Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_ADDRESS_MAP_H_ |
| 6 | #define V8_ADDRESS_MAP_H_ |
| 7 | |
| 8 | #include "src/assert-scope.h" |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 9 | #include "src/base/hashmap.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 10 | #include "src/objects.h" |
| 11 | |
| 12 | namespace v8 { |
| 13 | namespace internal { |
| 14 | |
| 15 | class AddressMapBase { |
| 16 | protected: |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 17 | static void SetValue(base::HashMap::Entry* entry, uint32_t v) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 18 | entry->value = reinterpret_cast<void*>(v); |
| 19 | } |
| 20 | |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 21 | static uint32_t GetValue(base::HashMap::Entry* entry) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 22 | return static_cast<uint32_t>(reinterpret_cast<intptr_t>(entry->value)); |
| 23 | } |
| 24 | |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 25 | inline static base::HashMap::Entry* LookupEntry(base::HashMap* map, |
| 26 | HeapObject* obj, |
| 27 | bool insert) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 28 | if (insert) { |
| 29 | map->LookupOrInsert(Key(obj), Hash(obj)); |
| 30 | } |
| 31 | return map->Lookup(Key(obj), Hash(obj)); |
| 32 | } |
| 33 | |
| 34 | private: |
| 35 | static uint32_t Hash(HeapObject* obj) { |
| 36 | return static_cast<int32_t>(reinterpret_cast<intptr_t>(obj->address())); |
| 37 | } |
| 38 | |
| 39 | static void* Key(HeapObject* obj) { |
| 40 | return reinterpret_cast<void*>(obj->address()); |
| 41 | } |
| 42 | }; |
| 43 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 44 | class RootIndexMap : public AddressMapBase { |
| 45 | public: |
| 46 | explicit RootIndexMap(Isolate* isolate); |
| 47 | |
| 48 | static const int kInvalidRootIndex = -1; |
| 49 | |
| 50 | int Lookup(HeapObject* obj) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 51 | base::HashMap::Entry* entry = LookupEntry(map_, obj, false); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 52 | if (entry) return GetValue(entry); |
| 53 | return kInvalidRootIndex; |
| 54 | } |
| 55 | |
| 56 | private: |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 57 | base::HashMap* map_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 58 | |
| 59 | DISALLOW_COPY_AND_ASSIGN(RootIndexMap); |
| 60 | }; |
| 61 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 62 | class SerializerReference { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 63 | public: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 64 | SerializerReference() : bitfield_(Special(kInvalidValue)) {} |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 65 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 66 | static SerializerReference FromBitfield(uint32_t bitfield) { |
| 67 | return SerializerReference(bitfield); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 68 | } |
| 69 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 70 | static SerializerReference BackReference(AllocationSpace space, |
| 71 | uint32_t chunk_index, |
| 72 | uint32_t chunk_offset) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 73 | DCHECK(IsAligned(chunk_offset, kObjectAlignment)); |
| 74 | DCHECK_NE(LO_SPACE, space); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 75 | return SerializerReference( |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 76 | SpaceBits::encode(space) | ChunkIndexBits::encode(chunk_index) | |
| 77 | ChunkOffsetBits::encode(chunk_offset >> kObjectAlignmentBits)); |
| 78 | } |
| 79 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 80 | static SerializerReference LargeObjectReference(uint32_t index) { |
| 81 | return SerializerReference(SpaceBits::encode(LO_SPACE) | |
| 82 | ValueIndexBits::encode(index)); |
| 83 | } |
| 84 | |
| 85 | static SerializerReference AttachedReference(uint32_t index) { |
| 86 | return SerializerReference(SpaceBits::encode(kAttachedReferenceSpace) | |
| 87 | ValueIndexBits::encode(index)); |
| 88 | } |
| 89 | |
| 90 | static SerializerReference DummyReference() { |
| 91 | return SerializerReference(Special(kDummyValue)); |
| 92 | } |
| 93 | |
| 94 | bool is_valid() const { return bitfield_ != Special(kInvalidValue); } |
| 95 | |
| 96 | bool is_back_reference() const { |
| 97 | return SpaceBits::decode(bitfield_) <= LAST_SPACE; |
| 98 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 99 | |
| 100 | AllocationSpace space() const { |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 101 | DCHECK(is_back_reference()); |
| 102 | return static_cast<AllocationSpace>(SpaceBits::decode(bitfield_)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | uint32_t chunk_offset() const { |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 106 | DCHECK(is_back_reference()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 107 | return ChunkOffsetBits::decode(bitfield_) << kObjectAlignmentBits; |
| 108 | } |
| 109 | |
| 110 | uint32_t large_object_index() const { |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 111 | DCHECK(is_back_reference()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 112 | DCHECK(chunk_index() == 0); |
| 113 | return ChunkOffsetBits::decode(bitfield_); |
| 114 | } |
| 115 | |
| 116 | uint32_t chunk_index() const { |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 117 | DCHECK(is_back_reference()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 118 | return ChunkIndexBits::decode(bitfield_); |
| 119 | } |
| 120 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 121 | uint32_t back_reference() const { |
| 122 | DCHECK(is_back_reference()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 123 | return bitfield_ & (ChunkOffsetBits::kMask | ChunkIndexBits::kMask); |
| 124 | } |
| 125 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 126 | bool is_attached_reference() const { |
| 127 | return SpaceBits::decode(bitfield_) == kAttachedReferenceSpace; |
| 128 | } |
| 129 | |
| 130 | int attached_reference_index() const { |
| 131 | DCHECK(is_attached_reference()); |
| 132 | return ValueIndexBits::decode(bitfield_); |
| 133 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 134 | |
| 135 | private: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 136 | explicit SerializerReference(uint32_t bitfield) : bitfield_(bitfield) {} |
| 137 | |
| 138 | inline static uint32_t Special(int value) { |
| 139 | return SpaceBits::encode(kSpecialValueSpace) | |
| 140 | ValueIndexBits::encode(value); |
| 141 | } |
| 142 | |
| 143 | // We use the 32-bit bitfield to encode either a back reference, a special |
| 144 | // value, or an attached reference index. |
| 145 | // Back reference: |
| 146 | // [ Space index ] [ Chunk index ] [ Chunk offset ] |
| 147 | // [ LO_SPACE ] [ large object index ] |
| 148 | // Special value |
| 149 | // [ kSpecialValueSpace ] [ Special value index ] |
| 150 | // Attached reference |
| 151 | // [ kAttachedReferenceSpace ] [ Attached reference index ] |
| 152 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 153 | static const int kChunkOffsetSize = kPageSizeBits - kObjectAlignmentBits; |
| 154 | static const int kChunkIndexSize = 32 - kChunkOffsetSize - kSpaceTagSize; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 155 | static const int kValueIndexSize = kChunkOffsetSize + kChunkIndexSize; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 156 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 157 | static const int kSpecialValueSpace = LAST_SPACE + 1; |
| 158 | static const int kAttachedReferenceSpace = kSpecialValueSpace + 1; |
| 159 | STATIC_ASSERT(kAttachedReferenceSpace < (1 << kSpaceTagSize)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 160 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 161 | static const int kInvalidValue = 0; |
| 162 | static const int kDummyValue = 1; |
| 163 | |
| 164 | // The chunk offset can also be used to encode the index of special values. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 165 | class ChunkOffsetBits : public BitField<uint32_t, 0, kChunkOffsetSize> {}; |
| 166 | class ChunkIndexBits |
| 167 | : public BitField<uint32_t, ChunkOffsetBits::kNext, kChunkIndexSize> {}; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 168 | class ValueIndexBits : public BitField<uint32_t, 0, kValueIndexSize> {}; |
| 169 | STATIC_ASSERT(ChunkIndexBits::kNext == ValueIndexBits::kNext); |
| 170 | class SpaceBits : public BitField<int, kValueIndexSize, kSpaceTagSize> {}; |
| 171 | STATIC_ASSERT(SpaceBits::kNext == 32); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 172 | |
| 173 | uint32_t bitfield_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 174 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 175 | friend class SerializerReferenceMap; |
| 176 | }; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 177 | |
| 178 | // Mapping objects to their location after deserialization. |
| 179 | // This is used during building, but not at runtime by V8. |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 180 | class SerializerReferenceMap : public AddressMapBase { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 181 | public: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 182 | SerializerReferenceMap() |
| 183 | : no_allocation_(), |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 184 | map_(base::HashMap::PointersMatch), |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 185 | attached_reference_index_(0) {} |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 186 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 187 | SerializerReference Lookup(HeapObject* obj) { |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 188 | base::HashMap::Entry* entry = LookupEntry(&map_, obj, false); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 189 | return entry ? SerializerReference(GetValue(entry)) : SerializerReference(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 190 | } |
| 191 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 192 | void Add(HeapObject* obj, SerializerReference b) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 193 | DCHECK(b.is_valid()); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 194 | DCHECK_NULL(LookupEntry(&map_, obj, false)); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 195 | base::HashMap::Entry* entry = LookupEntry(&map_, obj, true); |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 196 | SetValue(entry, b.bitfield_); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 197 | } |
| 198 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 199 | SerializerReference AddAttachedReference(HeapObject* attached_reference) { |
| 200 | SerializerReference reference = |
| 201 | SerializerReference::AttachedReference(attached_reference_index_++); |
| 202 | Add(attached_reference, reference); |
| 203 | return reference; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 204 | } |
| 205 | |
| 206 | private: |
| 207 | DisallowHeapAllocation no_allocation_; |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 208 | base::HashMap map_; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 209 | int attached_reference_index_; |
| 210 | DISALLOW_COPY_AND_ASSIGN(SerializerReferenceMap); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 211 | }; |
| 212 | |
| 213 | } // namespace internal |
| 214 | } // namespace v8 |
| 215 | |
| 216 | #endif // V8_ADDRESS_MAP_H_ |