On 14/11/2014 21:23, Yuras Shumovich wrote:
I was reviewing some exception handling code in base library, and I found this line: https://phabricator.haskell.org/diffusion/GHC/browse/master/libraries/base/Control/Concurrent/QSem.hs;165072b334ebb2ccbef38a963ac4d126f1e08c96$74 Here mask is used, but I looks completely useless for me. waitQSem itself should be called with async exceptions masked, otherwise there is no way to prevent resource leak. Do anyone know why mask is used here?
I wrote that code. It looks like mask_ is important, otherwise an async exception might leave the MVar empty, no? We can't assume that waitQSem is always called inside a mask_, so it does its own mask_.
Cheers, Simon
I wonder whether an author of the code tried to do something different, so there actually can be a bug hidden here. Probably uninterruptibleMask_ should be used here? (I don't think so though.) Thanks, Yuras _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
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