Always visit object class from VisitReferences
We don't want to unload classes which have instances.
Slight increase in CMS GC time from ~6.5s to ~7.3s on
EvaluateAndApplyChanges.
Bug: 22720414
Change-Id: I467ff9c9d55163d2a90b999aef3bdd7b3f648bac
diff --git a/runtime/mirror/class-inl.h b/runtime/mirror/class-inl.h
index ac9cb09..cd678f6 100644
--- a/runtime/mirror/class-inl.h
+++ b/runtime/mirror/class-inl.h
@@ -669,9 +669,9 @@
return size;
}
-template <bool kVisitClass, typename Visitor>
+template <typename Visitor>
inline void Class::VisitReferences(mirror::Class* klass, const Visitor& visitor) {
- VisitInstanceFieldsReferences<kVisitClass>(klass, visitor);
+ VisitInstanceFieldsReferences(klass, visitor);
// Right after a class is allocated, but not yet loaded
// (kStatusNotReady, see ClassLinker::LoadClass()), GC may find it
// and scan it. IsTemp() may call Class::GetAccessFlags() but may
@@ -683,7 +683,7 @@
// Temp classes don't ever populate imt/vtable or static fields and they are not even
// allocated with the right size for those. Also, unresolved classes don't have fields
// linked yet.
- VisitStaticFieldsReferences<kVisitClass>(this, visitor);
+ VisitStaticFieldsReferences(this, visitor);
}
// Since this class is reachable, we must also visit the associated roots when we scan it.
VisitNativeRoots(visitor, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index f20cc6e..055b3e5 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -872,8 +872,8 @@
h_new_class_obj->SetClassSize(new_length_);
// Visit all of the references to make sure there is no from space references in the native
// roots.
- h_new_class_obj->VisitReferences<true>(h_new_class_obj->GetClass(),
- ReadBarrierOnNativeRootsVisitor());
+ static_cast<mirror::Object*>(h_new_class_obj.Get())->VisitReferences(
+ ReadBarrierOnNativeRootsVisitor(), VoidFunctor());
}
private:
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index dc60a38..3f375be 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -1021,10 +1021,6 @@
void SetPreverifiedFlagOnAllMethods(size_t pointer_size)
SHARED_REQUIRES(Locks::mutator_lock_);
- template <bool kVisitClass, typename Visitor>
- void VisitReferences(mirror::Class* klass, const Visitor& visitor)
- SHARED_REQUIRES(Locks::mutator_lock_);
-
// Get the descriptor of the class. In a few cases a std::string is required, rather than
// always create one the storage argument is populated and its internal c_str() returned. We do
// this to avoid memory allocation in the common case.
@@ -1153,6 +1149,10 @@
static MemberOffset EmbeddedImTableOffset(size_t pointer_size);
static MemberOffset EmbeddedVTableOffset(size_t pointer_size);
+ template <typename Visitor>
+ void VisitReferences(mirror::Class* klass, const Visitor& visitor)
+ SHARED_REQUIRES(Locks::mutator_lock_);
+
// Defining class loader, or null for the "bootstrap" system loader.
HeapReference<ClassLoader> class_loader_;
@@ -1279,6 +1279,7 @@
static GcRoot<Class> java_lang_Class_;
friend struct art::ClassOffsets; // for verifying offset information
+ friend class Object; // For VisitReferences
DISALLOW_IMPLICIT_CONSTRUCTORS(Class);
};
diff --git a/runtime/mirror/class_loader-inl.h b/runtime/mirror/class_loader-inl.h
index 35f3664..e22ddd7 100644
--- a/runtime/mirror/class_loader-inl.h
+++ b/runtime/mirror/class_loader-inl.h
@@ -25,10 +25,10 @@
namespace art {
namespace mirror {
-template <const bool kVisitClass, VerifyObjectFlags kVerifyFlags, typename Visitor>
+template <VerifyObjectFlags kVerifyFlags, typename Visitor>
inline void ClassLoader::VisitReferences(mirror::Class* klass, const Visitor& visitor) {
// Visit instance fields first.
- VisitInstanceFieldsReferences<kVisitClass>(klass, visitor);
+ VisitInstanceFieldsReferences(klass, visitor);
// Visit classes loaded after.
ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
ClassTable* const class_table = GetClassTable();
diff --git a/runtime/mirror/class_loader.h b/runtime/mirror/class_loader.h
index 21c652a..f27b615 100644
--- a/runtime/mirror/class_loader.h
+++ b/runtime/mirror/class_loader.h
@@ -46,14 +46,15 @@
SetField64<false>(OFFSET_OF_OBJECT_MEMBER(ClassLoader, class_table_),
reinterpret_cast<uint64_t>(class_table));
}
+
+ private:
// Visit instance fields of the class loader as well as its associated classes.
// Null class loader is handled by ClassLinker::VisitClassRoots.
- template <const bool kVisitClass, VerifyObjectFlags kVerifyFlags, typename Visitor>
+ template <VerifyObjectFlags kVerifyFlags, typename Visitor>
void VisitReferences(mirror::Class* klass, const Visitor& visitor)
SHARED_REQUIRES(Locks::mutator_lock_)
REQUIRES(!Locks::classlinker_classes_lock_);
- private:
// Field order required by test "ValidateFieldOrderOfJavaCppUnionClasses".
HeapReference<Object> packages_;
HeapReference<ClassLoader> parent_;
@@ -63,6 +64,7 @@
uint64_t class_table_;
friend struct art::ClassLoaderOffsets; // for verifying offset information
+ friend class Object; // For VisitReferences
DISALLOW_IMPLICIT_CONSTRUCTORS(ClassLoader);
};
diff --git a/runtime/mirror/object-inl.h b/runtime/mirror/object-inl.h
index 7b1660b..586ae30 100644
--- a/runtime/mirror/object-inl.h
+++ b/runtime/mirror/object-inl.h
@@ -942,13 +942,10 @@
return success;
}
-template<bool kVisitClass, bool kIsStatic, typename Visitor>
+template<bool kIsStatic, typename Visitor>
inline void Object::VisitFieldsReferences(uint32_t ref_offsets, const Visitor& visitor) {
if (!kIsStatic && (ref_offsets != mirror::Class::kClassWalkSuper)) {
// Instance fields and not the slow-path.
- if (kVisitClass) {
- visitor(this, ClassOffset(), kIsStatic);
- }
uint32_t field_offset = mirror::kObjectHeaderSize;
while (ref_offsets != 0) {
if ((ref_offsets & 1) != 0) {
@@ -974,9 +971,9 @@
? klass->GetFirstReferenceStaticFieldOffset(
Runtime::Current()->GetClassLinker()->GetImagePointerSize())
: klass->GetFirstReferenceInstanceFieldOffset();
- for (size_t i = 0; i < num_reference_fields; ++i) {
+ for (size_t i = 0u; i < num_reference_fields; ++i) {
// TODO: Do a simpler check?
- if (kVisitClass || field_offset.Uint32Value() != ClassOffset().Uint32Value()) {
+ if (field_offset.Uint32Value() != ClassOffset().Uint32Value()) {
visitor(this, field_offset, kIsStatic);
}
field_offset = MemberOffset(field_offset.Uint32Value() +
@@ -986,19 +983,17 @@
}
}
-template<bool kVisitClass, typename Visitor>
+template<typename Visitor>
inline void Object::VisitInstanceFieldsReferences(mirror::Class* klass, const Visitor& visitor) {
- VisitFieldsReferences<kVisitClass, false>(
- klass->GetReferenceInstanceOffsets<kVerifyNone>(), visitor);
+ VisitFieldsReferences<false>(klass->GetReferenceInstanceOffsets<kVerifyNone>(), visitor);
}
-template<bool kVisitClass, typename Visitor>
+template<typename Visitor>
inline void Object::VisitStaticFieldsReferences(mirror::Class* klass, const Visitor& visitor) {
DCHECK(!klass->IsTemp());
- klass->VisitFieldsReferences<kVisitClass, true>(0, visitor);
+ klass->VisitFieldsReferences<true>(0, visitor);
}
-
template<VerifyObjectFlags kVerifyFlags>
inline bool Object::IsClassLoader() {
return GetClass<kVerifyFlags>()->IsClassLoaderClass();
@@ -1010,25 +1005,23 @@
return down_cast<mirror::ClassLoader*>(this);
}
-template <const bool kVisitClass, VerifyObjectFlags kVerifyFlags, typename Visitor,
- typename JavaLangRefVisitor>
+template <VerifyObjectFlags kVerifyFlags, typename Visitor, typename JavaLangRefVisitor>
inline void Object::VisitReferences(const Visitor& visitor,
const JavaLangRefVisitor& ref_visitor) {
mirror::Class* klass = GetClass<kVerifyFlags>();
+ visitor(this, ClassOffset(), false);
if (klass == Class::GetJavaLangClass()) {
- AsClass<kVerifyNone>()->VisitReferences<kVisitClass>(klass, visitor);
+ AsClass<kVerifyNone>()->VisitReferences(klass, visitor);
} else if (klass->IsArrayClass() || klass->IsStringClass()) {
if (klass->IsObjectArrayClass<kVerifyNone>()) {
- AsObjectArray<mirror::Object, kVerifyNone>()->VisitReferences<kVisitClass>(visitor);
- } else if (kVisitClass) {
- visitor(this, ClassOffset(), false);
+ AsObjectArray<mirror::Object, kVerifyNone>()->VisitReferences(visitor);
}
} else if (klass->IsClassLoaderClass()) {
mirror::ClassLoader* class_loader = AsClassLoader<kVerifyFlags>();
- class_loader->VisitReferences<kVisitClass, kVerifyFlags>(klass, visitor);
+ class_loader->VisitReferences<kVerifyFlags>(klass, visitor);
} else {
DCHECK(!klass->IsVariableSize());
- VisitInstanceFieldsReferences<kVisitClass>(klass, visitor);
+ VisitInstanceFieldsReferences(klass, visitor);
if (UNLIKELY(klass->IsTypeOfReferenceClass<kVerifyNone>())) {
ref_visitor(klass, AsReference());
}
diff --git a/runtime/mirror/object.cc b/runtime/mirror/object.cc
index df680b5..4d94130 100644
--- a/runtime/mirror/object.cc
+++ b/runtime/mirror/object.cc
@@ -85,7 +85,7 @@
// object above, copy references fields one by one again with a
// RB. TODO: Optimize this later?
CopyReferenceFieldsWithReadBarrierVisitor visitor(dest);
- src->VisitReferences<true>(visitor, visitor);
+ src->VisitReferences(visitor, visitor);
}
gc::Heap* heap = Runtime::Current()->GetHeap();
// Perform write barriers on copied object references.
diff --git a/runtime/mirror/object.h b/runtime/mirror/object.h
index 4967a14..3cec29c 100644
--- a/runtime/mirror/object.h
+++ b/runtime/mirror/object.h
@@ -446,8 +446,9 @@
}
// TODO fix thread safety analysis broken by the use of template. This should be
// SHARED_REQUIRES(Locks::mutator_lock_).
- template <const bool kVisitClass, VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
- typename Visitor, typename JavaLangRefVisitor = VoidFunctor>
+ template <VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
+ typename Visitor,
+ typename JavaLangRefVisitor = VoidFunctor>
void VisitReferences(const Visitor& visitor, const JavaLangRefVisitor& ref_visitor)
NO_THREAD_SAFETY_ANALYSIS;
@@ -481,13 +482,13 @@
}
// TODO: Fixme when anotatalysis works with visitors.
- template<bool kVisitClass, bool kIsStatic, typename Visitor>
+ template<bool kIsStatic, typename Visitor>
void VisitFieldsReferences(uint32_t ref_offsets, const Visitor& visitor) HOT_ATTR
NO_THREAD_SAFETY_ANALYSIS;
- template<bool kVisitClass, typename Visitor>
+ template<typename Visitor>
void VisitInstanceFieldsReferences(mirror::Class* klass, const Visitor& visitor) HOT_ATTR
SHARED_REQUIRES(Locks::mutator_lock_);
- template<bool kVisitClass, typename Visitor>
+ template<typename Visitor>
void VisitStaticFieldsReferences(mirror::Class* klass, const Visitor& visitor) HOT_ATTR
SHARED_REQUIRES(Locks::mutator_lock_);
diff --git a/runtime/mirror/object_array-inl.h b/runtime/mirror/object_array-inl.h
index 4a7e7b3..5b73557 100644
--- a/runtime/mirror/object_array-inl.h
+++ b/runtime/mirror/object_array-inl.h
@@ -269,11 +269,8 @@
(i * sizeof(HeapReference<Object>)));
}
-template<class T> template<const bool kVisitClass, typename Visitor>
+template<class T> template<typename Visitor>
void ObjectArray<T>::VisitReferences(const Visitor& visitor) {
- if (kVisitClass) {
- visitor(this, ClassOffset(), false);
- }
const size_t length = static_cast<size_t>(GetLength());
for (size_t i = 0; i < length; ++i) {
visitor(this, OffsetOfElement(i), false);
diff --git a/runtime/mirror/object_array.h b/runtime/mirror/object_array.h
index 607b000..b45cafd 100644
--- a/runtime/mirror/object_array.h
+++ b/runtime/mirror/object_array.h
@@ -83,14 +83,15 @@
ObjectArray<T>* CopyOf(Thread* self, int32_t new_length)
SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
- // TODO fix thread safety analysis broken by the use of template. This should be
- // SHARED_REQUIRES(Locks::mutator_lock_).
- template<const bool kVisitClass, typename Visitor>
- void VisitReferences(const Visitor& visitor) NO_THREAD_SAFETY_ANALYSIS;
-
static MemberOffset OffsetOfElement(int32_t i);
private:
+ // TODO fix thread safety analysis broken by the use of template. This should be
+ // SHARED_REQUIRES(Locks::mutator_lock_).
+ template<typename Visitor>
+ void VisitReferences(const Visitor& visitor) NO_THREAD_SAFETY_ANALYSIS;
+
+ friend class Object; // For VisitReferences
DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectArray);
};