xref: /aosp_15_r20/art/runtime/mirror/class-refvisitor-inl.h (revision 795d594fd825385562da6b089ea9b2033f3abf5a)
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_CLASS_REFVISITOR_INL_H_
18 #define ART_RUNTIME_MIRROR_CLASS_REFVISITOR_INL_H_
19 
20 #include "class-inl.h"
21 
22 #include "art_field-inl.h"
23 #include "class_ext-inl.h"
24 
25 namespace art HIDDEN {
26 namespace mirror {
27 
28 // NO_THREAD_SAFETY_ANALYSIS for mutator_lock_ and heap_bitmap_lock_, as
29 // requirements for these vary depending on the visitor.
30 template <VerifyObjectFlags kVerifyFlags, typename Visitor>
VisitStaticFieldsReferences(const Visitor & visitor)31 inline void Class::VisitStaticFieldsReferences(const Visitor& visitor) NO_THREAD_SAFETY_ANALYSIS {
32   DCHECK(!IsTemp<kVerifyFlags>());
33   const size_t num_reference_fields = NumReferenceStaticFields();
34   if (num_reference_fields > 0u) {
35     // Presumably GC can happen when we are cross compiling, it should not cause performance
36     // problems to do pointer size logic.
37     MemberOffset field_offset = GetFirstReferenceStaticFieldOffset<kVerifyFlags>(
38         Runtime::Current()->GetClassLinker()->GetImagePointerSize());
39     for (size_t i = 0u; i < num_reference_fields; ++i) {
40       DCHECK_NE(field_offset.Uint32Value(), ClassOffset().Uint32Value());
41       visitor(this, field_offset, /*is_static=*/true);
42       field_offset =
43           MemberOffset(field_offset.Uint32Value() + sizeof(mirror::HeapReference<mirror::Object>));
44     }
45   }
46 }
47 
48 template <bool kVisitNativeRoots,
49           VerifyObjectFlags kVerifyFlags,
50           ReadBarrierOption kReadBarrierOption,
51           typename Visitor>
VisitReferences(ObjPtr<Class> klass,const Visitor & visitor)52 inline void Class::VisitReferences(ObjPtr<Class> klass, const Visitor& visitor) {
53   VisitInstanceFieldsReferences<kVerifyFlags>(klass.Ptr(), visitor);
54   // Right after a class is allocated, but not yet loaded
55   // (ClassStatus::kNotReady, see ClassLinker::LoadClass()), GC may find it
56   // and scan it. IsTemp() may call Class::GetAccessFlags() but may
57   // fail in the DCHECK in Class::GetAccessFlags() because the class
58   // status is ClassStatus::kNotReady. To avoid it, rely on IsResolved()
59   // only. This is fine because a temp class never goes into the
60   // ClassStatus::kResolved state.
61   if (IsResolved<kVerifyFlags>()) {
62     // Temp classes don't ever populate imt/vtable or static fields and they are not even
63     // allocated with the right size for those. Also, unresolved classes don't have fields
64     // linked yet.
65     VisitStaticFieldsReferences<kVerifyFlags>(visitor);
66   }
67   if (kVisitNativeRoots) {
68     // Since this class is reachable, we must also visit the associated roots when we scan it.
69     VisitNativeRoots<kReadBarrierOption>(
70         visitor, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
71   }
72 }
73 
74 template<ReadBarrierOption kReadBarrierOption, bool kVisitProxyMethod, class Visitor>
VisitNativeRoots(Visitor & visitor,PointerSize pointer_size)75 void Class::VisitNativeRoots(Visitor& visitor, PointerSize pointer_size) {
76   VisitFields<kReadBarrierOption>([&](ArtField* field) REQUIRES_SHARED(art::Locks::mutator_lock_) {
77     field->VisitRoots(visitor);
78     if (kIsDebugBuild && !gUseUserfaultfd && IsResolved()) {
79       CHECK_EQ(field->GetDeclaringClass<kReadBarrierOption>(), this)
80           << GetStatus() << field->GetDeclaringClass()->PrettyClass() << " != " << PrettyClass();
81     }
82   });
83   // Don't use VisitMethods because we don't want to hit the class-ext methods twice.
84   for (ArtMethod& method : GetMethods(pointer_size)) {
85     method.VisitRoots<kReadBarrierOption, kVisitProxyMethod>(visitor, pointer_size);
86   }
87   ObjPtr<ClassExt> ext(GetExtData<kDefaultVerifyFlags, kReadBarrierOption>());
88   if (!ext.IsNull()) {
89     ext->VisitNativeRoots<kReadBarrierOption, kVisitProxyMethod>(visitor, pointer_size);
90   }
91 }
92 
93 template<ReadBarrierOption kReadBarrierOption>
VisitObsoleteDexCaches(DexCacheVisitor & visitor)94 void Class::VisitObsoleteDexCaches(DexCacheVisitor& visitor) {
95   ObjPtr<ClassExt> ext(GetExtData<kDefaultVerifyFlags, kReadBarrierOption>());
96   if (!ext.IsNull()) {
97     ext->VisitDexCaches<kDefaultVerifyFlags, kReadBarrierOption>(visitor);
98   }
99 }
100 
101 template<ReadBarrierOption kReadBarrierOption, class Visitor>
VisitObsoleteClass(Visitor & visitor)102 void Class::VisitObsoleteClass(Visitor& visitor) {
103   ObjPtr<ClassExt> ext(GetExtData<kDefaultVerifyFlags, kReadBarrierOption>());
104   if (!ext.IsNull()) {
105     ObjPtr<Class> klass = ext->GetObsoleteClass<kDefaultVerifyFlags, kReadBarrierOption>();
106     visitor(klass);
107   }
108 }
109 
110 template<ReadBarrierOption kReadBarrierOption, class Visitor>
VisitMethods(Visitor visitor,PointerSize pointer_size)111 void Class::VisitMethods(Visitor visitor, PointerSize pointer_size) {
112   for (ArtMethod& method : GetMethods(pointer_size)) {
113     visitor(&method);
114   }
115   ObjPtr<ClassExt> ext(GetExtData<kDefaultVerifyFlags, kReadBarrierOption>());
116   if (!ext.IsNull()) {
117     ext->VisitMethods<kReadBarrierOption, Visitor>(visitor, pointer_size);
118   }
119 }
120 
121 template<ReadBarrierOption kReadBarrierOption, class Visitor>
VisitFields(Visitor visitor)122 void Class::VisitFields(Visitor visitor) {
123   for (ArtField& sfield : GetSFieldsUnchecked()) {
124     visitor(&sfield);
125   }
126   for (ArtField& ifield : GetIFieldsUnchecked()) {
127     visitor(&ifield);
128   }
129 }
130 
131 }  // namespace mirror
132 }  // namespace art
133 
134 #endif  // ART_RUNTIME_MIRROR_CLASS_REFVISITOR_INL_H_
135