module SimpleH.Reactive.Time (
Time,
timeVal,
Seconds,
timeIO,waitTill,currentTime
) where
import SimpleH
import Control.Concurrent
import SimpleH.Reactive.TimeVal
import System.IO.Unsafe
import Data.IORef
import System.Clock
data Time t = Time (TimeVal t -> TimeVal t) (TimeVal t -> TimeVal t)
instance (Eq t,Show t) => Show (Time t) where show = show . timeVal
instance Ord t => Eq (Time t) where
a == b = compare a b == EQ
instance Ord t => Ord (Time t) where
compare ~(Time fa fa') ~(Time fb fb') =
cmp fa fb' `unamb` invertOrd (cmp fb fa')
where cmp f f' = compare a (f'$!a)
where a = f maxBound
instance Ord t => Semigroup (Time t) where
~(Time fa fa') + ~(Time fb fb') = Time (mapT max fa fb) (mapT max fa' fb')
instance Ord t => Monoid (Time t) where
zero = minBound
instance Ord t => Ring (Time t) where
one = maxBound
~(Time fa fa') * ~(Time fb fb') = Time (mapT min fa fb) (mapT min fa' fb')
instance Ord t => Orderable (Time t) where
inOrder a b = (a*b,if z then b else a,z)
where z = a<=b
mapT :: (t -> t -> a) -> (t -> t) -> (t -> t) -> t -> a
mapT f fa fb h = f a (fb$!a) `unamb` f b (fa$!b)
where a = fa h ; b = fb h
instance Bounded (Time t) where
minBound = Time (pure minBound) (pure minBound)
maxBound = Time (pure maxBound) (pure maxBound)
instance Unit Time where
pure t = Time (pure (pure t)) (pure (pure t))
amb :: IO a -> IO a -> IO a
ma `amb` mb = do
res <- newEmptyMVar
ta <- forkIO $ ma >>= putMVar res . Left
tb <- forkIO $ mb >>= putMVar res . Right
takeMVar res >>= \c -> case c of
Left a -> killThread tb >> return a
Right a -> killThread ta >> return a
unamb :: a -> a -> a
unamb = warp2 (from _thunk) amb
type Seconds = Double
timeVal :: Time t -> TimeVal t
timeVal (Time fa _) = fa maxBound
timeIO :: IO a -> IO (Time Seconds)
timeIO io = do
sem <- newEmptyMVar
minAction <- newIORef $ \tm -> Since<$>case tm of
Always -> currentTime
Since t -> (waitTill t >> currentTime) `amb` readMVar sem
Never -> readMVar sem
maxAction <- newIORef $ \tm -> case tm of
Always -> Since<$>readMVar sem
Since t -> (waitTill t >> pure Never) `amb` (Since<$>readMVar sem)
Never -> Since<$>currentTime
let refAction ref = \t -> unsafePerformIO (join (readIORef ref<*>pure t))
_ <- forkIO $ do
t <- io >> currentTime
writeIORef minAction (const (pure (pure t)))
writeIORef maxAction (const (pure (pure t)))
putMVar sem t
return $ Time (refAction minAction) (refAction maxAction)
waitTill :: Seconds -> IO ()
waitTill t = do
now <- t `seq` currentTime
when (t>now) $ threadDelay (floor $ (tnow)*1000000)
seconds :: TimeSpec -> Seconds
seconds t = fromIntegral (sec t) + fromIntegral (nsec t)/1000000000 :: Seconds
currentTime :: IO Seconds
currentTime = seconds<$>getTime Realtime