Re: [cdt-dev] [DSF] timeouts

[Pawel Piech <pawel.piech@xxxxxxxxxxxxx>]

There are two issues here:
1) Should there be a timeout mechanism for MI commands that do not 
complete in a timely fashion.
2) Fault tolerance for asynchronous calls not being completed due to 
programming errors.

For first issue a timeout seems like an appropriate solution.  The 
timeout could be specified at command creation and handled by the 
command control service.  In other cases a timeout at the query may be 
appropriate as well.
For the second issue we definitely need some improvement, though I'm not 
sure if timeouts are an appropriate solution.  The problem with timeout 
is that you have to specify a timeout value that is large enough that it 
won't get triggered accidentally on a heavily loaded systems, but small 
enough that it won't appear as if the UI was hanging.  Another option to 
add fault tolerance for async calls would be to instrument the DSF 
executor better to detect when a request monitor is being orphaned due 
to a runtime exception.  This wouldn't be a complete fix, but it would 
probably cover most of the cases of uncompleted async. calls we see 
now.  Finally the best way to add fault tolerance is to improve the 
automated testing ;-)

Cheers,
Pawel

On 06/23/2010 06:53 AM, Marc Khouzam wrote:
> Yes, I'm starting to be concerned about our lack
> of 'timeout' support.
>
> This is a question for DSF in general I believe.
>
> Currently, most calls are asynchronous and are left to
> complete whenever they do, if at all.
>
> However, some calls are done within a synchronous DSF
> Query, and executed in the UI-thread.  If any of those
> don't complete, we are in trouble.  The Query class
> provides with a get(long timeout, TimeUnit unit)
> which we should probably use in those cases.
>
> Outside those UI-thread cases, I believe we could
> still hang a view if a command never complete and
> the update.done() is never called.  Isn't that the case?
>
> Marc
>
>
>    
> > -----Original Message-----
> > From: cdt-dev-bounces@xxxxxxxxxxx
> > [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of John Cortell
> > Sent: Wednesday, June 23, 2010 8:11 AM
> > To: CDT General developers list.; 'cdt-dev@xxxxxxxxxxx'
> > Subject: Re: [cdt-dev] [DSF] timeouts
> >
> > See
> >
> > https://bugs.eclipse.org/bugs/show_bug.cgi?id=310274#c23
> >
> > This is a discussion we tabled until after Helios. Maybe now is a
> > good time to return to it.
> >
> > John
> >
> > At 04:53 AM 6/23/2010, Vladimir Prus wrote:
> >
> >      
> > > Does DSF have a mechanism to timeout when a command takes too much
> > > time? One case I've run into right now is failure to call done on
> > > a request monitor. Another viable case is when a target is stuck
> > > for whatever reason. I could not find any provisious for marking
> > > an operation failed after a while -- have I missed something?
> > >
> > > Thanks,
> > >
> > > --
> > > Vladimir Prus
> > > CodeSourcery
> > > vladimir@xxxxxxxxxxxxxxxx
> > > (650) 331-3385 x722
> > > _______________________________________________
> > > cdt-dev mailing list
> > > cdt-dev@xxxxxxxxxxx
> > > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> > >        
> >
> > _______________________________________________
> > cdt-dev mailing list
> > cdt-dev@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> > _______________________________________________
> >      
> cdt-dev mailing list
> cdt-dev@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/cdt-dev
>