Copyright	Copyright (C) 2012-2018 Mitsutoshi Aoe
License	BSD-style (see the file LICENSE)
Maintainer	Mitsutoshi Aoe <maoe@foldr.in>
Stability	experimental
Safe Haskell	None
Language	Haskell98

Control.Concurrent.Async.Lifted.Safe

Contents

Asynchronous actions
Convenient utilities

Description

This is a safe variant of Control.Concurrent.Async.Lifted.

This module assumes your monad stack to satisfy StM m a ~ a so you can't mess up monadic effects. If your monad stack is stateful, use Control.Concurrent.Async.Lifted with special care.

Synopsis

data Async a
class StM m a ~ a => Pure m a
type family Forall (p :: k -> Constraint) :: Constraint
async :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m (Async a)
asyncBound :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m (Async a)
asyncOn :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m (Async a)
asyncWithUnmask :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => ((forall b. m b -> m b) -> m a) -> m (Async a)
asyncOnWithUnmask :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => Int -> ((forall b. m b -> m b) -> m a) -> m (Async a)
withAsync :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> (Async a -> m b) -> m b
withAsyncBound :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> (Async a -> m b) -> m b
withAsyncOn :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> (Async a -> m b) -> m b
withAsyncWithUnmask :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => ((forall c. m c -> m c) -> m a) -> (Async a -> m b) -> m b
withAsyncOnWithUnmask :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => Int -> ((forall c. m c -> m c) -> m a) -> (Async a -> m b) -> m b
wait :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m a
poll :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m (Maybe (Either SomeException a))
waitCatch :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m (Either SomeException a)
cancel :: MonadBase IO m => Async a -> m ()
uninterruptibleCancel :: MonadBase IO m => Async a -> m ()
cancelWith :: (MonadBase IO m, Exception e) => Async a -> e -> m ()
asyncThreadId :: Async a -> ThreadId
data AsyncCancelled = AsyncCancelled
waitSTM :: Async a -> STM a
pollSTM :: Async a -> STM (Maybe (Either SomeException a))
waitCatchSTM :: Async a -> STM (Either SomeException a)
waitAny :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, a)
waitAnyCatch :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, Either SomeException a)
waitAnyCancel :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, a)
waitAnyCatchCancel :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, Either SomeException a)
waitEither :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either a b)
waitEitherCatch :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either (Either SomeException a) (Either SomeException b))
waitEitherCancel :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either a b)
waitEitherCatchCancel :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either (Either SomeException a) (Either SomeException b))
waitEither_ :: MonadBase IO m => Async a -> Async b -> m ()
waitBoth :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (a, b)
waitAnySTM :: [Async a] -> STM (Async a, a)
waitAnyCatchSTM :: [Async a] -> STM (Async a, Either SomeException a)
waitEitherSTM :: Async a -> Async b -> STM (Either a b)
waitEitherCatchSTM :: Async a -> Async b -> STM (Either (Either SomeException a) (Either SomeException b))
waitEitherSTM_ :: Async a -> Async b -> STM ()
waitBothSTM :: Async a -> Async b -> STM (a, b)
link :: MonadBase IO m => Async a -> m ()
link2 :: MonadBase IO m => Async a -> Async b -> m ()
data ExceptionInLinkedThread where
- ExceptionInLinkedThread :: forall a. Async a -> SomeException -> ExceptionInLinkedThread
race :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m (Either a b)
race_ :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m ()
concurrently :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m (a, b)
concurrently_ :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m ()
mapConcurrently :: (Traversable t, MonadBaseControl IO m, Forall (Pure m)) => (a -> m b) -> t a -> m (t b)
mapConcurrently_ :: (Foldable t, MonadBaseControl IO m, Forall (Pure m)) => (a -> m b) -> t a -> m ()
forConcurrently :: (Traversable t, MonadBaseControl IO m, Forall (Pure m)) => t a -> (a -> m b) -> m (t b)
forConcurrently_ :: (Foldable t, MonadBaseControl IO m, Forall (Pure m)) => t a -> (a -> m b) -> m ()
replicateConcurrently :: (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m [a]
replicateConcurrently_ :: (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m ()
data Concurrently m a where
- Concurrently :: Forall (Pure m) => {..} -> Concurrently m a
compareAsyncs :: Async a -> Async b -> Ordering

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
Instance details Defined in Control.Concurrent.Async Methods fmap :: (a -> b) -> Async a -> Async b # (<$) :: a -> Async b -> Async a #
Eq (Async a)
Instance details Defined in Control.Concurrent.Async Methods (==) :: Async a -> Async a -> Bool # (/=) :: Async a -> Async a -> Bool #
Ord (Async a)
Instance details Defined in Control.Concurrent.Async Methods compare :: Async a -> Async a -> Ordering # (<) :: Async a -> Async a -> Bool # (<=) :: Async a -> Async a -> Bool # (>) :: Async a -> Async a -> Bool # (>=) :: Async a -> Async a -> Bool # max :: Async a -> Async a -> Async a # min :: Async a -> Async a -> Async a #
Hashable (Async a)
Instance details Defined in Control.Concurrent.Async Methods hashWithSalt :: Int -> Async a -> Int # hash :: Async a -> Int #

class StM m a ~ a => Pure m a #

Most of the functions in this module have Forall (Pure m) in their constraints, which means they require the monad m satisfies StM m a ~ a for all a.

Instances

StM m a ~ a => Pure m a #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe

type family Forall (p :: k -> Constraint) :: Constraint #

A representation of the quantified constraint forall a. p a.

Instances

type Forall (p :: k -> Constraint)
Instance details Defined in Data.Constraint.Forall type Forall (p :: k -> Constraint) = Forall_ p

Spawning

async :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m (Async a) #

Generalized version of async.

asyncBound :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m (Async a) #

Generalized version of asyncBound.

asyncOn :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m (Async a) #

Generalized version of asyncOn.

asyncWithUnmask :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => ((forall b. m b -> m b) -> m a) -> m (Async a) #

Generalized version of asyncWithUnmask.

asyncOnWithUnmask :: forall m a. (MonadBaseControl IO m, Forall (Pure m)) => Int -> ((forall b. m b -> m b) -> m a) -> m (Async a) #

Generalized version of asyncOnWithUnmask.

Spawning with automatic `cancel`ation

withAsync :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> (Async a -> m b) -> m b #

Generalized version of withAsync.

withAsyncBound :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> (Async a -> m b) -> m b #

Generalized version of withAsyncBound.

withAsyncOn :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> (Async a -> m b) -> m b #

Generalized version of withAsyncOn.

withAsyncWithUnmask :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => ((forall c. m c -> m c) -> m a) -> (Async a -> m b) -> m b #

Generalized version of withAsyncWithUnmask.

withAsyncOnWithUnmask :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => Int -> ((forall c. m c -> m c) -> m a) -> (Async a -> m b) -> m b #

Generalized version of withAsyncOnWithUnmask.

Quering `Async`s

wait :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m a #

Generalized version of wait.

poll :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m (Maybe (Either SomeException a)) #

Generalized version of poll.

waitCatch :: forall m a. (MonadBase IO m, Forall (Pure m)) => Async a -> m (Either SomeException a) #

Generalized version of waitCatch.

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

Generalized version of cancel.

uninterruptibleCancel :: MonadBase IO m => Async a -> m () #

Generalized version of uninterruptibleCancel.

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

Generalized version of cancelWith.

asyncThreadId :: Async a -> ThreadId #

Returns the ThreadId of the thread running the given Async.

data AsyncCancelled #

The exception thrown by cancel to terminate a thread.

Constructors

AsyncCancelled

Instances

Eq AsyncCancelled
Instance details Defined in Control.Concurrent.Async Methods (==) :: AsyncCancelled -> AsyncCancelled -> Bool # (/=) :: AsyncCancelled -> AsyncCancelled -> Bool #
Show AsyncCancelled
Instance details Defined in Control.Concurrent.Async Methods showsPrec :: Int -> AsyncCancelled -> ShowS # show :: AsyncCancelled -> String # showList :: [AsyncCancelled] -> ShowS #
Exception AsyncCancelled
Instance details Defined in Control.Concurrent.Async Methods toException :: AsyncCancelled -> SomeException # fromException :: SomeException -> Maybe AsyncCancelled # displayException :: AsyncCancelled -> String #

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 :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, a) #

Generalized version of waitAny.

waitAnyCatch :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, Either SomeException a) #

Generalized version of waitAnyCatch.

waitAnyCancel :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, a) #

Generalized version of waitAnyCancel.

waitAnyCatchCancel :: forall m a. (MonadBase IO m, Forall (Pure m)) => [Async a] -> m (Async a, Either SomeException a) #

Generalized version of waitAnyCatchCancel.

waitEither :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either a b) #

Generalized version of waitEither.

waitEitherCatch :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either (Either SomeException a) (Either SomeException b)) #

Generalized version of waitEitherCatch.

waitEitherCancel :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either a b) #

Generalized version of waitEitherCancel.

waitEitherCatchCancel :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (Either (Either SomeException a) (Either SomeException b)) #

Generalized version of waitEitherCatchCancel.

waitEither_ :: MonadBase IO m => Async a -> Async b -> m () #

Generalized version of waitEither_

waitBoth :: forall m a b. (MonadBase IO m, Forall (Pure m)) => Async a -> Async b -> m (a, b) #

Generalized version of waitBoth.

Waiting for multiple `Async`s in STM

waitAnySTM :: [Async a] -> STM (Async a, a) #

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

Since: async-2.1.0

waitAnyCatchSTM :: [Async a] -> STM (Async a, Either SomeException a) #

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

Since: async-2.1.0

waitEitherSTM :: Async a -> Async b -> STM (Either a b) #

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

Since: async-2.1.0

waitEitherCatchSTM :: Async a -> Async b -> STM (Either (Either SomeException a) (Either SomeException b)) #

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

Since: async-2.1.0

waitEitherSTM_ :: Async a -> Async b -> STM () #

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

Since: async-2.1.0

waitBothSTM :: Async a -> Async b -> STM (a, b) #

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

Since: async-2.1.0

Linking

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

Generalized version of link.

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

Generalized version of link2.

data ExceptionInLinkedThread where #

Constructors

ExceptionInLinkedThread :: forall a. Async a -> SomeException -> ExceptionInLinkedThread

Instances

Show ExceptionInLinkedThread
Instance details Defined in Control.Concurrent.Async Methods showsPrec :: Int -> ExceptionInLinkedThread -> ShowS # show :: ExceptionInLinkedThread -> String # showList :: [ExceptionInLinkedThread] -> ShowS #
Exception ExceptionInLinkedThread
Instance details Defined in Control.Concurrent.Async Methods toException :: ExceptionInLinkedThread -> SomeException # fromException :: SomeException -> Maybe ExceptionInLinkedThread # displayException :: ExceptionInLinkedThread -> String #

Convenient utilities

race :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m (Either a b) #

Generalized version of race.

race_ :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m () #

Generalized version of race_.

concurrently :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m (a, b) #

Generalized version of concurrently.

concurrently_ :: forall m a b. (MonadBaseControl IO m, Forall (Pure m)) => m a -> m b -> m () #

Generalized version of concurrently_.

mapConcurrently :: (Traversable t, MonadBaseControl IO m, Forall (Pure m)) => (a -> m b) -> t a -> m (t b) #

Generalized version of mapConcurrently.

mapConcurrently_ :: (Foldable t, MonadBaseControl IO m, Forall (Pure m)) => (a -> m b) -> t a -> m () #

Generalized version of mapConcurrently_.

forConcurrently :: (Traversable t, MonadBaseControl IO m, Forall (Pure m)) => t a -> (a -> m b) -> m (t b) #

Generalized version of forConcurrently.

forConcurrently_ :: (Foldable t, MonadBaseControl IO m, Forall (Pure m)) => t a -> (a -> m b) -> m () #

Generalized version of forConcurrently_.

replicateConcurrently :: (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m [a] #

Generalized version of replicateConcurrently.

replicateConcurrently_ :: (MonadBaseControl IO m, Forall (Pure m)) => Int -> m a -> m () #

Generalized version of replicateConcurrently_.

data Concurrently m a where #

Generalized version of Concurrently.

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

Calling runConcurrently on a value of type Concurrently m a will execute the IO-based lifted 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 :: Forall (Pure m) => { runConcurrently :: m a } -> Concurrently m a

Instances

Functor m => Functor (Concurrently m) #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe Methods fmap :: (a -> b) -> Concurrently m a -> Concurrently m b # (<$) :: a -> Concurrently m b -> Concurrently m a #
(MonadBaseControl IO m, Forall (Pure m)) => Applicative (Concurrently m) #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe Methods pure :: a -> Concurrently m a # (<>) :: Concurrently m (a -> b) -> Concurrently m a -> Concurrently m b # liftA2 :: (a -> b -> c) -> Concurrently m a -> Concurrently m b -> Concurrently m c # (>) :: Concurrently m a -> Concurrently m b -> Concurrently m b # (<*) :: Concurrently m a -> Concurrently m b -> Concurrently m a #
(MonadBaseControl IO m, Forall (Pure m)) => Alternative (Concurrently m) #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe Methods empty :: Concurrently m a # (<\|>) :: Concurrently m a -> Concurrently m a -> Concurrently m a # some :: Concurrently m a -> Concurrently m [a] # many :: Concurrently m a -> Concurrently m [a] #
(MonadBaseControl IO m, Semigroup a, Forall (Pure m)) => Semigroup (Concurrently m a) #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe Methods (<>) :: Concurrently m a -> Concurrently m a -> Concurrently m a # sconcat :: NonEmpty (Concurrently m a) -> Concurrently m a # stimes :: Integral b => b -> Concurrently m a -> Concurrently m a #
(MonadBaseControl IO m, Semigroup a, Monoid a, Forall (Pure m)) => Monoid (Concurrently m a) #
Instance details Defined in Control.Concurrent.Async.Lifted.Safe Methods mempty :: Concurrently m a # mappend :: Concurrently m a -> Concurrently m a -> Concurrently m a # mconcat :: [Concurrently m a] -> Concurrently m a #

compareAsyncs :: Async a -> Async b -> Ordering #

Compare two Asyncs that may have different types

Asynchronous actions

Spawning

Spawning with automatic cancelation

Quering Asyncs

STM operations

Waiting for multiple Asyncs

Waiting for multiple Asyncs in STM

Linking

Convenient utilities

Spawning with automatic `cancel`ation

Quering `Async`s

Waiting for multiple `Async`s

Waiting for multiple `Async`s in STM