Control.Concurrent.Actor.Internal

Module exposing more of hactor's internals. Use with caution.

Types

data ActorMessage msg => ActorHandle msg

An ActorHandle acts as a reference to a specific actor.

Constructors

ActorHandle

Fields

ahContext :: ActorContext msg

ahThread :: ThreadId

class ActorMessage msg

The ActorMessage class must be implemented by any type that will be sent as a message to actors. Any given type of actor will have one ActorMessage type that is sent to that actor. This ensures type safety. Currently this is simply a dummy class with nothing in it, but things may be added in the future.

Instances

ActorMessage ()

type ActorM msg = ReaderT (ActorContext msg) IO

The base actor monad.

Sending Messages

send :: (ActorMessage msg, ActorMessage msg') => ActorHandle msg -> msg -> ActorM msg' ()

Sends a message to the given actor handle. This is secretly just sendIO lifted into an actor monad.

sendIO :: ActorMessage msg => ActorHandle msg -> msg -> IO ()

Sends a message to the given actor handle from within the IO monad.

Receiving Messages

receive :: ActorMessage msg => ActorM msg msg

Reads a message from the actor's mail box. If there are no messages, blocks until one is received. If you don't want this, use receiveMaybe instead.

receiveMaybe :: ActorMessage msg => ActorM msg (Maybe msg)

Reads a message from the actor's mail box. If there are no messages, returns Nothing.

receiveSTM :: ActorMessage msg => ActorM msg (STM msg)

An ActorM action which returns an STM action to receive a message.

Spawning Actors

spawnActor :: ActorMessage msg => ActorM msg () -> IO (ActorHandle msg)

Spawns the given actor on another thread and returns a handle to it.

runActor :: ActorMessage msg => ActorM msg () -> IO ()

Runs the given actor on the current thread. This function effectively turns the current thread into the actor's thread. Obviously, this means that this function will block until the actor exits. You probably want to use this for your "main" actor.

Getting Information

self :: ActorMessage msg => ActorM msg (ActorHandle msg)

Gets a handle to the current actor.

actorThread :: ActorMessage msg => ActorHandle msg -> ThreadId

Gets the thread ID for the given actor handle.

Internals

data ActorMessage msg => ActorContext msg

The ActorContext holds shared information about a given actor. This is information such as the actor's mail box, the list of actors it's linked to, etc.

Constructors

ActorContext

Fields

acMailBox :: MailBox msg

type MailBox msg = TChan msg

The type for the actor's mail box.

getContext :: ActorMessage msg => ActorM msg (ActorContext msg)

Gets the internal context object for the current actor. This is an internal function and may be dangerous. Use with caution.

getMailBox :: ActorMessage msg => ActorM msg (MailBox msg)

Retrieves the mail box for the current actor. This is an internal function and may be dangerous. Use with caution.