Move Class.newInstance to native
Avoids 1 allocation and several JNI transitions.
Before:
Class_classNewInstance: 4462.39 ns; σ=39.42 ns @ 3 trials
After:
Class_classNewInstance: 1073.39 ns; σ=24.14 ns @ 10 trials
Bug: 20269715
Bug: 20566996
Change-Id: Icd52155ce79a978a4d869855bfdfd7735abd8187
diff --git a/runtime/native/java_lang_Class.cc b/runtime/native/java_lang_Class.cc
index b0d923b..48a8bc7 100644
--- a/runtime/native/java_lang_Class.cc
+++ b/runtime/native/java_lang_Class.cc
@@ -29,6 +29,7 @@
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/string-inl.h"
+#include "reflection.h"
#include "scoped_thread_state_change.h"
#include "scoped_fast_native_object_access.h"
#include "ScopedLocalRef.h"
@@ -391,8 +392,8 @@
nullptr;
}
-jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
- jboolean publicOnly) {
+static jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
+ jboolean publicOnly) {
ScopedFastNativeObjectAccess soa(env);
StackHandleScope<5> hs(soa.Self());
auto* klass = DecodeClass(soa, javaThis);
@@ -457,6 +458,74 @@
return soa.AddLocalReference<jobjectArray>(ret.Get());
}
+static jobject Class_newInstance(JNIEnv* env, jobject javaThis) {
+ ScopedFastNativeObjectAccess soa(env);
+ StackHandleScope<4> hs(soa.Self());
+ auto klass = hs.NewHandle(DecodeClass(soa, javaThis));
+ if (UNLIKELY(klass->GetPrimitiveType() != 0 || klass->IsInterface() || klass->IsArrayClass() ||
+ klass->IsAbstract())) {
+ soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
+ "%s cannot be instantiated", PrettyClass(klass.Get()).c_str());
+ return nullptr;
+ }
+ auto caller = hs.NewHandle<mirror::Class>(nullptr);
+ // Verify that we can access the class.
+ if (!klass->IsPublic()) {
+ caller.Assign(GetCallingClass(soa.Self(), 1));
+ if (caller.Get() != nullptr && !caller->CanAccess(klass.Get())) {
+ soa.Self()->ThrowNewExceptionF(
+ "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
+ PrettyClass(klass.Get()).c_str(), PrettyClass(caller.Get()).c_str());
+ return nullptr;
+ }
+ }
+ auto* constructor = klass->GetDeclaredConstructor(
+ soa.Self(), NullHandle<mirror::ObjectArray<mirror::Class>>());
+ if (UNLIKELY(constructor == nullptr)) {
+ soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
+ "%s has no zero argument constructor",
+ PrettyClass(klass.Get()).c_str());
+ return nullptr;
+ }
+ auto receiver = hs.NewHandle(klass->AllocObject(soa.Self()));
+ if (UNLIKELY(receiver.Get() == nullptr)) {
+ soa.Self()->AssertPendingOOMException();
+ return nullptr;
+ }
+ // Verify that we can access the constructor.
+ auto* declaring_class = constructor->GetDeclaringClass();
+ if (!constructor->IsPublic()) {
+ if (caller.Get() == nullptr) {
+ caller.Assign(GetCallingClass(soa.Self(), 1));
+ }
+ if (UNLIKELY(caller.Get() != nullptr && !VerifyAccess(
+ soa.Self(), receiver.Get(), declaring_class, constructor->GetAccessFlags(),
+ caller.Get()))) {
+ soa.Self()->ThrowNewExceptionF(
+ "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
+ PrettyMethod(constructor).c_str(), PrettyClass(caller.Get()).c_str());
+ return nullptr;
+ }
+ }
+ // Ensure that we are initialized.
+ if (UNLIKELY(!declaring_class->IsInitialized())) {
+ if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(
+ soa.Self(), hs.NewHandle(declaring_class), true, true)) {
+ soa.Self()->AssertPendingException();
+ return nullptr;
+ }
+ }
+ // Invoke the constructor.
+ JValue result;
+ uint32_t args[1] = { static_cast<uint32_t>(reinterpret_cast<uintptr_t>(receiver.Get())) };
+ constructor->Invoke(soa.Self(), args, sizeof(args), &result, "V");
+ if (UNLIKELY(soa.Self()->IsExceptionPending())) {
+ return nullptr;
+ }
+ // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
+ return soa.AddLocalReference<jobject>(receiver.Get());
+}
+
static JNINativeMethod gMethods[] = {
NATIVE_METHOD(Class, classForName,
"!(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;"),
@@ -474,6 +543,7 @@
NATIVE_METHOD(Class, getNameNative, "!()Ljava/lang/String;"),
NATIVE_METHOD(Class, getProxyInterfaces, "!()[Ljava/lang/Class;"),
NATIVE_METHOD(Class, getPublicDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
+ NATIVE_METHOD(Class, newInstance, "!()Ljava/lang/Object;"),
};
void register_java_lang_Class(JNIEnv* env) {