Hi Tom, you can do this with Twilight STM. I recently uploaded the first version on hackage[1]. The next version including a better algorithm and examples is about to be released in a few days.
Twilight STM features include tagging of variables and fine-grained conflict detection, flexible isolation level semantics (snapshot isolation and opacity) as well as safe integration of I/O. - Annette [1] http://hackage.haskell.org/package/twilight-stm Am 28.09.2010 15:35, schrieb Tom Hawkins: > Has anyone in the STM community considered the ability to read a TVar, > such that it would allow the transaction to complete even if the TVar > was modified by another transaction? (I am assuming this is not how > STM works by default.) For example: > > looselyReadTVar :: TVar a -> STM a > > Atom [1] has similar semantics to STM. If Atom were to relax it's > rule atomicity in this fashion, it could open the door to improved > task scheduling and higher levels of program description. Has STM > research already gone down this path? > > -Tom > > [1] http://hackage.haskell.org/package/atom > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
