20 lines
543 B
Haskell
20 lines
543 B
Haskell
{- parallel processes
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-
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- Copyright 2012 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Utility.Parallel where
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import Common
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{- Runs an action in parallel with a set of values.
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- Returns values that caused the action to fail. -}
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inParallel :: (v -> IO ()) -> [v] -> IO [v]
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inParallel a l = do
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pids <- mapM (forkProcess . a) l
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statuses <- mapM (getProcessStatus True False) pids
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return $ map fst $ filter (failed . snd) $ zip l statuses
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where
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failed v = v /= Just (Exited ExitSuccess)
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