Re: [jetty-users] problem with continuation reuse - how to sync timeout

[Christoph Läubrich <laeubi@xxxxxxxxxxxxxx>]

Thanks for your response. This would mean I had to keep track of all 
background task and make some kind of syncronization between the servlet 
and the background task what is something I would avoid!
Would it then be safe to acces the state of a Continuation from 
different threads while in the web-cycle?


Am 03.11.2014 18:01, schrieb Simone Bordet:
> Hi,
>
> On Mon, Nov 3, 2014 at 1:51 PM, Christoph Läubrich
> <laeubi@xxxxxxxxxxxxxx>  wrote:
>    
> > I'm using jetty-8 (embedded) and have a servlet that upon request starts
> > some (lengthy) computation in the background and wants to return this to the
> > user after completion.
> > I try to use the
> > https://wiki.eclipse.org/Jetty/Feature/Continuations#Suspend_Continue_Pattern
> > (even though the problem will exits also with suspend/resume).
> > The problem occurs when I set a timeout (I just want the task to wait a
> > certian amaount of time for completion and cancel it then):
> >
> > If the continuation times out I send an error back to the client (see code
> > below), but my async task still holds a reference to the continuation. Since
> > jetty reuses the continuation object after timeout, when the task now
> > finished and tries to contine the continuation I get problems since
> >    a) The continuation is reused but for a completely different request
> >    b) The continuation is reused but not reasigend yet
> >      
> When the continuation expires, you should set a flag to your
> background task to *not* use the continuation, since the response has
> already been sent.
>
>