changeset 215:7cd3dfada49b

Sample unsafe publication test.
author shade
date Sat, 24 Jan 2015 01:30:32 +0300
parents fc7efa97034e
children 480a21ea8192
files tests-custom/src/main/java/org/openjdk/jcstress/tests/unsafe/UnsafePublication.java
diffstat 1 files changed, 85 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests-custom/src/main/java/org/openjdk/jcstress/tests/unsafe/UnsafePublication.java	Sat Jan 24 01:30:32 2015 +0300
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2014, 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package org.openjdk.jcstress.tests.unsafe;
+
+import org.openjdk.jcstress.annotations.Actor;
+import org.openjdk.jcstress.annotations.Description;
+import org.openjdk.jcstress.annotations.Expect;
+import org.openjdk.jcstress.annotations.JCStressTest;
+import org.openjdk.jcstress.annotations.Outcome;
+import org.openjdk.jcstress.annotations.State;
+import org.openjdk.jcstress.infra.results.IntResult1;
+
+@JCStressTest
+@Description("Tests if unsafe publication is unsafe.")
+@Outcome(id = "[-1]", expect = Expect.ACCEPTABLE, desc = "The object is not yet published")
+@Outcome(id = "[0]", expect = Expect.ACCEPTABLE, desc = "The object is published, but all fields are 0.")
+@Outcome(id = "[1]", expect = Expect.ACCEPTABLE, desc = "The object is published, at least 1 field is visible.")
+@Outcome(id = "[2]", expect = Expect.ACCEPTABLE, desc = "The object is published, at least 2 fields are visible.")
+@Outcome(id = "[3]", expect = Expect.ACCEPTABLE, desc = "The object is published, at least 3 fields are visible.")
+@Outcome(id = "[4]", expect = Expect.ACCEPTABLE, desc = "The object is published, all fields are visible.")
+@State
+public class UnsafePublication {
+
+    /*
+       Implementation notes:
+         * This showcases how compiler can move the publishing store past the field stores.
+         * We need to provide constructor with some external value. If we put the constants in the
+           constructor, then compiler can store all the fields with a single bulk store.
+         * This test is best to be run with either 32-bit VM, or 64-bit VM with -XX:-UseCompressedOops:
+           it seems the compressed references mechanics moves the reference store after the field
+           stores, even though not required by JMM.
+     */
+
+    int x = 1;
+
+    MyObject o;
+
+    @Actor
+    public void publish() {
+        o = new MyObject(x);
+    }
+
+    @Actor
+    public void consume(IntResult1 res) {
+        MyObject lo = o;
+        if (lo != null) {
+            res.r1 = lo.x00 + lo.x01 + lo.x02 + lo.x03;
+        } else {
+            res.r1 = -1;
+        }
+    }
+
+    static class MyObject {
+        int x00, x01, x02, x03;
+        public MyObject(int x) {
+            x00 = x;
+            x01 = x;
+            x02 = x;
+            x03 = x;
+        }
+    }
+
+}