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 DCHECK(klass->IsInstantiableNonArray()) << klass->PrettyDescriptor();
76 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
77 return;
78 }
79
80 if ((class_flags & kClassFlagNoReferenceFields) != 0) {
81 CheckNoReferenceField<kVerifyFlags, kReadBarrierOption>(klass);
82 return;
83 }
84
85 DCHECK(!klass->IsStringClass<kVerifyFlags>());
86 if (class_flags == kClassFlagClass) {
87 DCHECK(klass->IsClassClass<kVerifyFlags>());
88 DCHECK(klass->IsInstantiableNonArray()) << klass->PrettyDescriptor();
89 ObjPtr<Class> as_klass = AsClass<kVerifyNone>();
90 as_klass->VisitReferences<kVisitNativeRoots, kVerifyFlags, kReadBarrierOption>(klass, visitor);
91 return;
92 }
93
94 if ((class_flags & kClassFlagObjectArray) != 0) {
95 DCHECK((klass->IsObjectArrayClass<kVerifyFlags, kReadBarrierOption>()));
96 AsObjectArray<mirror::Object, kVerifyNone>()->VisitReferences(visitor);
97 return;
98 }
99
100 if ((class_flags & kClassFlagReference) != 0) {
101 DCHECK(klass->IsInstantiableNonArray()) << klass->PrettyDescriptor();
102 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
103 ref_visitor(klass, AsReference<kVerifyFlags, kReadBarrierOption>());
104 return;
105 }
106
107 if (class_flags == kClassFlagDexCache) {
108 DCHECK(klass->IsInstantiableNonArray()) << klass->PrettyDescriptor();
109 DCHECK(klass->IsDexCacheClass<kVerifyFlags>());
110 ObjPtr<mirror::DexCache> const dex_cache = AsDexCache<kVerifyFlags, kReadBarrierOption>();
111 dex_cache->VisitReferences<kVisitNativeRoots,
112 kVerifyFlags,
113 kReadBarrierOption>(klass, visitor);
114 return;
115 }
116
117 if (class_flags == kClassFlagClassLoader) {
118 DCHECK(klass->IsInstantiableNonArray()) << klass->PrettyDescriptor();
119 DCHECK(klass->IsClassLoaderClass<kVerifyFlags>());
120 ObjPtr<mirror::ClassLoader> const class_loader =
121 AsClassLoader<kVerifyFlags, kReadBarrierOption>();
122 class_loader->VisitReferences<kVisitNativeRoots,
123 kVerifyFlags,
124 kReadBarrierOption>(klass, visitor);
125 return;
126 }
127
128 LOG(FATAL) << "Unexpected class flags: " << std::hex << class_flags
129 << " for " << klass->PrettyClass();
130 }
131
132 // Could be called with from-space address of the object as we access klass and
133 // length (in case of arrays/strings) and we don't want to cause cascading faults.
134 template <bool kFetchObjSize,
135 bool kVisitNativeRoots,
136 VerifyObjectFlags kVerifyFlags,
137 ReadBarrierOption kReadBarrierOption,
138 typename Visitor>
VisitRefsForCompaction(const Visitor & visitor,MemberOffset begin,MemberOffset end)139 inline size_t Object::VisitRefsForCompaction(const Visitor& visitor,
140 MemberOffset begin,
141 MemberOffset end) {
142 constexpr VerifyObjectFlags kSizeOfFlags = RemoveThisFlags(kVerifyFlags);
143 size_t size;
144 // We want to continue using pre-compact klass to avoid cascading faults.
145 ObjPtr<Class> klass = GetClass<kVerifyFlags, kReadBarrierOption>();
146 DCHECK(klass != nullptr) << "obj=" << this;
147 const uint32_t class_flags = klass->GetClassFlags<kVerifyNone>();
148 if (LIKELY(class_flags == kClassFlagNormal) || class_flags == kClassFlagRecord) {
149 CheckNormalClass<kVerifyFlags>(klass);
150 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
151 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
152 } else if ((class_flags & kClassFlagNoReferenceFields) != 0) {
153 if ((class_flags & kClassFlagString) != 0) {
154 size = kFetchObjSize ? static_cast<String*>(this)->SizeOf<kSizeOfFlags>() : 0;
155 } else if ((class_flags & kClassFlagPrimitiveArray) != 0) {
156 ObjPtr<Array> arr = ObjPtr<Array>::DownCast(this);
157 size = kFetchObjSize ?
158 arr->SizeOf<kSizeOfFlags>(class_flags >> kArrayComponentSizeShiftShift) :
159 0;
160 } else {
161 // Only possibility left is of a normal klass instance with no references.
162 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
163 }
164 } else if (class_flags == kClassFlagClass) {
165 DCHECK(klass->IsClassClass<kVerifyFlags>());
166 ObjPtr<Class> as_klass = ObjPtr<Class>::DownCast(this);
167 as_klass->VisitReferences<kVisitNativeRoots, kVerifyFlags, kReadBarrierOption>(klass,
168 visitor);
169 size = kFetchObjSize ? as_klass->SizeOf<kSizeOfFlags>() : 0;
170 } else if ((class_flags & kClassFlagObjectArray) != 0) {
171 ObjPtr<ObjectArray<Object>> obj_arr = ObjPtr<ObjectArray<Object>>::DownCast(this);
172 obj_arr->VisitReferences(visitor, begin, end);
173 size = kFetchObjSize ?
174 obj_arr->SizeOf<kSizeOfFlags>(class_flags >> kArrayComponentSizeShiftShift) :
175 0;
176 } else if ((class_flags & kClassFlagReference) != 0) {
177 VisitInstanceFieldsReferences<kVerifyFlags, kReadBarrierOption>(klass, visitor);
178 // Visit referent also as this is about updating the reference only.
179 // There is no reference processing happening here.
180 visitor(this, mirror::Reference::ReferentOffset(), /* is_static= */ false);
181 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
182 } else if (class_flags == kClassFlagDexCache) {
183 DCHECK(klass->IsDexCacheClass<kVerifyFlags>());
184 ObjPtr<DexCache> const dex_cache = ObjPtr<DexCache>::DownCast(this);
185 dex_cache->VisitReferences<kVisitNativeRoots,
186 kVerifyFlags,
187 kReadBarrierOption>(klass, visitor);
188 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
189 } else if (class_flags == kClassFlagClassLoader) {
190 DCHECK(klass->IsClassLoaderClass<kVerifyFlags>());
191 ObjPtr<ClassLoader> const class_loader = ObjPtr<ClassLoader>::DownCast(this);
192 class_loader->VisitReferences<kVisitNativeRoots,
193 kVerifyFlags,
194 kReadBarrierOption>(klass, visitor);
195 size = kFetchObjSize ? klass->GetObjectSize<kSizeOfFlags>() : 0;
196 } else {
197 LOG(FATAL) << "Unexpected class flags: " << std::hex << class_flags
198 << " for " << klass->PrettyClass();
199 size = -1;
200 }
201 visitor(this, ClassOffset(), /* is_static= */ false);
202 return size;
203 }
204
205 } // namespace mirror
206 } // namespace art
207
208 #endif // ART_RUNTIME_MIRROR_OBJECT_REFVISITOR_INL_H_
209