Control.Concurrent.EQueue.STMEQueue

This module provides an EQueue implimentation that uses STM to wait on the first available event among a set of possible events. When Waited on it can provide up to one event from every available event source when it provides one event, allowing coalescing.

Documentation

data STMEQueue a

A basic example implimentation of an EQueue using STM. This implimentation must look at every registered event source leading to inefficiency in systems with a very large number of sources. For most systems it should be a sufficient implimentation though.

Constructors

STMEQueue

Fields

• _eqActiveSources :: TVar (Map Unique (STM (Maybe a)))

Instances

EQueueW STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Associated Types

type WaitPolicy STMEQueue :: Type

Methods

waitEQ :: MonadIO m => STMEQueue a -> WaitPolicy STMEQueue -> m [a]

EQueue STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

Methods

registerSemi :: (MonadIO m, Semigroup b) => STMEQueue a -> (b -> a) -> m (b -> IO (), IO ())

registerQueued :: MonadIO m => STMEQueue a -> m (a -> IO (), IO ())

type WaitPolicy STMEQueue

Defined in Control.Concurrent.EQueue.STMEQueue

type WaitPolicy STMEQueue = STMEQueueWait

register :: MonadIO m => STMEQueue a -> STM (Maybe a) -> m (IO ())

Passed an STM dequeueing the current value of this signal. Returns an action to unregister said.

newSTMEQueue :: MonadIO m => m (STMEQueue a)

Create a new STMEQueue which initally has no event sources registered.

data STMEQueueWait

The policy for waiting on an STMEQueue.

Constructors

ReturnImmediate

Immediately return, even if no events are available.

RequireEvent

Wait for at least one event to be available before returning.

Instances

Eq STMEQueueWait

Defined in Control.Concurrent.EQueue.STMEQueue

Methods

(==) :: STMEQueueWait -> STMEQueueWait -> Bool

(/=) :: STMEQueueWait -> STMEQueueWait -> Bool