| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ART_SRC_GC_MOD_UNION_TABLE_H_ |
| #define ART_SRC_GC_MOD_UNION_TABLE_H_ |
| |
| #include "globals.h" |
| #include "safe_map.h" |
| |
| #include <set> |
| #include <vector> |
| |
| namespace art { |
| namespace mirror { |
| class Object; |
| } |
| class ContinuousSpace; |
| class Heap; |
| class HeapBitmap; |
| class MarkSweep; |
| class Space; |
| class SpaceBitmap; |
| |
| // Base class |
| class ModUnionTable { |
| public: |
| typedef std::vector<const mirror::Object*> ReferenceArray; |
| typedef std::set<byte*> ClearedCards; |
| |
| ModUnionTable(Heap* heap) : heap_(heap) { |
| |
| } |
| |
| virtual ~ModUnionTable() { |
| |
| } |
| |
| // Clear cards which map to a memory range of a space. |
| virtual void ClearCards(ContinuousSpace* space) = 0; |
| |
| // Update the mod-union table. |
| virtual void Update() = 0; |
| |
| // Mark all references which are stored in the mod union table. |
| virtual void MarkReferences(MarkSweep* mark_sweep) = 0; |
| |
| // Verification, sanity checks that we don't have clean cards which conflict with out cached data |
| // for said cards. Exclusive lock is required since verify sometimes uses |
| // SpaceBitmap::VisitMarkedRange and VisitMarkedRange can't know if the callback will modify the |
| // bitmap or not. |
| virtual void Verify() EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) = 0; |
| |
| Heap* GetHeap() { |
| return heap_; |
| } |
| |
| protected: |
| Heap* heap_; |
| }; |
| |
| // Bitmap implementation. |
| // DEPRECATED, performs strictly less well than merely caching which cards were dirty. |
| class ModUnionTableBitmap : public ModUnionTable { |
| public: |
| ModUnionTableBitmap(Heap* heap); |
| virtual ~ModUnionTableBitmap(); |
| |
| // Clear space cards. |
| void ClearCards(ContinuousSpace* space); |
| |
| // Update table based on cleared cards. |
| void Update() |
| EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Mark all references to the alloc space(s). |
| void MarkReferences(MarkSweep* mark_sweep) EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_); |
| |
| protected: |
| // Cleared card array, used to update the mod-union table. |
| std::vector<byte*> cleared_cards_; |
| |
| // One bitmap per image space. |
| // TODO: Add support for Zygote spaces? |
| typedef SafeMap<ContinuousSpace*, SpaceBitmap*> BitmapMap; |
| BitmapMap bitmaps_; |
| }; |
| |
| // Reference caching implementation. Caches references pointing to alloc space(s) for each card. |
| class ModUnionTableReferenceCache : public ModUnionTable { |
| public: |
| typedef SafeMap<const byte*, ReferenceArray > ReferenceMap; |
| |
| ModUnionTableReferenceCache(Heap* heap); |
| virtual ~ModUnionTableReferenceCache(); |
| |
| // Clear and store cards for a space. |
| void ClearCards(ContinuousSpace* space); |
| |
| // Update table based on cleared cards. |
| void Update() |
| EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Mark all references to the alloc space(s). |
| void MarkReferences(MarkSweep* mark_sweep) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) |
| EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_); |
| |
| // Exclusive lock is required since verify uses SpaceBitmap::VisitMarkedRange and |
| // VisitMarkedRange can't know if the callback will modify the bitmap or not. |
| void Verify() EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_); |
| |
| // Function that tells whether or not to add a reference to the table. |
| virtual bool AddReference(const mirror::Object* obj, const mirror::Object* ref) = 0; |
| |
| protected: |
| // Cleared card array, used to update the mod-union table. |
| ClearedCards cleared_cards_; |
| |
| // Maps from dirty cards to their corresponding alloc space references. |
| ReferenceMap references_; |
| }; |
| |
| // Card caching implementation. Keeps track of which cards we cleared and only this information. |
| class ModUnionTableCardCache : public ModUnionTable { |
| public: |
| typedef SafeMap<const byte*, ReferenceArray > ReferenceMap; |
| |
| ModUnionTableCardCache(Heap* heap); |
| virtual ~ModUnionTableCardCache(); |
| |
| // Clear and store cards for a space. |
| void ClearCards(ContinuousSpace* space); |
| |
| // Nothing to update. |
| void Update() {} |
| |
| // Mark all references to the alloc space(s). |
| void MarkReferences(MarkSweep* mark_sweep) |
| EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) |
| SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); |
| |
| // Nothing to verify. |
| void Verify() {} |
| |
| protected: |
| // Cleared card array, used to update the mod-union table. |
| ClearedCards cleared_cards_; |
| }; |
| |
| } // namespace art |
| |
| #endif // ART_SRC_GC_MOD_UNION_TABLE_H_ |