Posted by metacello on Feb 25, 2011; 1:18am
URL: https://forum.world.st/Issue-114-in-metacello-tight-currentVersion-loop-tp3323714p3323730.html


Comment #1 on issue 114 by [hidden email]: tight #currentVersion loop
http://code.google.com/p/metacello/issues/detail?id=114

It looks like MetacelloPlatform>>stackCacheFor:at:doing: can catch the loop  
with the following implementation:

stackCacheFor: cacheName at: key doing: aBlock
   self
     useStackCacheDuring: [:dict | | cache hasEntry |
       hasEntry := true.
       cache := dict at: cacheName ifAbsent: [].
       cache ~~ nil
         ifTrue: [ | value |
           value := cache
             at: key
             ifAbsent: [
               cache at: key put: #inProgress.
               hasEntry := false ].
           hasEntry
             ifTrue: [
               value == #inProgress ifTrue: [ self error: 'LOOP' ].
               ^value ]]
         ifFalse: [
           cache := Dictionary new.
           dict at: cacheName put: cache.
           cache at: key put: #inProgress.
           hasEntry := false ].
       ^[ aBlock value: cache ] ensure: [
         (hasEntry not and: [ (cache at: key) == #inProgress ])
           ifTrue: [ cache removeKey: key ]]]
     defaultDictionary: nil

Need to build some test cases to verify...