when the session is destroyed, and your listener calls getId(), it might
throw an exception that the session has already been invalidated.
I believe its a IllegalStateException,
this issue has been fixed in the most recent version
Filip
Klotz Jr, Dennis wrote:
Thanks Leon for replying.
I wanted to give a bit of feedback on this issue. It turns out that
Concurrency was not the issue at all. The real problem was concealed by
something that I am still puzzled about.
Apparently when an HttpSessionListener class has an exception, it is
never sent to catalina.out or catalina.err (I do not have log4j setup)
and because of this, a problem with my logic was never being noticed.
During a sessionDestroyed() event I was attempting to cleanup old
session beans that I personally created, only there was an exception
that occurred and thus a memory leak. I never had any output for the run
time exception in a log file...
Is this a known issue?
-Dennis Klotz
-----Original Message-----
From: Leon Rosenberg [mailto:[EMAIL PROTECTED]
Sent: Tuesday, March 14, 2006 3:39 PM
To: Tomcat Users List
Subject: Re: Concurrency question for servlets
Hi,
from the tomcat source
package org.apache.catalina.core;
public class ApplicationContext
implements ServletContext {
....
public Object getAttribute(String name) {
synchronized (attributes) {
return (attributes.get(name));
}
}
to answer your question:
Question:
Do I need to put the getServletContext().getAttribute() inside of a
synchronized (this) block? I am thinking I do.
nope :-) It's already synchronized.
Leon
Btw, why should concurrency issues produce a memory leak? A dead lock
or an infinite loop -> absolutely, but memory leaks? Would be first
time I met this issue, but you're never too old to learn :-)
On 3/14/06, Klotz Jr, Dennis <[EMAIL PROTECTED]> wrote:
Hello.
I hope everyone is having a great day! I hope you have a moment for a
quick question.
I am fighting a memory leak problem and I want to try and rule in or
out
concurrency issues. So given:
Servlet Code:
-----
public enum XMSContextAttributes { applicationContext };
public void doGet (HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException
{
HXMSApplicationContext applicationContext;
applicationContext = getServletContext ().getAttribute
(XMSContextAttributes.applicationContext.name ());
...do something useful here...
}
-----
Notes:
The applicationContext object is being created by a
ServletContextListener, and it contains two important
ConcurrentHashMap
objects.
But the applicationContext object itself has no concurrency
protection... I access it inside of the doGet of certain servlets...
Question:
Do I need to put the getServletContext().getAttribute() inside of a
synchronized (this) block? I am thinking I do.
Thank you.
-Dennis Klotz
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
