Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 1 | // Copyright 2011 Google Inc. All Rights Reserved. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 2 | |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 3 | #include "mark_sweep.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 4 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 5 | #include <climits> |
| 6 | #include <vector> |
| 7 | |
| 8 | #include "heap.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 9 | #include "logging.h" |
| 10 | #include "macros.h" |
| 11 | #include "mark_stack.h" |
| 12 | #include "object.h" |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 13 | #include "space.h" |
Brian Carlstrom | 578bbdc | 2011-07-21 14:07:47 -0700 | [diff] [blame] | 14 | #include "thread.h" |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 15 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 16 | namespace art { |
| 17 | |
| 18 | size_t MarkSweep::reference_referent_offset_ = 0; // TODO |
| 19 | size_t MarkSweep::reference_queue_offset_ = 0; // TODO |
| 20 | size_t MarkSweep::reference_queueNext_offset_ = 0; // TODO |
| 21 | size_t MarkSweep::reference_pendingNext_offset_ = 0; // TODO |
| 22 | size_t MarkSweep::finalizer_reference_zombie_offset_ = 0; // TODO |
| 23 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 24 | bool MarkSweep::Init() { |
Brian Carlstrom | 4a289ed | 2011-08-16 17:17:49 -0700 | [diff] [blame] | 25 | mark_stack_ = MarkStack::Create(); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 26 | if (mark_stack_ == NULL) { |
| 27 | return false; |
| 28 | } |
| 29 | |
| 30 | mark_bitmap_ = Heap::GetMarkBits(); |
| 31 | live_bitmap_ = Heap::GetLiveBits(); |
| 32 | |
| 33 | // TODO: if concurrent, clear the card table. |
| 34 | |
| 35 | // TODO: check that the mark bitmap is entirely clear. |
| 36 | |
| 37 | return true; |
| 38 | } |
| 39 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 40 | void MarkSweep::MarkObject0(const Object* obj, bool check_finger) { |
| 41 | DCHECK(obj != NULL); |
| 42 | if (obj < condemned_) { |
| 43 | DCHECK(IsMarked(obj)); |
| 44 | return; |
| 45 | } |
| 46 | bool is_marked = mark_bitmap_->Test(obj); |
| 47 | // This object was not previously marked. |
| 48 | if (!is_marked) { |
| 49 | mark_bitmap_->Set(obj); |
| 50 | if (check_finger && obj < finger_) { |
| 51 | // The object must be pushed on to the mark stack. |
| 52 | mark_stack_->Push(obj); |
| 53 | } |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | // Used to mark objects when recursing. Recursion is done by moving |
| 58 | // the finger across the bitmaps in address order and marking child |
| 59 | // objects. Any newly-marked objects whose addresses are lower than |
| 60 | // the finger won't be visited by the bitmap scan, so those objects |
| 61 | // need to be added to the mark stack. |
| 62 | void MarkSweep::MarkObject(const Object* obj) { |
| 63 | if (obj != NULL) { |
| 64 | MarkObject0(obj, true); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // Marks all objects in the root set. |
| 69 | void MarkSweep::MarkRoots() { |
Elliott Hughes | 53b6131 | 2011-08-12 18:28:20 -0700 | [diff] [blame] | 70 | UNIMPLEMENTED(FATAL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 71 | } |
| 72 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 73 | void MarkSweep::ScanBitmapCallback(Object* obj, void* finger, void* arg) { |
| 74 | MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg); |
| 75 | mark_sweep->finger_ = reinterpret_cast<Object*>(finger); |
| 76 | mark_sweep->ScanObject(obj); |
| 77 | } |
| 78 | |
| 79 | // Populates the mark stack based on the set of marked objects and |
| 80 | // recursively marks until the mark stack is emptied. |
| 81 | void MarkSweep::RecursiveMark() { |
| 82 | void* arg = reinterpret_cast<void*>(this); |
| 83 | const std::vector<Space*>& spaces = Heap::GetSpaces(); |
| 84 | for (size_t i = 0; i < spaces.size(); ++i) { |
| 85 | if (spaces[i]->IsCondemned()) { |
| 86 | uintptr_t base = reinterpret_cast<uintptr_t>(spaces[i]->GetBase()); |
| 87 | uintptr_t limit = reinterpret_cast<uintptr_t>(spaces[i]->GetLimit()); |
| 88 | mark_bitmap_->ScanWalk(base, limit, &MarkSweep::ScanBitmapCallback, arg); |
| 89 | } |
| 90 | } |
| 91 | finger_ = reinterpret_cast<Object*>(~0); |
| 92 | ProcessMarkStack(); |
| 93 | } |
| 94 | |
| 95 | void MarkSweep::ReMarkRoots() { |
Elliott Hughes | 53b6131 | 2011-08-12 18:28:20 -0700 | [diff] [blame] | 96 | UNIMPLEMENTED(FATAL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 99 | void MarkSweep::SweepSystemWeaks() { |
Elliott Hughes | 53b6131 | 2011-08-12 18:28:20 -0700 | [diff] [blame] | 100 | UNIMPLEMENTED(FATAL); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 101 | } |
| 102 | |
| 103 | void MarkSweep::SweepCallback(size_t num_ptrs, void **ptrs, void *arg) { |
| 104 | // TODO, lock heap if concurrent |
| 105 | Space* space = static_cast<Space*>(arg); |
| 106 | for (size_t i = 0; i < num_ptrs; ++i) { |
| 107 | Object* obj = static_cast<Object*>(ptrs[i]); |
| 108 | space->Free(obj); |
| 109 | } |
| 110 | // TODO, unlock heap if concurrent |
| 111 | } |
| 112 | |
| 113 | void MarkSweep::Sweep() { |
| 114 | const std::vector<Space*>& spaces = Heap::GetSpaces(); |
| 115 | for (size_t i = 0; i < spaces.size(); ++i) { |
| 116 | if (spaces[i]->IsCondemned()) { |
| 117 | uintptr_t base = reinterpret_cast<uintptr_t>(spaces[i]->GetBase()); |
| 118 | uintptr_t limit = reinterpret_cast<uintptr_t>(spaces[i]->GetLimit()); |
| 119 | void* arg = static_cast<void*>(spaces[i]); |
| 120 | HeapBitmap::SweepWalk(*live_bitmap_, *mark_bitmap_, base, limit, |
| 121 | &MarkSweep::SweepCallback, arg); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 126 | // Scans instance fields. |
| 127 | void MarkSweep::ScanInstanceFields(const Object* obj) { |
| 128 | DCHECK(obj != NULL); |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 129 | Class* klass = obj->GetClass(); |
| 130 | DCHECK(klass != NULL); |
| 131 | ScanFields(obj, |
| 132 | klass->GetReferenceInstanceOffsets(), |
| 133 | false); |
| 134 | } |
| 135 | |
| 136 | // Scans static storage on a Class. |
| 137 | void MarkSweep::ScanStaticFields(const Class* klass) { |
| 138 | DCHECK(klass != NULL); |
| 139 | ScanFields(klass, |
| 140 | klass->GetReferenceStaticOffsets(), |
| 141 | true); |
| 142 | } |
| 143 | |
| 144 | void MarkSweep::ScanFields(const Object* obj, |
| 145 | uint32_t ref_offsets, |
| 146 | bool is_static) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 147 | if (ref_offsets != CLASS_WALK_SUPER) { |
| 148 | // Found a reference offset bitmap. Mark the specified offsets. |
| 149 | while (ref_offsets != 0) { |
| 150 | size_t right_shift = CLZ(ref_offsets); |
| 151 | size_t byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift); |
| 152 | const Object* ref = obj->GetFieldObject(byte_offset); |
| 153 | MarkObject(ref); |
| 154 | ref_offsets &= ~(CLASS_HIGH_BIT >> right_shift); |
| 155 | } |
| 156 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 157 | // There is no reference offset bitmap. In the non-static case, |
| 158 | // walk up the class inheritance hierarchy and find reference |
| 159 | // offsets the hard way. In the static case, just consider this |
| 160 | // class. |
| 161 | for (const Class* klass = is_static ? obj->AsClass() : obj->GetClass(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 162 | klass != NULL; |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 163 | klass = is_static ? NULL : klass->GetSuperClass()) { |
| 164 | size_t num_reference_fields = (is_static |
| 165 | ? klass->NumReferenceStaticFields() |
| 166 | : klass->NumReferenceInstanceFields()); |
| 167 | for (size_t i = 0; i < num_reference_fields; ++i) { |
| 168 | Field* field = (is_static |
| 169 | ? klass->GetStaticField(i) |
| 170 | : klass->GetInstanceField(i)); |
| 171 | size_t field_offset = field->GetOffset(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 172 | const Object* ref = obj->GetFieldObject(field_offset); |
| 173 | MarkObject(ref); |
| 174 | } |
| 175 | } |
| 176 | } |
| 177 | } |
| 178 | |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 179 | void MarkSweep::ScanInterfaces(const Class* klass) { |
| 180 | DCHECK(klass != NULL); |
| 181 | for (size_t i = 0; i < klass->NumInterfaces(); ++i) { |
| 182 | MarkObject(klass->GetInterface(i)); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | // Scans the header, static field references, and interface pointers |
| 187 | // of a class object. |
| 188 | void MarkSweep::ScanClass(const Object* obj) { |
| 189 | DCHECK(obj != NULL); |
| 190 | DCHECK(obj->IsClass()); |
| 191 | const Class* klass = obj->AsClass(); |
| 192 | MarkObject(klass->GetClass()); |
| 193 | if (klass->IsArray()) { |
| 194 | MarkObject(klass->GetComponentType()); |
| 195 | } |
| 196 | if (klass->IsLoaded()) { |
| 197 | MarkObject(klass->GetSuperClass()); |
| 198 | } |
| 199 | MarkObject(klass->GetClassLoader()); |
| 200 | ScanInstanceFields(obj); |
| 201 | ScanStaticFields(klass); |
| 202 | // TODO: scan methods |
| 203 | // TODO: scan instance fields |
| 204 | if (klass->IsLoaded()) { |
| 205 | ScanInterfaces(klass); |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | // Scans the header of all array objects. If the array object is |
| 210 | // specialized to a reference type, scans the array data as well. |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 211 | void MarkSweep::ScanArray(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 212 | DCHECK(obj != NULL); |
| 213 | DCHECK(obj->GetClass() != NULL); |
| 214 | MarkObject(obj->GetClass()); |
| 215 | if (obj->IsObjectArray()) { |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 216 | const ObjectArray<Object>* array = obj->AsObjectArray<Object>(); |
Elliott Hughes | d8ddfd5 | 2011-08-15 14:32:53 -0700 | [diff] [blame] | 217 | for (int32_t i = 0; i < array->GetLength(); ++i) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 218 | const Object* element = array->Get(i); |
| 219 | MarkObject(element); |
| 220 | } |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | void MarkSweep::EnqueuePendingReference(Object* ref, Object** list) { |
| 225 | DCHECK(ref != NULL); |
| 226 | DCHECK(list != NULL); |
| 227 | size_t offset = reference_pendingNext_offset_; |
| 228 | if (*list == NULL) { |
| 229 | ref->SetFieldObject(offset, ref); |
| 230 | *list = ref; |
| 231 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 232 | Object* head = (*list)->GetFieldObject(offset); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 233 | ref->SetFieldObject(offset, head); |
| 234 | (*list)->SetFieldObject(offset, ref); |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | Object* MarkSweep::DequeuePendingReference(Object** list) { |
| 239 | DCHECK(list != NULL); |
| 240 | DCHECK(*list != NULL); |
| 241 | size_t offset = reference_pendingNext_offset_; |
| 242 | Object* head = (*list)->GetFieldObject(offset); |
| 243 | Object* ref; |
| 244 | if (*list == head) { |
| 245 | ref = *list; |
| 246 | *list = NULL; |
| 247 | } else { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 248 | Object* next = head->GetFieldObject(offset); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 249 | (*list)->SetFieldObject(offset, next); |
| 250 | ref = head; |
| 251 | } |
| 252 | ref->SetFieldObject(offset, NULL); |
| 253 | return ref; |
| 254 | } |
| 255 | |
| 256 | // Process the "referent" field in a java.lang.ref.Reference. If the |
| 257 | // referent has not yet been marked, put it on the appropriate list in |
| 258 | // the gcHeap for later processing. |
| 259 | void MarkSweep::DelayReferenceReferent(Object* obj) { |
| 260 | DCHECK(obj != NULL); |
| 261 | DCHECK(obj->GetClass() != NULL); |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 262 | DCHECK(obj->IsReference()); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 263 | Object* pending = obj->GetFieldObject(reference_pendingNext_offset_); |
| 264 | Object* referent = obj->GetFieldObject(reference_referent_offset_); |
| 265 | if (pending == NULL && referent != NULL && !IsMarked(referent)) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 266 | Object** list = NULL; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 267 | if (obj->IsSoftReference()) { |
| 268 | list = &soft_reference_list_; |
| 269 | } else if (obj->IsWeakReference()) { |
| 270 | list = &weak_reference_list_; |
| 271 | } else if (obj->IsFinalizerReference()) { |
| 272 | list = &finalizer_reference_list_; |
| 273 | } else if (obj->IsPhantomReference()) { |
| 274 | list = &phantom_reference_list_; |
| 275 | } |
| 276 | DCHECK(list != NULL); |
| 277 | EnqueuePendingReference(obj, list); |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | // Scans the header and field references of a data object. If the |
| 282 | // scanned object is a reference subclass, it is scheduled for later |
| 283 | // processing |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 284 | void MarkSweep::ScanOther(const Object* obj) { |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 285 | DCHECK(obj != NULL); |
| 286 | DCHECK(obj->GetClass() != NULL); |
| 287 | MarkObject(obj->GetClass()); |
| 288 | ScanInstanceFields(obj); |
| 289 | if (obj->IsReference()) { |
| 290 | DelayReferenceReferent(const_cast<Object*>(obj)); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | // Scans an object reference. Determines the type of the reference |
| 295 | // and dispatches to a specialized scanning routine. |
| 296 | void MarkSweep::ScanObject(const Object* obj) { |
| 297 | DCHECK(obj != NULL); |
| 298 | DCHECK(obj->GetClass() != NULL); |
| 299 | DCHECK(IsMarked(obj)); |
| 300 | if (obj->IsClass()) { |
| 301 | ScanClass(obj); |
| 302 | } else if (obj->IsArray()) { |
| 303 | ScanArray(obj); |
| 304 | } else { |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 305 | ScanOther(obj); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 306 | } |
| 307 | } |
| 308 | |
| 309 | // Scan anything that's on the mark stack. We can't use the bitmaps |
| 310 | // anymore, so use a finger that points past the end of them. |
| 311 | void MarkSweep::ProcessMarkStack() { |
| 312 | while (!mark_stack_->IsEmpty()) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 313 | const Object* obj = mark_stack_->Pop(); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 314 | ScanObject(obj); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | void MarkSweep::ScanDirtyObjects() { |
| 319 | ProcessMarkStack(); |
| 320 | } |
| 321 | |
| 322 | void MarkSweep::ClearReference(Object* ref) { |
| 323 | DCHECK(ref != NULL); |
| 324 | ref->SetFieldObject(reference_referent_offset_, NULL); |
| 325 | } |
| 326 | |
| 327 | bool MarkSweep::IsEnqueuable(const Object* ref) { |
| 328 | DCHECK(ref != NULL); |
| 329 | const Object* queue = ref->GetFieldObject(reference_queue_offset_); |
| 330 | const Object* queue_next = ref->GetFieldObject(reference_queueNext_offset_); |
| 331 | return (queue != NULL) && (queue_next == NULL); |
| 332 | } |
| 333 | |
| 334 | void MarkSweep::EnqueueReference(Object* ref) { |
| 335 | DCHECK(ref != NULL); |
| 336 | CHECK(ref->GetFieldObject(reference_queue_offset_) != NULL); |
| 337 | CHECK(ref->GetFieldObject(reference_queueNext_offset_) == NULL); |
| 338 | EnqueuePendingReference(ref, &cleared_reference_list_); |
| 339 | } |
| 340 | |
| 341 | // Walks the reference list marking any references subject to the |
| 342 | // reference clearing policy. References with a black referent are |
| 343 | // removed from the list. References with white referents biased |
| 344 | // toward saving are blackened and also removed from the list. |
| 345 | void MarkSweep::PreserveSomeSoftReferences(Object** list) { |
| 346 | DCHECK(list != NULL); |
| 347 | Object* clear = NULL; |
| 348 | size_t counter = 0; |
| 349 | while (*list != NULL) { |
| 350 | Object* ref = DequeuePendingReference(list); |
| 351 | Object* referent = ref->GetFieldObject(reference_referent_offset_); |
| 352 | if (referent == NULL) { |
| 353 | // Referent was cleared by the user during marking. |
| 354 | continue; |
| 355 | } |
| 356 | bool is_marked = IsMarked(referent); |
| 357 | if (!is_marked && ((++counter) & 1)) { |
| 358 | // Referent is white and biased toward saving, mark it. |
| 359 | MarkObject(referent); |
| 360 | is_marked = true; |
| 361 | } |
| 362 | if (!is_marked) { |
| 363 | // Referent is white, queue it for clearing. |
| 364 | EnqueuePendingReference(ref, &clear); |
| 365 | } |
| 366 | } |
| 367 | *list = clear; |
| 368 | // Restart the mark with the newly black references added to the |
| 369 | // root set. |
| 370 | ProcessMarkStack(); |
| 371 | } |
| 372 | |
| 373 | // Unlink the reference list clearing references objects with white |
| 374 | // referents. Cleared references registered to a reference queue are |
| 375 | // scheduled for appending by the heap worker thread. |
| 376 | void MarkSweep::ClearWhiteReferences(Object** list) { |
| 377 | DCHECK(list != NULL); |
| 378 | size_t offset = reference_referent_offset_; |
| 379 | while (*list != NULL) { |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 380 | Object* ref = DequeuePendingReference(list); |
| 381 | Object* referent = ref->GetFieldObject(offset); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 382 | if (referent != NULL && !IsMarked(referent)) { |
| 383 | // Referent is white, clear it. |
| 384 | ClearReference(ref); |
| 385 | if (IsEnqueuable(ref)) { |
| 386 | EnqueueReference(ref); |
| 387 | } |
| 388 | } |
| 389 | } |
| 390 | DCHECK(*list == NULL); |
| 391 | } |
| 392 | |
| 393 | // Enqueues finalizer references with white referents. White |
| 394 | // referents are blackened, moved to the zombie field, and the |
| 395 | // referent field is cleared. |
| 396 | void MarkSweep::EnqueueFinalizerReferences(Object** list) { |
| 397 | DCHECK(list != NULL); |
| 398 | size_t referent_offset = reference_referent_offset_; |
| 399 | size_t zombie_offset = finalizer_reference_zombie_offset_; |
| 400 | bool has_enqueued = false; |
| 401 | while (*list != NULL) { |
| 402 | Object* ref = DequeuePendingReference(list); |
| 403 | Object* referent = ref->GetFieldObject(referent_offset); |
| 404 | if (referent != NULL && !IsMarked(referent)) { |
| 405 | MarkObject(referent); |
| 406 | // If the referent is non-null the reference must queuable. |
| 407 | DCHECK(IsEnqueuable(ref)); |
| 408 | ref->SetFieldObject(zombie_offset, referent); |
| 409 | ClearReference(ref); |
| 410 | EnqueueReference(ref); |
| 411 | has_enqueued = true; |
| 412 | } |
| 413 | } |
| 414 | if (has_enqueued) { |
| 415 | ProcessMarkStack(); |
| 416 | } |
| 417 | DCHECK(*list == NULL); |
| 418 | } |
| 419 | |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 420 | // Process reference class instances and schedule finalizations. |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 421 | void MarkSweep::ProcessReferences(Object** soft_references, bool clear_soft, |
| 422 | Object** weak_references, |
| 423 | Object** finalizer_references, |
| 424 | Object** phantom_references) { |
| 425 | DCHECK(soft_references != NULL); |
| 426 | DCHECK(weak_references != NULL); |
| 427 | DCHECK(finalizer_references != NULL); |
| 428 | DCHECK(phantom_references != NULL); |
| 429 | |
| 430 | // Unless we are in the zygote or required to clear soft references |
| 431 | // with white references, preserve some white referents. |
| 432 | if (clear_soft) { |
| 433 | PreserveSomeSoftReferences(soft_references); |
| 434 | } |
| 435 | |
| 436 | // Clear all remaining soft and weak references with white |
| 437 | // referents. |
| 438 | ClearWhiteReferences(soft_references); |
| 439 | ClearWhiteReferences(weak_references); |
| 440 | |
| 441 | // Preserve all white objects with finalize methods and schedule |
| 442 | // them for finalization. |
| 443 | EnqueueFinalizerReferences(finalizer_references); |
| 444 | |
| 445 | // Clear all f-reachable soft and weak references with white |
| 446 | // referents. |
| 447 | ClearWhiteReferences(soft_references); |
| 448 | ClearWhiteReferences(weak_references); |
| 449 | |
| 450 | // Clear all phantom references with white referents. |
| 451 | ClearWhiteReferences(phantom_references); |
| 452 | |
| 453 | // At this point all reference lists should be empty. |
| 454 | DCHECK(*soft_references == NULL); |
| 455 | DCHECK(*weak_references == NULL); |
| 456 | DCHECK(*finalizer_references == NULL); |
| 457 | DCHECK(*phantom_references == NULL); |
| 458 | } |
| 459 | |
| 460 | // Pushes a list of cleared references out to the managed heap. |
| 461 | void MarkSweep::EnqueueClearedReferences(Object** cleared) { |
| 462 | DCHECK(cleared != NULL); |
| 463 | if (*cleared != NULL) { |
| 464 | Thread* self = Thread::Current(); |
| 465 | DCHECK(self != NULL); |
| 466 | // TODO: Method *meth = gDvm.methJavaLangRefReferenceQueueAdd; |
| 467 | // DCHECK(meth != NULL); |
| 468 | // JValue unused; |
Brian Carlstrom | 4873d46 | 2011-08-21 15:23:39 -0700 | [diff] [blame] | 469 | // Object* reference = *cleared; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 470 | // TODO: dvmCallMethod(self, meth, NULL, &unused, reference); |
Elliott Hughes | 53b6131 | 2011-08-12 18:28:20 -0700 | [diff] [blame] | 471 | UNIMPLEMENTED(FATAL); |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 472 | *cleared = NULL; |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | MarkSweep::~MarkSweep() { |
Carl Shapiro | 58551df | 2011-07-24 03:09:51 -0700 | [diff] [blame] | 477 | delete mark_stack_; |
Carl Shapiro | 69759ea | 2011-07-21 18:13:35 -0700 | [diff] [blame] | 478 | mark_bitmap_->Clear(); |
| 479 | } |
| 480 | |
| 481 | } // namespace art |