Safe Haskell	None
Language	Haskell2010

Control.Monad.Class.MonadTimer

Synopsis

class Monad m => MonadDelay m where
- threadDelay :: DiffTime -> m ()
class (MonadSTM m, MonadDelay m) => MonadTimer m where
- data Timeout m :: Type
- newTimeout :: DiffTime -> m (Timeout m)
- readTimeout :: Timeout m -> STM m TimeoutState
- updateTimeout :: Timeout m -> DiffTime -> m ()
- cancelTimeout :: Timeout m -> m ()
- awaitTimeout :: Timeout m -> STM m Bool
- registerDelay :: DiffTime -> m (TVar m Bool)
- timeout :: DiffTime -> m a -> m (Maybe a)
data TimeoutState
- = TimeoutPending
- | TimeoutFired
- | TimeoutCancelled
data DiffTime
diffTimeToMicrosecondsAsInt :: DiffTime -> Int
microsecondsAsIntToDiffTime :: Int -> DiffTime

Documentation

class Monad m => MonadDelay m where Source #

Minimal complete definition

Nothing

Methods

threadDelay :: DiffTime -> m () Source #

default threadDelay :: MonadTimer m => DiffTime -> m () Source #

Instances

Instances details

MonadDelay IO Source #	With `threadDelay` one can use arbitrary large `DiffTime`s, which is an advantage over `threadDelay`.
Instance details Defined in Control.Monad.Class.MonadTimer Methods threadDelay :: DiffTime -> IO () Source #
MonadDelay m => MonadDelay (ReaderT r m) Source #
Instance details Defined in Control.Monad.Class.MonadTimer Methods threadDelay :: DiffTime -> ReaderT r m () Source #

class (MonadSTM m, MonadDelay m) => MonadTimer m where Source #

Minimal complete definition

newTimeout, readTimeout, updateTimeout, cancelTimeout, timeout

Associated Types

data Timeout m :: Type Source #

Methods

newTimeout :: DiffTime -> m (Timeout m) Source #

Create a new timeout which will fire at the given time duration in the future.

The timeout will start in the TimeoutPending state and either fire at or after the given time leaving it in the TimeoutFired state, or it may be cancelled with cancelTimeout, leaving it in the TimeoutCancelled state.

Timeouts cannot be reset to the pending state once fired or cancelled (as this would be very racy). You should create a new timeout if you need this functionality.

readTimeout :: Timeout m -> STM m TimeoutState Source #

Read the current state of a timeout. This does not block, but returns the current state. It is your responsibility to use retry to wait.

Alternatively you may wish to use the convenience utility awaitTimeout to wait for just the fired or cancelled outcomes.

You should consider the cancelled state if you plan to use cancelTimeout.

updateTimeout :: Timeout m -> DiffTime -> m () Source #

cancelTimeout :: Timeout m -> m () Source #

Cancel a timeout (unless it has already fired), putting it into the TimeoutCancelled state. Code reading and acting on the timeout state need to handle such cancellation appropriately.

It is safe to race this concurrently against the timer firing. It will have no effect if the timer fires first.

awaitTimeout :: Timeout m -> STM m Bool Source #

Returns True when the timeout is fired, or False if it is cancelled.

registerDelay :: DiffTime -> m (TVar m Bool) Source #

default registerDelay :: MonadFork m => DiffTime -> m (TVar m Bool) Source #

timeout :: DiffTime -> m a -> m (Maybe a) Source #

Instances

Instances details

MonadTimer IO Source #
Instance details Defined in Control.Monad.Class.MonadTimer Associated Types data Timeout IO Source # Methods newTimeout :: DiffTime -> IO (Timeout IO) Source # readTimeout :: Timeout IO -> STM IO TimeoutState Source # updateTimeout :: Timeout IO -> DiffTime -> IO () Source # cancelTimeout :: Timeout IO -> IO () Source # awaitTimeout :: Timeout IO -> STM IO Bool Source # registerDelay :: DiffTime -> IO (TVar IO Bool) Source # timeout :: DiffTime -> IO a -> IO (Maybe a) Source #
(MonadTimer m, MonadFork m) => MonadTimer (ReaderT r m) Source #
Instance details Defined in Control.Monad.Class.MonadTimer Associated Types data Timeout (ReaderT r m) Source # Methods newTimeout :: DiffTime -> ReaderT r m (Timeout (ReaderT r m)) Source # readTimeout :: Timeout (ReaderT r m) -> STM (ReaderT r m) TimeoutState Source # updateTimeout :: Timeout (ReaderT r m) -> DiffTime -> ReaderT r m () Source # cancelTimeout :: Timeout (ReaderT r m) -> ReaderT r m () Source # awaitTimeout :: Timeout (ReaderT r m) -> STM (ReaderT r m) Bool Source # registerDelay :: DiffTime -> ReaderT r m (TVar (ReaderT r m) Bool) Source # timeout :: DiffTime -> ReaderT r m a -> ReaderT r m (Maybe a) Source #

data TimeoutState Source #

Constructors

TimeoutPending
TimeoutFired
TimeoutCancelled

data DiffTime #

This is a length of time, as measured by a clock. Conversion functions will treat it as seconds. It has a precision of 10^-12 s.

Instances

Instances details

Enum DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods succ :: DiffTime -> DiffTime # pred :: DiffTime -> DiffTime # toEnum :: Int -> DiffTime # fromEnum :: DiffTime -> Int # enumFrom :: DiffTime -> [DiffTime] # enumFromThen :: DiffTime -> DiffTime -> [DiffTime] # enumFromTo :: DiffTime -> DiffTime -> [DiffTime] # enumFromThenTo :: DiffTime -> DiffTime -> DiffTime -> [DiffTime] #
Eq DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (==) :: DiffTime -> DiffTime -> Bool # (/=) :: DiffTime -> DiffTime -> Bool #
Fractional DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (/) :: DiffTime -> DiffTime -> DiffTime # recip :: DiffTime -> DiffTime # fromRational :: Rational -> DiffTime #
Data DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> DiffTime -> c DiffTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c DiffTime # toConstr :: DiffTime -> Constr # dataTypeOf :: DiffTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c DiffTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c DiffTime) # gmapT :: (forall b. Data b => b -> b) -> DiffTime -> DiffTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> DiffTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> DiffTime -> r # gmapQ :: (forall d. Data d => d -> u) -> DiffTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> DiffTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> DiffTime -> m DiffTime #
Num DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (+) :: DiffTime -> DiffTime -> DiffTime # (-) :: DiffTime -> DiffTime -> DiffTime # (*) :: DiffTime -> DiffTime -> DiffTime # negate :: DiffTime -> DiffTime # abs :: DiffTime -> DiffTime # signum :: DiffTime -> DiffTime # fromInteger :: Integer -> DiffTime #
Ord DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods compare :: DiffTime -> DiffTime -> Ordering # (<) :: DiffTime -> DiffTime -> Bool # (<=) :: DiffTime -> DiffTime -> Bool # (>) :: DiffTime -> DiffTime -> Bool # (>=) :: DiffTime -> DiffTime -> Bool # max :: DiffTime -> DiffTime -> DiffTime # min :: DiffTime -> DiffTime -> DiffTime #
Real DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods toRational :: DiffTime -> Rational #
RealFrac DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods properFraction :: Integral b => DiffTime -> (b, DiffTime) # truncate :: Integral b => DiffTime -> b # round :: Integral b => DiffTime -> b # ceiling :: Integral b => DiffTime -> b # floor :: Integral b => DiffTime -> b #
Show DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods showsPrec :: Int -> DiffTime -> ShowS # show :: DiffTime -> String # showList :: [DiffTime] -> ShowS #
NFData DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods rnf :: DiffTime -> () #

diffTimeToMicrosecondsAsInt :: DiffTime -> Int Source #

microsecondsAsIntToDiffTime :: Int -> DiffTime Source #