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_MIRROR_OBJECT_REFVISITOR_INL_H_
18 #define ART_RUNTIME_MIRROR_OBJECT_REFVISITOR_INL_H_
19
20 #include "object-inl.h"
21
22 #include "class-refvisitor-inl.h"
23 #include "class_loader-inl.h"
24 #include "dex_cache-inl.h"
25
26 namespace art HIDDEN {
27 namespace mirror {
28
29 template <VerifyObjectFlags kVerifyFlags,
30 ReadBarrierOption kReadBarrierOption>
CheckNoReferenceField(ObjPtr<mirror::Class> klass)31 static void CheckNoReferenceField(ObjPtr<mirror::Class> klass)
32 REQUIRES_SHARED(art::Locks::mutator_lock_) {
33 if (!kIsDebugBuild) {
34 return;
35 }
36 CHECK(!klass->IsClassClass<kVerifyFlags>());
37 CHECK((!klass->IsObjectArrayClass<kVerifyFlags, kReadBarrierOption>()));
38 // String still has instance fields for reflection purposes but these don't exist in
39 // actual string instances.
40 if (!klass->IsStringClass<kVerifyFlags>()) {
41 size_t total_reference_instance_fields = 0;
42 ObjPtr<Class> super_class = klass;
43 do {
44 total_reference_instance_fields +=
45 super_class->NumReferenceInstanceFields<kVerifyFlags>();
46 super_class = super_class->GetSuperClass<kVerifyFlags, kReadBarrierOption>();
47 } while (super_class != nullptr);
48 // The only reference field should be the object's class.
49 CHECK_EQ(total_reference_instance_fields, 1u);
50 }
51 }
52
53 template <VerifyObjectFlags kVerifyFlags>
CheckNormalClass(ObjPtr<mirror::Class> klass)54 static void CheckNormalClass(ObjPtr<mirror::Class> klass)
55 REQUIRES_SHARED(art::Locks::mutator_lock_) {
56 DCHECK(!klass->IsVariableSize<kVerifyFlags>());
57 DCHECK(!klass->IsClassClass<kVerifyFlags>());
58 DCHECK(!klass->IsStringClass<kVerifyFlags>());
59 DCHECK(!klass->IsClassLoaderClass<kVerifyFlags>());
60 DCHECK(!klass->IsArrayClass<kVerifyFlags>());
61 }
62
63 template <bool kVisitNativeRoots,
64 VerifyObjectFlags kVerifyFlags,
65 ReadBarrierOption kReadBarrierOption,
66 typename Visitor,
67 typename JavaLangRefVisitor>
VisitReferences(const Visitor & visitor,const JavaLangRefVisitor & ref_visitor)68 inline void Object::VisitReferences(const Visitor& visitor,
69 const JavaLangRefVisitor& ref_visitor) {
70 visitor(this, ClassOffset(), /* is_static= */ false);
71 ObjPtr<Class> klass = GetClass<kVerifyFlags, kReadBarrierOption>();
72 const uint32_t class_flags = klass->GetClassFlags<kVerifyNone>();
73 if (LIKELY(class_flags == kClassFlagNormal) || class_flags == kClassFlagRecord) {
74 CheckNormalClass<kVerifyFlags>(klass);
75 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
76 return;
77 }
78
79 if ((class_flags & kClassFlagNoReferenceFields) != 0) {
80 CheckNoReferenceField<kVerifyFlags, kReadBarrierOption>(klass);
81 return;
82 }
83
84 DCHECK(!klass->IsStringClass<kVerifyFlags>());
85 if (class_flags == kClassFlagClass) {
86 DCHECK(klass->IsClassClass<kVerifyFlags>());
87 ObjPtr<Class> as_klass = AsClass<kVerifyNone>();
88 as_klass->VisitReferences<kVisitNativeRoots, kVerifyFlags, kReadBarrierOption>(klass, visitor);
89 return;
90 }
91
92 if (class_flags == kClassFlagObjectArray) {
93 DCHECK((klass->IsObjectArrayClass<kVerifyFlags, kReadBarrierOption>()));
94 AsObjectArray<mirror::Object, kVerifyNone>()->VisitReferences(visitor);
95 return;
96 }
97
98 if ((class_flags & kClassFlagReference) != 0) {
99 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
100 ref_visitor(klass, AsReference<kVerifyFlags, kReadBarrierOption>());
101 return;
102 }
103
104 if (class_flags == kClassFlagDexCache) {
105 DCHECK(klass->IsDexCacheClass<kVerifyFlags>());
106 ObjPtr<mirror::DexCache> const dex_cache = AsDexCache<kVerifyFlags, kReadBarrierOption>();
107 dex_cache->VisitReferences<kVisitNativeRoots,
108 kVerifyFlags,
109 kReadBarrierOption>(klass, visitor);
110 return;
111 }
112
113 if (class_flags == kClassFlagClassLoader) {
114 DCHECK(klass->IsClassLoaderClass<kVerifyFlags>());
115 ObjPtr<mirror::ClassLoader> const class_loader =
116 AsClassLoader<kVerifyFlags, kReadBarrierOption>();
117 class_loader->VisitReferences<kVisitNativeRoots,
118 kVerifyFlags,
119 kReadBarrierOption>(klass, visitor);
120 return;
121 }
122
123 LOG(FATAL) << "Unexpected class flags: " << std::hex << class_flags
124 << " for " << klass->PrettyClass();
125 }
126
127 // Could be called with from-space address of the object as we access klass and
128 // length (in case of arrays/strings) and we don't want to cause cascading faults.
129 template <bool kFetchObjSize,
130 bool kVisitNativeRoots,
131 VerifyObjectFlags kVerifyFlags,
132 ReadBarrierOption kReadBarrierOption,
133 typename Visitor>
VisitRefsForCompaction(const Visitor & visitor,MemberOffset begin,MemberOffset end)134 inline size_t Object::VisitRefsForCompaction(const Visitor& visitor,
135 MemberOffset begin,
136 MemberOffset end) {
137 constexpr VerifyObjectFlags kSizeOfFlags = RemoveThisFlags(kVerifyFlags);
138 size_t size;
139 // We want to continue using pre-compact klass to avoid cascading faults.
140 ObjPtr<Class> klass = GetClass<kVerifyFlags, kReadBarrierOption>();
141 DCHECK(klass != nullptr) << "obj=" << this;
142 const uint32_t class_flags = klass->GetClassFlags<kVerifyNone>();
143 if (LIKELY(class_flags == kClassFlagNormal) || class_flags == kClassFlagRecord) {
144 CheckNormalClass<kVerifyFlags>(klass);
145 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
146 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
147 } else if ((class_flags & kClassFlagNoReferenceFields) != 0) {
148 if ((class_flags & kClassFlagString) != 0) {
149 size = kFetchObjSize ? static_cast<String*>(this)->SizeOf<kSizeOfFlags>() : 0;
150 } else if (klass->IsArrayClass<kVerifyFlags>()) {
151 // TODO: We can optimize this by implementing a SizeOf() version which takes
152 // component-size-shift as an argument, thereby avoiding multiple loads of
153 // component_type.
154 size = kFetchObjSize
155 ? static_cast<Array*>(this)->SizeOf<kSizeOfFlags, kReadBarrierOption>()
156 : 0;
157 } else {
158 // Only possibility left is of a normal klass instance with no references.
159 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
160 }
161 } else if (class_flags == kClassFlagClass) {
162 DCHECK(klass->IsClassClass<kVerifyFlags>());
163 ObjPtr<Class> as_klass = ObjPtr<Class>::DownCast(this);
164 as_klass->VisitReferences<kVisitNativeRoots, kVerifyFlags, kReadBarrierOption>(klass,
165 visitor);
166 size = kFetchObjSize ? as_klass->SizeOf<kSizeOfFlags>() : 0;
167 } else if (class_flags == kClassFlagObjectArray) {
168 ObjPtr<ObjectArray<Object>> obj_arr = ObjPtr<ObjectArray<Object>>::DownCast(this);
169 obj_arr->VisitReferences(visitor, begin, end);
170 size = kFetchObjSize ?
171 obj_arr->SizeOf<kSizeOfFlags, kReadBarrierOption, /*kIsObjArray*/ true>() :
172 0;
173 } else if ((class_flags & kClassFlagReference) != 0) {
174 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
175 // Visit referent also as this is about updating the reference only.
176 // There is no reference processing happening here.
177 visitor(this, mirror::Reference::ReferentOffset(), /* is_static= */ false);
178 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
179 } else if (class_flags == kClassFlagDexCache) {
180 DCHECK(klass->IsDexCacheClass<kVerifyFlags>());
181 ObjPtr<DexCache> const dex_cache = ObjPtr<DexCache>::DownCast(this);
182 dex_cache->VisitReferences<kVisitNativeRoots,
183 kVerifyFlags,
184 kReadBarrierOption>(klass, visitor);
185 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
186 } else if (class_flags == kClassFlagClassLoader) {
187 DCHECK(klass->IsClassLoaderClass<kVerifyFlags>());
188 ObjPtr<ClassLoader> const class_loader = ObjPtr<ClassLoader>::DownCast(this);
189 class_loader->VisitReferences<kVisitNativeRoots,
190 kVerifyFlags,
191 kReadBarrierOption>(klass, visitor);
192 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
193 } else {
194 LOG(FATAL) << "Unexpected class flags: " << std::hex << class_flags
195 << " for " << klass->PrettyClass();
196 size = -1;
197 }
198 visitor(this, ClassOffset(), /* is_static= */ false);
199 return size;
200 }
201
202 } // namespace mirror
203 } // namespace art
204
205 #endif // ART_RUNTIME_MIRROR_OBJECT_REFVISITOR_INL_H_
206