Java plugin exits memory.

Question

Our application employs an applet to move large amounts of data over TCP and UDP sockets. When we run multiple instances (different tabs in the browse but share the same VM) the applets will run for a while then Java.exe will exit memory (i.e. disappear from the active process list). Note that we predominantly run on windows.
I attached a debugger to Java.exe and noticed that just before it exits, it reports a large number of Access Violation exceptions:
First-chance exception at 0x01f96c92 in java.exe: 0xC0000005: Access violation reading location 0x00150100.
Followed by several lines like:
The thread 'Win32 Thread' (0x86c) has exited with code 0 (0x0).
Finally:
The program '[4060] java.exe: Native' has exited with code 0 (0x0).
As far as the applets are concerned, the first sign of trouble is that the socket returns a disconnect (e.g. a read returns -1). The applet goes through its shut down sequence but encounters many exceptions as it tries to make callbacks into our JavaScript code that is responsible for displaying status messages. For example:
java.io.IOException: namedPipe shutdown
at sun.plugin2.message.transport.NamedPipeTransport$SerializerImpl.flush(Unknown Source)
at sun.plugin2.message.transport.NamedPipeTransport.signalDataWritten(Unknown Source)
at sun.plugin2.message.transport.SerializingTransport.write(Unknown Source)
at sun.plugin2.message.Pipe.send(Unknown Source)
at sun.plugin2.main.client.PluginMain.sendAppletAck(Unknown Source)
at sun.plugin2.main.client.PluginMain.access$1700(Unknown Source)
at sun.plugin2.main.client.PluginMain$StartAppletListener.appletReady(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.fireAppletReady(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.stopWaitingForAppletStart(Unknown Source)
at sun.plugin2.main.client.MessagePassingExecutionContext.getJSObject(Unknown Source)
at sun.plugin2.applet2.Plugin2Host.getJSObject(Unknown Source)
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter$AppletContextImpl.getJSObject(Unknown Source)
at netscape.javascript.JSObject.getWindow(Unknown Source)
or
java.lang.NullPointerException
at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
(when the applet attempts to execute the following line:
AccessController.doPrivileged(new PrivilegedAction().....
This happens on 1.7.0_13-b20 and 1.6.xx, also, the amount of data transferred by the applet does not matter. i.e. I could transfer huge amounts through one applet without problem but could not transfer lesser amounts over parallel applets.
Finally, I gave the VM more memory (-Xmx parameter) without change in behaviour.
I would appreciate any pointer on how to proceed to troubleshoot this behaviour and see what are we doing to make the JVM behave this way.

Answer 1

You might want to read an article about memory leaks in Java:
http://www-106.ibm.com/developerworks/library/j-leaks/