Scheduler.Internal

Documentation

data SchedulerIO s a where

An IO computation that must be performed in a scheduler of type s.

Constructors

SchedulerIO :: Scheduler s => IO a -> SchedulerIO s a

Instances

Scheduler s => Monad (SchedulerIO s)

Functor (SchedulerIO s)

Scheduler s => Applicative (SchedulerIO s)

Scheduler s => MonadIO (SchedulerIO s)

(Scheduler s, Show v) => Show (SchedulerIO s v)

Unsafely executes a SchedulerIO action and shows the result. This is for DEBUGGING PURPOSES ONLY.

unsafeRunSchedulerIO :: Scheduler s => SchedulerIO s a -> IO a

Extracts the underlying IO action from a SchedulerIO action.

This can be unsafe because the type system does not have enough information to determine whether the calling code is running on an appropriate scheduler.

class Scheduler s where

Represents a queue of IO actions which can be executed in FIFO order.

Methods

schedule :: s -> SchedulerIO s () -> IO Disposable

Schedules an action on the scheduler. Returns a disposable which can be used to cancel it.

schedulerMain :: s -> IO ()

Executes all current and future actions enqueued on the given scheduler.

Instances

Scheduler BackgroundScheduler

Scheduler MainScheduler

newtype BackgroundScheduler

A scheduler which runs enqueued actions in a dedicated background thread.

Constructors

BackgroundScheduler (TQueue (ScheduledAction BackgroundScheduler))

Instances

Scheduler BackgroundScheduler

data ScheduledAction s

Represents an action on a scheduler, along with a flag indicating whether it should be canceled.

newScheduledAction :: Scheduler s => SchedulerIO s () -> IO (ScheduledAction s, Disposable)

Creates a new scheduled action, and returns a disposable which can be used to cancel it.

executeScheduledAction :: Scheduler s => s -> ScheduledAction s -> IO ()

Executes the given action, then re-enters schedulerMain.