git-annex/Utility/ThreadScheduler.hs
Joey Hess c2d6c02c27
Added dependency on unbounded-delays
And stop vendoring part of it.

This is a free dependency because tasty depends on it.

Sponsored-by: Leon Schuermann on Patreon
2024-02-27 13:11:59 -04:00

67 lines
1.5 KiB
Haskell

{- thread scheduling
-
- Copyright 2012-2024 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
module Utility.ThreadScheduler (
Seconds(..),
Microseconds,
runEvery,
threadDelaySeconds,
waitForTermination,
oneSecond,
unboundDelay,
) where
import Control.Monad
import Control.Concurrent
import qualified Control.Concurrent.Thread.Delay as Unbounded
#ifndef mingw32_HOST_OS
import Control.Monad.IfElse
import System.Posix.IO
#endif
#ifndef mingw32_HOST_OS
import System.Posix.Signals
import System.Posix.Terminal
#endif
newtype Seconds = Seconds { fromSeconds :: Int }
deriving (Eq, Ord, Show)
type Microseconds = Integer
{- Runs an action repeatedly forever, sleeping at least the specified number
- of seconds in between. -}
runEvery :: Seconds -> IO a -> IO a
runEvery n a = forever $ do
threadDelaySeconds n
a
threadDelaySeconds :: Seconds -> IO ()
threadDelaySeconds (Seconds n) = unboundDelay (fromIntegral n * oneSecond)
{- Like threadDelay, but not bounded by an Int. -}
unboundDelay :: Microseconds -> IO ()
unboundDelay = Unbounded.delay
{- Pauses the main thread, letting children run until program termination. -}
waitForTermination :: IO ()
waitForTermination = do
#ifdef mingw32_HOST_OS
forever $ threadDelaySeconds (Seconds 6000)
#else
lock <- newEmptyMVar
let check sig = void $
installHandler sig (CatchOnce $ putMVar lock ()) Nothing
check softwareTermination
whenM (queryTerminal stdInput) $
check keyboardSignal
takeMVar lock
#endif
oneSecond :: Microseconds
oneSecond = 1000000