Set vtable in class object to null after linking.
This is follow-up work of embedding imt and vtable for
faster interface/virtual call dispatching.
Once vtable becomes embedded, the original vtable is nulled.
Change-Id: I307696657d1e283654169dbecb8f7815c42bbabc
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 6c5679e..c40424b 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -3570,9 +3570,9 @@
MethodHelper super_mh(hs.NewHandle<mirror::ArtMethod>(nullptr));
if (klass->HasSuperClass() &&
klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) {
- for (int i = klass->GetSuperClass()->GetVTable()->GetLength() - 1; i >= 0; --i) {
- mh.ChangeMethod(klass->GetVTable()->GetWithoutChecks(i));
- super_mh.ChangeMethod(klass->GetSuperClass()->GetVTable()->GetWithoutChecks(i));
+ for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) {
+ mh.ChangeMethod(klass->GetVTableEntry(i));
+ super_mh.ChangeMethod(klass->GetSuperClass()->GetVTableEntry(i));
if (mh.GetMethod() != super_mh.GetMethod() &&
!mh.HasSameSignatureWithDifferentClassLoaders(&super_mh)) {
ThrowLinkageError(klass.Get(),
@@ -3730,10 +3730,6 @@
// This will notify waiters on new_class that saw the not yet resolved
// class in the class_table_ during EnsureResolved.
new_class_h->SetStatus(mirror::Class::kStatusResolved, self);
-
- // Only embedded imt should be used from this point.
- new_class_h->SetImTable(NULL);
- // TODO: remove vtable and only use embedded vtable.
}
return true;
}
@@ -3866,17 +3862,31 @@
bool ClassLinker::LinkVirtualMethods(Thread* self, Handle<mirror::Class> klass) {
if (klass->HasSuperClass()) {
uint32_t max_count = klass->NumVirtualMethods() +
- klass->GetSuperClass()->GetVTable()->GetLength();
- size_t actual_count = klass->GetSuperClass()->GetVTable()->GetLength();
+ klass->GetSuperClass()->GetVTableLength();
+ size_t actual_count = klass->GetSuperClass()->GetVTableLength();
CHECK_LE(actual_count, max_count);
- // TODO: do not assign to the vtable field until it is fully constructed.
StackHandleScope<3> hs(self);
- Handle<mirror::ObjectArray<mirror::ArtMethod>> vtable(
- hs.NewHandle(klass->GetSuperClass()->GetVTable()->CopyOf(self, max_count)));
- if (UNLIKELY(vtable.Get() == NULL)) {
- CHECK(self->IsExceptionPending()); // OOME.
- return false;
+ Handle<mirror::ObjectArray<mirror::ArtMethod>> vtable;
+ mirror::Class* super_class = klass->GetSuperClass();
+ if (super_class->ShouldHaveEmbeddedImtAndVTable()) {
+ vtable = hs.NewHandle(AllocArtMethodArray(self, max_count));
+ if (UNLIKELY(vtable.Get() == nullptr)) {
+ CHECK(self->IsExceptionPending()); // OOME.
+ return false;
+ }
+ int len = super_class->GetVTableLength();
+ for (int i=0; i<len; i++) {
+ vtable->Set<false>(i, super_class->GetVTableEntry(i));
+ }
+ } else {
+ CHECK(super_class->GetVTable() != nullptr) << PrettyClass(super_class);
+ vtable = hs.NewHandle(super_class->GetVTable()->CopyOf(self, max_count));
+ if (UNLIKELY(vtable.Get() == nullptr)) {
+ CHECK(self->IsExceptionPending()); // OOME.
+ return false;
+ }
}
+
// See if any of our virtual methods override the superclass.
MethodHelper local_mh(hs.NewHandle<mirror::ArtMethod>(nullptr));
MethodHelper super_mh(hs.NewHandle<mirror::ArtMethod>(nullptr));
diff --git a/runtime/class_linker_test.cc b/runtime/class_linker_test.cc
index 21fe006..8e16d9b 100644
--- a/runtime/class_linker_test.cc
+++ b/runtime/class_linker_test.cc
@@ -91,7 +91,7 @@
EXPECT_EQ(0U, primitive->NumInstanceFields());
EXPECT_EQ(0U, primitive->NumStaticFields());
EXPECT_EQ(0U, primitive->NumDirectInterfaces());
- EXPECT_TRUE(primitive->GetVTable() == NULL);
+ EXPECT_FALSE(primitive->HasVTable());
EXPECT_EQ(0, primitive->GetIfTableCount());
EXPECT_TRUE(primitive->GetIfTable() == NULL);
EXPECT_EQ(kAccPublic | kAccFinal | kAccAbstract, primitive->GetAccessFlags());
@@ -143,7 +143,7 @@
EXPECT_EQ(0U, array->NumInstanceFields());
EXPECT_EQ(0U, array->NumStaticFields());
EXPECT_EQ(2U, array->NumDirectInterfaces());
- EXPECT_TRUE(array->GetVTable() != NULL);
+ EXPECT_TRUE(array->ShouldHaveEmbeddedImtAndVTable());
EXPECT_EQ(2, array->GetIfTableCount());
ASSERT_TRUE(array->GetIfTable() != NULL);
mirror::Class* direct_interface0 = mirror::Class::GetDirectInterface(self, array, 0);
@@ -216,7 +216,7 @@
EXPECT_NE(0U, klass->NumDirectMethods());
}
}
- EXPECT_EQ(klass->IsInterface(), klass->GetVTable() == NULL);
+ EXPECT_EQ(klass->IsInterface(), !klass->HasVTable());
mirror::IfTable* iftable = klass->GetIfTable();
for (int i = 0; i < klass->GetIfTableCount(); i++) {
mirror::Class* interface = iftable->GetInterface(i);
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index 90c8fcf..cb0be04 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -390,26 +390,26 @@
case kDirect:
return resolved_method;
case kVirtual: {
- mirror::ObjectArray<mirror::ArtMethod>* vtable = (*this_object)->GetClass()->GetVTable();
+ mirror::Class* klass = (*this_object)->GetClass();
uint16_t vtable_index = resolved_method->GetMethodIndex();
if (access_check &&
- (vtable == nullptr || vtable_index >= static_cast<uint32_t>(vtable->GetLength()))) {
+ (!klass->HasVTable() ||
+ vtable_index >= static_cast<uint32_t>(klass->GetVTableLength()))) {
// Behavior to agree with that of the verifier.
ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(),
resolved_method->GetName(), resolved_method->GetSignature());
return nullptr; // Failure.
}
- DCHECK(vtable != nullptr);
- return vtable->GetWithoutChecks(vtable_index);
+ DCHECK(klass->HasVTable()) << PrettyClass(klass);
+ return klass->GetVTableEntry(vtable_index);
}
case kSuper: {
mirror::Class* super_class = (*referrer)->GetDeclaringClass()->GetSuperClass();
uint16_t vtable_index = resolved_method->GetMethodIndex();
- mirror::ObjectArray<mirror::ArtMethod>* vtable;
if (access_check) {
// Check existence of super class.
- vtable = (super_class != nullptr) ? super_class->GetVTable() : nullptr;
- if (vtable == nullptr || vtable_index >= static_cast<uint32_t>(vtable->GetLength())) {
+ if (super_class == nullptr || !super_class->HasVTable() ||
+ vtable_index >= static_cast<uint32_t>(super_class->GetVTableLength())) {
// Behavior to agree with that of the verifier.
ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(),
resolved_method->GetName(), resolved_method->GetSignature());
@@ -418,10 +418,9 @@
} else {
// Super class must exist.
DCHECK(super_class != nullptr);
- vtable = super_class->GetVTable();
}
- DCHECK(vtable != nullptr);
- return vtable->GetWithoutChecks(vtable_index);
+ DCHECK(super_class->HasVTable());
+ return super_class->GetVTableEntry(vtable_index);
}
case kInterface: {
uint32_t imt_index = resolved_method->GetDexMethodIndex() % mirror::Class::kImtSize;
@@ -555,11 +554,11 @@
} else if (is_direct) {
return resolved_method;
} else if (type == kSuper) {
- return referrer->GetDeclaringClass()->GetSuperClass()->GetVTable()->
- Get(resolved_method->GetMethodIndex());
+ return referrer->GetDeclaringClass()->GetSuperClass()
+ ->GetVTableEntry(resolved_method->GetMethodIndex());
} else {
DCHECK(type == kVirtual);
- return this_object->GetClass()->GetVTable()->Get(resolved_method->GetMethodIndex());
+ return this_object->GetClass()->GetVTableEntry(resolved_method->GetMethodIndex());
}
}
diff --git a/runtime/interpreter/interpreter_common.h b/runtime/interpreter/interpreter_common.h
index 1bcd27e..5a1d01e 100644
--- a/runtime/interpreter/interpreter_common.h
+++ b/runtime/interpreter/interpreter_common.h
@@ -140,7 +140,8 @@
return false;
}
const uint32_t vtable_idx = (is_range) ? inst->VRegB_3rc() : inst->VRegB_35c();
- ArtMethod* const method = receiver->GetClass()->GetVTable()->GetWithoutChecks(vtable_idx);
+ CHECK(receiver->GetClass()->ShouldHaveEmbeddedImtAndVTable());
+ ArtMethod* const method = receiver->GetClass()->GetEmbeddedVTableEntry(vtable_idx);
if (UNLIKELY(method == nullptr)) {
CHECK(self->IsExceptionPending());
result->SetJ(0);
diff --git a/runtime/mirror/art_method.cc b/runtime/mirror/art_method.cc
index 167f848..211ba1d 100644
--- a/runtime/mirror/art_method.cc
+++ b/runtime/mirror/art_method.cc
@@ -130,12 +130,11 @@
Class* declaring_class = GetDeclaringClass();
Class* super_class = declaring_class->GetSuperClass();
uint16_t method_index = GetMethodIndex();
- ObjectArray<ArtMethod>* super_class_vtable = super_class->GetVTable();
ArtMethod* result = NULL;
// Did this method override a super class method? If so load the result from the super class'
// vtable
- if (super_class_vtable != NULL && method_index < super_class_vtable->GetLength()) {
- result = super_class_vtable->Get(method_index);
+ if (super_class->HasVTable() && method_index < super_class->GetVTableLength()) {
+ result = super_class->GetVTableEntry(method_index);
} else {
// Method didn't override superclass method so search interfaces
if (IsProxyMethod()) {
diff --git a/runtime/mirror/class-inl.h b/runtime/mirror/class-inl.h
index 329a984..c3754d7 100644
--- a/runtime/mirror/class-inl.h
+++ b/runtime/mirror/class-inl.h
@@ -161,6 +161,37 @@
CHECK(method == GetImTable()->Get(i));
}
+inline bool Class::HasVTable() {
+ return (GetVTable() != nullptr) || ShouldHaveEmbeddedImtAndVTable();
+}
+
+inline int32_t Class::GetVTableLength() {
+ if (ShouldHaveEmbeddedImtAndVTable()) {
+ return GetEmbeddedVTableLength();
+ }
+ return (GetVTable() != nullptr) ? GetVTable()->GetLength() : 0;
+}
+
+inline ArtMethod* Class::GetVTableEntry(uint32_t i) {
+ if (ShouldHaveEmbeddedImtAndVTable()) {
+ return GetEmbeddedVTableEntry(i);
+ }
+ return (GetVTable() != nullptr) ? GetVTable()->Get(i) : nullptr;
+}
+
+inline int32_t Class::GetEmbeddedVTableLength() {
+ return GetField32(EmbeddedVTableLengthOffset());
+}
+
+inline void Class::SetEmbeddedVTableLength(int32_t len) {
+ SetField32<false>(EmbeddedVTableLengthOffset(), len);
+}
+
+inline ArtMethod* Class::GetEmbeddedVTableEntry(uint32_t i) {
+ uint32_t offset = EmbeddedVTableOffset().Uint32Value() + i * sizeof(VTableEntry);
+ return GetFieldObject<mirror::ArtMethod>(MemberOffset(offset));
+}
+
inline void Class::SetEmbeddedVTableEntry(uint32_t i, ArtMethod* method) {
uint32_t offset = EmbeddedVTableOffset().Uint32Value() + i * sizeof(VTableEntry);
SetFieldObject<false>(MemberOffset(offset), method);
@@ -340,12 +371,12 @@
DCHECK(!method->GetDeclaringClass()->IsInterface() || method->IsMiranda());
// The argument method may from a super class.
// Use the index to a potentially overridden one for this instance's class.
- return GetVTable()->Get(method->GetMethodIndex());
+ return GetVTableEntry(method->GetMethodIndex());
}
inline ArtMethod* Class::FindVirtualMethodForSuper(ArtMethod* method) {
DCHECK(!method->GetDeclaringClass()->IsInterface());
- return GetSuperClass()->GetVTable()->Get(method->GetMethodIndex());
+ return GetSuperClass()->GetVTableEntry(method->GetMethodIndex());
}
inline ArtMethod* Class::FindVirtualMethodForVirtualOrInterface(ArtMethod* method) {
@@ -534,13 +565,19 @@
if (has_embedded_tables) {
uint32_t embedded_imt_size = kImtSize * sizeof(ImTableEntry);
uint32_t embedded_vtable_size = num_vtable_entries * sizeof(VTableEntry);
- size += embedded_imt_size + embedded_vtable_size;
+ size += embedded_imt_size +
+ sizeof(int32_t) /* vtable len */ +
+ embedded_vtable_size;
}
// Space used by reference statics.
size += num_ref_static_fields * sizeof(HeapReference<Object>);
// Possible pad for alignment.
- if (((size & 7) != 0) && (num_64bit_static_fields > 0) && (num_32bit_static_fields == 0)) {
+ if (((size & 7) != 0) && (num_64bit_static_fields > 0)) {
size += sizeof(uint32_t);
+ if (num_32bit_static_fields != 0) {
+ // Shuffle one 32 bit static field forward.
+ num_32bit_static_fields--;
+ }
}
// Space used for primitive static fields.
size += (num_32bit_static_fields * sizeof(uint32_t)) +
@@ -574,7 +611,10 @@
pos += sizeof(ImTableEntry);
}
- count = ((GetVTable() != NULL) ? GetVTable()->GetLength() : 0);
+ // Skip vtable length.
+ pos += sizeof(int32_t);
+
+ count = GetEmbeddedVTableLength();
for (size_t i = 0; i < count; ++i) {
MemberOffset offset = MemberOffset(pos);
visitor(this, offset, true);
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 189c537..a218b1c 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -827,10 +827,18 @@
}
table = GetVTableDuringLinking();
- CHECK(table != nullptr);
+ CHECK(table != nullptr) << PrettyClass(this);
+ SetEmbeddedVTableLength(table->GetLength());
for (int32_t i = 0; i < table->GetLength(); i++) {
SetEmbeddedVTableEntry(i, table->Get(i));
}
+
+ SetImTable(nullptr);
+ // Keep java.lang.Object class's vtable around for since it's easier
+ // to be reused by array classes during their linking.
+ if (!IsObjectClass()) {
+ SetVTable(nullptr);
+ }
}
// The pre-fence visitor for Class::CopyOf().
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index 648bdde..0525abf 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -692,18 +692,34 @@
return MemberOffset(sizeof(Class));
}
- static MemberOffset EmbeddedVTableOffset() {
+ static MemberOffset EmbeddedVTableLengthOffset() {
return MemberOffset(sizeof(Class) + kImtSize * sizeof(mirror::Class::ImTableEntry));
}
+ static MemberOffset EmbeddedVTableOffset() {
+ return MemberOffset(sizeof(Class) + kImtSize * sizeof(mirror::Class::ImTableEntry) + sizeof(int32_t));
+ }
+
bool ShouldHaveEmbeddedImtAndVTable() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return IsInstantiable();
}
+ bool HasVTable() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
ArtMethod* GetEmbeddedImTableEntry(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void SetEmbeddedImTableEntry(uint32_t i, ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ int32_t GetVTableLength() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ ArtMethod* GetVTableEntry(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ int32_t GetEmbeddedVTableLength() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ void SetEmbeddedVTableLength(int32_t len) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ ArtMethod* GetEmbeddedVTableEntry(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
void SetEmbeddedVTableEntry(uint32_t i, ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void PopulateEmbeddedImtAndVTable() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index fbd710c..82c196d 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -3253,7 +3253,7 @@
return nullptr;
}
mirror::Class* super_klass = super.GetClass();
- if (res_method->GetMethodIndex() >= super_klass->GetVTable()->GetLength()) {
+ if (res_method->GetMethodIndex() >= super_klass->GetVTableLength()) {
Fail(VERIFY_ERROR_NO_METHOD) << "invalid invoke-super from "
<< PrettyMethod(dex_method_idx_, *dex_file_)
<< " to super " << super
@@ -3278,20 +3278,21 @@
VLOG(verifier) << "Failed to get mirror::Class* from '" << actual_arg_type << "'";
return nullptr;
}
- mirror::ObjectArray<mirror::ArtMethod>* vtable = nullptr;
mirror::Class* klass = actual_arg_type.GetClass();
+ mirror::Class* dispatch_class;
if (klass->IsInterface()) {
// Derive Object.class from Class.class.getSuperclass().
mirror::Class* object_klass = klass->GetClass()->GetSuperClass();
CHECK(object_klass->IsObjectClass());
- vtable = object_klass->GetVTable();
+ dispatch_class = object_klass;
} else {
- vtable = klass->GetVTable();
+ dispatch_class = klass;
}
- CHECK(vtable != nullptr) << PrettyDescriptor(klass);
+ CHECK(dispatch_class->HasVTable()) << PrettyDescriptor(dispatch_class);
uint16_t vtable_index = is_range ? inst->VRegB_3rc() : inst->VRegB_35c();
- CHECK_LT(static_cast<int32_t>(vtable_index), vtable->GetLength()) << PrettyDescriptor(klass);
- mirror::ArtMethod* res_method = vtable->Get(vtable_index);
+ CHECK_LT(static_cast<int32_t>(vtable_index), dispatch_class->GetVTableLength())
+ << PrettyDescriptor(klass);
+ mirror::ArtMethod* res_method = dispatch_class->GetVTableEntry(vtable_index);
CHECK(!Thread::Current()->IsExceptionPending());
return res_method;
}