Stability	experimental
Maintainer	Mitsutoshi Aoe <maoe@foldr.in>
Safe Haskell	None

Control.Concurrent.Async.Lifted

Contents

Asynchronous actions
- Spawning
- Spawning with automatic cancelation
- Quering Asyncs
- STM operations
- Waiting for multiple Asyncs
- Linking
Convenient utilities

Description

This is a wrapped version of Control.Concurrent.Async with types generalized from IO to all monads in either MonadBase or MonadBaseControl.

Synopsis

Asynchronous actions

data Async a

An asynchronous action spawned by async or withAsync. Asynchronous actions are executed in a separate thread, and operations are provided for waiting for asynchronous actions to complete and obtaining their results (see e.g. wait).

Instances

Functor Async
Eq (Async a)
Ord (Async a)

Spawning

async :: MonadBaseControl IO m => m a -> m (Async (StM m a))Source

Generalized version of async.

asyncBound :: MonadBaseControl IO m => m a -> m (Async (StM m a))Source

Generalized version of asyncBound.

asyncOn :: MonadBaseControl IO m => Int -> m a -> m (Async (StM m a))Source

Generalized version of asyncOn.

asyncWithUnmask :: MonadBaseControl IO m => ((forall b. m b -> m b) -> m a) -> m (Async (StM m a))Source

Generalized version of asyncWithUnmask.

asyncOnWithUnmask :: MonadBaseControl IO m => Int -> ((forall b. m b -> m b) -> m a) -> m (Async (StM m a))Source

Generalized version of asyncOnWithUnmask.

Spawning with automatic `cancel`ation

withAsync :: MonadBaseControl IO m => m a -> (Async (StM m a) -> m b) -> m bSource

Generalized version of withAsync.

withAsyncBound :: MonadBaseControl IO m => m a -> (Async (StM m a) -> m b) -> m bSource

Generalized version of withAsyncBound.

withAsyncOn :: MonadBaseControl IO m => Int -> m a -> (Async (StM m a) -> m b) -> m bSource

Generalized version of withAsyncOn.

withAsyncWithUnmask :: MonadBaseControl IO m => ((forall c. m c -> m c) -> m a) -> (Async (StM m a) -> m b) -> m bSource

Generalized version of withAsyncWithUnmask.

withAsyncOnWithUnmask :: MonadBaseControl IO m => Int -> ((forall c. m c -> m c) -> m a) -> (Async (StM m a) -> m b) -> m bSource

Generalized version of withAsyncOnWithUnmask.

Quering `Async`s

wait :: MonadBaseControl IO m => Async (StM m a) -> m aSource

Generalized version of wait.

poll :: MonadBaseControl IO m => Async (StM m a) -> m (Maybe (Either SomeException a))Source

Generalized version of poll.

waitCatch :: MonadBaseControl IO m => Async (StM m a) -> m (Either SomeException a)Source

Generalized version of waitCatch.

cancel :: MonadBase IO m => Async (StM m a) -> m ()Source

Generalized version of catch.

cancelWith :: (MonadBase IO m, Exception e) => Async (StM m a) -> e -> m ()Source

Generalized version of cancelWith.

asyncThreadId :: Async a -> ThreadId

Returns the ThreadId of the thread running the given Async.

STM operations

waitSTM :: Async a -> STM a

A version of wait that can be used inside an STM transaction.

pollSTM :: Async a -> STM (Maybe (Either SomeException a))

A version of poll that can be used inside an STM transaction.

waitCatchSTM :: Async a -> STM (Either SomeException a)

A version of waitCatch that can be used inside an STM transaction.

Waiting for multiple `Async`s

waitAny :: MonadBaseControl IO m => [Async (StM m a)] -> m (Async (StM m a), a)Source

Generalized version of waitAny.

waitAnyCatch :: MonadBaseControl IO m => [Async (StM m a)] -> m (Async (StM m a), Either SomeException a)Source

Generalized version of waitAnyCatch.

waitAnyCancel :: MonadBase IO m => [Async a] -> m (Async a, a)Source

Generalized version of waitAnyCancel.

waitAnyCatchCancel :: MonadBaseControl IO m => [Async (StM m a)] -> m (Async (StM m a), Either SomeException a)Source

Generalized version of waitAnyCatchCancel.

waitEither :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m (Either a b)Source

Generalized version of waitEither.

waitEitherCatch :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m (Either (Either SomeException a) (Either SomeException b))Source

Generalized version of waitEitherCatch.

waitEitherCancel :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m (Either a b)Source

Generalized version of waitEitherCancel.

waitEitherCatchCancel :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m (Either (Either SomeException a) (Either SomeException b))Source

Generalized version of waitEitherCatchCancel.

waitEither_ :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m ()Source

Generalized version of waitEither_.

waitBoth :: MonadBaseControl IO m => Async (StM m a) -> Async (StM m b) -> m (a, b)Source

Generalized version of waitBoth.

Linking

link :: MonadBase IO m => Async (StM m a) -> m ()Source

Generalized version of link.

link2 :: MonadBase IO m => Async (StM m a) -> Async (StM m b) -> m ()Source

Generalized version of link2.

Convenient utilities

race :: MonadBaseControl IO m => m a -> m b -> m (Either a b)Source

Generalized version of race.

race_ :: MonadBaseControl IO m => m a -> m b -> m ()Source

Generalized version of race_.

concurrently :: MonadBaseControl IO m => m a -> m b -> m (a, b)Source

Generalized version of concurrently.

mapConcurrently :: (Traversable t, MonadBaseControl IO m) => (a -> m b) -> t a -> m (t b)Source

Generalized version of mapConcurrently.

newtype Concurrently a

A value of type Concurrently a is an IO operation that can be composed with other Concurrently values, using the Applicative and Alternative instances.

Calling runConcurrently on a value of type Concurrently a will execute the IO operations it contains concurrently, before delivering the result of type a.

For example

 (page1, page2, page3) <- runConcurrently $ (,,) <$> Concurrently (getURL "url1") <*> Concurrently (getURL "url2") <*> Concurrently (getURL "url3")

Constructors

Concurrently
Fields runConcurrently :: IO a