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Preserve message ordering (!!)

main
Tony Garnock-Jones 11 months ago
parent
commit
c2c80215d4
  1. 78
      src/main/java/org/syndicate_lang/actors/Actor.java
  2. 6
      src/test/java/org/syndicate_lang/actors/example/example2/Forwarder.java
  3. 2
      src/test/java/org/syndicate_lang/actors/example/example2/Main.java

78
src/main/java/org/syndicate_lang/actors/Actor.java

@ -6,9 +6,9 @@ import java.util.Map;
import java.util.Set;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.function.Supplier;
import java.util.logging.Level;
import java.util.logging.Logger;
@ -32,6 +32,25 @@ public class Actor implements Executor {
private Map<Object, Remote<BiConsumer<Actor, Object>>> _monitors = null;
private Consumer<Actor> _exitTrap = null;
private final static class WorkItem extends AtomicReference<WorkItem> {
Runnable work;
Runnable ifNotAlive;
public WorkItem(Runnable work, Runnable ifNotAlive) {
this.work = work;
this.ifNotAlive = ifNotAlive;
}
public final void clear() {
this.work = null;
this.ifNotAlive = null;
}
}
private WorkItem head = new WorkItem(null, null);
private final AtomicReference<WorkItem> tail = new AtomicReference<>(head);
private final AtomicLong workItemCount = new AtomicLong(0);
public static Actor current() {
return _currentActor.get();
}
@ -107,25 +126,29 @@ public class Actor implements Executor {
return new Remote<>(this, o);
}
private void _perform(Runnable work, Runnable ifNotAlive) {
private void _performSync(Runnable work, Runnable ifNotAlive) {
synchronized (this) {
_currentActor.set(this);
try {
if (!_alive) {
if (ifNotAlive != null) ifNotAlive.run();
} else {
try {
work.run();
} catch (Throwable exn) {
this._stop(false, exn);
}
}
_perform(work, ifNotAlive);
} finally {
_currentActor.set(null);
}
}
}
private void _perform(Runnable work, Runnable ifNotAlive) {
if (!_alive) {
if (ifNotAlive != null) ifNotAlive.run();
} else {
try {
work.run();
} catch (Throwable exn) {
this._stop(false, exn);
}
}
}
public Promise<?> stop() {
return stop(null);
}
@ -187,9 +210,34 @@ public class Actor implements Executor {
public void later(long delayMilliseconds, Runnable work, Runnable ifNotAlive) {
if (delayMilliseconds == 0) {
_executor.execute(() -> this._perform(work, ifNotAlive));
{
WorkItem i = new WorkItem(work, ifNotAlive);
tail.getAndSet(i).set(i);
}
if (workItemCount.getAndIncrement() == 0) {
_executor.execute(() -> {
synchronized (this) {
_currentActor.set(this);
try {
long batch = workItemCount.get();
while (batch > 0) {
for (int count = 0; count < batch; count++) {
WorkItem i = null;
while (i == null) i = head.get();
head = i;
this._perform(i.work, i.ifNotAlive);
i.clear();
}
batch = workItemCount.addAndGet(-batch);
}
} finally {
_currentActor.set(null);
}
}
});
}
} else {
_scheduledExecutor.schedule(() -> this._perform(work, ifNotAlive), delayMilliseconds, TimeUnit.MILLISECONDS);
_scheduledExecutor.schedule(() -> this._performSync(work, ifNotAlive), delayMilliseconds, TimeUnit.MILLISECONDS);
}
}
@ -200,7 +248,7 @@ public class Actor implements Executor {
public PeriodicTimer every(long initialDelayMilliseconds, long periodMilliseconds, Runnable f) {
return new PeriodicTimer(
_scheduledExecutor.scheduleAtFixedRate(
() -> this._perform(f, null),
() -> this._performSync(f, null),
initialDelayMilliseconds,
periodMilliseconds,
TimeUnit.MILLISECONDS));
@ -214,7 +262,9 @@ public class Actor implements Executor {
}
_executor.shutdown();
_scheduledExecutor.shutdown();
//noinspection ResultOfMethodCallIgnored
_executor.awaitTermination(5, TimeUnit.MINUTES);
//noinspection ResultOfMethodCallIgnored
_scheduledExecutor.awaitTermination(5, TimeUnit.MINUTES);
}

6
src/test/java/org/syndicate_lang/actors/example/example2/Forwarder.java

@ -6,18 +6,20 @@ public class Forwarder implements IForwarder {
private final int _index;
private final List<IForwarder> _actors;
private final IForwarder _main;
private final int _nActors;
private final int _nRounds;
public Forwarder(int index, List<IForwarder> actors, IForwarder main, int nRounds) {
public Forwarder(int index, List<IForwarder> actors, IForwarder main, int nActors, int nRounds) {
this._index = index;
this._actors = actors;
this._main = main;
this._nActors = nActors;
this._nRounds = nRounds;
}
@Override
public void handleMessage(int hopCount) {
int index = (this._index + 1) % this._actors.size();
int index = (this._index + 1) % this._nActors;
IForwarder target = hopCount >= this._nRounds - 1 ? _main : this._actors.get(index);
target.handleMessage(hopCount + 1);
}

2
src/test/java/org/syndicate_lang/actors/example/example2/Main.java

@ -32,7 +32,7 @@ public class Main implements IForwarder {
List<IForwarder> _actors = new ArrayList<>();
final IForwarder me = Actor.ref(this).asyncProxy(IForwarder.class);
for (int i = 0; i < _nActors; i++) {
Remote<IForwarder> a = Actor.forObject(new Forwarder(i, _actors, me, this._nRounds));
Remote<IForwarder> a = Actor.forObject(new Forwarder(i, _actors, me, this._nActors, this._nRounds));
a.getActor().link();
_actors.add(a.asyncProxy(IForwarder.class));
}

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