Mercurial > hg > truffle
diff test/compiler/7190310/Test7190310_unsafe.java @ 6615:09aad8452938
7190310: Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops
Summary: In C2 add software membar after load from Reference.referent field to prevent commoning of loads across safepoint since GC can change its value. In C1 always generate Reference.get() intrinsic.
Reviewed-by: roland, twisti, dholmes, johnc
author | kvn |
---|---|
date | Mon, 20 Aug 2012 09:58:58 -0700 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/compiler/7190310/Test7190310_unsafe.java Mon Aug 20 09:58:58 2012 -0700 @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2012, 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. + * + */ + +/* + * @test + * @bug 7190310 + * @summary Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops + * @run main/othervm -Xbatch Test7190310_unsafe + */ + +import java.lang.ref.*; +import java.lang.reflect.*; +import sun.misc.Unsafe; + +public class Test7190310_unsafe { + + static class TestObject { + public String toString() { + return "TestObject"; + } + }; + + private static TestObject str = new TestObject(); + private static final WeakReference ref = new WeakReference(str); + + private TestObject obj; + + public static void main(String[] args) throws Exception { + Class c = Test7190310_unsafe.class.getClassLoader().loadClass("sun.misc.Unsafe"); + Field f = c.getDeclaredField("theUnsafe"); + f.setAccessible(true); + Unsafe unsafe = (Unsafe)f.get(c); + + f = Reference.class.getDeclaredField("referent"); + f.setAccessible(true); + long referent_offset = unsafe.objectFieldOffset(f); + + Test7190310_unsafe t = new Test7190310_unsafe(); + TestObject o = new TestObject(); + t.obj = o; + + // Warmup (compile methods) + System.err.println("Warmup"); + Object obj = null; + for (int i = 0; i < 11000; i++) { + obj = getRef0(ref); + } + for (int i = 0; i < 11000; i++) { + obj = getRef1(unsafe, ref, referent_offset); + } + for (int i = 0; i < 11000; i++) { + obj = getRef2(unsafe, ref, referent_offset); + } + for (int i = 0; i < 11000; i++) { + obj = getRef3(unsafe, ref, referent_offset); + } + for (int i = 0; i < 11000; i++) { + obj = getRef4(unsafe, t, referent_offset); + } + + // Access verification + System.err.println("Verification"); + if (!verifyGet(referent_offset, unsafe)) { + System.exit(97); + } + + obj = getRef3(unsafe, t, referent_offset); + if (obj != o) { + System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + o); + System.exit(97); + } + obj = getRef4(unsafe, t, referent_offset); + if (obj != o) { + System.out.println("FAILED: unsafe.getObject(Test7190310, " + referent_offset + ") " + obj + " != " + o); + System.exit(97); + } + } + + static boolean verifyGet(long referent_offset, Unsafe unsafe) throws Exception { + // Access verification + System.out.println("referent: " + str); + Object obj = getRef0(ref); + if (obj != str) { + System.out.println("FAILED: weakRef.get() " + obj + " != " + str); + return false; + } + obj = getRef1(unsafe, ref, referent_offset); + if (obj != str) { + System.out.println("FAILED: unsafe.getObject(weakRef, " + referent_offset + ") " + obj + " != " + str); + return false; + } + obj = getRef2(unsafe, ref, referent_offset); + if (obj != str) { + System.out.println("FAILED: unsafe.getObject(abstRef, " + referent_offset + ") " + obj + " != " + str); + return false; + } + obj = getRef3(unsafe, ref, referent_offset); + if (obj != str) { + System.out.println("FAILED: unsafe.getObject(Object, " + referent_offset + ") " + obj + " != " + str); + return false; + } + return true; + } + + static Object getRef0(WeakReference ref) throws Exception { + return ref.get(); + } + static Object getRef1(Unsafe unsafe, WeakReference ref, long referent_offset) throws Exception { + return unsafe.getObject(ref, referent_offset); + } + static Object getRef2(Unsafe unsafe, Reference ref, long referent_offset) throws Exception { + return unsafe.getObject(ref, referent_offset); + } + static Object getRef3(Unsafe unsafe, Object ref, long referent_offset) throws Exception { + return unsafe.getObject(ref, referent_offset); + } + static Object getRef4(Unsafe unsafe, Test7190310_unsafe ref, long referent_offset) throws Exception { + return unsafe.getObject(ref, referent_offset); + } +} +