edu.vub.at.actors.natives
Class ELActor

java.lang.Object
  edu.vub.at.actors.eventloops.EventLoop
      edu.vub.at.actors.natives.ELActor

Direct Known Subclasses:

ELDiscoveryActor

public class ELActor

extends EventLoop

An instance of the class ELActor represents a programmer-defined AmbientTalk/2 actor. The event queue of the actor event loop serves as the actor's 'meta-level' queue. The events in the 'meta-level' queue are handled by the actor's mirror object. This mirror is normally an instance of NATActorMirror, but it can be any programmer-defined object that adheres to the ATActorMirror interface.

Author:

tvcutsem

Nested Class Summary

Nested classes inherited from class edu.vub.at.actors.eventloops.EventLoop

EventLoop.EventProcessor

Field Summary

private ATObject	behaviour_
protected ELVirtualMachine	host_
private ATActorMirror	mirror_
protected ReceptionistsSet	receptionists_

Fields inherited from class edu.vub.at.actors.eventloops.EventLoop

eventQueue_, processor_

Constructor Summary

	ELActor(ATActorMirror mirror, ELVirtualMachine host)
protected	ELActor(ELVirtualMachine host) constructor dedicated to initialization of discovery actor

Method Summary

static ELActor	currentActor()
void	event_accept(Packet serializedMessage) The main entry point for any asynchronous messages sent to this actor by external sources (e.g. the VM or other local actors).
void	event_acceptSelfSend(ATAsyncMessage msg) The main entry point for any asynchronous self-sends.
protected void	event_init(BlockingFuture future, Packet parametersPkt, Packet initcodePkt) The initial event sent by the actor mirror to its event loop to intialize itself.
void	event_serviceJoined(Packet requiredStripePkt, ATFarReference myHandler, Packet discoveredStripePkt, Packet remoteServicePkt) When the discovery manager receives a publication from another local actor or another remote VM, the actor is asked to compare the incoming publication against a subscription that it had announced previously.
NATLocalFarRef	export(ATObject object) Export the given local object such that it is now remotely accessible via the returned object id.
ATActorMirror	getActorMirror()
ELVirtualMachine	getHost()
void	handle(Event event) Actor event loops handle events by allowing the meta-level events to process themselves.
protected void	initRootObject() Initialises the root using the contents of the init file stored by the hosting virtual machine.
protected void	initSharedFields() Initialises various fields in the lexical root of the actor, which are defined in the context of every actor.
ATObject	resolve(ATObjectID id, ATStripe[] stripes) Resolve the given object id into a local reference.
void	setActorMirror(ATActorMirror mirror)
ATObject	sync_event_eval(ATAbstractGrammar ast) This method should only be used for purposes such as the IAT shell or unit testing.
java.lang.Object	sync_event_performTest(Callable c) This method should only be used for purposes of unit testing.
java.lang.Object	sync_event_symbioticInvocation(Callable invocation) This method is invoked by a coercer in order to schedule a symbiotic invocation from the Java world, which should be synchronous to the Java thread, but which must be scheduled asynchronously to comply with the AT/2 actor model.

Methods inherited from class edu.vub.at.actors.eventloops.EventLoop

currentEventLoop, execute, owner, receive, receiveAndWait, receivePrioritized, stopProcessing, toEventLoop, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

mirror_

private ATActorMirror mirror_

host_

protected final ELVirtualMachine host_

receptionists_

protected final ReceptionistsSet receptionists_

behaviour_

private ATObject behaviour_

Constructor Detail

ELActor

public ELActor(ATActorMirror mirror,
               ELVirtualMachine host)

ELActor

protected ELActor(ELVirtualMachine host)

constructor dedicated to initialization of discovery actor

Method Detail

currentActor

public static final ELActor currentActor()

handle

public void handle(Event event)

Actor event loops handle events by allowing the meta-level events to process themselves.

Specified by:

handle in class EventLoop

Parameters:

event - the event object which was dequeued and which should be processed

getActorMirror

public ATActorMirror getActorMirror()

setActorMirror

public void setActorMirror(ATActorMirror mirror)

getHost

public ELVirtualMachine getHost()

export

public NATLocalFarRef export(ATObject object)
                      throws InterpreterException

Export the given local object such that it is now remotely accessible via the returned object id.

Parameters:

object - a **near** reference to the object to export

Returns:

a unique identifier by which this object can be retrieved via the resolve method.

Throws:

XIllegalOperation - if the passed object is a far reference, i.e. non-local

InterpreterException

resolve

public ATObject resolve(ATObjectID id,
                        ATStripe[] stripes)

Resolve the given object id into a local reference. There are three cases to consider: A) The given id designates an object local to this actor: the returned object will be a **near** reference to the object (i.e. the object itself) B) The given id designates a far (non-local) object that lives in the same address space as this actor: the returned object wil be a **far** reference to the object. C) The given id designates a far object that lives on a remote machine: the returned object will be a **far** and **remote** reference to the object.

Parameters:

id - the identifier of the object to resolve

Returns:

a near or far reference to the object, depending on where the designated object lives

initRootObject

protected void initRootObject()
                       throws InterpreterException

Initialises the root using the contents of the init file stored by the hosting virtual machine.

Throws:

InterpreterException

initSharedFields

protected void initSharedFields()
                         throws InterpreterException

Initialises various fields in the lexical root of the actor, which are defined in the context of every actor. Candidates are a "system" field which allows the program to perform IO operations or a "~" field denoting the current working directory.

Throws:

InterpreterException - when initialisation of a field fails

event_init

protected void event_init(BlockingFuture future,
                          Packet parametersPkt,
                          Packet initcodePkt)

The initial event sent by the actor mirror to its event loop to intialize itself.

Parameters:

future - the synchronization point with the creating actor, needs to be fulfilled with a far ref to the behaviour.

parametersPkt - the serialized parameters for the initialization code

initcodePkt - the serialized initialization code

event_acceptSelfSend

public void event_acceptSelfSend(ATAsyncMessage msg)

The main entry point for any asynchronous self-sends. Asynchronous self-sends do not undergo any form of parameter passing, there is no need to serialize and deserialize the message parameter in a Packet.

event_accept

public void event_accept(Packet serializedMessage)

The main entry point for any asynchronous messages sent to this actor by external sources (e.g. the VM or other local actors).

sync_event_symbioticInvocation

public java.lang.Object sync_event_symbioticInvocation(Callable invocation)
                                                throws java.lang.Exception

This method is invoked by a coercer in order to schedule a symbiotic invocation from the Java world, which should be synchronous to the Java thread, but which must be scheduled asynchronously to comply with the AT/2 actor model.

Parameters:

invocation - a functor object that will perform the symbiotic invocation

Returns:

the result of the symbiotic invocation

Throws:

java.lang.Exception - if the symbiotic invocation fails

sync_event_eval

public ATObject sync_event_eval(ATAbstractGrammar ast)
                         throws InterpreterException

This method should only be used for purposes such as the IAT shell or unit testing. It allows an external thread to make this actor evaluate an arbitrary expression.

Parameters:

ast - an abstract syntax tree to be evaluated by the receiving actor (in the scope of its behaviour).

Returns:

the result of the evaluation

Throws:

InterpreterException - if the evaluation fails

sync_event_performTest

public java.lang.Object sync_event_performTest(Callable c)
                                        throws java.lang.Exception

This method should only be used for purposes of unit testing. It allows arbitary code to be scheduled by external threads such as unit testing frameworks.

Throws:

java.lang.Exception

event_serviceJoined

public void event_serviceJoined(Packet requiredStripePkt,
                                ATFarReference myHandler,
                                Packet discoveredStripePkt,
                                Packet remoteServicePkt)

When the discovery manager receives a publication from another local actor or another remote VM, the actor is asked to compare the incoming publication against a subscription that it had announced previously.

Parameters:

myHandler - the closure specified as a handler for the actor's subscription