# HG changeset patch # User dholmes # Date 1368762027 14400 # Node ID 1ba508fcd3e2b30fd12069431268edfc869b349e # Parent b334821dad9232fa7b17ff1aa3c729dd5e7d5127# Parent 074ba6269cf4e4c1d6613f17e9dc662ee8437346 Merge diff -r b334821dad92 -r 1ba508fcd3e2 src/share/vm/classfile/classFileParser.cpp --- a/src/share/vm/classfile/classFileParser.cpp Thu May 16 21:19:49 2013 -0400 +++ b/src/share/vm/classfile/classFileParser.cpp Thu May 16 23:40:27 2013 -0400 @@ -1719,15 +1719,28 @@ coll->set_annotation(id); if (id == AnnotationCollector::_sun_misc_Contended) { + // @Contended can optionally specify the contention group. + // + // Contended group defines the equivalence class over the fields: + // the fields within the same contended group are not treated distinct. + // The only exception is default group, which does not incur the + // equivalence. Naturally, contention group for classes is meaningless. + // + // While the contention group is specified as String, annotation + // values are already interned, and we might as well use the constant + // pool index as the group tag. + // + u2 group_index = 0; // default contended group if (count == 1 && s_size == (index - index0) // match size && s_tag_val == *(abase + tag_off) && member == vmSymbols::value_name()) { - u2 group_index = Bytes::get_Java_u2(abase + s_con_off); - coll->set_contended_group(group_index); - } else { - coll->set_contended_group(0); // default contended group + group_index = Bytes::get_Java_u2(abase + s_con_off); + if (_cp->symbol_at(group_index)->utf8_length() == 0) { + group_index = 0; // default contended group + } } + coll->set_contended_group(group_index); } } } diff -r b334821dad92 -r 1ba508fcd3e2 test/runtime/contended/DefaultValue.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/runtime/contended/DefaultValue.java Thu May 16 23:40:27 2013 -0400 @@ -0,0 +1,185 @@ +/* + * Copyright (c) 2013, 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 sun.misc.Unsafe; +import sun.misc.Contended; + +/* + * @test + * @bug 8014509 + * @summary \@Contended: explicit default value behaves differently from the implicit value + * + * @run main/othervm -XX:-RestrictContended DefaultValue + */ +public class DefaultValue { + + private static final Unsafe U; + private static int ADDRESS_SIZE; + private static int HEADER_SIZE; + + static { + // steal Unsafe + try { + Field unsafe = Unsafe.class.getDeclaredField("theUnsafe"); + unsafe.setAccessible(true); + U = (Unsafe) unsafe.get(null); + } catch (NoSuchFieldException | IllegalAccessException e) { + throw new IllegalStateException(e); + } + + // 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.getField(field1); + Field f2 = klass.getField(field2); + + 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 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; + + if (!arePaddedPairwise(R1.class, "int1", "int2")) { + System.err.println("R1 failed"); + endResult &= false; + } + + if (!arePaddedPairwise(R2.class, "int1", "int2")) { + System.err.println("R2 failed"); + endResult &= false; + } + + if (!arePaddedPairwise(R3.class, "int1", "int2")) { + System.err.println("R3 failed"); + endResult &= false; + } + + System.out.println(endResult ? "Test PASSES" : "Test FAILS"); + if (!endResult) { + throw new Error("Test failed"); + } + } + + public static class R1 { + @Contended + public int int1; + @Contended + public int int2; + } + + public static class R2 { + @Contended("") + public int int1; + @Contended("") + public int int2; + } + + public static class R3 { + @Contended() + public int int1; + @Contended() + public int int2; + } + +} +