remembered_set.cc revision 3b05e9ba874449dbff65b01b8781001f7d93eea6
1/* 2 * Copyright (C) 2014 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 "remembered_set.h" 18 19#include "base/stl_util.h" 20#include "card_table-inl.h" 21#include "heap_bitmap.h" 22#include "gc/collector/mark_sweep.h" 23#include "gc/collector/mark_sweep-inl.h" 24#include "gc/collector/semi_space.h" 25#include "gc/heap.h" 26#include "gc/space/space.h" 27#include "mirror/art_field-inl.h" 28#include "mirror/object-inl.h" 29#include "mirror/class-inl.h" 30#include "mirror/object_array-inl.h" 31#include "space_bitmap-inl.h" 32#include "thread.h" 33#include "UniquePtr.h" 34 35namespace art { 36namespace gc { 37namespace accounting { 38 39class RememberedSetCardVisitor { 40 public: 41 explicit RememberedSetCardVisitor(RememberedSet::CardSet* const dirty_cards) 42 : dirty_cards_(dirty_cards) {} 43 44 void operator()(byte* card, byte expected_value, byte new_value) const { 45 if (expected_value == CardTable::kCardDirty) { 46 dirty_cards_->insert(card); 47 } 48 } 49 50 private: 51 RememberedSet::CardSet* const dirty_cards_; 52}; 53 54void RememberedSet::ClearCards() { 55 CardTable* card_table = GetHeap()->GetCardTable(); 56 RememberedSetCardVisitor card_visitor(&dirty_cards_); 57 // Clear dirty cards in the space and insert them into the dirty card set. 58 card_table->ModifyCardsAtomic(space_->Begin(), space_->End(), AgeCardVisitor(), card_visitor); 59} 60 61class RememberedSetReferenceVisitor { 62 public: 63 RememberedSetReferenceVisitor(MarkHeapReferenceCallback* callback, 64 space::ContinuousSpace* target_space, 65 bool* const contains_reference_to_target_space, void* arg) 66 : callback_(callback), target_space_(target_space), arg_(arg), 67 contains_reference_to_target_space_(contains_reference_to_target_space) {} 68 69 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 70 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 71 DCHECK(obj != nullptr); 72 mirror::HeapReference<mirror::Object>* ref_ptr = obj->GetFieldObjectReferenceAddr(offset); 73 if (target_space_->HasAddress(ref_ptr->AsMirrorPtr())) { 74 *contains_reference_to_target_space_ = true; 75 callback_(ref_ptr, arg_); 76 DCHECK(!target_space_->HasAddress(ref_ptr->AsMirrorPtr())); 77 } 78 } 79 80 private: 81 MarkHeapReferenceCallback* const callback_; 82 space::ContinuousSpace* const target_space_; 83 void* const arg_; 84 bool* const contains_reference_to_target_space_; 85}; 86 87class RememberedSetObjectVisitor { 88 public: 89 RememberedSetObjectVisitor(MarkHeapReferenceCallback* callback, 90 space::ContinuousSpace* target_space, 91 bool* const contains_reference_to_target_space, void* arg) 92 : callback_(callback), target_space_(target_space), arg_(arg), 93 contains_reference_to_target_space_(contains_reference_to_target_space) {} 94 95 void operator()(mirror::Object* obj) const EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) 96 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 97 RememberedSetReferenceVisitor ref_visitor(callback_, target_space_, 98 contains_reference_to_target_space_, arg_); 99 obj->VisitReferences<kMovingClasses>(ref_visitor); 100 } 101 102 private: 103 MarkHeapReferenceCallback* const callback_; 104 space::ContinuousSpace* const target_space_; 105 void* const arg_; 106 bool* const contains_reference_to_target_space_; 107}; 108 109void RememberedSet::UpdateAndMarkReferences(MarkHeapReferenceCallback* callback, 110 space::ContinuousSpace* target_space, void* arg) { 111 CardTable* card_table = heap_->GetCardTable(); 112 bool contains_reference_to_target_space = false; 113 RememberedSetObjectVisitor obj_visitor(callback, target_space, 114 &contains_reference_to_target_space, arg); 115 SpaceBitmap* bitmap = space_->GetLiveBitmap(); 116 CardSet remove_card_set; 117 for (byte* const card_addr : dirty_cards_) { 118 contains_reference_to_target_space = false; 119 uintptr_t start = reinterpret_cast<uintptr_t>(card_table->AddrFromCard(card_addr)); 120 DCHECK(space_->HasAddress(reinterpret_cast<mirror::Object*>(start))); 121 bitmap->VisitMarkedRange(start, start + CardTable::kCardSize, obj_visitor); 122 if (!contains_reference_to_target_space) { 123 // It was in the dirty card set, but it didn't actually contain 124 // a reference to the target space. So, remove it from the dirty 125 // card set so we won't have to scan it again (unless it gets 126 // dirty again.) 127 remove_card_set.insert(card_addr); 128 } 129 } 130 131 // Remove the cards that didn't contain a reference to the target 132 // space from the dirty card set. 133 for (byte* const card_addr : remove_card_set) { 134 DCHECK(dirty_cards_.find(card_addr) != dirty_cards_.end()); 135 dirty_cards_.erase(card_addr); 136 } 137} 138 139void RememberedSet::Dump(std::ostream& os) { 140 CardTable* card_table = heap_->GetCardTable(); 141 os << "RememberedSet dirty cards: ["; 142 for (const byte* card_addr : dirty_cards_) { 143 auto start = reinterpret_cast<uintptr_t>(card_table->AddrFromCard(card_addr)); 144 auto end = start + CardTable::kCardSize; 145 os << reinterpret_cast<void*>(start) << "-" << reinterpret_cast<void*>(end) << "\n"; 146 } 147 os << "]"; 148} 149 150void RememberedSet::AssertAllDirtyCardsAreWithinSpace() const { 151 CardTable* card_table = heap_->GetCardTable(); 152 for (const byte* card_addr : dirty_cards_) { 153 auto start = reinterpret_cast<byte*>(card_table->AddrFromCard(card_addr)); 154 auto end = start + CardTable::kCardSize; 155 DCHECK_LE(space_->Begin(), start); 156 DCHECK_LE(end, space_->Limit()); 157 } 158} 159 160} // namespace accounting 161} // namespace gc 162} // namespace art 163