/* * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import java.io.BufferedReader; import java.io.InputStreamReader; import java.lang.Class; import java.lang.String; import java.lang.System; import java.lang.management.ManagementFactory; import java.lang.management.RuntimeMXBean; import java.util.ArrayList; import java.util.List; import java.util.concurrent.CyclicBarrier; import java.util.regex.Matcher; import java.util.regex.Pattern; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import jdk.internal.misc.Unsafe; import jdk.internal.vm.annotation.Contended; /* * @test * @bug 8003985 * @summary Support Contended Annotation - JEP 142 * @modules java.base/jdk.internal.misc * @modules java.base/jdk.internal.vm.annotation * @run main/othervm -XX:-RestrictContended Basic */ public class Basic { private static final Unsafe U = Unsafe.getUnsafe(); private static int ADDRESS_SIZE; private static int HEADER_SIZE; static { // When running with CompressedOops on 64-bit platform, the address size // reported by Unsafe is still 8, while the real reference fields are 4 bytes long. // Try to guess the reference field size with this naive trick. try { long off1 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj1")); long off2 = U.objectFieldOffset(CompressedOopsClass.class.getField("obj2")); ADDRESS_SIZE = (int) Math.abs(off2 - off1); HEADER_SIZE = (int) Math.min(off1, off2); } catch (NoSuchFieldException e) { ADDRESS_SIZE = -1; } } static class CompressedOopsClass { public Object obj1; public Object obj2; } public static boolean arePaddedPairwise(Class klass, String field1, String field2) throws Exception { Field f1 = klass.getDeclaredField(field1); Field f2 = klass.getDeclaredField(field2); if (isStatic(f1) != isStatic(f2)) { return true; // these guys are in naturally disjoint locations } int diff = offset(f1) - offset(f2); if (diff < 0) { // f1 is first return (offset(f2) - (offset(f1) + getSize(f1))) > 64; } else { // f2 is first return (offset(f1) - (offset(f2) + getSize(f2))) > 64; } } public static boolean isPadded(Class klass, String field1) throws Exception { Field f1 = klass.getDeclaredField(field1); if (isStatic(f1)) { return offset(f1) > 128 + 64; } return offset(f1) > 64; } public static boolean sameLayout(Class klass1, Class klass2) throws Exception { for (Field f1 : klass1.getDeclaredFields()) { Field f2 = klass2.getDeclaredField(f1.getName()); if (offset(f1) != offset(f2)) { return false; } } for (Field f2 : klass1.getDeclaredFields()) { Field f1 = klass2.getDeclaredField(f2.getName()); if (offset(f1) != offset(f2)) { return false; } } return true; } public static boolean isStatic(Field field) { return Modifier.isStatic(field.getModifiers()); } public static int offset(Field field) { if (isStatic(field)) { return (int) U.staticFieldOffset(field); } else { return (int) U.objectFieldOffset(field); } } public static int getSize(Field field) { Class type = field.getType(); if (type == byte.class) { return 1; } if (type == boolean.class) { return 1; } if (type == short.class) { return 2; } if (type == char.class) { return 2; } if (type == int.class) { return 4; } if (type == float.class) { return 4; } if (type == long.class) { return 8; } if (type == double.class) { return 8; } return ADDRESS_SIZE; } public static void main(String[] args) throws Exception { boolean endResult = true; // --------------- INSTANCE FIELDS --------------------- if (arePaddedPairwise(Test1.class, "int1", "int2") || isPadded(Test1.class, "int1") || isPadded(Test1.class, "int2")) { System.err.println("Test1 failed"); endResult &= false; } if (!arePaddedPairwise(Test2.class, "int1", "int2") || !isPadded(Test2.class, "int1") || isPadded(Test2.class, "int2")) { System.err.println("Test2 failed"); endResult &= false; } if (!arePaddedPairwise(Test3.class, "int1", "int2") || !isPadded(Test3.class, "int1") || !isPadded(Test3.class, "int2")) { System.err.println("Test3 failed"); endResult &= false; } if (arePaddedPairwise(Test4.class, "int1", "int2") || !isPadded(Test4.class, "int1") || !isPadded(Test4.class, "int2")) { System.err.println("Test4 failed"); endResult &= false; } if (!arePaddedPairwise(Test5.class, "int1", "int2") || !isPadded(Test5.class, "int1") || !isPadded(Test5.class, "int2")) { System.err.println("Test5 failed"); endResult &= false; } if (!arePaddedPairwise(Test6.class, "int1", "int2") || !isPadded(Test6.class, "int1") || !isPadded(Test6.class, "int2")) { System.err.println("Test6 failed"); endResult &= false; } if (arePaddedPairwise(Test7.class, "int1", "int2") || !isPadded(Test7.class, "int1") || !isPadded(Test7.class, "int2")) { System.err.println("Test7 failed"); endResult &= false; } if (!arePaddedPairwise(Test8.class, "int1", "int2") || !isPadded(Test8.class, "int1") || !isPadded(Test8.class, "int2")) { System.err.println("Test8 failed"); endResult &= false; } if (!arePaddedPairwise(Test9.class, "int1", "int2") || !isPadded(Test9.class, "int1") || !isPadded(Test9.class, "int2")) { System.err.println("Test9 failed"); endResult &= false; } if (!sameLayout(Test4.class, Test7.class)) { System.err.println("Test4 and Test7 have different layouts"); endResult &= false; } if (!sameLayout(Test5.class, Test6.class)) { System.err.println("Test5 and Test6 have different layouts"); endResult &= false; } if (!sameLayout(Test8.class, Test9.class)) { System.err.println("Test8 and Test9 have different layouts"); endResult &= false; } System.out.println(endResult ? "Test PASSES" : "Test FAILS"); if (!endResult) { throw new Error("Test failed"); } } // ----------------------------------- INSTANCE FIELDS ----------------------------------------- // naturally packed public static class Test1 { private int int1; private int int2; } // int1 is padded public static class Test2 { @Contended private int int1; private int int2; } // both fields are padded public static class Test3 { @Contended private int int1; @Contended private int int2; } // fields are padded in the singular group public static class Test4 { @Contended("sameGroup") private int int1; @Contended("sameGroup") private int int2; } // fields are padded in disjoint groups public static class Test5 { @Contended("diffGroup1") private int int1; @Contended("diffGroup2") private int int2; } // fields are padded in disjoint groups public static class Test6 { @Contended private int int1; @Contended("diffGroup2") private int int2; } // fields are padded in the singular group @Contended public static class Test7 { private int int1; private int int2; } // all fields are padded as the group, and one field is padded specifically @Contended public static class Test8 { @Contended private int int1; private int int2; } // all fields are padded as the group, and one field is padded specifically @Contended public static class Test9 { @Contended("group") private int int1; private int int2; } }