1 /*
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.
15  */
16 
17 #ifndef ART_RUNTIME_CLASS_LINKER_INL_H_
18 #define ART_RUNTIME_CLASS_LINKER_INL_H_
19 
20 #include "art_field.h"
21 #include "class_linker.h"
22 #include "gc_root-inl.h"
23 #include "gc/heap-inl.h"
24 #include "mirror/class_loader.h"
25 #include "mirror/dex_cache-inl.h"
26 #include "mirror/iftable.h"
27 #include "mirror/object_array.h"
28 #include "handle_scope-inl.h"
29 
30 namespace art {
31 
FindSystemClass(Thread * self,const char * descriptor)32 inline mirror::Class* ClassLinker::FindSystemClass(Thread* self, const char* descriptor) {
33   return FindClass(self, descriptor, NullHandle<mirror::ClassLoader>());
34 }
35 
FindArrayClass(Thread * self,mirror::Class ** element_class)36 inline mirror::Class* ClassLinker::FindArrayClass(Thread* self, mirror::Class** element_class) {
37   for (size_t i = 0; i < kFindArrayCacheSize; ++i) {
38     // Read the cached array class once to avoid races with other threads setting it.
39     mirror::Class* array_class = find_array_class_cache_[i].Read();
40     if (array_class != nullptr && array_class->GetComponentType() == *element_class) {
41       return array_class;
42     }
43   }
44   DCHECK(!(*element_class)->IsPrimitiveVoid());
45   std::string descriptor = "[";
46   std::string temp;
47   descriptor += (*element_class)->GetDescriptor(&temp);
48   StackHandleScope<2> hs(Thread::Current());
49   Handle<mirror::ClassLoader> class_loader(hs.NewHandle((*element_class)->GetClassLoader()));
50   HandleWrapper<mirror::Class> h_element_class(hs.NewHandleWrapper(element_class));
51   mirror::Class* array_class = FindClass(self, descriptor.c_str(), class_loader);
52   // Benign races in storing array class and incrementing index.
53   size_t victim_index = find_array_class_cache_next_victim_;
54   find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class);
55   find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize;
56   return array_class;
57 }
58 
ResolveString(uint32_t string_idx,ArtMethod * referrer)59 inline mirror::String* ClassLinker::ResolveString(uint32_t string_idx,
60                                                   ArtMethod* referrer) {
61   mirror::Class* declaring_class = referrer->GetDeclaringClass();
62   mirror::String* resolved_string = declaring_class->GetDexCacheStrings()->Get(string_idx);
63   if (UNLIKELY(resolved_string == nullptr)) {
64     StackHandleScope<1> hs(Thread::Current());
65     Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
66     const DexFile& dex_file = *dex_cache->GetDexFile();
67     resolved_string = ResolveString(dex_file, string_idx, dex_cache);
68     if (resolved_string != nullptr) {
69       DCHECK_EQ(dex_cache->GetResolvedString(string_idx), resolved_string);
70     }
71   }
72   return resolved_string;
73 }
74 
ResolveType(uint16_t type_idx,ArtMethod * referrer)75 inline mirror::Class* ClassLinker::ResolveType(uint16_t type_idx,
76                                                ArtMethod* referrer) {
77   mirror::Class* resolved_type = referrer->GetDexCacheResolvedType(type_idx);
78   if (UNLIKELY(resolved_type == nullptr)) {
79     mirror::Class* declaring_class = referrer->GetDeclaringClass();
80     StackHandleScope<2> hs(Thread::Current());
81     Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
82     Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
83     const DexFile& dex_file = *dex_cache->GetDexFile();
84     resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader);
85     // Note: We cannot check here to see whether we added the type to the cache. The type
86     //       might be an erroneous class, which results in it being hidden from us.
87   }
88   return resolved_type;
89 }
90 
ResolveType(uint16_t type_idx,ArtField * referrer)91 inline mirror::Class* ClassLinker::ResolveType(uint16_t type_idx, ArtField* referrer) {
92   mirror::Class* declaring_class = referrer->GetDeclaringClass();
93   mirror::DexCache* dex_cache_ptr = declaring_class->GetDexCache();
94   mirror::Class* resolved_type = dex_cache_ptr->GetResolvedType(type_idx);
95   if (UNLIKELY(resolved_type == nullptr)) {
96     StackHandleScope<2> hs(Thread::Current());
97     Handle<mirror::DexCache> dex_cache(hs.NewHandle(dex_cache_ptr));
98     Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
99     const DexFile& dex_file = *dex_cache->GetDexFile();
100     resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader);
101     // Note: We cannot check here to see whether we added the type to the cache. The type
102     //       might be an erroneous class, which results in it being hidden from us.
103   }
104   return resolved_type;
105 }
106 
GetResolvedMethod(uint32_t method_idx,ArtMethod * referrer)107 inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) {
108   ArtMethod* resolved_method = referrer->GetDexCacheResolvedMethod(
109       method_idx, image_pointer_size_);
110   if (resolved_method == nullptr || resolved_method->IsRuntimeMethod()) {
111     return nullptr;
112   }
113   return resolved_method;
114 }
115 
ResolveMethod(Thread * self,uint32_t method_idx,ArtMethod * referrer,InvokeType type)116 inline ArtMethod* ClassLinker::ResolveMethod(Thread* self, uint32_t method_idx,
117                                              ArtMethod* referrer, InvokeType type) {
118   ArtMethod* resolved_method = GetResolvedMethod(method_idx, referrer);
119   if (UNLIKELY(resolved_method == nullptr)) {
120     mirror::Class* declaring_class = referrer->GetDeclaringClass();
121     StackHandleScope<2> hs(self);
122     Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
123     Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
124     const DexFile* dex_file = h_dex_cache->GetDexFile();
125     resolved_method = ResolveMethod(*dex_file, method_idx, h_dex_cache, h_class_loader, referrer,
126                                     type);
127   }
128   // Note: We cannot check here to see whether we added the method to the cache. It
129   //       might be an erroneous class, which results in it being hidden from us.
130   return resolved_method;
131 }
132 
GetResolvedField(uint32_t field_idx,mirror::DexCache * dex_cache)133 inline ArtField* ClassLinker::GetResolvedField(uint32_t field_idx, mirror::DexCache* dex_cache) {
134   return dex_cache->GetResolvedField(field_idx, image_pointer_size_);
135 }
136 
GetResolvedField(uint32_t field_idx,mirror::Class * field_declaring_class)137 inline ArtField* ClassLinker::GetResolvedField(
138     uint32_t field_idx, mirror::Class* field_declaring_class) {
139   return GetResolvedField(field_idx, field_declaring_class->GetDexCache());
140 }
141 
ResolveField(uint32_t field_idx,ArtMethod * referrer,bool is_static)142 inline ArtField* ClassLinker::ResolveField(uint32_t field_idx, ArtMethod* referrer,
143                                            bool is_static) {
144   mirror::Class* declaring_class = referrer->GetDeclaringClass();
145   ArtField* resolved_field = GetResolvedField(field_idx, declaring_class);
146   if (UNLIKELY(resolved_field == nullptr)) {
147     StackHandleScope<2> hs(Thread::Current());
148     Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
149     Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
150     const DexFile& dex_file = *dex_cache->GetDexFile();
151     resolved_field = ResolveField(dex_file, field_idx, dex_cache, class_loader, is_static);
152     // Note: We cannot check here to see whether we added the field to the cache. The type
153     //       might be an erroneous class, which results in it being hidden from us.
154   }
155   return resolved_field;
156 }
157 
AllocObject(Thread * self)158 inline mirror::Object* ClassLinker::AllocObject(Thread* self) {
159   return GetClassRoot(kJavaLangObject)->Alloc<true, false>(self,
160       Runtime::Current()->GetHeap()->GetCurrentAllocator());
161 }
162 
163 template <class T>
AllocObjectArray(Thread * self,size_t length)164 inline mirror::ObjectArray<T>* ClassLinker::AllocObjectArray(Thread* self, size_t length) {
165   return mirror::ObjectArray<T>::Alloc(self, GetClassRoot(kObjectArrayClass), length);
166 }
167 
AllocClassArray(Thread * self,size_t length)168 inline mirror::ObjectArray<mirror::Class>* ClassLinker::AllocClassArray(Thread* self,
169                                                                         size_t length) {
170   return mirror::ObjectArray<mirror::Class>::Alloc(self, GetClassRoot(kClassArrayClass), length);
171 }
172 
AllocStringArray(Thread * self,size_t length)173 inline mirror::ObjectArray<mirror::String>* ClassLinker::AllocStringArray(Thread* self,
174                                                                           size_t length) {
175   return mirror::ObjectArray<mirror::String>::Alloc(self, GetClassRoot(kJavaLangStringArrayClass),
176                                                     length);
177 }
178 
AllocIfTable(Thread * self,size_t ifcount)179 inline mirror::IfTable* ClassLinker::AllocIfTable(Thread* self, size_t ifcount) {
180   return down_cast<mirror::IfTable*>(
181       mirror::IfTable::Alloc(self, GetClassRoot(kObjectArrayClass),
182                              ifcount * mirror::IfTable::kMax));
183 }
184 
GetClassRoot(ClassRoot class_root)185 inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root)
186     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
187   DCHECK(!class_roots_.IsNull());
188   mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
189   mirror::Class* klass = class_roots->Get(class_root);
190   DCHECK(klass != nullptr);
191   return klass;
192 }
193 
GetDexCache(size_t idx)194 inline mirror::DexCache* ClassLinker::GetDexCache(size_t idx) {
195   dex_lock_.AssertSharedHeld(Thread::Current());
196   DCHECK(idx < dex_caches_.size());
197   return dex_caches_[idx].Read();
198 }
199 
200 }  // namespace art
201 
202 #endif  // ART_RUNTIME_CLASS_LINKER_INL_H_
203