[squeak-dev] Squeak 4.6 release candidate

David T. Lewis lewis at mail.msen.com
Sat Jul 4 16:20:22 UTC 2015


On Thu, Jul 02, 2015 at 02:26:23PM -0500, Chris Muller wrote:
> We have a release candidate image.
> 
>   http://ftp.squeak.org/4.6/
> 
> The new sources file is required.
> 
> Please test your apps.  This could be the final image unless major
> issues are uncovered.
>

When running the release candidate image on an interpreter VM, I am getting
VM crashes apparently related to scanning memory. Symptoms are not consistent,
but examples include:

  lewis at LexIT:~/squeak/Squeak4.6$ 
  sweep failed to find exact end of memory
  
  27167072 GradientFillStyle>scaledAlphaMix:of:with:
  27166824 GradientFillStyle>computePixelRampOfSize:
  27164672 OrderedCollection>do:
  27163608 GradientFillStyle>computePixelRampOfSize:
  27163516 GradientFillStyle class>?
  27163332 LRUCache>at:
    ...
  
  lewis at LexIT:~/squeak/Squeak4.6$ 
  Recursive not understood error encountered
  
  26746900 WeakKeyDictionary>fixCollisionsFrom:
  26746808 Dictionary>removeKey:ifAbsent:
  26746716 WeakRegistry>remove:ifAbsent:
  26746624 BlockClosure>on:do:
  26746508 BlockClosure>ifError:
  26746392 Semaphore>critical:ifError:
  26746300 Semaphore>critical:
  26746208 BlockClosure>ensure:
  26746056 Semaphore>critical:
  26745920 Semaphore>critical:ifError:
  26745808 WeakRegistry>protected:
  26745692 WeakRegistry>remove:ifAbsent:
  26745600 StandardFileStream class>unregister:
  26745508 StandardFileStream>unregister
  26745416 StandardFileStream>close
    ...

Initially, I thought that saving the image from the interpreter VM resolved
the problem, but it turns out not to be the case.

This happens with the unix VM downloaded from squeakvm.org (which is now a
couple of years old), and it also happens with a fully up to date VM that
I compile myself. It does not happen with Cog.

Interestingly, just scanning through object memory like this does not
cause a crash:

  obj := Object someObject.
  [obj := obj nextObject. obj ~= 0] whileTrue.

This does not happen on my updated trunk image, so it appears to be related
to something in the release candidate image only.

I'm sorry I cannot be more specific as to the cause, but I thought it worth
reporting.

Dave
 


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