1 /*
2  * Copyright (C) 2018 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_RUNTIME_INTERN_TABLE_INL_H_
18 #define ART_RUNTIME_INTERN_TABLE_INL_H_
19 
20 #include "intern_table.h"
21 
22 #include "gc/space/image_space.h"
23 #include "image.h"
24 #include "mirror/string-inl.h"  // Required for ToModifiedUtf8 below.
25 
26 namespace art {
27 
28 template <typename Visitor>
AddImageStringsToTable(gc::space::ImageSpace * image_space,const Visitor & visitor)29 inline void InternTable::AddImageStringsToTable(gc::space::ImageSpace* image_space,
30                                                 const Visitor& visitor) {
31   DCHECK(image_space != nullptr);
32   // Only add if we have the interned strings section.
33   const ImageHeader& header = image_space->GetImageHeader();
34   const ImageSection& section = header.GetInternedStringsSection();
35   if (section.Size() > 0) {
36     AddTableFromMemory(image_space->Begin() + section.Offset(), visitor, !header.IsAppImage());
37   }
38 }
39 
40 template <typename Visitor>
AddTableFromMemory(const uint8_t * ptr,const Visitor & visitor,bool is_boot_image)41 inline size_t InternTable::AddTableFromMemory(const uint8_t* ptr,
42                                               const Visitor& visitor,
43                                               bool is_boot_image) {
44   size_t read_count = 0;
45   UnorderedSet set(ptr, /*make copy*/false, &read_count);
46   {
47     // Hold the lock while calling the visitor to prevent possible race
48     // conditions with another thread adding intern strings.
49     MutexLock mu(Thread::Current(), *Locks::intern_table_lock_);
50     // Visit the unordered set, may remove elements.
51     visitor(set);
52     if (!set.empty()) {
53       strong_interns_.AddInternStrings(std::move(set), is_boot_image);
54     }
55   }
56   return read_count;
57 }
58 
AddInternStrings(UnorderedSet && intern_strings,bool is_boot_image)59 inline void InternTable::Table::AddInternStrings(UnorderedSet&& intern_strings,
60                                                  bool is_boot_image) {
61   static constexpr bool kCheckDuplicates = kIsDebugBuild;
62   if (kCheckDuplicates) {
63     // Avoid doing read barriers since the space might not yet be added to the heap.
64     // See b/117803941
65     for (GcRoot<mirror::String>& string : intern_strings) {
66       CHECK(Find(string.Read<kWithoutReadBarrier>()) == nullptr)
67           << "Already found " << string.Read<kWithoutReadBarrier>()->ToModifiedUtf8()
68           << " in the intern table";
69     }
70   }
71   // Insert at the front since we add new interns into the back.
72   tables_.insert(tables_.begin(),
73                  InternalTable(std::move(intern_strings), is_boot_image));
74 }
75 
76 template <typename Visitor>
VisitInterns(const Visitor & visitor,bool visit_boot_images,bool visit_non_boot_images)77 inline void InternTable::VisitInterns(const Visitor& visitor,
78                                       bool visit_boot_images,
79                                       bool visit_non_boot_images) {
80   auto visit_tables = [&](std::vector<Table::InternalTable>& tables)
81       NO_THREAD_SAFETY_ANALYSIS {
82     for (Table::InternalTable& table : tables) {
83       // Determine if we want to visit the table based on the flags..
84       const bool visit =
85           (visit_boot_images && table.IsBootImage()) ||
86           (visit_non_boot_images && !table.IsBootImage());
87       if (visit) {
88         for (auto& intern : table.set_) {
89           visitor(intern);
90         }
91       }
92     }
93   };
94   visit_tables(strong_interns_.tables_);
95   visit_tables(weak_interns_.tables_);
96 }
97 
CountInterns(bool visit_boot_images,bool visit_non_boot_images)98 inline size_t InternTable::CountInterns(bool visit_boot_images,
99                                         bool visit_non_boot_images) const {
100   size_t ret = 0u;
101   auto visit_tables = [&](const std::vector<Table::InternalTable>& tables)
102       NO_THREAD_SAFETY_ANALYSIS {
103     for (const Table::InternalTable& table : tables) {
104       // Determine if we want to visit the table based on the flags..
105       const bool visit =
106           (visit_boot_images && table.IsBootImage()) ||
107           (visit_non_boot_images && !table.IsBootImage());
108       if (visit) {
109         ret += table.set_.size();
110       }
111     }
112   };
113   visit_tables(strong_interns_.tables_);
114   visit_tables(weak_interns_.tables_);
115   return ret;
116 }
117 
118 }  // namespace art
119 
120 #endif  // ART_RUNTIME_INTERN_TABLE_INL_H_
121