Safe Haskell	None
Language	Haskell2010

Ki

Contents

Scope
Spawning threads
Miscellaneous
Exceptions

Synopsis

data Scope
scoped :: (Scope -> IO a) -> IO a
wait :: Scope -> IO ()
waitSTM :: Scope -> STM ()
waitFor :: Scope -> Duration -> IO ()
data Thread a
fork :: Scope -> IO a -> IO (Thread a)
fork_ :: Scope -> IO () -> IO ()
forkWithUnmask :: Scope -> ((forall x. IO x -> IO x) -> IO a) -> IO (Thread a)
forkWithUnmask_ :: Scope -> ((forall x. IO x -> IO x) -> IO ()) -> IO ()
async :: Scope -> IO a -> IO (Thread (Either ThreadFailed a))
asyncWithUnmask :: Scope -> ((forall x. IO x -> IO x) -> IO a) -> IO (Thread (Either ThreadFailed a))
await :: Thread a -> IO a
awaitSTM :: Thread a -> STM a
awaitFor :: Thread a -> Duration -> IO (Maybe a)
data Duration
microseconds :: Duration
milliseconds :: Duration
seconds :: Duration
timeoutSTM :: Duration -> STM (IO a) -> IO a -> IO a
sleep :: Duration -> IO ()
data ThreadFailed = ThreadFailed {
- threadId :: ThreadId
- exception :: SomeException
}

Scope

data Scope Source #

A scope delimits the lifetime of all threads created within it.

scoped :: (Scope -> IO a) -> IO a Source #

Open a scope, perform an IO action with it, then close the scope.

When the scope is closed, all remaining threads created within it are killed.

Throws:

The exception thrown by the callback to scoped itself, if any.
ThreadFailed containing the first exception a thread created with fork throws, if any.

Examples

Expand

scoped \scope -> do
  fork_ scope worker1
  fork_ scope worker2
  wait scope

wait :: Scope -> IO () Source #

Wait until all threads created within a scope finish.

waitSTM :: Scope -> STM () Source #

STM variant of wait.

waitFor :: Scope -> Duration -> IO () Source #

Variant of wait that waits for up to the given duration.

Spawning threads

There are two variants of thread-creating functions with different exception-propagation semantics.

If a thread created with fork throws an exception, it is immediately propagated up the call tree to the thread that created its scope.
If a thread created with async throws an exception, it is not propagated up the call tree, but can be observed by await.

data Thread a Source #

A running thread.

Instances

Instances details

Functor Thread Source #
Instance details Defined in Ki.Thread Methods fmap :: (a -> b) -> Thread a -> Thread b # (<$) :: a -> Thread b -> Thread a #
Eq (Thread a) Source #
Instance details Defined in Ki.Thread Methods (==) :: Thread a -> Thread a -> Bool # (/=) :: Thread a -> Thread a -> Bool #
Ord (Thread a) Source #
Instance details Defined in Ki.Thread Methods compare :: Thread a -> Thread a -> Ordering # (<) :: Thread a -> Thread a -> Bool # (<=) :: Thread a -> Thread a -> Bool # (>) :: Thread a -> Thread a -> Bool # (>=) :: Thread a -> Thread a -> Bool # max :: Thread a -> Thread a -> Thread a # min :: Thread a -> Thread a -> Thread a #
Generic (Thread a) Source #
Instance details Defined in Ki.Thread Associated Types type Rep (Thread a) :: Type -> Type # Methods from :: Thread a -> Rep (Thread a) x # to :: Rep (Thread a) x -> Thread a #
type Rep (Thread a) Source #
Instance details Defined in Ki.Thread type Rep (Thread a) = D1 ('MetaData "Thread" "Ki.Thread" "ki-0-inplace" 'False) (C1 ('MetaCons "Thread" 'PrefixI 'True) (S1 ('MetaSel ('Just "threadId") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 ThreadId) :*: S1 ('MetaSel ('Just "action") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 (STM a))))

Fork

fork :: Scope -> IO a -> IO (Thread a) Source #

Create a thread within a scope to compute a value concurrently.

If the thread throws an exception, the exception is wrapped in ThreadFailed and immediately propagated up the call tree to the thread that opened its scope.

Throws:

Calls error if the scope is closed.

fork_ :: Scope -> IO () -> IO () Source #

Variant of fork that does not return a handle to the created thread.

Throws:

Calls error if the scope is closed.

forkWithUnmask :: Scope -> ((forall x. IO x -> IO x) -> IO a) -> IO (Thread a) Source #

Variant of fork that provides the thread a function that unmasks asynchronous exceptions.

Throws:

Calls error if the scope is closed.

forkWithUnmask_ :: Scope -> ((forall x. IO x -> IO x) -> IO ()) -> IO () Source #

Variant of forkWithUnmask that does not return a handle to the created thread.

Throws:

Calls error if the scope is closed.

Async

async :: Scope -> IO a -> IO (Thread (Either ThreadFailed a)) Source #

Create a thread within a scope to compute a value concurrently.

Throws:

Calls error if the scope is closed.

asyncWithUnmask :: Scope -> ((forall x. IO x -> IO x) -> IO a) -> IO (Thread (Either ThreadFailed a)) Source #

Variant of async that provides the thread a function that unmasks asynchronous exceptions.

Throws:

Calls error if the scope is closed.

Await

await :: Thread a -> IO a Source #

Wait for a thread to finish.

Throws:

ThreadFailed if the thread threw an exception and was created with fork.

awaitSTM :: Thread a -> STM a Source #

STM variant of await.

Throws:

ThreadFailed if the thread threw an exception and was created with fork.

awaitFor :: Thread a -> Duration -> IO (Maybe a) Source #

Variant of await that waits for up to the given duration.

Throws:

ThreadFailed if the thread threw an exception and was created with fork.

Miscellaneous

data Duration Source #

A length of time with microsecond precision. Numeric literals are treated as seconds.

Instances

Instances details

Enum Duration Source #
Instance details Defined in Ki.Duration Methods succ :: Duration -> Duration # pred :: Duration -> Duration # toEnum :: Int -> Duration # fromEnum :: Duration -> Int # enumFrom :: Duration -> [Duration] # enumFromThen :: Duration -> Duration -> [Duration] # enumFromTo :: Duration -> Duration -> [Duration] # enumFromThenTo :: Duration -> Duration -> Duration -> [Duration] #
Eq Duration Source #
Instance details Defined in Ki.Duration Methods (==) :: Duration -> Duration -> Bool # (/=) :: Duration -> Duration -> Bool #
Fractional Duration Source #
Instance details Defined in Ki.Duration Methods (/) :: Duration -> Duration -> Duration # recip :: Duration -> Duration # fromRational :: Rational -> Duration #
Data Duration Source #
Instance details Defined in Ki.Duration Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Duration -> c Duration # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Duration # toConstr :: Duration -> Constr # dataTypeOf :: Duration -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Duration) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Duration) # gmapT :: (forall b. Data b => b -> b) -> Duration -> Duration # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Duration -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Duration -> r # gmapQ :: (forall d. Data d => d -> u) -> Duration -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Duration -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Duration -> m Duration # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Duration -> m Duration # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Duration -> m Duration #
Num Duration Source #
Instance details Defined in Ki.Duration Methods (+) :: Duration -> Duration -> Duration # (-) :: Duration -> Duration -> Duration # (*) :: Duration -> Duration -> Duration # negate :: Duration -> Duration # abs :: Duration -> Duration # signum :: Duration -> Duration # fromInteger :: Integer -> Duration #
Ord Duration Source #
Instance details Defined in Ki.Duration Methods compare :: Duration -> Duration -> Ordering # (<) :: Duration -> Duration -> Bool # (<=) :: Duration -> Duration -> Bool # (>) :: Duration -> Duration -> Bool # (>=) :: Duration -> Duration -> Bool # max :: Duration -> Duration -> Duration # min :: Duration -> Duration -> Duration #
Read Duration Source #
Instance details Defined in Ki.Duration Methods readsPrec :: Int -> ReadS Duration # readList :: ReadS [Duration] # readPrec :: ReadPrec Duration # readListPrec :: ReadPrec [Duration] #
Real Duration Source #
Instance details Defined in Ki.Duration Methods toRational :: Duration -> Rational #
RealFrac Duration Source #
Instance details Defined in Ki.Duration Methods properFraction :: Integral b => Duration -> (b, Duration) # truncate :: Integral b => Duration -> b # round :: Integral b => Duration -> b # ceiling :: Integral b => Duration -> b # floor :: Integral b => Duration -> b #
Show Duration Source #
Instance details Defined in Ki.Duration Methods showsPrec :: Int -> Duration -> ShowS # show :: Duration -> String # showList :: [Duration] -> ShowS #
Generic Duration Source #
Instance details Defined in Ki.Duration Associated Types type Rep Duration :: Type -> Type # Methods from :: Duration -> Rep Duration x # to :: Rep Duration x -> Duration #
type Rep Duration Source #
Instance details Defined in Ki.Duration type Rep Duration = D1 ('MetaData "Duration" "Ki.Duration" "ki-0-inplace" 'True) (C1 ('MetaCons "Duration" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Fixed E6))))

microseconds :: Duration Source #

One microsecond.

milliseconds :: Duration Source #

One millisecond.

seconds :: Duration Source #

One second.

timeoutSTM :: Duration -> STM (IO a) -> IO a -> IO a Source #

Wait for an STM action to return an IO action, or if the given duration elapses, return the given IO action instead.

sleep :: Duration -> IO () Source #

Duration-based threadDelay.

Exceptions

data ThreadFailed Source #

A thread failed, either by throwing or being thrown an exception.

Constructors

ThreadFailed
Fields threadId :: ThreadId exception :: SomeException

Instances

Instances details

Show ThreadFailed Source #
Instance details Defined in Ki.ThreadFailed Methods showsPrec :: Int -> ThreadFailed -> ShowS # show :: ThreadFailed -> String # showList :: [ThreadFailed] -> ShowS #
Exception ThreadFailed Source #
Instance details Defined in Ki.ThreadFailed Methods toException :: ThreadFailed -> SomeException # fromException :: SomeException -> Maybe ThreadFailed # displayException :: ThreadFailed -> String #