Urgent problem with Singleton

[David Hemingway]

Hi,

I have a task scheduler thread that implements ServletContextListener and starts up as 
a listener with the following code from my web.xml:

<listener>
        <listener-class>
                mypackage.MyServlet
        </listener-class>
</listener>

My problem is however I need this to be a singleton, its imperative. There always 
seems to be about 3 threads created though. I have tried numerous things including 
making this servlet call a singleton class to do the task scheduling but it still ends 
up with 3 threads. This is causing terrible concurrency problems that wouldn't exist 
if this was working properly. My serlvet code currently resembles the following:

boolean hasBeenInitialized = false; 

 public void contextInitialized(ServletContextEvent sce)
 {
    if(!hasBeenInitialized)
    {
        //Start up the task scheduler thread
        hasBeenInitialized = true; 
    }
}
    

I am using Tomcat 4.1.18, Apache 1.3.27 under RedHat 7.3. I didn't have this problem 
under wn32 only Linux. Any help, or ideas on how I can get this to be a single 
instance would be greatly appreciated. Thank you

regards,
Dave