Cabal/src/Distribution/Types/ParStrat.hs

   1 module Distribution.Types.ParStrat where
   2
   3 -- | How to control parallelism, e.g. a fixed number of jobs or by using a system semaphore.
   4 data ParStratX sem
   5   = -- | Compile in parallel with the given number of jobs (`-jN` or `-j`).
   6     NumJobs (Maybe Int)
   7   | -- | `--semaphore`: use a system semaphore to control parallelism.
   8     UseSem sem
   9   | -- | No parallelism (neither `-jN` nor `--semaphore`, but could be `-j1`).
  10     Serial
  11   deriving (Show)
  12
  13 -- | Used by Cabal to indicate that we want to use this specific semaphore (created by cabal-install)
  14 type ParStrat = ParStratX String
  15
  16 -- | Used by cabal-install to say we want to create a semaphore with N slots.
  17 type ParStratInstall = ParStratX Int
  18
  19 -- | Determine if the parallelism strategy enables parallel builds.
  20 isParallelBuild :: ParStratX n -> Bool
  21 isParallelBuild Serial = False
  22 isParallelBuild (NumJobs (Just 1)) = False
  23 isParallelBuild (NumJobs _) = True
  24 isParallelBuild UseSem{} = True