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" |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 28 | #include "jni_internal.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 29 | #include "logging.h" |
| 30 | #include "macros.h" |
| 31 | #include "mark_stack.h" |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 32 | #include "monitor.h" |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 33 | #include "mutex.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 34 | #include "object.h" |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 35 | #include "runtime.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 36 | #include "space.h" |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 37 | #include "timing_logger.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 38 | #include "thread.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 39 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 40 | #define MARK_STACK_PREFETCH 1 |
| 41 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 42 | namespace art { |
| 43 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 44 | class SetFingerVisitor { |
| 45 | public: |
| 46 | SetFingerVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 47 | |
| 48 | } |
| 49 | |
| 50 | void operator ()(void* finger) const { |
| 51 | mark_sweep_->SetFinger(reinterpret_cast<Object*>(finger)); |
| 52 | } |
| 53 | |
| 54 | private: |
| 55 | MarkSweep* const mark_sweep_; |
| 56 | }; |
| 57 | |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 58 | MarkSweep::MarkSweep(MarkStack* mark_stack) |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 59 | : current_mark_bitmap_(NULL), |
| 60 | mark_stack_(mark_stack), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 61 | heap_(NULL), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 62 | finger_(NULL), |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 63 | immune_begin_(NULL), |
| 64 | immune_end_(NULL), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 65 | soft_reference_list_(NULL), |
| 66 | weak_reference_list_(NULL), |
| 67 | finalizer_reference_list_(NULL), |
| 68 | phantom_reference_list_(NULL), |
| 69 | cleared_reference_list_(NULL), |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 70 | freed_bytes_(0), freed_objects_(0), |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 71 | class_count_(0), array_count_(0), other_count_(0) { |
| 72 | DCHECK(mark_stack_ != NULL); |
| 73 | } |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 74 | |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 75 | void MarkSweep::Init() { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 76 | heap_ = Runtime::Current()->GetHeap(); |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 77 | mark_stack_->Reset(); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 78 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 79 | const Spaces& spaces = heap_->GetSpaces(); |
| 80 | // TODO: C++0x auto |
| 81 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 82 | if (current_mark_bitmap_ == NULL || (*cur)->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT) { |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 83 | current_mark_bitmap_ = (*cur)->GetMarkBitmap(); |
| 84 | break; |
| 85 | } |
| 86 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 87 | if (current_mark_bitmap_ == NULL) { |
| 88 | GetHeap()->DumpSpaces(); |
| 89 | DCHECK(false) << "current_mark_bitmap_ == NULL"; |
| 90 | } |
buzbee | 0d966cf | 2011-09-08 17:34:58 -0700 | [diff] [blame] | 91 | // TODO: if concurrent, enable card marking in compiler |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 92 | // TODO: check that the mark bitmap is entirely clear. |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 93 | } |
| 94 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 95 | inline void MarkSweep::MarkObject0(const Object* obj, bool check_finger) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 96 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 97 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 98 | if (obj >= immune_begin_ && obj < immune_end_) { |
| 99 | DCHECK(IsMarked(obj)); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 100 | return; |
| 101 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 102 | |
| 103 | // Try to take advantage of locality of references within a space, failing this find the space |
| 104 | // the hard way. |
Ian Rogers | 506de0c | 2012-09-17 15:39:06 -0700 | [diff] [blame] | 105 | if (UNLIKELY(!current_mark_bitmap_->HasAddress(obj))) { |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 106 | SpaceBitmap* new_bitmap = heap_->GetMarkBitmap()->GetSpaceBitmap(obj); |
| 107 | if (new_bitmap != NULL) { |
| 108 | current_mark_bitmap_ = new_bitmap; |
| 109 | } else { |
| 110 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 111 | SpaceSetMap* large_objects = large_object_space->GetMarkObjects(); |
| 112 | if (!large_objects->Test(obj)) { |
Mathieu Chartier | 83cf328 | 2012-09-26 17:54:27 -0700 | [diff] [blame] | 113 | CHECK(large_object_space->Contains(obj)) << "Attempting to mark object " << obj << " not in large object space"; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 114 | large_objects->Set(obj); |
| 115 | // Don't need to check finger since large objects never have any object references. |
| 116 | } |
| 117 | // TODO: Improve clarity of control flow in this function? |
| 118 | return; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 119 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 120 | } |
| 121 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 122 | // This object was not previously marked. |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 123 | if (!current_mark_bitmap_->Test(obj)) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 124 | current_mark_bitmap_->Set(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 125 | if (check_finger && obj < finger_) { |
| 126 | // The object must be pushed on to the mark stack. |
| 127 | mark_stack_->Push(obj); |
| 128 | } |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | // Used to mark objects when recursing. Recursion is done by moving |
| 133 | // the finger across the bitmaps in address order and marking child |
| 134 | // objects. Any newly-marked objects whose addresses are lower than |
| 135 | // the finger won't be visited by the bitmap scan, so those objects |
| 136 | // need to be added to the mark stack. |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 137 | void MarkSweep::MarkObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 138 | if (obj != NULL) { |
| 139 | MarkObject0(obj, true); |
| 140 | } |
| 141 | } |
| 142 | |
Elliott Hughes | cf4c6c4 | 2011-09-01 15:16:42 -0700 | [diff] [blame] | 143 | void MarkSweep::MarkObjectVisitor(const Object* root, void* arg) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 144 | DCHECK(root != NULL); |
| 145 | DCHECK(arg != NULL); |
| 146 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 147 | mark_sweep->MarkObject0(root, false); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 148 | } |
| 149 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 150 | void MarkSweep::ReMarkObjectVisitor(const Object* root, void* arg) { |
| 151 | DCHECK(root != NULL); |
| 152 | DCHECK(arg != NULL); |
| 153 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| 154 | mark_sweep->MarkObject0(root, true); |
| 155 | } |
| 156 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 157 | // Marks all objects in the root set. |
| 158 | void MarkSweep::MarkRoots() { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 159 | Runtime::Current()->VisitRoots(MarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 160 | } |
| 161 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 162 | class CheckObjectVisitor { |
| 163 | public: |
| 164 | CheckObjectVisitor(MarkSweep* const mark_sweep) |
| 165 | : mark_sweep_(mark_sweep) { |
| 166 | |
| 167 | } |
| 168 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 169 | 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] | 170 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 171 | Locks::mutator_lock_) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 172 | mark_sweep_->CheckReference(obj, ref, offset, is_static); |
| 173 | } |
| 174 | |
| 175 | private: |
| 176 | MarkSweep* const mark_sweep_; |
| 177 | }; |
| 178 | |
| 179 | void MarkSweep::CheckObject(const Object* obj) { |
| 180 | DCHECK(obj != NULL); |
| 181 | CheckObjectVisitor visitor(this); |
| 182 | VisitObjectReferences(obj, visitor); |
| 183 | } |
| 184 | |
| 185 | void MarkSweep::VerifyImageRootVisitor(Object* root, void* arg) { |
| 186 | DCHECK(root != NULL); |
| 187 | DCHECK(arg != NULL); |
| 188 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 189 | DCHECK(mark_sweep->heap_->GetMarkBitmap()->Test(root)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 190 | mark_sweep->CheckObject(root); |
| 191 | } |
| 192 | |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 193 | void MarkSweep::CopyMarkBits(ContinuousSpace* space) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 194 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 195 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 196 | mark_bitmap->CopyFrom(live_bitmap); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 197 | } |
| 198 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 199 | class ScanImageRootVisitor { |
| 200 | public: |
| 201 | ScanImageRootVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 202 | } |
| 203 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 204 | void operator ()(const Object* root) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 205 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 206 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 207 | DCHECK(root != NULL); |
| 208 | mark_sweep_->ScanObject(root); |
| 209 | } |
| 210 | |
| 211 | private: |
| 212 | MarkSweep* const mark_sweep_; |
| 213 | }; |
| 214 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 215 | void MarkSweep::ScanGrayObjects(bool update_finger) { |
| 216 | const Spaces& spaces = heap_->GetSpaces(); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 217 | CardTable* card_table = heap_->GetCardTable(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 218 | ScanImageRootVisitor image_root_visitor(this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 219 | SetFingerVisitor finger_visitor(this); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 220 | // TODO: C++ 0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 221 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 222 | ContinuousSpace* space = *it; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 223 | byte* begin = space->Begin(); |
| 224 | byte* end = space->End(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 225 | // Image spaces are handled properly since live == marked for them. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 226 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
| 227 | if (update_finger) { |
| 228 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, finger_visitor); |
| 229 | } else { |
| 230 | card_table->Scan(mark_bitmap, begin, end, image_root_visitor, IdentityFunctor()); |
| 231 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 232 | } |
| 233 | } |
| 234 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 235 | class CheckBitmapVisitor { |
| 236 | public: |
| 237 | CheckBitmapVisitor(MarkSweep* mark_sweep) : mark_sweep_(mark_sweep) { |
| 238 | |
| 239 | } |
| 240 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 241 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 242 | SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, |
| 243 | Locks::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 244 | DCHECK(obj != NULL); |
| 245 | mark_sweep_->CheckObject(obj); |
| 246 | } |
| 247 | |
| 248 | private: |
| 249 | MarkSweep* mark_sweep_; |
| 250 | }; |
| 251 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 252 | void MarkSweep::VerifyImageRoots() { |
| 253 | // Verify roots ensures that all the references inside the image space point |
| 254 | // objects which are either in the image space or marked objects in the alloc |
| 255 | // space |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 256 | CheckBitmapVisitor visitor(this); |
| 257 | const Spaces& spaces = heap_->GetSpaces(); |
| 258 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 259 | if ((*it)->IsImageSpace()) { |
| 260 | ImageSpace* space = (*it)->AsImageSpace(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 261 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 262 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 263 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 264 | DCHECK(live_bitmap != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 265 | live_bitmap->VisitMarkedRange(begin, end, visitor, IdentityFunctor()); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 266 | } |
| 267 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 268 | } |
| 269 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 270 | class ScanObjectVisitor { |
| 271 | public: |
| 272 | ScanObjectVisitor(MarkSweep* const mark_sweep) : mark_sweep_(mark_sweep) { |
| 273 | |
| 274 | } |
| 275 | |
| 276 | void operator ()(const Object* obj) const |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 277 | EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| 278 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 279 | mark_sweep_->ScanObject(obj); |
| 280 | } |
| 281 | |
| 282 | private: |
| 283 | MarkSweep* const mark_sweep_; |
| 284 | }; |
| 285 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 286 | // Populates the mark stack based on the set of marked objects and |
| 287 | // recursively marks until the mark stack is emptied. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 288 | void MarkSweep::RecursiveMark(bool partial, TimingLogger& timings) { |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 289 | // RecursiveMark will build the lists of known instances of the Reference classes. |
| 290 | // See DelayReferenceReferent for details. |
| 291 | CHECK(soft_reference_list_ == NULL); |
| 292 | CHECK(weak_reference_list_ == NULL); |
| 293 | CHECK(finalizer_reference_list_ == NULL); |
| 294 | CHECK(phantom_reference_list_ == NULL); |
| 295 | CHECK(cleared_reference_list_ == NULL); |
| 296 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 297 | const Spaces& spaces = heap_->GetSpaces(); |
| 298 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 299 | SetFingerVisitor set_finger_visitor(this); |
| 300 | ScanObjectVisitor scan_visitor(this); |
| 301 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 302 | ContinuousSpace* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 303 | if (space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT || |
| 304 | (!partial && space->GetGcRetentionPolicy() == GCRP_FULL_COLLECT) |
| 305 | ) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 306 | current_mark_bitmap_ = space->GetMarkBitmap(); |
| 307 | if (current_mark_bitmap_ == NULL) { |
| 308 | GetHeap()->DumpSpaces(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 309 | LOG(FATAL) << "invalid bitmap"; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 310 | } |
| 311 | // 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] | 312 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 313 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 314 | current_mark_bitmap_->VisitMarkedRange(begin, end, scan_visitor, set_finger_visitor); |
Mathieu Chartier | 7664f5c | 2012-06-08 18:15:32 -0700 | [diff] [blame] | 315 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 316 | } |
| 317 | finger_ = reinterpret_cast<Object*>(~0); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 318 | timings.AddSplit("RecursiveMark"); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 319 | // TODO: tune the frequency of emptying the mark stack |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 320 | ProcessMarkStack(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 321 | timings.AddSplit("ProcessMarkStack"); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 322 | } |
| 323 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 324 | void MarkSweep::RecursiveMarkCards(CardTable* card_table, const std::vector<byte*>& cards, |
| 325 | TimingLogger& timings) { |
| 326 | ScanImageRootVisitor image_root_visitor(this); |
| 327 | SetFingerVisitor finger_visitor(this); |
| 328 | for (size_t i = 0;i < cards.size();) { |
| 329 | Object* start_obj = reinterpret_cast<Object*>(card_table->AddrFromCard(cards[i])); |
| 330 | uintptr_t begin = reinterpret_cast<uintptr_t>(start_obj); |
| 331 | uintptr_t end = begin + GC_CARD_SIZE; |
| 332 | for (++i; reinterpret_cast<uintptr_t>(cards[i]) == end && i < cards.size(); ++i) { |
| 333 | end += GC_CARD_SIZE; |
| 334 | } |
| 335 | if (current_mark_bitmap_ == NULL || !current_mark_bitmap_->HasAddress(start_obj)) { |
| 336 | current_mark_bitmap_ = heap_->GetMarkBitmap()->GetSpaceBitmap(start_obj); |
| 337 | #ifndef NDEBUG |
| 338 | if (current_mark_bitmap_ == NULL) { |
| 339 | GetHeap()->DumpSpaces(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 340 | LOG(FATAL) << "Object " << reinterpret_cast<const void*>(start_obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 341 | } |
| 342 | #endif |
| 343 | } |
| 344 | current_mark_bitmap_->VisitMarkedRange(begin, end, image_root_visitor, finger_visitor); |
| 345 | } |
| 346 | timings.AddSplit("RecursiveMarkCards"); |
| 347 | ProcessMarkStack(); |
| 348 | timings.AddSplit("ProcessMarkStack"); |
| 349 | } |
| 350 | |
| 351 | bool MarkSweep::IsMarkedCallback(const Object* object, void* arg) { |
| 352 | return |
| 353 | reinterpret_cast<MarkSweep*>(arg)->IsMarked(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 354 | !reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object); |
| 355 | } |
| 356 | |
| 357 | bool MarkSweep::IsLiveCallback(const Object* object, void* arg) { |
| 358 | return |
| 359 | reinterpret_cast<MarkSweep*>(arg)->GetHeap()->GetLiveBitmap()->Test(object) || |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 360 | !reinterpret_cast<MarkSweep*>(arg)->IsMarked(object); |
| 361 | } |
| 362 | |
| 363 | void MarkSweep::RecursiveMarkDirtyObjects(bool update_finger) { |
| 364 | ScanGrayObjects(update_finger); |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 365 | ProcessMarkStack(); |
| 366 | } |
| 367 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 368 | void MarkSweep::ReMarkRoots() { |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 369 | Runtime::Current()->VisitRoots(ReMarkObjectVisitor, this); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 370 | } |
| 371 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 372 | void MarkSweep::SweepJniWeakGlobals(bool swap_bitmaps) { |
| 373 | HeapBitmap* live_bitmap = GetHeap()->GetLiveBitmap(); |
| 374 | HeapBitmap* mark_bitmap = GetHeap()->GetMarkBitmap(); |
| 375 | |
| 376 | if (swap_bitmaps) { |
| 377 | std::swap(live_bitmap, mark_bitmap); |
| 378 | } |
| 379 | |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 380 | JavaVMExt* vm = Runtime::Current()->GetJavaVM(); |
| 381 | MutexLock mu(vm->weak_globals_lock); |
| 382 | IndirectReferenceTable* table = &vm->weak_globals; |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 383 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 384 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 385 | const Object** entry = *it; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 386 | if (live_bitmap->Test(*entry) && !mark_bitmap->Test(*entry)) { |
Elliott Hughes | 410c0c8 | 2011-09-01 17:58:25 -0700 | [diff] [blame] | 387 | *entry = kClearedJniWeakGlobal; |
| 388 | } |
| 389 | } |
| 390 | } |
| 391 | |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 392 | void MarkSweep::SweepSystemWeaks(bool swap_bitmaps) { |
| 393 | Runtime* runtime = Runtime::Current(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 394 | // The callbacks check |
| 395 | // !is_marked where is_marked is the callback but we want |
| 396 | // !IsMarked && IsLive |
| 397 | // So compute !(!IsMarked && IsLive) which is equal to (IsMarked || !IsLive). |
| 398 | // Or for swapped (IsLive || !IsMarked). |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 399 | runtime->GetInternTable()->SweepInternTableWeaks(swap_bitmaps ? IsLiveCallback : IsMarkedCallback, |
| 400 | this); |
| 401 | runtime->GetMonitorList()->SweepMonitorList(swap_bitmaps ? IsLiveCallback : IsMarkedCallback, |
| 402 | this); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 403 | SweepJniWeakGlobals(swap_bitmaps); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 404 | } |
| 405 | |
Mathieu Chartier | c7b83a0 | 2012-09-11 18:07:39 -0700 | [diff] [blame] | 406 | bool MarkSweep::VerifyIsLiveCallback(const Object* obj, void* arg) { |
| 407 | reinterpret_cast<MarkSweep*>(arg)->VerifyIsLive(obj); |
| 408 | // We don't actually want to sweep the object, so lets return "marked" |
| 409 | return true; |
| 410 | } |
| 411 | |
| 412 | void MarkSweep::VerifyIsLive(const Object* obj) { |
| 413 | Heap* heap = GetHeap(); |
| 414 | if (!heap->GetLiveBitmap()->Test(obj)) { |
| 415 | if (std::find(heap->allocation_stack_->Begin(), heap->allocation_stack_->End(), obj) == |
| 416 | heap->allocation_stack_->End()) { |
| 417 | // Object not found! |
| 418 | heap->DumpSpaces(); |
| 419 | LOG(FATAL) << "Found dead object " << obj; |
| 420 | } |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | void MarkSweep::VerifySystemWeaks() { |
| 425 | Runtime* runtime = Runtime::Current(); |
| 426 | // Verify system weaks, uses a special IsMarked callback which always returns true. |
| 427 | runtime->GetInternTable()->SweepInternTableWeaks(VerifyIsLiveCallback, this); |
| 428 | runtime->GetMonitorList()->SweepMonitorList(VerifyIsLiveCallback, this); |
| 429 | |
| 430 | JavaVMExt* vm = runtime->GetJavaVM(); |
| 431 | MutexLock mu(vm->weak_globals_lock); |
| 432 | IndirectReferenceTable* table = &vm->weak_globals; |
| 433 | typedef IndirectReferenceTable::iterator It; // TODO: C++0x auto |
| 434 | for (It it = table->begin(), end = table->end(); it != end; ++it) { |
| 435 | const Object** entry = *it; |
| 436 | VerifyIsLive(*entry); |
| 437 | } |
| 438 | } |
| 439 | |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 440 | struct SweepCallbackContext { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 441 | MarkSweep* mark_sweep; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 442 | AllocSpace* space; |
| 443 | }; |
| 444 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 445 | void MarkSweep::SweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 446 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
Mathieu Chartier | 654d3a2 | 2012-07-11 17:54:18 -0700 | [diff] [blame] | 447 | |
Elliott Hughes | 307f75d | 2011-10-12 18:04:40 -0700 | [diff] [blame] | 448 | size_t freed_objects = num_ptrs; |
| 449 | size_t freed_bytes = 0; |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 450 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 451 | MarkSweep* mark_sweep = context->mark_sweep; |
| 452 | Heap* heap = mark_sweep->GetHeap(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 453 | AllocSpace* space = context->space; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 454 | // Use a bulk free, that merges consecutive objects before freeing or free per object? |
| 455 | // Documentation suggests better free performance with merging, but this may be at the expensive |
| 456 | // of allocation. |
| 457 | // TODO: investigate performance |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 458 | static const bool kUseFreeList = true; |
| 459 | if (kUseFreeList) { |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 460 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 461 | Object* obj = static_cast<Object*>(ptrs[i]); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 462 | freed_bytes += space->AllocationSize(obj); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 463 | } |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 464 | // AllocSpace::FreeList clears the value in ptrs, so perform after clearing the live bit |
| 465 | space->FreeList(num_ptrs, ptrs); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 466 | } else { |
| 467 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 468 | Object* obj = static_cast<Object*>(ptrs[i]); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 469 | freed_bytes += space->AllocationSize(obj); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 470 | space->Free(obj); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 471 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 472 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 473 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 474 | heap->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 475 | mark_sweep->freed_objects_ += freed_objects; |
| 476 | mark_sweep->freed_bytes_ += freed_bytes; |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 477 | } |
| 478 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 479 | void MarkSweep::ZygoteSweepCallback(size_t num_ptrs, Object** ptrs, void* arg) { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 480 | Locks::heap_bitmap_lock_->AssertExclusiveHeld(Thread::Current()); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 481 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 482 | SweepCallbackContext* context = static_cast<SweepCallbackContext*>(arg); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 483 | Heap* heap = context->mark_sweep->GetHeap(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 484 | // We don't free any actual memory to avoid dirtying the shared zygote pages. |
| 485 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 486 | Object* obj = static_cast<Object*>(ptrs[i]); |
| 487 | heap->GetLiveBitmap()->Clear(obj); |
| 488 | heap->GetCardTable()->MarkCard(obj); |
| 489 | } |
| 490 | } |
| 491 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 492 | void MarkSweep::SweepArray(TimingLogger& logger, MarkStack* allocations, bool swap_bitmaps) { |
| 493 | size_t freed_bytes = 0; |
| 494 | AllocSpace* space = heap_->GetAllocSpace(); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 495 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 496 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 497 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
| 498 | // TODO: Fix when sweeping weaks works properly with mutators unpaused + allocation list. |
| 499 | // SweepSystemWeaks(swap_bitmaps); |
| 500 | |
| 501 | // Newly allocated objects MUST be in the alloc space and those are the only objects which we are |
| 502 | // going to free. |
| 503 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 504 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 505 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
| 506 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 507 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 508 | if (swap_bitmaps) { |
| 509 | std::swap(live_bitmap, mark_bitmap); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 510 | std::swap(large_live_objects, large_mark_objects); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 511 | } |
| 512 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 513 | size_t freed_large_objects = 0; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 514 | size_t count = allocations->Size(); |
| 515 | Object** objects = allocations->Begin(); |
| 516 | Object** out = objects; |
| 517 | |
| 518 | // Empty the allocation stack. |
| 519 | for (size_t i = 0;i < count;++i) { |
| 520 | Object* obj = objects[i]; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 521 | // There should only be objects in the AllocSpace/LargeObjectSpace in the allocation stack. |
| 522 | if (LIKELY(mark_bitmap->HasAddress(obj))) { |
| 523 | if (!mark_bitmap->Test(obj)) { |
| 524 | // Don't bother un-marking since we clear the mark bitmap anyways. |
| 525 | *(out++) = obj; |
| 526 | size_t size = space->AllocationSize(obj); |
| 527 | freed_bytes += size; |
| 528 | } |
| 529 | } else if (!large_mark_objects->Test(obj)) { |
| 530 | ++freed_large_objects; |
| 531 | size_t size = large_object_space->AllocationSize(obj); |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 532 | freed_bytes += size; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 533 | large_object_space->Free(obj); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 534 | } |
| 535 | } |
| 536 | logger.AddSplit("Process allocation stack"); |
| 537 | |
| 538 | size_t freed_objects = out - objects; |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 539 | VLOG(heap) << "Freed " << freed_objects << "/" << count |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 540 | << " objects with size " << PrettySize(freed_bytes); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 541 | space->FreeList(freed_objects, objects); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 542 | heap_->RecordFree(freed_objects + freed_large_objects, freed_bytes); |
Mathieu Chartier | 40e978b | 2012-09-07 11:38:36 -0700 | [diff] [blame] | 543 | freed_objects_ += freed_objects; |
| 544 | freed_bytes_ += freed_bytes; |
| 545 | logger.AddSplit("FreeList"); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 546 | allocations->Reset(); |
| 547 | logger.AddSplit("Reset stack"); |
| 548 | } |
| 549 | |
| 550 | void MarkSweep::Sweep(bool partial, bool swap_bitmaps) { |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 551 | DCHECK(mark_stack_->IsEmpty()); |
| 552 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 553 | // If we don't swap bitmaps then newly allocated Weaks go into the live bitmap but not mark |
| 554 | // bitmap, resulting in occasional frees of Weaks which are still in use. |
| 555 | // SweepSystemWeaks(swap_bitmaps); |
| 556 | |
Mathieu Chartier | 46a2363 | 2012-08-07 18:44:40 -0700 | [diff] [blame] | 557 | const Spaces& spaces = heap_->GetSpaces(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 558 | SweepCallbackContext scc; |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 559 | scc.mark_sweep = this; |
| 560 | // TODO: C++0x auto |
| 561 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 562 | ContinuousSpace* space = *it; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 563 | if ( |
| 564 | space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT || |
| 565 | (!partial && space->GetGcRetentionPolicy() == GCRP_FULL_COLLECT) |
| 566 | ) { |
| 567 | uintptr_t begin = reinterpret_cast<uintptr_t>(space->Begin()); |
| 568 | uintptr_t end = reinterpret_cast<uintptr_t>(space->End()); |
| 569 | scc.space = space->AsAllocSpace(); |
| 570 | SpaceBitmap* live_bitmap = space->GetLiveBitmap(); |
| 571 | SpaceBitmap* mark_bitmap = space->GetMarkBitmap(); |
Mathieu Chartier | fd678be | 2012-08-30 14:50:54 -0700 | [diff] [blame] | 572 | if (swap_bitmaps) { |
| 573 | std::swap(live_bitmap, mark_bitmap); |
| 574 | } |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 575 | if (space->GetGcRetentionPolicy() == GCRP_ALWAYS_COLLECT) { |
| 576 | // 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] | 577 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 578 | &SweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 579 | } else { |
| 580 | // 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] | 581 | SpaceBitmap::SweepWalk(*live_bitmap, *mark_bitmap, begin, end, |
| 582 | &ZygoteSweepCallback, reinterpret_cast<void*>(&scc)); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 583 | } |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 584 | } |
| 585 | } |
| 586 | } |
| 587 | |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 588 | void MarkSweep::SweepLargeObjects(bool swap_bitmaps) { |
| 589 | // Sweep large objects |
| 590 | LargeObjectSpace* large_object_space = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 591 | SpaceSetMap* large_live_objects = large_object_space->GetLiveObjects(); |
| 592 | SpaceSetMap* large_mark_objects = large_object_space->GetMarkObjects(); |
| 593 | if (swap_bitmaps) { |
| 594 | std::swap(large_live_objects, large_mark_objects); |
| 595 | } |
| 596 | SpaceSetMap::Objects& live_objects = large_live_objects->GetObjects(); |
| 597 | // O(n*log(n)) but hopefully there are not too many large objects. |
| 598 | size_t freed_objects = 0; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 599 | size_t freed_bytes = 0; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 600 | // TODO: C++0x |
| 601 | for (SpaceSetMap::Objects::iterator it = live_objects.begin(); it != live_objects.end(); ++it) { |
| 602 | if (!large_mark_objects->Test(*it)) { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 603 | freed_bytes += large_object_space->AllocationSize(*it); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 604 | large_object_space->Free(const_cast<Object*>(*it)); |
| 605 | ++freed_objects; |
| 606 | } |
| 607 | } |
| 608 | freed_objects_ += freed_objects; |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 609 | freed_bytes_ += freed_bytes; |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 610 | // Large objects don't count towards bytes_allocated. |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame^] | 611 | GetHeap()->RecordFree(freed_objects, freed_bytes); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 612 | } |
| 613 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 614 | // Scans instance fields. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 615 | inline void MarkSweep::ScanInstanceFields(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 616 | DCHECK(obj != NULL); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 617 | Class* klass = obj->GetClass(); |
| 618 | DCHECK(klass != NULL); |
Elliott Hughes | 2da5036 | 2011-10-10 16:57:08 -0700 | [diff] [blame] | 619 | ScanFields(obj, klass->GetReferenceInstanceOffsets(), false); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 620 | } |
| 621 | |
| 622 | // Scans static storage on a Class. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 623 | inline void MarkSweep::ScanStaticFields(const Class* klass) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 624 | DCHECK(klass != NULL); |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 625 | ScanFields(klass, klass->GetReferenceStaticOffsets(), true); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 626 | } |
| 627 | |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 628 | 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] | 629 | if (ref_offsets != CLASS_WALK_SUPER) { |
| 630 | // Found a reference offset bitmap. Mark the specified offsets. |
| 631 | while (ref_offsets != 0) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 632 | const size_t right_shift = CLZ(ref_offsets); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 633 | MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift); |
| 634 | const Object* ref = obj->GetFieldObject<const Object*>(byte_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 635 | MarkObject(ref); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 636 | ref_offsets ^= CLASS_HIGH_BIT >> right_shift; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 637 | } |
| 638 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 639 | // There is no reference offset bitmap. In the non-static case, |
| 640 | // walk up the class inheritance hierarchy and find reference |
| 641 | // offsets the hard way. In the static case, just consider this |
| 642 | // class. |
| 643 | for (const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 644 | klass != NULL; |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 645 | klass = is_static ? NULL : klass->GetSuperClass()) { |
| 646 | size_t num_reference_fields = (is_static |
| 647 | ? klass->NumReferenceStaticFields() |
| 648 | : klass->NumReferenceInstanceFields()); |
| 649 | for (size_t i = 0; i < num_reference_fields; ++i) { |
| 650 | Field* field = (is_static |
| 651 | ? klass->GetStaticField(i) |
| 652 | : klass->GetInstanceField(i)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 653 | MemberOffset field_offset = field->GetOffset(); |
| 654 | const Object* ref = obj->GetFieldObject<const Object*>(field_offset, false); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 655 | MarkObject(ref); |
| 656 | } |
| 657 | } |
| 658 | } |
| 659 | } |
| 660 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 661 | 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] | 662 | const Spaces& spaces = heap_->GetSpaces(); |
| 663 | // TODO: C++0x auto |
| 664 | for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) { |
| 665 | if ((*cur)->IsAllocSpace() && (*cur)->Contains(ref)) { |
| 666 | DCHECK(IsMarked(obj)); |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 667 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 668 | bool is_marked = IsMarked(ref); |
| 669 | if (!is_marked) { |
| 670 | LOG(INFO) << **cur; |
| 671 | LOG(WARNING) << (is_static ? "Static ref'" : "Instance ref'") << PrettyTypeOf(ref) |
| 672 | << "' (" << reinterpret_cast<const void*>(ref) << ") in '" << PrettyTypeOf(obj) |
| 673 | << "' (" << reinterpret_cast<const void*>(obj) << ") at offset " |
| 674 | << reinterpret_cast<void*>(offset.Int32Value()) << " wasn't marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 675 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 676 | const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
| 677 | DCHECK(klass != NULL); |
| 678 | const ObjectArray<Field>* fields = is_static ? klass->GetSFields() : klass->GetIFields(); |
| 679 | DCHECK(fields != NULL); |
| 680 | bool found = false; |
| 681 | for (int32_t i = 0; i < fields->GetLength(); ++i) { |
| 682 | const Field* cur = fields->Get(i); |
| 683 | if (cur->GetOffset().Int32Value() == offset.Int32Value()) { |
| 684 | LOG(WARNING) << "Field referencing the alloc space was " << PrettyField(cur); |
| 685 | found = true; |
| 686 | break; |
| 687 | } |
| 688 | } |
| 689 | if (!found) { |
| 690 | LOG(WARNING) << "Could not find field in object alloc space with offset " << offset.Int32Value(); |
| 691 | } |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 692 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 693 | bool obj_marked = heap_->GetCardTable()->IsDirty(obj); |
| 694 | if (!obj_marked) { |
| 695 | LOG(WARNING) << "Object '" << PrettyTypeOf(obj) << "' " |
| 696 | << "(" << reinterpret_cast<const void*>(obj) << ") contains references to " |
| 697 | << "the alloc space, but wasn't card marked"; |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 698 | } |
| 699 | } |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 700 | } |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 701 | break; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 702 | } |
| 703 | } |
| 704 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 705 | // Scans the header, static field references, and interface pointers |
| 706 | // of a class object. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 707 | inline void MarkSweep::ScanClass(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 708 | #ifndef NDEBUG |
| 709 | ++class_count_; |
| 710 | #endif |
Brian Carlstrom | 693267a | 2011-09-06 09:25:34 -0700 | [diff] [blame] | 711 | ScanInstanceFields(obj); |
Brian Carlstrom | 40381fb | 2011-10-19 14:13:40 -0700 | [diff] [blame] | 712 | ScanStaticFields(obj->AsClass()); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 713 | } |
| 714 | |
| 715 | // Scans the header of all array objects. If the array object is |
| 716 | // specialized to a reference type, scans the array data as well. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 717 | inline void MarkSweep::ScanArray(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 718 | #ifndef NDEBUG |
| 719 | ++array_count_; |
| 720 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 721 | MarkObject(obj->GetClass()); |
| 722 | if (obj->IsObjectArray()) { |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 723 | const ObjectArray<Object>* array = obj->AsObjectArray<Object>(); |
Elliott Hughes | d8ddfd5 | 2011-08-15 14:32:53 -0700 | [diff] [blame] | 724 | for (int32_t i = 0; i < array->GetLength(); ++i) { |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 725 | const Object* element = array->GetWithoutChecks(i); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 726 | MarkObject(element); |
| 727 | } |
| 728 | } |
| 729 | } |
| 730 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 731 | // Process the "referent" field in a java.lang.ref.Reference. If the |
| 732 | // referent has not yet been marked, put it on the appropriate list in |
| 733 | // the gcHeap for later processing. |
| 734 | void MarkSweep::DelayReferenceReferent(Object* obj) { |
| 735 | DCHECK(obj != NULL); |
Brian Carlstrom | 1f87008 | 2011-08-23 16:02:11 -0700 | [diff] [blame] | 736 | Class* klass = obj->GetClass(); |
| 737 | DCHECK(klass != NULL); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 738 | DCHECK(klass->IsReferenceClass()); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 739 | Object* pending = obj->GetFieldObject<Object*>(heap_->GetReferencePendingNextOffset(), false); |
| 740 | Object* referent = heap_->GetReferenceReferent(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 741 | if (pending == NULL && referent != NULL && !IsMarked(referent)) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 742 | Object** list = NULL; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 743 | if (klass->IsSoftReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 744 | list = &soft_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 745 | } else if (klass->IsWeakReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 746 | list = &weak_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 747 | } else if (klass->IsFinalizerReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 748 | list = &finalizer_reference_list_; |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 749 | } else if (klass->IsPhantomReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 750 | list = &phantom_reference_list_; |
| 751 | } |
Brian Carlstrom | 0796af0 | 2011-10-12 14:31:45 -0700 | [diff] [blame] | 752 | DCHECK(list != NULL) << PrettyClass(klass) << " " << std::hex << klass->GetAccessFlags(); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 753 | heap_->EnqueuePendingReference(obj, list); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 754 | } |
| 755 | } |
| 756 | |
| 757 | // Scans the header and field references of a data object. If the |
| 758 | // scanned object is a reference subclass, it is scheduled for later |
Elliott Hughes | adb460d | 2011-10-05 17:02:34 -0700 | [diff] [blame] | 759 | // processing. |
Elliott Hughes | b066311 | 2011-10-19 18:16:37 -0700 | [diff] [blame] | 760 | inline void MarkSweep::ScanOther(const Object* obj) { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 761 | #ifndef NDEBUG |
| 762 | ++other_count_; |
| 763 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 764 | ScanInstanceFields(obj); |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 765 | if (obj->GetClass()->IsReferenceClass()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 766 | DelayReferenceReferent(const_cast<Object*>(obj)); |
| 767 | } |
| 768 | } |
| 769 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 770 | void MarkSweep::ScanRoot(const Object* obj) { |
| 771 | ScanObject(obj); |
| 772 | } |
| 773 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 774 | // Scans an object reference. Determines the type of the reference |
| 775 | // and dispatches to a specialized scanning routine. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 776 | void MarkSweep::ScanObject(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 777 | DCHECK(obj != NULL); |
| 778 | DCHECK(obj->GetClass() != NULL); |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 779 | #ifndef NDEBUG |
| 780 | if (!IsMarked(obj)) { |
| 781 | heap_->DumpSpaces(); |
| 782 | LOG(FATAL) << "Scanning unmarked object " << reinterpret_cast<const void*>(obj); |
| 783 | } |
| 784 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 785 | if (obj->IsClass()) { |
| 786 | ScanClass(obj); |
Brian Carlstrom | b63ec39 | 2011-08-27 17:38:27 -0700 | [diff] [blame] | 787 | } else if (obj->IsArrayInstance()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 788 | ScanArray(obj); |
| 789 | } else { |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 790 | ScanOther(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 791 | } |
| 792 | } |
| 793 | |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 794 | // Scan anything that's on the mark stack. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 795 | void MarkSweep::ProcessMarkStack() { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 796 | #if MARK_STACK_PREFETCH |
| 797 | const size_t fifo_size = 4; |
| 798 | const size_t fifo_mask = fifo_size - 1; |
| 799 | const Object* fifo[fifo_size]; |
| 800 | for (size_t i = 0;i < fifo_size;++i) { |
| 801 | fifo[i] = NULL; |
| 802 | } |
| 803 | size_t fifo_pos = 0; |
| 804 | size_t fifo_count = 0; |
| 805 | for (;;) { |
| 806 | const Object* obj = fifo[fifo_pos & fifo_mask]; |
| 807 | if (obj != NULL) { |
| 808 | ScanObject(obj); |
| 809 | fifo[fifo_pos & fifo_mask] = NULL; |
| 810 | --fifo_count; |
| 811 | } |
| 812 | |
| 813 | if (!mark_stack_->IsEmpty()) { |
| 814 | const Object* obj = mark_stack_->Pop(); |
| 815 | DCHECK(obj != NULL); |
| 816 | fifo[fifo_pos & fifo_mask] = obj; |
| 817 | __builtin_prefetch(obj); |
| 818 | fifo_count++; |
| 819 | } |
| 820 | fifo_pos++; |
| 821 | |
| 822 | if (!fifo_count) { |
| 823 | CHECK(mark_stack_->IsEmpty()) << mark_stack_->Size(); |
| 824 | break; |
| 825 | } |
| 826 | } |
| 827 | #else |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 828 | while (!mark_stack_->IsEmpty()) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 829 | const Object* obj = mark_stack_->Pop(); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 830 | DCHECK(obj != NULL); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 831 | ScanObject(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 832 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 833 | #endif |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 834 | } |
| 835 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 836 | // Walks the reference list marking any references subject to the |
| 837 | // reference clearing policy. References with a black referent are |
| 838 | // removed from the list. References with white referents biased |
| 839 | // toward saving are blackened and also removed from the list. |
| 840 | void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| 841 | DCHECK(list != NULL); |
| 842 | Object* clear = NULL; |
| 843 | size_t counter = 0; |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 844 | |
| 845 | DCHECK(mark_stack_->IsEmpty()); |
| 846 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 847 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 848 | Object* ref = heap_->DequeuePendingReference(list); |
| 849 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 850 | if (referent == NULL) { |
| 851 | // Referent was cleared by the user during marking. |
| 852 | continue; |
| 853 | } |
| 854 | bool is_marked = IsMarked(referent); |
| 855 | if (!is_marked && ((++counter) & 1)) { |
| 856 | // Referent is white and biased toward saving, mark it. |
| 857 | MarkObject(referent); |
| 858 | is_marked = true; |
| 859 | } |
| 860 | if (!is_marked) { |
| 861 | // Referent is white, queue it for clearing. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 862 | heap_->EnqueuePendingReference(ref, &clear); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 863 | } |
| 864 | } |
| 865 | *list = clear; |
| 866 | // Restart the mark with the newly black references added to the |
| 867 | // root set. |
| 868 | ProcessMarkStack(); |
| 869 | } |
| 870 | |
| 871 | // Unlink the reference list clearing references objects with white |
| 872 | // referents. Cleared references registered to a reference queue are |
| 873 | // scheduled for appending by the heap worker thread. |
| 874 | void MarkSweep::ClearWhiteReferences(Object** list) { |
| 875 | DCHECK(list != NULL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 876 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 877 | Object* ref = heap_->DequeuePendingReference(list); |
| 878 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 879 | if (referent != NULL && !IsMarked(referent)) { |
| 880 | // Referent is white, clear it. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 881 | heap_->ClearReferenceReferent(ref); |
| 882 | if (heap_->IsEnqueuable(ref)) { |
| 883 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 884 | } |
| 885 | } |
| 886 | } |
| 887 | DCHECK(*list == NULL); |
| 888 | } |
| 889 | |
| 890 | // Enqueues finalizer references with white referents. White |
| 891 | // referents are blackened, moved to the zombie field, and the |
| 892 | // referent field is cleared. |
| 893 | void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| 894 | DCHECK(list != NULL); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 895 | MemberOffset zombie_offset = heap_->GetFinalizerReferenceZombieOffset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 896 | bool has_enqueued = false; |
| 897 | while (*list != NULL) { |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 898 | Object* ref = heap_->DequeuePendingReference(list); |
| 899 | Object* referent = heap_->GetReferenceReferent(ref); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 900 | if (referent != NULL && !IsMarked(referent)) { |
| 901 | MarkObject(referent); |
| 902 | // If the referent is non-null the reference must queuable. |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 903 | DCHECK(heap_->IsEnqueuable(ref)); |
Ian Rogers | 0cfe1fb | 2011-08-26 03:29:44 -0700 | [diff] [blame] | 904 | ref->SetFieldObject(zombie_offset, referent, false); |
Elliott Hughes | b3bd5f0 | 2012-03-08 21:05:27 -0800 | [diff] [blame] | 905 | heap_->ClearReferenceReferent(ref); |
| 906 | heap_->EnqueueReference(ref, &cleared_reference_list_); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 907 | has_enqueued = true; |
| 908 | } |
| 909 | } |
| 910 | if (has_enqueued) { |
| 911 | ProcessMarkStack(); |
| 912 | } |
| 913 | DCHECK(*list == NULL); |
| 914 | } |
| 915 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 916 | // Process reference class instances and schedule finalizations. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 917 | void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| 918 | Object** weak_references, |
| 919 | Object** finalizer_references, |
| 920 | Object** phantom_references) { |
| 921 | DCHECK(soft_references != NULL); |
| 922 | DCHECK(weak_references != NULL); |
| 923 | DCHECK(finalizer_references != NULL); |
| 924 | DCHECK(phantom_references != NULL); |
| 925 | |
| 926 | // Unless we are in the zygote or required to clear soft references |
| 927 | // with white references, preserve some white referents. |
Ian Rogers | 2945e24 | 2012-06-03 14:45:16 -0700 | [diff] [blame] | 928 | if (!clear_soft && !Runtime::Current()->IsZygote()) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 929 | PreserveSomeSoftReferences(soft_references); |
| 930 | } |
| 931 | |
| 932 | // Clear all remaining soft and weak references with white |
| 933 | // referents. |
| 934 | ClearWhiteReferences(soft_references); |
| 935 | ClearWhiteReferences(weak_references); |
| 936 | |
| 937 | // Preserve all white objects with finalize methods and schedule |
| 938 | // them for finalization. |
| 939 | EnqueueFinalizerReferences(finalizer_references); |
| 940 | |
| 941 | // Clear all f-reachable soft and weak references with white |
| 942 | // referents. |
| 943 | ClearWhiteReferences(soft_references); |
| 944 | ClearWhiteReferences(weak_references); |
| 945 | |
| 946 | // Clear all phantom references with white referents. |
| 947 | ClearWhiteReferences(phantom_references); |
| 948 | |
| 949 | // At this point all reference lists should be empty. |
| 950 | DCHECK(*soft_references == NULL); |
| 951 | DCHECK(*weak_references == NULL); |
| 952 | DCHECK(*finalizer_references == NULL); |
| 953 | DCHECK(*phantom_references == NULL); |
| 954 | } |
| 955 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 956 | MarkSweep::~MarkSweep() { |
Elliott Hughes | 352a424 | 2011-10-31 15:15:21 -0700 | [diff] [blame] | 957 | #ifndef NDEBUG |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 958 | 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] | 959 | #endif |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 960 | // Ensure that the mark stack is empty. |
| 961 | CHECK(mark_stack_->IsEmpty()); |
| 962 | |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 963 | // Clear all of the alloc spaces' mark bitmaps. |
| 964 | const Spaces& spaces = heap_->GetSpaces(); |
| 965 | // TODO: C++0x auto |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 966 | for (Spaces::const_iterator it = spaces.begin(); it != spaces.end(); ++it) { |
| 967 | if ((*it)->GetGcRetentionPolicy() != GCRP_NEVER_COLLECT) { |
| 968 | (*it)->GetMarkBitmap()->Clear(); |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 969 | } |
| 970 | } |
Mathieu Chartier | 5301cd2 | 2012-05-31 12:11:36 -0700 | [diff] [blame] | 971 | mark_stack_->Reset(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 972 | |
| 973 | // Reset the marked large objects. |
| 974 | LargeObjectSpace* large_objects = GetHeap()->GetLargeObjectsSpace(); |
Mathieu Chartier | e0f0cb3 | 2012-08-28 11:26:00 -0700 | [diff] [blame] | 975 | large_objects->GetMarkObjects()->Clear(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 976 | } |
| 977 | |
| 978 | } // namespace art |