Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "reference_queue.h" |
| 18 | |
| 19 | #include "accounting/card_table-inl.h" |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 20 | #include "collector/concurrent_copying.h" |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 21 | #include "heap.h" |
| 22 | #include "mirror/class-inl.h" |
| 23 | #include "mirror/object-inl.h" |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 24 | #include "mirror/reference-inl.h" |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 25 | |
| 26 | namespace art { |
| 27 | namespace gc { |
| 28 | |
Mathieu Chartier | a5a53ef | 2014-09-12 12:58:05 -0700 | [diff] [blame] | 29 | ReferenceQueue::ReferenceQueue(Mutex* lock) : lock_(lock), list_(nullptr) { |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 30 | } |
| 31 | |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 32 | void ReferenceQueue::AtomicEnqueueIfNotEnqueued(Thread* self, mirror::Reference* ref) { |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 33 | DCHECK(ref != nullptr); |
Mathieu Chartier | a5a53ef | 2014-09-12 12:58:05 -0700 | [diff] [blame] | 34 | MutexLock mu(self, *lock_); |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 35 | if (!ref->IsEnqueued()) { |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 36 | EnqueuePendingReference(ref); |
| 37 | } |
| 38 | } |
| 39 | |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 40 | void ReferenceQueue::EnqueueReference(mirror::Reference* ref) { |
| 41 | CHECK(ref->IsEnqueuable()); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 42 | EnqueuePendingReference(ref); |
| 43 | } |
| 44 | |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 45 | void ReferenceQueue::EnqueuePendingReference(mirror::Reference* ref) { |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 46 | DCHECK(ref != nullptr); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 47 | if (IsEmpty()) { |
| 48 | // 1 element cyclic queue, ie: Reference ref = ..; ref.pendingNext = ref; |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 49 | list_ = ref; |
| 50 | } else { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 51 | mirror::Reference* head = list_->GetPendingNext(); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 52 | if (Runtime::Current()->IsActiveTransaction()) { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 53 | ref->SetPendingNext<true>(head); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 54 | } else { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 55 | ref->SetPendingNext<false>(head); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 56 | } |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 57 | } |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 58 | if (Runtime::Current()->IsActiveTransaction()) { |
| 59 | list_->SetPendingNext<true>(ref); |
| 60 | } else { |
| 61 | list_->SetPendingNext<false>(ref); |
| 62 | } |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 63 | } |
| 64 | |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 65 | mirror::Reference* ReferenceQueue::DequeuePendingReference() { |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 66 | DCHECK(!IsEmpty()); |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 67 | mirror::Reference* head = list_->GetPendingNext(); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 68 | DCHECK(head != nullptr); |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 69 | mirror::Reference* ref; |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 70 | // Note: the following code is thread-safe because it is only called from ProcessReferences which |
| 71 | // is single threaded. |
| 72 | if (list_ == head) { |
| 73 | ref = list_; |
| 74 | list_ = nullptr; |
| 75 | } else { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 76 | mirror::Reference* next = head->GetPendingNext(); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 77 | if (Runtime::Current()->IsActiveTransaction()) { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 78 | list_->SetPendingNext<true>(next); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 79 | } else { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 80 | list_->SetPendingNext<false>(next); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 81 | } |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 82 | ref = head; |
| 83 | } |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 84 | if (Runtime::Current()->IsActiveTransaction()) { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 85 | ref->SetPendingNext<true>(nullptr); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 86 | } else { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 87 | ref->SetPendingNext<false>(nullptr); |
Sebastien Hertz | d2fe10a | 2014-01-15 10:20:56 +0100 | [diff] [blame] | 88 | } |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 89 | Heap* heap = Runtime::Current()->GetHeap(); |
| 90 | if (kUseBakerOrBrooksReadBarrier && heap->CurrentCollectorType() == kCollectorTypeCC && |
| 91 | heap->ConcurrentCopyingCollector()->IsActive()) { |
Hiroshi Yamauchi | 70c08d3 | 2015-09-10 16:01:30 -0700 | [diff] [blame] | 92 | // Change the gray ptr we left in ConcurrentCopying::ProcessMarkStackRef() to black or white. |
| 93 | // We check IsActive() above because we don't want to do this when the zygote compaction |
| 94 | // collector (SemiSpace) is running. |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 95 | CHECK(ref != nullptr); |
Hiroshi Yamauchi | 70c08d3 | 2015-09-10 16:01:30 -0700 | [diff] [blame] | 96 | collector::ConcurrentCopying* concurrent_copying = heap->ConcurrentCopyingCollector(); |
| 97 | const bool is_moving = concurrent_copying->RegionSpace()->IsInToSpace(ref); |
| 98 | if (ref->GetReadBarrierPointer() == ReadBarrier::GrayPtr()) { |
| 99 | if (is_moving) { |
| 100 | ref->AtomicSetReadBarrierPointer(ReadBarrier::GrayPtr(), ReadBarrier::WhitePtr()); |
| 101 | CHECK_EQ(ref->GetReadBarrierPointer(), ReadBarrier::WhitePtr()); |
| 102 | } else { |
| 103 | ref->AtomicSetReadBarrierPointer(ReadBarrier::GrayPtr(), ReadBarrier::BlackPtr()); |
| 104 | CHECK_EQ(ref->GetReadBarrierPointer(), ReadBarrier::BlackPtr()); |
| 105 | } |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 106 | } else { |
Hiroshi Yamauchi | 70c08d3 | 2015-09-10 16:01:30 -0700 | [diff] [blame] | 107 | // In ConcurrentCopying::ProcessMarkStackRef() we may leave a black or white Reference in the |
| 108 | // queue and find it here, which is OK. Check that the color makes sense depending on whether |
| 109 | // the Reference is moving or not and that the referent has been marked. |
| 110 | if (is_moving) { |
| 111 | CHECK_EQ(ref->GetReadBarrierPointer(), ReadBarrier::WhitePtr()) |
| 112 | << "ref=" << ref << " rb_ptr=" << ref->GetReadBarrierPointer(); |
| 113 | } else { |
| 114 | CHECK_EQ(ref->GetReadBarrierPointer(), ReadBarrier::BlackPtr()) |
| 115 | << "ref=" << ref << " rb_ptr=" << ref->GetReadBarrierPointer(); |
| 116 | } |
| 117 | mirror::Object* referent = ref->GetReferent<kWithoutReadBarrier>(); |
Hiroshi Yamauchi | d2bb5ba | 2015-09-14 15:10:50 -0700 | [diff] [blame] | 118 | // The referent could be null if it's cleared by a mutator (Reference.clear()). |
| 119 | if (referent != nullptr) { |
| 120 | CHECK(concurrent_copying->IsInToSpace(referent)) |
| 121 | << "ref=" << ref << " rb_ptr=" << ref->GetReadBarrierPointer() |
| 122 | << " referent=" << referent; |
| 123 | } |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 124 | } |
| 125 | } |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 126 | return ref; |
| 127 | } |
| 128 | |
| 129 | void ReferenceQueue::Dump(std::ostream& os) const { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 130 | mirror::Reference* cur = list_; |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 131 | os << "Reference starting at list_=" << list_ << "\n"; |
Mathieu Chartier | 9e2094f | 2014-12-11 18:43:48 -0800 | [diff] [blame] | 132 | if (cur == nullptr) { |
| 133 | return; |
| 134 | } |
| 135 | do { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 136 | mirror::Reference* pending_next = cur->GetPendingNext(); |
Mathieu Chartier | 9e2094f | 2014-12-11 18:43:48 -0800 | [diff] [blame] | 137 | os << "Reference= " << cur << " PendingNext=" << pending_next; |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 138 | if (cur->IsFinalizerReferenceInstance()) { |
| 139 | os << " Zombie=" << cur->AsFinalizerReference()->GetZombie(); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 140 | } |
| 141 | os << "\n"; |
| 142 | cur = pending_next; |
Mathieu Chartier | 9e2094f | 2014-12-11 18:43:48 -0800 | [diff] [blame] | 143 | } while (cur != list_); |
| 144 | } |
| 145 | |
| 146 | size_t ReferenceQueue::GetLength() const { |
| 147 | size_t count = 0; |
| 148 | mirror::Reference* cur = list_; |
| 149 | if (cur != nullptr) { |
| 150 | do { |
| 151 | ++count; |
| 152 | cur = cur->GetPendingNext(); |
| 153 | } while (cur != list_); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 154 | } |
Mathieu Chartier | 9e2094f | 2014-12-11 18:43:48 -0800 | [diff] [blame] | 155 | return count; |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 156 | } |
| 157 | |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 158 | void ReferenceQueue::ClearWhiteReferences(ReferenceQueue* cleared_references, |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 159 | collector::GarbageCollector* collector) { |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 160 | while (!IsEmpty()) { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 161 | mirror::Reference* ref = DequeuePendingReference(); |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 162 | mirror::HeapReference<mirror::Object>* referent_addr = ref->GetReferentReferenceAddr(); |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 163 | if (referent_addr->AsMirrorPtr() != nullptr && |
| 164 | !collector->IsMarkedHeapReference(referent_addr)) { |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 165 | // Referent is white, clear it. |
| 166 | if (Runtime::Current()->IsActiveTransaction()) { |
| 167 | ref->ClearReferent<true>(); |
| 168 | } else { |
| 169 | ref->ClearReferent<false>(); |
| 170 | } |
| 171 | if (ref->IsEnqueuable()) { |
| 172 | cleared_references->EnqueuePendingReference(ref); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 173 | } |
| 174 | } |
| 175 | } |
| 176 | } |
| 177 | |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 178 | void ReferenceQueue::EnqueueFinalizerReferences(ReferenceQueue* cleared_references, |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 179 | collector::GarbageCollector* collector) { |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 180 | while (!IsEmpty()) { |
Mathieu Chartier | 8fa2dad | 2014-03-13 12:22:56 -0700 | [diff] [blame] | 181 | mirror::FinalizerReference* ref = DequeuePendingReference()->AsFinalizerReference(); |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 182 | mirror::HeapReference<mirror::Object>* referent_addr = ref->GetReferentReferenceAddr(); |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 183 | if (referent_addr->AsMirrorPtr() != nullptr && |
| 184 | !collector->IsMarkedHeapReference(referent_addr)) { |
| 185 | mirror::Object* forward_address = collector->MarkObject(referent_addr->AsMirrorPtr()); |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 186 | // If the referent is non-null the reference must queuable. |
| 187 | DCHECK(ref->IsEnqueuable()); |
| 188 | // Move the updated referent to the zombie field. |
| 189 | if (Runtime::Current()->IsActiveTransaction()) { |
| 190 | ref->SetZombie<true>(forward_address); |
| 191 | ref->ClearReferent<true>(); |
| 192 | } else { |
| 193 | ref->SetZombie<false>(forward_address); |
| 194 | ref->ClearReferent<false>(); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 195 | } |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 196 | cleared_references->EnqueueReference(ref); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 197 | } |
| 198 | } |
| 199 | } |
| 200 | |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 201 | void ReferenceQueue::ForwardSoftReferences(MarkObjectVisitor* visitor) { |
Fred Shih | 530e1b5 | 2014-06-09 15:19:54 -0700 | [diff] [blame] | 202 | if (UNLIKELY(IsEmpty())) { |
| 203 | return; |
| 204 | } |
| 205 | mirror::Reference* const head = list_; |
| 206 | mirror::Reference* ref = head; |
| 207 | do { |
Mathieu Chartier | 308351a | 2014-06-15 12:39:02 -0700 | [diff] [blame] | 208 | mirror::HeapReference<mirror::Object>* referent_addr = ref->GetReferentReferenceAddr(); |
| 209 | if (referent_addr->AsMirrorPtr() != nullptr) { |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 210 | visitor->MarkHeapReference(referent_addr); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 211 | } |
Fred Shih | 530e1b5 | 2014-06-09 15:19:54 -0700 | [diff] [blame] | 212 | ref = ref->GetPendingNext(); |
| 213 | } while (LIKELY(ref != head)); |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 214 | } |
| 215 | |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 216 | void ReferenceQueue::UpdateRoots(IsMarkedVisitor* visitor) { |
Mathieu Chartier | 52e4b43 | 2014-06-10 11:22:31 -0700 | [diff] [blame] | 217 | if (list_ != nullptr) { |
Mathieu Chartier | 9750995 | 2015-07-13 14:35:43 -0700 | [diff] [blame] | 218 | list_ = down_cast<mirror::Reference*>(visitor->IsMarked(list_)); |
Mathieu Chartier | 52e4b43 | 2014-06-10 11:22:31 -0700 | [diff] [blame] | 219 | } |
| 220 | } |
| 221 | |
Mathieu Chartier | 39e3261 | 2013-11-12 16:28:05 -0800 | [diff] [blame] | 222 | } // namespace gc |
| 223 | } // namespace art |