | void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| 817 | DCHECK(list != NULL); |
| 818 | Object* clear = NULL; |
| 819 | size_t counter = 0; |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 820 | |
| 821 | DCHECK(mark_stack_->IsEmpty()); |
| 822 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 823 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 824 | Object* ref = heap_->DequeuePendingReference(list); |
| 825 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 826 | if (referent == NULL) { |
| 827 | // Referent was cleared by the user during marking. |
| 828 | continue; |
| 829 | } |
| 830 | bool is_marked = IsMarked(referent); |
| 831 | if (!is_marked && ((++counter) & 1)) { |
| 832 | // Referent is white and biased toward saving, mark it. |
| 833 | MarkObject(referent); |
| 834 | is_marked = true; |
| 835 | } |
| 836 | if (!is_marked) { |
| 837 | // Referent is white, queue it for clearing. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 838 | heap_->EnqueuePendingReference(ref, &clear); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 839 | } |
| 840 | } |
| 841 | *list = clear; |
| 842 | // Restart the mark with the newly black references added to the |
| 843 | // root set. |
| 844 | ProcessMarkStack(); |
| 845 | } |
| 846 | |
| 847 | // Unlink the reference list clearing references objects with white |
| 848 | // referents. Cleared references registered to a reference queue are |
| 849 | // scheduled for appending by the heap worker thread. |
| 850 | void MarkSweep::ClearWhiteReferences(Object** list) { |
| 851 | DCHECK(list != NULL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 852 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 853 | Object* ref = heap_->DequeuePendingReference(list); |
| 854 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 855 | if (referent != NULL && !IsMarked(referent)) { |
| 856 | // Referent is white, clear it. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 857 | heap_->ClearReferenceReferent(ref); |
| 858 | if (heap_->IsEnqueuable(ref)) { |
| 859 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 860 | } |
| 861 | } |
| 862 | } |
| 863 | DCHECK(*list == NULL); |
| 864 | } |
| 865 | |
| 866 | // Enqueues finalizer references with white referents. White |
| 867 | // referents are blackened, moved to the zombie field, and the |
| 868 | // referent field is cleared. |
| 869 | void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| 870 | DCHECK(list != NULL); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 871 | MemberOffset zombie_offset = heap_->GetFinalizerReferenceZombieOffset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 872 | bool has_enqueued = false; |
| 873 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 874 | Object* ref = heap_->DequeuePendingReference(list); |
| 875 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 876 | if (referent != NULL && !IsMarked(referent)) { |
| 877 | MarkObject(referent); |
| 878 | // If the referent is non-null the reference must queuable. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 879 | DCHECK(heap_->IsEnqueuable(ref)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 880 | ref->SetFieldObject(zombie_offset, referent, false); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 881 | heap_->ClearReferenceReferent(ref); |
| 882 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 883 | has_enqueued = true; |
| 884 | } |
| 885 | } |
| 886 | if (has_enqueued) { |
| 887 | ProcessMarkStack(); |
| 888 | } |
| 889 | DCHECK(*list == NULL); |
| 890 | } |
| 891 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 892 | // Process reference class instances and schedule finalizations. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 893 | void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| 894 | Object** weak_references, |
| 895 | Object** finalizer_references, |
| 896 | Object** phantom_references) { |
| 897 | DCHECK(soft_references != NULL); |
| 898 | DCHECK(weak_references != NULL); |
| 899 | DCHECK(finalizer_references != NULL); |
| 900 | DCHECK(phantom_references != NULL); |
| 901 | |
| 902 | // Unless we are in the zygote or required to clear soft references |
| 903 | // with white references, preserve some white referents. |
Ian Rogers | 2945e24 | 2012-06-03 14:45:16 -0700 | [diff] [blame] | 904 | if (!clear_soft && !Runtime::Current()->IsZygote()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 905 | PreserveSomeSoftReferences(soft_references); |
| 906 | } |
| 907 | |
| 908 | // Clear all remaining soft and weak references with white |
| 909 | // referents. |
| 910 | ClearWhiteReferences(soft_references); |
| 911 | ClearWhiteReferences(weak_references); |
| 912 | |
| 913 | // Preserve all white objects with finalize methods and schedule |
| 914 | // them for finalization. |
| 915 | EnqueueFinalizerReferences(finalizer_references); |
| 916 | |
| 917 | // Clear all f-reachable soft and weak references with white |
| 918 | // referents. |
| 919 | ClearWhiteReferences(soft_references); |
| 920 | ClearWhiteReferences(weak_references); |
| 921 | |
| 922 | // Clear all phantom references with white referents. |
| 923 | ClearWhiteReferences(phantom_references); |
| 924 | |
| 925 | // At this point all reference lists should be empty. |
| 926 | DCHECK(*soft_references == NULL); |
| 927 | DCHECK(*weak_references == NULL); |
| 928 | DCHECK(*finalizer_references == NULL); |
| 929 | DCHECK(*phantom_references == NULL); |
| 930 | } |
| 931 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 932 | MarkSweep::~MarkSweep() { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 933 | #ifndef NDEBUG |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 934 | VLOG(heap) << "MarkSweep scanned classes=" << class_count_ << " arrays=" << array_count_ << " other=" << other_count_; |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 935 | #endif |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 936 | // Ensure that the mark stack is empty. |
| 937 | CHECK(mark_stack_->IsEmpty()); |
| 938 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 939 | // Clear all of the alloc spaces' mark bitmaps. |
| 940 | const Spaces& spaces = heap_->GetSpaces(); |
| 941 | // TODO: C++0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 942 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 943 | if ((*it)->GetGcRetentionPolicy() != GCRP_NEVER_COLLECT) { |
| 944 | (*it)->GetMarkBitmap()->Clear(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 945 | } |
| 946 | } |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 947 | mark_stack_->Reset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 948 | } |
| 949 | |
| 950 | } // namespace art |