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<div class="moz-cite-prefix">On 05/06/2013 10:02 AM, Thomas Schatzl
wrote:<br>
</div>
<blockquote cite="mid:1367827347.2653.24.camel@cirrus" type="cite"><!--[if !IE]><DIV style="border-left: 2px solid #009900; border-right: 2px solid #009900; padding: 0px 15px; margin: 2px 0px;"><![endif]-->
<pre wrap="">I mean, if we fix this issue as you suggested (I am not against that, it
looks reasonable), I would not know what to do with the test program
except file another bug against the very same component with the same
problem, with the same fix suggestion.</pre>
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<br>
Hi Thomas,<br>
<br>
If you want a simple reproducer for OOME in ReferenceHandler's
Object.wait(), here is one:<br>
<br>
<br>
<tt>public class OOMEInReferenceHandler {</tt><tt><br>
</tt><tt><br>
</tt><tt> static Object[] fillHeap() {</tt><tt><br>
</tt><tt> Object[] first = null, last = null;</tt><tt><br>
</tt><tt> int size = 1 << 20;</tt><tt><br>
</tt><tt> while (size > 0) {</tt><tt><br>
</tt><tt> try {</tt><tt><br>
</tt><tt> Object[] array = new Object[size];</tt><tt><br>
</tt><tt> if (first == null) {</tt><tt><br>
</tt><tt> first = array;</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> else {</tt><tt><br>
</tt><tt> last[0] = array;</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> last = array;</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> catch (OutOfMemoryError oome) {</tt><tt><br>
</tt><tt> size = size >>> 1;</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> return first;</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt><br>
</tt><tt> public static void main(String[] args) throws Exception
{</tt><tt><br>
</tt><tt> ReferenceQueue<Object> refQueue = new
ReferenceQueue<Object>();</tt><tt><br>
</tt><tt> Object referent = new Object();</tt><tt><br>
</tt><tt> WeakReference<Object> weakRef = new
WeakReference<Object>(referent, refQueue);</tt><tt><br>
</tt><tt><br>
</tt><tt> ThreadGroup tg =
Thread.currentThread().getThreadGroup();</tt><tt><br>
</tt><tt> for (ThreadGroup tgn = tg;</tt><tt><br>
</tt><tt> tgn != null;</tt><tt><br>
</tt><tt> tg = tgn, tgn = tg.getParent());</tt><tt><br>
</tt><tt><br>
</tt><tt> Thread[] threads = new Thread[tg.activeCount()];</tt><tt><br>
</tt><tt> Thread referenceHandlerThread = null;</tt><tt><br>
</tt><tt> int n = tg.enumerate(threads);</tt><tt><br>
</tt><tt> for (int i = 0; i < n; i++) {</tt><tt><br>
</tt><tt> if("Reference
Handler".equals(threads[i].getName())) {</tt><tt><br>
</tt><tt> referenceHandlerThread = threads[i];</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt><br>
</tt><tt> if (referenceHandlerThread == null) {</tt><tt><br>
</tt><tt> throw new IllegalStateException("Couldn't find
Reference Handler thread.");</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt><br>
</tt><tt> Object waste = fillHeap();</tt><tt><br>
</tt><tt><br>
</tt><tt> referenceHandlerThread.interrupt();</tt><tt><br>
</tt><tt><br>
</tt><tt> Thread.sleep(1000L);</tt><tt><br>
</tt><tt> waste = null;</tt><tt><br>
</tt><tt> referent = null;</tt><tt><br>
</tt><tt> System.gc();</tt><tt><br>
</tt><tt> Thread.sleep(1000L);</tt><tt><br>
</tt><tt><br>
</tt><tt> System.out.println("weakRef.get() = " +
weakRef.get());</tt><tt><br>
</tt><tt> System.out.println("refQueue.poll() = " +
refQueue.poll());</tt><tt><br>
</tt><tt> }</tt><tt><br>
</tt><tt>}</tt><br>
<br>
<br>
<br>
... just run it with some low heap setting like -Xmx128m or so. It
doesn't need to be G1 garbage collector. Default will do.<br>
<br>
This prints on my computer:<br>
<br>
<tt>Exception: java.lang.OutOfMemoryError thrown from the
UncaughtExceptionHandler in thread "Reference Handler"</tt><tt><br>
</tt><tt>weakRef.get() = null</tt><tt><br>
</tt><tt>refQueue.poll() = null</tt><tt><br>
</tt><br>
<br>
Regards, Peter<br>
<br>
<br>
<br>
Regards, Peter<br>
<br>
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