Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 1 | /* |
Elliott Hughes | 2faa5f1 | 2012-01-30 14:42:07 -0800 | [diff] [blame] | 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. |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 15 | */ |
| 16 | |
| 17 | #ifndef DALVIK_ALLOC_CARDTABLE_H_ |
| 18 | #define DALVIK_ALLOC_CARDTABLE_H_ |
| 19 | |
| 20 | #include "globals.h" |
| 21 | #include "logging.h" |
| 22 | #include "mem_map.h" |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 23 | #include "space_bitmap.h" |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 24 | #include "UniquePtr.h" |
| 25 | |
| 26 | namespace art { |
| 27 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 28 | class Heap; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 29 | class Space; |
Mathieu Chartier | b062fdd | 2012-07-03 09:51:48 -0700 | [diff] [blame] | 30 | class SpaceBitmap; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 31 | class Object; |
| 32 | |
| 33 | #define GC_CARD_SHIFT 7 |
| 34 | #define GC_CARD_SIZE (1 << GC_CARD_SHIFT) |
| 35 | #define GC_CARD_CLEAN 0 |
| 36 | #define GC_CARD_DIRTY 0x70 |
| 37 | |
Elliott Hughes | 2faa5f1 | 2012-01-30 14:42:07 -0800 | [diff] [blame] | 38 | // Maintain a card table from the the write barrier. All writes of |
| 39 | // non-NULL values to heap addresses should go through an entry in |
| 40 | // WriteBarrier, and from there to here. |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 41 | class CardTable { |
| 42 | public: |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 43 | static CardTable* Create(const byte* heap_begin, size_t heap_capacity); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 44 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 45 | // Set the card associated with the given address to GC_CARD_DIRTY. |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 46 | void MarkCard(const void *addr) { |
Elliott Hughes | 24edeb5 | 2012-06-18 15:29:46 -0700 | [diff] [blame] | 47 | byte* card_addr = CardFromAddr(addr); |
| 48 | *card_addr = GC_CARD_DIRTY; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 49 | } |
| 50 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 51 | // Is the object on a dirty card? |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 52 | bool IsDirty(const Object* obj) const { |
| 53 | return *CardFromAddr(obj) == GC_CARD_DIRTY; |
| 54 | } |
| 55 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 56 | // Visit cards within memory range. |
| 57 | template <typename Visitor> |
| 58 | void VisitClear(const void* start, const void* end, const Visitor& visitor) { |
| 59 | byte* card_start = CardFromAddr(start); |
| 60 | byte* card_end = CardFromAddr(end); |
| 61 | for (byte* cur = card_start; cur != card_end; ++cur) { |
| 62 | if (*cur == GC_CARD_DIRTY) { |
| 63 | *cur = GC_CARD_CLEAN; |
| 64 | visitor(cur); |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 69 | // Returns a value that when added to a heap address >> GC_CARD_SHIFT will address the appropriate |
| 70 | // card table byte. For convenience this value is cached in every Thread |
| 71 | byte* GetBiasedBegin() const { |
| 72 | return biased_begin_; |
jeffhao | 39da035 | 2011-11-04 14:58:55 -0700 | [diff] [blame] | 73 | } |
| 74 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 75 | // For every dirty card between begin and end invoke the visitor with the specified argument. |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 76 | template <typename Visitor, typename FingerVisitor> |
| 77 | void Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_end, |
| 78 | const Visitor& visitor, const FingerVisitor& finger_visitor) const |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 79 | EXCLUSIVE_LOCKS_REQUIRED(GlobalSynchronization::heap_bitmap_lock_) |
| 80 | SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 81 | DCHECK(bitmap->HasAddress(scan_begin)); |
| 82 | DCHECK(bitmap->HasAddress(scan_end - 1)); // scan_end is the byte after the last byte we scan. |
| 83 | byte* card_cur = CardFromAddr(scan_begin); |
| 84 | byte* card_end = CardFromAddr(scan_end); |
| 85 | while (card_cur < card_end) { |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 86 | // Find the first dirty card. |
| 87 | card_cur = reinterpret_cast<byte*>(memchr(card_cur, GC_CARD_DIRTY, card_end - card_cur)); |
| 88 | if (card_cur == NULL) { |
| 89 | break; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 90 | } |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 91 | byte* run_start = card_cur++; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 92 | |
Mathieu Chartier | fd678be | 2012-08-30 14:50:54 -0700 | [diff] [blame^] | 93 | while (*card_cur == GC_CARD_DIRTY && card_cur < card_end) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 94 | card_cur++; |
| 95 | } |
| 96 | byte* run_end = card_cur; |
| 97 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 98 | uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(run_start)); |
| 99 | uintptr_t end = reinterpret_cast<uintptr_t>(AddrFromCard(run_end)); |
| 100 | bitmap->VisitMarkedRange(start, end, visitor, finger_visitor); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 101 | } |
| 102 | } |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 103 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 104 | // Assertion used to check the given address is covered by the card table |
| 105 | void CheckAddrIsInCardTable(const byte* addr) const; |
| 106 | |
Mathieu Chartier | 262e5ff | 2012-06-01 17:35:38 -0700 | [diff] [blame] | 107 | // Resets all of the bytes in the card table to clean. |
| 108 | void ClearCardTable(); |
| 109 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 110 | // Resets all of the bytes in the card table which do not map to the image space. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 111 | void ClearSpaceCards(Space* space); |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 112 | |
Mathieu Chartier | 357e9be | 2012-08-01 11:00:14 -0700 | [diff] [blame] | 113 | // Clean all the cards which map to a space. |
| 114 | void PreClearCards(Space* space, std::vector<byte*>& out_cards); |
| 115 | |
| 116 | // Returns all of the dirty cards which map to a space. |
| 117 | void GetDirtyCards(Space* space, std::vector<byte*>& out_cards) const; |
| 118 | |
Mathieu Chartier | b43b7d4 | 2012-06-19 13:15:09 -0700 | [diff] [blame] | 119 | // Returns the first address in the heap which maps to this card. |
| 120 | void* AddrFromCard(const byte *card_addr) const { |
| 121 | DCHECK(IsValidCard(card_addr)) |
| 122 | << " card_addr: " << reinterpret_cast<const void*>(card_addr) |
| 123 | << " begin: " << reinterpret_cast<void*>(mem_map_->Begin() + offset_) |
| 124 | << " end: " << reinterpret_cast<void*>(mem_map_->End()); |
| 125 | uintptr_t offset = card_addr - biased_begin_; |
| 126 | return reinterpret_cast<void*>(offset << GC_CARD_SHIFT); |
| 127 | } |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 128 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 129 | // Returns the address of the relevant byte in the card table, given an address on the heap. |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 130 | byte* CardFromAddr(const void *addr) const { |
Elliott Hughes | 24edeb5 | 2012-06-18 15:29:46 -0700 | [diff] [blame] | 131 | byte *card_addr = biased_begin_ + ((uintptr_t)addr >> GC_CARD_SHIFT); |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 132 | // Sanity check the caller was asking for address covered by the card table |
Elliott Hughes | 24edeb5 | 2012-06-18 15:29:46 -0700 | [diff] [blame] | 133 | DCHECK(IsValidCard(card_addr)) << "addr: " << addr |
| 134 | << " card_addr: " << reinterpret_cast<void*>(card_addr); |
| 135 | return card_addr; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 136 | } |
| 137 | |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 138 | private: |
| 139 | CardTable(MemMap* begin, byte* biased_begin, size_t offset); |
| 140 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 141 | // Returns true iff the card table address is within the bounds of the card table. |
Elliott Hughes | 24edeb5 | 2012-06-18 15:29:46 -0700 | [diff] [blame] | 142 | bool IsValidCard(const byte* card_addr) const { |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 143 | byte* begin = mem_map_->Begin() + offset_; |
| 144 | byte* end = mem_map_->End(); |
Elliott Hughes | 24edeb5 | 2012-06-18 15:29:46 -0700 | [diff] [blame] | 145 | return card_addr >= begin && card_addr < end; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 146 | } |
| 147 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 148 | // Verifies that all gray objects are on a dirty card. |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 149 | void VerifyCardTable(); |
| 150 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 151 | // Mmapped pages for the card table |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 152 | UniquePtr<MemMap> mem_map_; |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 153 | // Value used to compute card table addresses from object addresses, see GetBiasedBegin |
| 154 | byte* const biased_begin_; |
| 155 | // Card table doesn't begin at the beginning of the mem_map_, instead it is displaced by offset |
| 156 | // to allow the byte value of biased_begin_ to equal GC_CARD_DIRTY |
| 157 | const size_t offset_; |
Ian Rogers | 5d76c43 | 2011-10-31 21:42:49 -0700 | [diff] [blame] | 158 | }; |
| 159 | |
| 160 | } // namespace art |
| 161 | #endif // DALVIK_ALLOC_CARDTABLE_H_ |