SqueakSource is down again

Philippe Marschall philippe.marschall at gmail.com
Sun Dec 23 23:09:35 UTC 2007


2007/12/23, Lukas Renggli <renggli at gmail.com>:
> > > So which parts do we need to fix to make the Semaphore, Socket and
> > > image freezing problems go away?
> >
> > For semaphores I'd recommend the fixes that I've posted over the year.
>
> I loaded all your semaphore related patches a couple of months ago and
> squeaksource.com ran quietly and happily up to a few weeks ago. Then
> suddenly we got many processes hanging in Semaphore>>#critical:.
>
> > For image freezes -in particular in
> > Squeaksource- you probably need to fix the concurrency issues in
> > Squeaksource itself.
>
> What kind of concurrency issues in squeaksource.com itself could cause
> these problems?

We have concurrent, unsychronized writing access to shared data. Until
now we have been very lucky to get away with this without any
problems. It's certainly not the right way to do it.

Cheers
Philippe

> I know that the code is far from perfect, but I must
> also point out that we didn't loose a single of the more than 71'000
> versions during the past 4 years. We also never experienced a
> corrupted data model.
>
> I wonder how it can happen that semaphores are suddenly blocked? Might
> this be related to image saving happening while being within a
> critical section?
>
> Cheers,
> Lukas
>
> --
> Lukas Renggli
> http://www.lukas-renggli.ch
>
>



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