/*
* Quasar: lightweight threads and actors for the JVM.
* Copyright (c) 2013-2014, Parallel Universe Software Co. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 3.0
* as published by the Free Software Foundation.
*/
package co.paralleluniverse.actors;
import co.paralleluniverse.fibers.Fiber;
import co.paralleluniverse.fibers.Joinable;
import co.paralleluniverse.fibers.SuspendExecution;
import co.paralleluniverse.strands.Strand;
import co.paralleluniverse.strands.Stranded;
import co.paralleluniverse.strands.SuspendableCallable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* Responsible for running an actor in a strand, and responding to hot code swaps.
*
* @author pron
*/
class ActorRunner<V> implements SuspendableCallable<V>, Stranded, Joinable<V> {
private final LocalActorRef<?, V> actorRef;
private volatile Actor<?, V> actor;
private Strand strand;
ActorRunner(LocalActorRef<?, V> actorRef) {
this.actorRef = actorRef;
}
@Override
public V run() throws SuspendExecution, InterruptedException {
if (strand == null)
setStrand(Strand.currentStrand());
if (actor == null)
this.actor = (Actor<?, V>) actorRef.getActor();
assert actor == actorRef.getActor();
for (;;) {
try {
return actor.run0();
} catch (CodeSwap e) {
Actor<?, V> newActor = ActorLoader.getReplacementFor(actor);
if (newActor != actor) {
newActor.setStrand0(strand);
newActor.onCodeChange0();
actor.defunct();
this.actor = newActor;
}
assert actor == actorRef.getActor();
}
}
}
Actor<?, V> getActor() {
return actor;
}
@Override
public void setStrand(Strand strand) {
if (strand == this.strand)
return;
if (this.strand != null)
throw new IllegalStateException("Strand already set to " + strand);
this.strand = strand;
if (actor == null)
this.actor = (Actor<?, V>) actorRef.getActor();
actor.setStrand0(strand);
}
@Override
public Strand getStrand() {
return strand;
}
public final boolean isStarted() {
return strand != null && strand.getState().compareTo(Strand.State.STARTED) >= 0;
}
@Override
public void join() throws ExecutionException, InterruptedException {
strand.join();
}
@Override
public void join(long timeout, TimeUnit unit) throws ExecutionException, InterruptedException, TimeoutException {
strand.join(timeout, unit);
}
@Override
public final V get() throws InterruptedException, ExecutionException {
final Strand s = strand;
if (s == null)
throw new IllegalStateException("Actor strand not set (not started?)");
if (s instanceof Fiber)
return ((Fiber<V>) s).get();
else {
s.join();
return actor.getResult();
}
}
@Override
public final V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
if (strand instanceof Fiber)
return ((Fiber<V>) strand).get(timeout, unit);
else {
strand.join(timeout, unit);
return actor.getResult();
}
}
@Override
public boolean isDone() {
return actor.getDeathCause0() != null || strand.isTerminated();
}
}