Copyright Tristan Aubrey-Jones May 2008.
Abstract: A project investigating and developing an implicitly concurrent programming language, based on a metaphor taken from the physical world is reported. Uses a programming paradigm where programs consist of systems of autonomous agents, or active objects which communicate via message passing. A language enhancing Java with actors and linear types is presented. Example programs are written, compiled, and executed to evaluate the usefulness of the language. The language found to provide a familiar notation for implicit parallelism, and a compelling new model for concurrency, combining the performance of shared variables with the elegance of message passing.
Introductory Slides (PDF),
Report (PDF),
ActiveJava compiler prototype (ajavac),
ActiveJava runtime library (ajava_lang).
Examples:
calc - pocket calculator actor program dining - dining philosophers actor program (never deadlocks) sort - parallel quicksort implementation ("SortBenchmark" sorts 10,000 random integers using actors, java threads, and sequentially and compares)To compile examples use:
compile.bat ./calc compile.bat ./sort compile.bat ./diningTo run examples use:
run ./calc Main run ./dining Main run ./dining Main fast run ./sort Main run ./sort SortingBenchmark
import javax.swing.*;
import java.awt.*;
public aclass AContainer extends AComponent {
protected final Container container;
public AContainer(Container container) {
super(container);
this.container = container;
}
public static class AddComponent {
public AComponent value;
public int at = -1;
public AddComponent(AComponent value) {
this.value = value;
}
public AddComponent(AComponent value, int at) {
this(value);
this.at = at;
}
}
public react(AddComponent add) {
Component c = add.value.getComponent(new AComponent.ComponentAccessor.Get());
container.add(c, add.at);
}
public static class RemoveComponent {
public AComponent value;
public RemoveComponent(AComponent value) {
this.value = value;
}
}
public react(RemoveComponent rem) {
Component c = rem.value.getComponent(new AComponent.ComponentAccessor.Get());
container.remove(c);
}
public static aclass ContainerAccessor returns Container {
private Container c;
public ContainerAccessor(Container c) {
this.c = c;
}
public static class Get {}
public react (Get g) {
return c;
}
}
}