/* * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "jni.h" #include <iostream> #include "art_method.h" #include "jit/jit.h" #include "linear_alloc.h" #include "nativehelper/ScopedUtfChars.h" #include "runtime.h" #include "scoped_thread_state_change-inl.h" #include "thread-current-inl.h" namespace art { namespace { extern "C" JNIEXPORT jlong JNICALL Java_Main_getArtMethod(JNIEnv* env, jclass, jobject java_method) { ScopedObjectAccess soa(env); ArtMethod* method = ArtMethod::FromReflectedMethod(soa, java_method); return static_cast<jlong>(reinterpret_cast<uintptr_t>(method)); } extern "C" JNIEXPORT void JNICALL Java_Main_reuseArenaOfMethod(JNIEnv*, jclass, jlong art_method) { // Create a new allocation and use it to request a specified amount of arenas. // Hopefully one of them is a reused one, the one that covers the art_method pointer. std::unique_ptr<LinearAlloc> alloc(Runtime::Current()->CreateLinearAlloc()); do { // Ask for a byte - it's sufficient to get an arena and not have issues with size. alloc->Alloc(Thread::Current(), 1); } while (!alloc->Contains(reinterpret_cast<void*>(static_cast<uintptr_t>(art_method)))); } } // namespace } // namespace art