jdk/test/java/lang/ref/EnqueuePollRace.java
changeset 18815 5da35ed47cfa
child 27792 0c0ccfb397f7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/ref/EnqueuePollRace.java	Mon Jul 08 14:05:59 2013 +0200
@@ -0,0 +1,73 @@
+/*
+ * 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.
+ */
+
+/* @test
+ * @bug 8014890
+ * @summary Verify that a race between ReferenceQueue.enqueue() and poll() does not occur.
+ * @author thomas.schatzl@oracle.com
+ * @run main/othervm -XX:+UseSerialGC -Xmx10M EnqueuePollRace
+ */
+
+import java.lang.ref.*;
+
+public class EnqueuePollRace {
+
+    public static void main(String args[]) throws Exception {
+        new WeakRef().run();
+        System.out.println("Test passed.");
+    }
+
+    static class WeakRef {
+        ReferenceQueue<Object> queue = new ReferenceQueue<Object>();
+        final int numReferences = 100;
+        final Reference refs[] = new Reference[numReferences];
+        final int iterations = 1000;
+
+        void run() throws InterruptedException {
+            for (int i = 0; i < iterations; i++) {
+                queue = new ReferenceQueue<Object>();
+
+                for (int j = 0; j < refs.length; j++) {
+                    refs[j] = new WeakReference(new Object(), queue);
+                }
+
+                System.gc(); // enqueues references into the list of discovered references
+
+                // now manually enqueue all of them
+                for (int j = 0; j < refs.length; j++) {
+                    refs[j].enqueue();
+                }
+                // and get them back. There should be exactly numReferences
+                // entries in the queue now.
+                int foundReferences = 0;
+                while (queue.poll() != null) {
+                    foundReferences++;
+                }
+
+                if (foundReferences != refs.length) {
+                    throw new RuntimeException("Got " + foundReferences + " references in the queue, but expected " + refs.length);
+                }
+            }
+        }
+    }
+}