/* * Copyright (C) 2018 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.util.HashMap; public class Main { public static void main(String[] args) { System.loadLibrary(args[0]); // Jit compile HashMap.hash method, so that instrumentation stubs // will deoptimize it. ensureJitCompiled(HashMap.class, "hash"); Main key = new Main(); Integer value = new Integer(10); HashMap<Main, Integer> map = new HashMap<>(); map.put(key, value); Integer res = map.get(key); if (!value.equals(res)) { throw new Error("Expected 10, got " + res); } } public int hashCode() { // The call stack at this point is: // Main.main // HashMap.put // HashMap.hash // Main.hashCode // // The opcode at HashMap.hash is invoke-virtual-quick which the // instrumentation code did not expect and used to fetch the wrong // method index for it. deoptimizeAll(); return 42; } public static native void deoptimizeAll(); public static native void ensureJitCompiled(Class<?> cls, String methodName); }