diff --git a/runtime/transaction_test.cc b/runtime/transaction_test.cc
index 1dc2da0..3645ed2 100644
--- a/runtime/transaction_test.cc
+++ b/runtime/transaction_test.cc
@@ -27,56 +27,57 @@
 
 TEST_F(TransactionTest, Object_class) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;"));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;")));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
 
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  SirtRef<mirror::Object> sirt_obj(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  Handle<mirror::Object> h_obj(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
   Runtime::Current()->ExitTransactionMode();
 
   // Aborting transaction must not clear the Object::class field.
   transaction.Abort();
-  EXPECT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  EXPECT_EQ(h_obj->GetClass(), h_klass.Get());
 }
 
 TEST_F(TransactionTest, Object_monitor) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindSystemClass(soa.Self(),
-                                                                   "Ljava/lang/Object;"));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  SirtRef<mirror::Object> sirt_obj(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;")));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  Handle<mirror::Object> h_obj(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
 
   // Lock object's monitor outside the transaction.
-  sirt_obj->MonitorEnter(soa.Self());
-  uint32_t old_lock_word = sirt_obj->GetLockWord(false).GetValue();
+  h_obj->MonitorEnter(soa.Self());
+  uint32_t old_lock_word = h_obj->GetLockWord(false).GetValue();
 
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
   // Unlock object's monitor inside the transaction.
-  sirt_obj->MonitorExit(soa.Self());
-  uint32_t new_lock_word = sirt_obj->GetLockWord(false).GetValue();
+  h_obj->MonitorExit(soa.Self());
+  uint32_t new_lock_word = h_obj->GetLockWord(false).GetValue();
   Runtime::Current()->ExitTransactionMode();
 
   // Aborting transaction must not clear the Object::class field.
   transaction.Abort();
-  uint32_t aborted_lock_word = sirt_obj->GetLockWord(false).GetValue();
+  uint32_t aborted_lock_word = h_obj->GetLockWord(false).GetValue();
   EXPECT_NE(old_lock_word, new_lock_word);
   EXPECT_EQ(aborted_lock_word, new_lock_word);
 }
 
 TEST_F(TransactionTest, Array_length) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindSystemClass(soa.Self(),
-                                                                   "[Ljava/lang/Object;"));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "[Ljava/lang/Object;")));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
 
   constexpr int32_t kArraySize = 2;
 
@@ -84,304 +85,301 @@
   Runtime::Current()->EnterTransactionMode(&transaction);
 
   // Allocate an array during transaction.
-  SirtRef<mirror::Array> sirt_obj(soa.Self(),
-                                  mirror::Array::Alloc<true>(soa.Self(), sirt_klass.get(),
-                                                             kArraySize,
-                                                             sirt_klass->GetComponentSize(),
-                                                             Runtime::Current()->GetHeap()->GetCurrentAllocator()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  Handle<mirror::Array> h_obj(
+      hs.NewHandle(
+          mirror::Array::Alloc<true>(soa.Self(), h_klass.Get(), kArraySize,
+                                     h_klass->GetComponentSize(),
+                                     Runtime::Current()->GetHeap()->GetCurrentAllocator())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
   Runtime::Current()->ExitTransactionMode();
 
   // Aborting transaction must not clear the Object::class field.
   transaction.Abort();
-  EXPECT_EQ(sirt_obj->GetLength(), kArraySize);
+  EXPECT_EQ(h_obj->GetLength(), kArraySize);
 }
 
 TEST_F(TransactionTest, StaticFieldsTest) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction")));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<4> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction"))));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindClass(soa.Self(), "LStaticFieldsTest;",
-                                                             class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
-  ASSERT_TRUE(sirt_klass->IsInitialized());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LStaticFieldsTest;", class_loader)));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->EnsureInitialized(h_klass, true, true);
+  ASSERT_TRUE(h_klass->IsInitialized());
 
   // Lookup fields.
-  mirror::ArtField* booleanField = sirt_klass->FindDeclaredStaticField("booleanField", "Z");
+  mirror::ArtField* booleanField = h_klass->FindDeclaredStaticField("booleanField", "Z");
   ASSERT_TRUE(booleanField != nullptr);
   ASSERT_EQ(FieldHelper(booleanField).GetTypeAsPrimitiveType(), Primitive::kPrimBoolean);
-  ASSERT_EQ(booleanField->GetBoolean(sirt_klass.get()), false);
+  ASSERT_EQ(booleanField->GetBoolean(h_klass.Get()), false);
 
-  mirror::ArtField* byteField = sirt_klass->FindDeclaredStaticField("byteField", "B");
+  mirror::ArtField* byteField = h_klass->FindDeclaredStaticField("byteField", "B");
   ASSERT_TRUE(byteField != nullptr);
   ASSERT_EQ(FieldHelper(byteField).GetTypeAsPrimitiveType(), Primitive::kPrimByte);
-  ASSERT_EQ(byteField->GetByte(sirt_klass.get()), 0);
+  ASSERT_EQ(byteField->GetByte(h_klass.Get()), 0);
 
-  mirror::ArtField* charField = sirt_klass->FindDeclaredStaticField("charField", "C");
+  mirror::ArtField* charField = h_klass->FindDeclaredStaticField("charField", "C");
   ASSERT_TRUE(charField != nullptr);
   ASSERT_EQ(FieldHelper(charField).GetTypeAsPrimitiveType(), Primitive::kPrimChar);
-  ASSERT_EQ(charField->GetChar(sirt_klass.get()), 0u);
+  ASSERT_EQ(charField->GetChar(h_klass.Get()), 0u);
 
-  mirror::ArtField* shortField = sirt_klass->FindDeclaredStaticField("shortField", "S");
+  mirror::ArtField* shortField = h_klass->FindDeclaredStaticField("shortField", "S");
   ASSERT_TRUE(shortField != nullptr);
   ASSERT_EQ(FieldHelper(shortField).GetTypeAsPrimitiveType(), Primitive::kPrimShort);
-  ASSERT_EQ(shortField->GetShort(sirt_klass.get()), 0);
+  ASSERT_EQ(shortField->GetShort(h_klass.Get()), 0);
 
-  mirror::ArtField* intField = sirt_klass->FindDeclaredStaticField("intField", "I");
+  mirror::ArtField* intField = h_klass->FindDeclaredStaticField("intField", "I");
   ASSERT_TRUE(intField != nullptr);
   ASSERT_EQ(FieldHelper(intField).GetTypeAsPrimitiveType(), Primitive::kPrimInt);
-  ASSERT_EQ(intField->GetInt(sirt_klass.get()), 0);
+  ASSERT_EQ(intField->GetInt(h_klass.Get()), 0);
 
-  mirror::ArtField* longField = sirt_klass->FindDeclaredStaticField("longField", "J");
+  mirror::ArtField* longField = h_klass->FindDeclaredStaticField("longField", "J");
   ASSERT_TRUE(longField != nullptr);
   ASSERT_EQ(FieldHelper(longField).GetTypeAsPrimitiveType(), Primitive::kPrimLong);
-  ASSERT_EQ(longField->GetLong(sirt_klass.get()), static_cast<int64_t>(0));
+  ASSERT_EQ(longField->GetLong(h_klass.Get()), static_cast<int64_t>(0));
 
-  mirror::ArtField* floatField = sirt_klass->FindDeclaredStaticField("floatField", "F");
+  mirror::ArtField* floatField = h_klass->FindDeclaredStaticField("floatField", "F");
   ASSERT_TRUE(floatField != nullptr);
   ASSERT_EQ(FieldHelper(floatField).GetTypeAsPrimitiveType(), Primitive::kPrimFloat);
-  ASSERT_EQ(floatField->GetFloat(sirt_klass.get()), static_cast<float>(0.0f));
+  ASSERT_EQ(floatField->GetFloat(h_klass.Get()), static_cast<float>(0.0f));
 
-  mirror::ArtField* doubleField = sirt_klass->FindDeclaredStaticField("doubleField", "D");
+  mirror::ArtField* doubleField = h_klass->FindDeclaredStaticField("doubleField", "D");
   ASSERT_TRUE(doubleField != nullptr);
   ASSERT_EQ(FieldHelper(doubleField).GetTypeAsPrimitiveType(), Primitive::kPrimDouble);
-  ASSERT_EQ(doubleField->GetDouble(sirt_klass.get()), static_cast<double>(0.0));
+  ASSERT_EQ(doubleField->GetDouble(h_klass.Get()), static_cast<double>(0.0));
 
-  mirror::ArtField* objectField = sirt_klass->FindDeclaredStaticField("objectField",
+  mirror::ArtField* objectField = h_klass->FindDeclaredStaticField("objectField",
                                                                       "Ljava/lang/Object;");
   ASSERT_TRUE(objectField != nullptr);
   ASSERT_EQ(FieldHelper(objectField).GetTypeAsPrimitiveType(), Primitive::kPrimNot);
-  ASSERT_EQ(objectField->GetObject(sirt_klass.get()), nullptr);
+  ASSERT_EQ(objectField->GetObject(h_klass.Get()), nullptr);
 
   // Create a java.lang.Object instance to set objectField.
-  SirtRef<mirror::Class> object_klass(soa.Self(),
-                                      class_linker_->FindSystemClass(soa.Self(),
-                                                                     "Ljava/lang/Object;"));
-  ASSERT_TRUE(object_klass.get() != nullptr);
-  SirtRef<mirror::Object> sirt_obj(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  Handle<mirror::Class> object_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;")));
+  ASSERT_TRUE(object_klass.Get() != nullptr);
+  Handle<mirror::Object> h_obj(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
 
   // Modify fields inside transaction and abort it.
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  booleanField->SetBoolean<true>(sirt_klass.get(), true);
-  byteField->SetByte<true>(sirt_klass.get(), 1);
-  charField->SetChar<true>(sirt_klass.get(), 1u);
-  shortField->SetShort<true>(sirt_klass.get(), 1);
-  intField->SetInt<true>(sirt_klass.get(), 1);
-  longField->SetLong<true>(sirt_klass.get(), 1);
-  floatField->SetFloat<true>(sirt_klass.get(), 1.0);
-  doubleField->SetDouble<true>(sirt_klass.get(), 1.0);
-  objectField->SetObject<true>(sirt_klass.get(), sirt_obj.get());
+  booleanField->SetBoolean<true>(h_klass.Get(), true);
+  byteField->SetByte<true>(h_klass.Get(), 1);
+  charField->SetChar<true>(h_klass.Get(), 1u);
+  shortField->SetShort<true>(h_klass.Get(), 1);
+  intField->SetInt<true>(h_klass.Get(), 1);
+  longField->SetLong<true>(h_klass.Get(), 1);
+  floatField->SetFloat<true>(h_klass.Get(), 1.0);
+  doubleField->SetDouble<true>(h_klass.Get(), 1.0);
+  objectField->SetObject<true>(h_klass.Get(), h_obj.Get());
   Runtime::Current()->ExitTransactionMode();
   transaction.Abort();
 
   // Check values have properly been restored to their original (default) value.
-  EXPECT_EQ(booleanField->GetBoolean(sirt_klass.get()), false);
-  EXPECT_EQ(byteField->GetByte(sirt_klass.get()), 0);
-  EXPECT_EQ(charField->GetChar(sirt_klass.get()), 0u);
-  EXPECT_EQ(shortField->GetShort(sirt_klass.get()), 0);
-  EXPECT_EQ(intField->GetInt(sirt_klass.get()), 0);
-  EXPECT_EQ(longField->GetLong(sirt_klass.get()), static_cast<int64_t>(0));
-  EXPECT_EQ(floatField->GetFloat(sirt_klass.get()), static_cast<float>(0.0f));
-  EXPECT_EQ(doubleField->GetDouble(sirt_klass.get()), static_cast<double>(0.0));
-  EXPECT_EQ(objectField->GetObject(sirt_klass.get()), nullptr);
+  EXPECT_EQ(booleanField->GetBoolean(h_klass.Get()), false);
+  EXPECT_EQ(byteField->GetByte(h_klass.Get()), 0);
+  EXPECT_EQ(charField->GetChar(h_klass.Get()), 0u);
+  EXPECT_EQ(shortField->GetShort(h_klass.Get()), 0);
+  EXPECT_EQ(intField->GetInt(h_klass.Get()), 0);
+  EXPECT_EQ(longField->GetLong(h_klass.Get()), static_cast<int64_t>(0));
+  EXPECT_EQ(floatField->GetFloat(h_klass.Get()), static_cast<float>(0.0f));
+  EXPECT_EQ(doubleField->GetDouble(h_klass.Get()), static_cast<double>(0.0));
+  EXPECT_EQ(objectField->GetObject(h_klass.Get()), nullptr);
 }
 
 TEST_F(TransactionTest, InstanceFieldsTest) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction")));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<5> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction"))));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindClass(soa.Self(), "LInstanceFieldsTest;",
-                                                             class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
-  ASSERT_TRUE(sirt_klass->IsInitialized());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LInstanceFieldsTest;", class_loader)));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->EnsureInitialized(h_klass, true, true);
+  ASSERT_TRUE(h_klass->IsInitialized());
 
   // Allocate an InstanceFieldTest object.
-  SirtRef<mirror::Object> sirt_instance(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_instance.get() != nullptr);
+  Handle<mirror::Object> h_instance(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_instance.Get() != nullptr);
 
   // Lookup fields.
-  mirror::ArtField* booleanField = sirt_klass->FindDeclaredInstanceField("booleanField", "Z");
+  mirror::ArtField* booleanField = h_klass->FindDeclaredInstanceField("booleanField", "Z");
   ASSERT_TRUE(booleanField != nullptr);
   ASSERT_EQ(FieldHelper(booleanField).GetTypeAsPrimitiveType(), Primitive::kPrimBoolean);
-  ASSERT_EQ(booleanField->GetBoolean(sirt_instance.get()), false);
+  ASSERT_EQ(booleanField->GetBoolean(h_instance.Get()), false);
 
-  mirror::ArtField* byteField = sirt_klass->FindDeclaredInstanceField("byteField", "B");
+  mirror::ArtField* byteField = h_klass->FindDeclaredInstanceField("byteField", "B");
   ASSERT_TRUE(byteField != nullptr);
   ASSERT_EQ(FieldHelper(byteField).GetTypeAsPrimitiveType(), Primitive::kPrimByte);
-  ASSERT_EQ(byteField->GetByte(sirt_instance.get()), 0);
+  ASSERT_EQ(byteField->GetByte(h_instance.Get()), 0);
 
-  mirror::ArtField* charField = sirt_klass->FindDeclaredInstanceField("charField", "C");
+  mirror::ArtField* charField = h_klass->FindDeclaredInstanceField("charField", "C");
   ASSERT_TRUE(charField != nullptr);
   ASSERT_EQ(FieldHelper(charField).GetTypeAsPrimitiveType(), Primitive::kPrimChar);
-  ASSERT_EQ(charField->GetChar(sirt_instance.get()), 0u);
+  ASSERT_EQ(charField->GetChar(h_instance.Get()), 0u);
 
-  mirror::ArtField* shortField = sirt_klass->FindDeclaredInstanceField("shortField", "S");
+  mirror::ArtField* shortField = h_klass->FindDeclaredInstanceField("shortField", "S");
   ASSERT_TRUE(shortField != nullptr);
   ASSERT_EQ(FieldHelper(shortField).GetTypeAsPrimitiveType(), Primitive::kPrimShort);
-  ASSERT_EQ(shortField->GetShort(sirt_instance.get()), 0);
+  ASSERT_EQ(shortField->GetShort(h_instance.Get()), 0);
 
-  mirror::ArtField* intField = sirt_klass->FindDeclaredInstanceField("intField", "I");
+  mirror::ArtField* intField = h_klass->FindDeclaredInstanceField("intField", "I");
   ASSERT_TRUE(intField != nullptr);
   ASSERT_EQ(FieldHelper(intField).GetTypeAsPrimitiveType(), Primitive::kPrimInt);
-  ASSERT_EQ(intField->GetInt(sirt_instance.get()), 0);
+  ASSERT_EQ(intField->GetInt(h_instance.Get()), 0);
 
-  mirror::ArtField* longField = sirt_klass->FindDeclaredInstanceField("longField", "J");
+  mirror::ArtField* longField = h_klass->FindDeclaredInstanceField("longField", "J");
   ASSERT_TRUE(longField != nullptr);
   ASSERT_EQ(FieldHelper(longField).GetTypeAsPrimitiveType(), Primitive::kPrimLong);
-  ASSERT_EQ(longField->GetLong(sirt_instance.get()), static_cast<int64_t>(0));
+  ASSERT_EQ(longField->GetLong(h_instance.Get()), static_cast<int64_t>(0));
 
-  mirror::ArtField* floatField = sirt_klass->FindDeclaredInstanceField("floatField", "F");
+  mirror::ArtField* floatField = h_klass->FindDeclaredInstanceField("floatField", "F");
   ASSERT_TRUE(floatField != nullptr);
   ASSERT_EQ(FieldHelper(floatField).GetTypeAsPrimitiveType(), Primitive::kPrimFloat);
-  ASSERT_EQ(floatField->GetFloat(sirt_instance.get()), static_cast<float>(0.0f));
+  ASSERT_EQ(floatField->GetFloat(h_instance.Get()), static_cast<float>(0.0f));
 
-  mirror::ArtField* doubleField = sirt_klass->FindDeclaredInstanceField("doubleField", "D");
+  mirror::ArtField* doubleField = h_klass->FindDeclaredInstanceField("doubleField", "D");
   ASSERT_TRUE(doubleField != nullptr);
   ASSERT_EQ(FieldHelper(doubleField).GetTypeAsPrimitiveType(), Primitive::kPrimDouble);
-  ASSERT_EQ(doubleField->GetDouble(sirt_instance.get()), static_cast<double>(0.0));
+  ASSERT_EQ(doubleField->GetDouble(h_instance.Get()), static_cast<double>(0.0));
 
-  mirror::ArtField* objectField = sirt_klass->FindDeclaredInstanceField("objectField",
+  mirror::ArtField* objectField = h_klass->FindDeclaredInstanceField("objectField",
                                                                         "Ljava/lang/Object;");
   ASSERT_TRUE(objectField != nullptr);
   ASSERT_EQ(FieldHelper(objectField).GetTypeAsPrimitiveType(), Primitive::kPrimNot);
-  ASSERT_EQ(objectField->GetObject(sirt_instance.get()), nullptr);
+  ASSERT_EQ(objectField->GetObject(h_instance.Get()), nullptr);
 
   // Create a java.lang.Object instance to set objectField.
-  SirtRef<mirror::Class> object_klass(soa.Self(),
-                                      class_linker_->FindSystemClass(soa.Self(),
-                                                                     "Ljava/lang/Object;"));
-  ASSERT_TRUE(object_klass.get() != nullptr);
-  SirtRef<mirror::Object> sirt_obj(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  Handle<mirror::Class> object_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;")));
+  ASSERT_TRUE(object_klass.Get() != nullptr);
+  Handle<mirror::Object> h_obj(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
 
   // Modify fields inside transaction and abort it.
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  booleanField->SetBoolean<true>(sirt_instance.get(), true);
-  byteField->SetByte<true>(sirt_instance.get(), 1);
-  charField->SetChar<true>(sirt_instance.get(), 1u);
-  shortField->SetShort<true>(sirt_instance.get(), 1);
-  intField->SetInt<true>(sirt_instance.get(), 1);
-  longField->SetLong<true>(sirt_instance.get(), 1);
-  floatField->SetFloat<true>(sirt_instance.get(), 1.0);
-  doubleField->SetDouble<true>(sirt_instance.get(), 1.0);
-  objectField->SetObject<true>(sirt_instance.get(), sirt_obj.get());
+  booleanField->SetBoolean<true>(h_instance.Get(), true);
+  byteField->SetByte<true>(h_instance.Get(), 1);
+  charField->SetChar<true>(h_instance.Get(), 1u);
+  shortField->SetShort<true>(h_instance.Get(), 1);
+  intField->SetInt<true>(h_instance.Get(), 1);
+  longField->SetLong<true>(h_instance.Get(), 1);
+  floatField->SetFloat<true>(h_instance.Get(), 1.0);
+  doubleField->SetDouble<true>(h_instance.Get(), 1.0);
+  objectField->SetObject<true>(h_instance.Get(), h_obj.Get());
   Runtime::Current()->ExitTransactionMode();
   transaction.Abort();
 
   // Check values have properly been restored to their original (default) value.
-  EXPECT_EQ(booleanField->GetBoolean(sirt_instance.get()), false);
-  EXPECT_EQ(byteField->GetByte(sirt_instance.get()), 0);
-  EXPECT_EQ(charField->GetChar(sirt_instance.get()), 0u);
-  EXPECT_EQ(shortField->GetShort(sirt_instance.get()), 0);
-  EXPECT_EQ(intField->GetInt(sirt_instance.get()), 0);
-  EXPECT_EQ(longField->GetLong(sirt_instance.get()), static_cast<int64_t>(0));
-  EXPECT_EQ(floatField->GetFloat(sirt_instance.get()), static_cast<float>(0.0f));
-  EXPECT_EQ(doubleField->GetDouble(sirt_instance.get()), static_cast<double>(0.0));
-  EXPECT_EQ(objectField->GetObject(sirt_instance.get()), nullptr);
+  EXPECT_EQ(booleanField->GetBoolean(h_instance.Get()), false);
+  EXPECT_EQ(byteField->GetByte(h_instance.Get()), 0);
+  EXPECT_EQ(charField->GetChar(h_instance.Get()), 0u);
+  EXPECT_EQ(shortField->GetShort(h_instance.Get()), 0);
+  EXPECT_EQ(intField->GetInt(h_instance.Get()), 0);
+  EXPECT_EQ(longField->GetLong(h_instance.Get()), static_cast<int64_t>(0));
+  EXPECT_EQ(floatField->GetFloat(h_instance.Get()), static_cast<float>(0.0f));
+  EXPECT_EQ(doubleField->GetDouble(h_instance.Get()), static_cast<double>(0.0));
+  EXPECT_EQ(objectField->GetObject(h_instance.Get()), nullptr);
 }
 
 
 TEST_F(TransactionTest, StaticArrayFieldsTest) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction")));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<4> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction"))));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindClass(soa.Self(), "LStaticArrayFieldsTest;",
-                                                             class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
-  ASSERT_TRUE(sirt_klass->IsInitialized());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LStaticArrayFieldsTest;", class_loader)));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->EnsureInitialized(h_klass, true, true);
+  ASSERT_TRUE(h_klass->IsInitialized());
 
   // Lookup fields.
-  mirror::ArtField* booleanArrayField = sirt_klass->FindDeclaredStaticField("booleanArrayField", "[Z");
+  mirror::ArtField* booleanArrayField = h_klass->FindDeclaredStaticField("booleanArrayField", "[Z");
   ASSERT_TRUE(booleanArrayField != nullptr);
-  mirror::BooleanArray* booleanArray = booleanArrayField->GetObject(sirt_klass.get())->AsBooleanArray();
+  mirror::BooleanArray* booleanArray = booleanArrayField->GetObject(h_klass.Get())->AsBooleanArray();
   ASSERT_TRUE(booleanArray != nullptr);
   ASSERT_EQ(booleanArray->GetLength(), 1);
   ASSERT_EQ(booleanArray->GetWithoutChecks(0), false);
 
-  mirror::ArtField* byteArrayField = sirt_klass->FindDeclaredStaticField("byteArrayField", "[B");
+  mirror::ArtField* byteArrayField = h_klass->FindDeclaredStaticField("byteArrayField", "[B");
   ASSERT_TRUE(byteArrayField != nullptr);
-  mirror::ByteArray* byteArray = byteArrayField->GetObject(sirt_klass.get())->AsByteArray();
+  mirror::ByteArray* byteArray = byteArrayField->GetObject(h_klass.Get())->AsByteArray();
   ASSERT_TRUE(byteArray != nullptr);
   ASSERT_EQ(byteArray->GetLength(), 1);
   ASSERT_EQ(byteArray->GetWithoutChecks(0), 0);
 
-  mirror::ArtField* charArrayField = sirt_klass->FindDeclaredStaticField("charArrayField", "[C");
+  mirror::ArtField* charArrayField = h_klass->FindDeclaredStaticField("charArrayField", "[C");
   ASSERT_TRUE(charArrayField != nullptr);
-  mirror::CharArray* charArray = charArrayField->GetObject(sirt_klass.get())->AsCharArray();
+  mirror::CharArray* charArray = charArrayField->GetObject(h_klass.Get())->AsCharArray();
   ASSERT_TRUE(charArray != nullptr);
   ASSERT_EQ(charArray->GetLength(), 1);
   ASSERT_EQ(charArray->GetWithoutChecks(0), 0u);
 
-  mirror::ArtField* shortArrayField = sirt_klass->FindDeclaredStaticField("shortArrayField", "[S");
+  mirror::ArtField* shortArrayField = h_klass->FindDeclaredStaticField("shortArrayField", "[S");
   ASSERT_TRUE(shortArrayField != nullptr);
-  mirror::ShortArray* shortArray = shortArrayField->GetObject(sirt_klass.get())->AsShortArray();
+  mirror::ShortArray* shortArray = shortArrayField->GetObject(h_klass.Get())->AsShortArray();
   ASSERT_TRUE(shortArray != nullptr);
   ASSERT_EQ(shortArray->GetLength(), 1);
   ASSERT_EQ(shortArray->GetWithoutChecks(0), 0);
 
-  mirror::ArtField* intArrayField = sirt_klass->FindDeclaredStaticField("intArrayField", "[I");
+  mirror::ArtField* intArrayField = h_klass->FindDeclaredStaticField("intArrayField", "[I");
   ASSERT_TRUE(intArrayField != nullptr);
-  mirror::IntArray* intArray = intArrayField->GetObject(sirt_klass.get())->AsIntArray();
+  mirror::IntArray* intArray = intArrayField->GetObject(h_klass.Get())->AsIntArray();
   ASSERT_TRUE(intArray != nullptr);
   ASSERT_EQ(intArray->GetLength(), 1);
   ASSERT_EQ(intArray->GetWithoutChecks(0), 0);
 
-  mirror::ArtField* longArrayField = sirt_klass->FindDeclaredStaticField("longArrayField", "[J");
+  mirror::ArtField* longArrayField = h_klass->FindDeclaredStaticField("longArrayField", "[J");
   ASSERT_TRUE(longArrayField != nullptr);
-  mirror::LongArray* longArray = longArrayField->GetObject(sirt_klass.get())->AsLongArray();
+  mirror::LongArray* longArray = longArrayField->GetObject(h_klass.Get())->AsLongArray();
   ASSERT_TRUE(longArray != nullptr);
   ASSERT_EQ(longArray->GetLength(), 1);
   ASSERT_EQ(longArray->GetWithoutChecks(0), static_cast<int64_t>(0));
 
-  mirror::ArtField* floatArrayField = sirt_klass->FindDeclaredStaticField("floatArrayField", "[F");
+  mirror::ArtField* floatArrayField = h_klass->FindDeclaredStaticField("floatArrayField", "[F");
   ASSERT_TRUE(floatArrayField != nullptr);
-  mirror::FloatArray* floatArray = floatArrayField->GetObject(sirt_klass.get())->AsFloatArray();
+  mirror::FloatArray* floatArray = floatArrayField->GetObject(h_klass.Get())->AsFloatArray();
   ASSERT_TRUE(floatArray != nullptr);
   ASSERT_EQ(floatArray->GetLength(), 1);
   ASSERT_EQ(floatArray->GetWithoutChecks(0), static_cast<float>(0.0f));
 
-  mirror::ArtField* doubleArrayField = sirt_klass->FindDeclaredStaticField("doubleArrayField", "[D");
+  mirror::ArtField* doubleArrayField = h_klass->FindDeclaredStaticField("doubleArrayField", "[D");
   ASSERT_TRUE(doubleArrayField != nullptr);
-  mirror::DoubleArray* doubleArray = doubleArrayField->GetObject(sirt_klass.get())->AsDoubleArray();
+  mirror::DoubleArray* doubleArray = doubleArrayField->GetObject(h_klass.Get())->AsDoubleArray();
   ASSERT_TRUE(doubleArray != nullptr);
   ASSERT_EQ(doubleArray->GetLength(), 1);
   ASSERT_EQ(doubleArray->GetWithoutChecks(0), static_cast<double>(0.0f));
 
-  mirror::ArtField* objectArrayField = sirt_klass->FindDeclaredStaticField("objectArrayField",
+  mirror::ArtField* objectArrayField = h_klass->FindDeclaredStaticField("objectArrayField",
                                                                            "[Ljava/lang/Object;");
   ASSERT_TRUE(objectArrayField != nullptr);
   mirror::ObjectArray<mirror::Object>* objectArray =
-      objectArrayField->GetObject(sirt_klass.get())->AsObjectArray<mirror::Object>();
+      objectArrayField->GetObject(h_klass.Get())->AsObjectArray<mirror::Object>();
   ASSERT_TRUE(objectArray != nullptr);
   ASSERT_EQ(objectArray->GetLength(), 1);
   ASSERT_EQ(objectArray->GetWithoutChecks(0), nullptr);
 
   // Create a java.lang.Object instance to set objectField.
-  SirtRef<mirror::Class> object_klass(soa.Self(),
-                                      class_linker_->FindSystemClass(soa.Self(),
-                                                                     "Ljava/lang/Object;"));
-  ASSERT_TRUE(object_klass.get() != nullptr);
-  SirtRef<mirror::Object> sirt_obj(soa.Self(), sirt_klass->AllocObject(soa.Self()));
-  ASSERT_TRUE(sirt_obj.get() != nullptr);
-  ASSERT_EQ(sirt_obj->GetClass(), sirt_klass.get());
+  Handle<mirror::Class> object_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/Object;")));
+  ASSERT_TRUE(object_klass.Get() != nullptr);
+  Handle<mirror::Object> h_obj(hs.NewHandle(h_klass->AllocObject(soa.Self())));
+  ASSERT_TRUE(h_obj.Get() != nullptr);
+  ASSERT_EQ(h_obj->GetClass(), h_klass.Get());
 
   // Modify fields inside transaction and abort it.
   Transaction transaction;
@@ -394,7 +392,7 @@
   longArray->SetWithoutChecks<true>(0, 1);
   floatArray->SetWithoutChecks<true>(0, 1.0);
   doubleArray->SetWithoutChecks<true>(0, 1.0);
-  objectArray->SetWithoutChecks<true>(0, sirt_obj.get());
+  objectArray->SetWithoutChecks<true>(0, h_obj.Get());
   Runtime::Current()->ExitTransactionMode();
   transaction.Abort();
 
@@ -412,42 +410,41 @@
 
 TEST_F(TransactionTest, EmptyClass) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction")));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction"))));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindClass(soa.Self(),
-                                                             "LTransaction$EmptyStatic;",
-                                                             class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LTransaction$EmptyStatic;", class_loader)));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
 
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
+  class_linker_->EnsureInitialized(h_klass, true, true);
   Runtime::Current()->ExitTransactionMode();
   ASSERT_FALSE(soa.Self()->IsExceptionPending());
 }
 
 TEST_F(TransactionTest, StaticFieldClass) {
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction")));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(LoadDex("Transaction"))));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindClass(soa.Self(),
-                                                             "LTransaction$StaticFieldClass;",
-                                                             class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LTransaction$StaticFieldClass;",
+                                            class_loader)));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
 
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
+  class_linker_->EnsureInitialized(h_klass, true, true);
   Runtime::Current()->ExitTransactionMode();
   ASSERT_FALSE(soa.Self()->IsExceptionPending());
 }
@@ -455,39 +452,40 @@
 TEST_F(TransactionTest, BlacklistedClass) {
   ScopedObjectAccess soa(Thread::Current());
   jobject jclass_loader = LoadDex("Transaction");
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                            soa.Decode<mirror::ClassLoader*>(jclass_loader));
-  ASSERT_TRUE(class_loader.get() != nullptr);
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+  ASSERT_TRUE(class_loader.Get() != nullptr);
 
   // Load and verify java.lang.ExceptionInInitializerError and java.lang.InternalError which will
   // be thrown by class initialization due to native call.
-  SirtRef<mirror::Class> sirt_klass(soa.Self(),
-                                    class_linker_->FindSystemClass(soa.Self(),
-                                                                   "Ljava/lang/ExceptionInInitializerError;"));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
-  sirt_klass.reset(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/InternalError;"));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
+  Handle<mirror::Class> h_klass(
+      hs.NewHandle(class_linker_->FindSystemClass(soa.Self(),
+                                                  "Ljava/lang/ExceptionInInitializerError;")));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
+  h_klass.Assign(class_linker_->FindSystemClass(soa.Self(), "Ljava/lang/InternalError;"));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
 
   // Load and verify Transaction$NativeSupport used in class initialization.
-  sirt_klass.reset(class_linker_->FindClass(soa.Self(), "LTransaction$NativeSupport;",
-                                            class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
+  h_klass.Assign(class_linker_->FindClass(soa.Self(), "LTransaction$NativeSupport;",
+                                             class_loader));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
 
-  sirt_klass.reset(class_linker_->FindClass(soa.Self(), "LTransaction$BlacklistedClass;",
-                                            class_loader));
-  ASSERT_TRUE(sirt_klass.get() != nullptr);
-  class_linker_->VerifyClass(sirt_klass);
-  ASSERT_TRUE(sirt_klass->IsVerified());
+  h_klass.Assign(class_linker_->FindClass(soa.Self(), "LTransaction$BlacklistedClass;",
+                                             class_loader));
+  ASSERT_TRUE(h_klass.Get() != nullptr);
+  class_linker_->VerifyClass(h_klass);
+  ASSERT_TRUE(h_klass->IsVerified());
 
   Transaction transaction;
   Runtime::Current()->EnterTransactionMode(&transaction);
-  class_linker_->EnsureInitialized(sirt_klass, true, true);
+  class_linker_->EnsureInitialized(h_klass, true, true);
   Runtime::Current()->ExitTransactionMode();
   ASSERT_TRUE(soa.Self()->IsExceptionPending());
 }