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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 #include "dex_file_layout.h"
18 
19 
20 #include "base/bit_utils.h"
21 #include "base/mman.h"
22 #include "dex_file.h"
23 
24 namespace art {
25 
MadviseLargestPageAlignedRegion(const uint8_t * begin,const uint8_t * end,int advice)26 int DexLayoutSection::MadviseLargestPageAlignedRegion(const uint8_t* begin,
27                                                       const uint8_t* end,
28                                                       int advice) {
29 #ifdef _WIN32
30   UNUSED(begin);
31   UNUSED(end);
32   UNUSED(advice);
33   PLOG(WARNING) << "madvise is unsupported on Windows.";
34 #else
35   DCHECK_LE(begin, end);
36   begin = AlignUp(begin, kPageSize);
37   end = AlignDown(end, kPageSize);
38   if (begin < end) {
39     // TODO: remove the direct dependency on madvise here.
40     int result = madvise(const_cast<uint8_t*>(begin), end - begin, advice);
41     if (result != 0) {
42       PLOG(WARNING) << "madvise failed " << result;
43     }
44     return result;
45   }
46 #endif
47   return 0;
48 }
49 
Madvise(const DexFile * dex_file,int advice) const50 void DexLayoutSection::Subsection::Madvise(const DexFile* dex_file, int advice) const {
51   DCHECK(dex_file != nullptr);
52   DCHECK_LT(start_offset_, dex_file->Size());
53   DCHECK_LE(end_offset_, dex_file->Size());
54   MadviseLargestPageAlignedRegion(dex_file->Begin() + start_offset_,
55                                   dex_file->Begin() + end_offset_,
56                                   advice);
57 }
58 
MadviseAtLoad(const DexFile * dex_file) const59 void DexLayoutSections::MadviseAtLoad(const DexFile* dex_file) const {
60 #ifdef _WIN32
61   UNUSED(dex_file);
62   PLOG(WARNING) << "madvise is unsupported on Windows.";
63 #else
64   // The dex file is already defaulted to random access everywhere.
65   for (const DexLayoutSection& section : sections_) {
66     section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeStartupOnly)].Madvise(
67         dex_file,
68         MADV_WILLNEED);
69     section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeHot)].Madvise(
70         dex_file,
71         MADV_WILLNEED);
72   }
73 #endif
74 }
75 
operator <<(std::ostream & os,const DexLayoutSection & section)76 std::ostream& operator<<(std::ostream& os, const DexLayoutSection& section) {
77   for (size_t i = 0; i < static_cast<size_t>(LayoutType::kLayoutTypeCount); ++i) {
78     const DexLayoutSection::Subsection& part = section.parts_[i];
79     os << static_cast<LayoutType>(i) << "("
80        << part.start_offset_ << "-" << part.end_offset_ << ") ";
81   }
82   return os;
83 }
84 
operator <<(std::ostream & os,const DexLayoutSections & sections)85 std::ostream& operator<<(std::ostream& os, const DexLayoutSections& sections) {
86   for (size_t i = 0; i < static_cast<size_t>(DexLayoutSections::SectionType::kSectionCount); ++i) {
87     os << static_cast<DexLayoutSections::SectionType>(i) << ":" << sections.sections_[i] << "\n";
88   }
89   return os;
90 }
91 
92 }  // namespace art
93