Martin Stjernholm | c15e7e4 | 2020-12-02 22:50:53 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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 | #ifndef ART_LIBDEXFILE_DEX_DEX_FILE_LAYOUT_H_ |
| 18 | #define ART_LIBDEXFILE_DEX_DEX_FILE_LAYOUT_H_ |
| 19 | |
| 20 | #include <algorithm> |
| 21 | #include <cstdint> |
| 22 | #include <iosfwd> |
| 23 | |
| 24 | #include <android-base/logging.h> |
| 25 | |
| 26 | namespace art { |
| 27 | |
| 28 | class DexFile; |
| 29 | |
| 30 | enum class LayoutType : uint8_t { |
| 31 | // Layout of things that are hot (commonly accessed), these should be pinned or madvised will |
| 32 | // need. |
| 33 | kLayoutTypeHot, |
| 34 | // Layout of things that are randomly used. These should be advised to random access. |
| 35 | // Without layout, this is the default mode when loading a dex file. |
| 36 | kLayoutTypeSometimesUsed, |
| 37 | // Layout of things that are only used during startup, these can be madvised after launch. |
| 38 | kLayoutTypeStartupOnly, |
| 39 | // Layout of things that are needed probably only once (class initializers). These can be |
| 40 | // madvised during trim events. |
| 41 | kLayoutTypeUsedOnce, |
| 42 | // Layout of things that are thought to be unused. These things should be advised to random |
| 43 | // access. |
| 44 | kLayoutTypeUnused, |
| 45 | // Unused value, just the number of elements in the enum. |
| 46 | kLayoutTypeCount, |
| 47 | }; |
| 48 | std::ostream& operator<<(std::ostream& os, LayoutType collector_type); |
| 49 | |
| 50 | // Return the "best" layout option if the same item has multiple different layouts. |
| 51 | static inline LayoutType MergeLayoutType(LayoutType a, LayoutType b) { |
| 52 | return std::min(a, b); |
| 53 | } |
| 54 | |
Martin Stjernholm | c15e7e4 | 2020-12-02 22:50:53 +0000 | [diff] [blame] | 55 | // A dex layout section such as code items or strings. Each section is composed of subsections |
| 56 | // that are laid out adjacently to each other such as (hot, unused, startup, etc...). |
| 57 | class DexLayoutSection { |
| 58 | public: |
| 59 | // A subsection is a a continuous range of dex file that is all part of the same layout hint. |
| 60 | class Subsection { |
| 61 | public: |
| 62 | // Use uint32_t to handle 32/64 bit cross compilation. |
| 63 | uint32_t start_offset_ = 0u; |
| 64 | uint32_t end_offset_ = 0u; |
| 65 | |
| 66 | bool Contains(uint32_t offset) const { |
| 67 | return start_offset_ <= offset && offset < end_offset_; |
| 68 | } |
| 69 | |
| 70 | bool Size() const { |
| 71 | DCHECK_LE(start_offset_, end_offset_); |
| 72 | return end_offset_ - start_offset_; |
| 73 | } |
| 74 | |
| 75 | void CombineSection(uint32_t start_offset, uint32_t end_offset) { |
| 76 | DCHECK_LE(start_offset, end_offset); |
| 77 | if (start_offset_ == end_offset_) { |
| 78 | start_offset_ = start_offset; |
| 79 | end_offset_ = end_offset; |
| 80 | } else { |
| 81 | start_offset_ = std::min(start_offset_, start_offset); |
| 82 | end_offset_ = std::max(end_offset_, end_offset); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | void Madvise(const DexFile* dex_file, int advice) const; |
| 87 | }; |
| 88 | |
| 89 | // Madvise the largest page-aligned region contained in [begin, end). |
| 90 | static int MadviseLargestPageAlignedRegion(const uint8_t* begin, const uint8_t* end, int advice); |
| 91 | |
| 92 | Subsection parts_[static_cast<size_t>(LayoutType::kLayoutTypeCount)]; |
| 93 | }; |
| 94 | |
| 95 | // A set of dex layout sections, currently there is only one section for code and one for strings. |
| 96 | class DexLayoutSections { |
| 97 | public: |
| 98 | enum class SectionType : uint8_t { |
| 99 | kSectionTypeCode, |
| 100 | kSectionTypeStrings, |
| 101 | kSectionCount, |
| 102 | }; |
| 103 | |
android-t1 | 3d2c5b2 | 2022-10-12 13:43:18 +0800 | [diff] [blame] | 104 | // Advise load access about the dex file based on layout. The caller is expected to have already |
Martin Stjernholm | c15e7e4 | 2020-12-02 22:50:53 +0000 | [diff] [blame] | 105 | // madvised to MADV_RANDOM. |
android-t1 | 3d2c5b2 | 2022-10-12 13:43:18 +0800 | [diff] [blame] | 106 | void MadviseAtLoad(const DexFile* dex_file) const; |
Martin Stjernholm | c15e7e4 | 2020-12-02 22:50:53 +0000 | [diff] [blame] | 107 | |
| 108 | DexLayoutSection sections_[static_cast<size_t>(SectionType::kSectionCount)]; |
| 109 | }; |
| 110 | |
| 111 | std::ostream& operator<<(std::ostream& os, DexLayoutSections::SectionType collector_type); |
| 112 | std::ostream& operator<<(std::ostream& os, const DexLayoutSection& section); |
| 113 | std::ostream& operator<<(std::ostream& os, const DexLayoutSections& sections); |
| 114 | |
| 115 | } // namespace art |
| 116 | |
| 117 | #endif // ART_LIBDEXFILE_DEX_DEX_FILE_LAYOUT_H_ |