changeset 7221:0b8dab7fec54

7038914: VM could throw uncaught OOME in ReferenceHandler thread Summary: Catch OutOfMemoryError in reference handler thread if caused by allocation of an InterruptedException Reviewed-by: dholmes, alanb
author plevart
date Mon, 27 May 2013 09:41:44 +0200
parents d78f91ab0e96
children 9bbf2237071e
files src/share/classes/java/lang/ref/Reference.java test/java/lang/ref/OOMEInReferenceHandler.java
diffstat 2 files changed, 129 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/classes/java/lang/ref/Reference.java	Mon May 27 15:18:00 2013 +0400
+++ b/src/share/classes/java/lang/ref/Reference.java	Mon May 27 09:41:44 2013 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 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
@@ -138,8 +138,23 @@
                         pending = r.discovered;
                         r.discovered = null;
                     } else {
+                        // The waiting on the lock may cause an OOME because it may try to allocate
+                        // exception objects, so also catch OOME here to avoid silent exit of the
+                        // reference handler thread.
+                        //
+                        // Explicitly define the order of the two exceptions we catch here
+                        // when waiting for the lock.
+                        //
+                        // We do not want to try to potentially load the InterruptedException class
+                        // (which would be done if this was its first use, and InterruptedException
+                        // were checked first) in this situation.
+                        //
+                        // This may lead to the VM not ever trying to load the InterruptedException
+                        // class again.
                         try {
-                            lock.wait();
+                            try {
+                                lock.wait();
+                            } catch (OutOfMemoryError x) { }
                         } catch (InterruptedException x) { }
                         continue;
                     }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/java/lang/ref/OOMEInReferenceHandler.java	Mon May 27 09:41:44 2013 +0200
@@ -0,0 +1,112 @@
+/*
+ * 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 7038914
+ * @summary Verify that the reference handler does not die after an OOME allocating the InterruptedException object
+ * @run main/othervm -Xmx16M -XX:-UseTLAB OOMEInReferenceHandler
+ * @author peter.levart@gmail.com
+ */
+
+import java.lang.ref.*;
+
+public class OOMEInReferenceHandler {
+     static Object[] fillHeap() {
+         Object[] first = null, last = null;
+         int size = 1 << 20;
+         while (size > 0) {
+             try {
+                 Object[] array = new Object[size];
+                 if (first == null) {
+                     first = array;
+                 } else {
+                     last[0] = array;
+                 }
+                 last = array;
+             } catch (OutOfMemoryError oome) {
+                 size = size >>> 1;
+             }
+         }
+         return first;
+     }
+
+     public static void main(String[] args) throws Exception {
+         // preinitialize the InterruptedException class so that the reference handler
+         // does not die due to OOME when loading the class if it is the first use
+         InterruptedException ie = new InterruptedException("dummy");
+
+         ThreadGroup tg = Thread.currentThread().getThreadGroup();
+         for (
+             ThreadGroup tgn = tg;
+             tgn != null;
+             tg = tgn, tgn = tg.getParent()
+             )
+             ;
+
+         Thread[] threads = new Thread[tg.activeCount()];
+         Thread referenceHandlerThread = null;
+         int n = tg.enumerate(threads);
+         for (int i = 0; i < n; i++) {
+             if ("Reference Handler".equals(threads[i].getName())) {
+                 referenceHandlerThread = threads[i];
+             }
+         }
+
+         if (referenceHandlerThread == null) {
+             throw new IllegalStateException("Couldn't find Reference Handler thread.");
+         }
+
+         ReferenceQueue<Object> refQueue = new ReferenceQueue<>();
+         Object referent = new Object();
+         WeakReference<Object> weakRef = new WeakReference<>(referent, refQueue);
+
+         Object waste = fillHeap();
+
+         referenceHandlerThread.interrupt();
+
+         // allow referenceHandlerThread some time to throw OOME
+         Thread.sleep(500L);
+
+         // release waste & referent
+         waste = null;
+         referent = null;
+
+         // wait at most 10 seconds for success or failure
+         for (int i = 0; i < 20; i++) {
+             if (refQueue.poll() != null) {
+                 // Reference Handler thread still working -> success
+                 return;
+             }
+             System.gc();
+             Thread.sleep(500L); // wait a little to allow GC to do it's work before allocating objects
+             if (!referenceHandlerThread.isAlive()) {
+                 // Reference Handler thread died -> failure
+                 throw new Exception("Reference Handler thread died.");
+             }
+         }
+
+         // no sure answer after 10 seconds
+         throw new IllegalStateException("Reference Handler thread stuck.");
+     }
+}