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
--- a/jdk/src/share/classes/java/lang/ref/Reference.java Mon May 27 15:18:00 2013 +0400
+++ b/jdk/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/jdk/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.");
+ }
+}