Hi all.

I was showing Gary Chambers today how Albatross (the Seaside  
functional testing framework) would hang when tests within it failed.  
This is in a (I think!) web-dev image, based on 3.10. The hang was an  
unsignalled Semaphore.

It turned out to be because the class-side method  
#timeoutSemaphore:afterMSecs: message on the class side of Delay looks  
like this (I have omitted the lengthy comment):

timeoutSemaphore: aSemaphore afterMSecs: anInteger
	^ (self forMilliseconds: anInteger) schedule

Clearly from this, if you use (as Albatross does, together with a  
number of other classes) Semaphore>>#waitTimeoutMSecs:, which in turn  
sends #timeoutSemaphore:afterMSecs: the semaphore which sends itself  
to Delay never gets signalled!

I checked that this version was what it should be, according to the  
3.10 MC repository (http://source.squeakfoundation.org/310), and it's  
the same version as is in there.

We tried this simple alternative (comment again omitted):

timeoutSemaphore: aSemaphore afterMSecs: anInteger
	^ (self new setDelay: anInteger forSemaphore: aSemaphore) schedule

Since #forMilliseconds: on Delay sends to #setDelay:forSemaphore: on  
Delay anyway.

Hey-presto. No image crash/lock (always a good sign for changes on  
Semaphore, Delay et al!), and Albatross now acts as expected.

So, is this change crazy? It seems so simple and obvious that its  
almost sure to be wrong just by that fact :)

Cheers,
Simon




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