/* * Copyright (C) 2016 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. */ import java.lang.reflect.Method; public class Main { public static void main(String[] args) { System.loadLibrary(args[0]); // Get all methods. We cannot call getDeclaredMethod("foo") as // that would make "foo" a strong root. Method[] methods = Main.class.getDeclaredMethods(); // Call getName on the methods, which is implemented by using the dex // cache and calling setResolvedString. for (int i = 0; i < methods.length; i++) { methods[i].getName(); } // Compile Main.foo. "foo" needs to be a strong root for JIT compilation. // We stress test this: // - avoid strongly interning "foo" by doing "f" + "oo" // - call GC so that weaks can be collected. // - invoke foo() to make sure "foo" hasn't been collected. ensureJitCompiled(Main.class, "f" + "oo"); Runtime.getRuntime().gc(); foo(); } public static void foo() { System.out.println("foo"); } public static native void ensureJitCompiled(Class cls, String method_name); }