ActiveJava

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 ./dining
To run examples use:
run ./calc Main
run ./dining Main
run ./dining Main fast
run ./sort Main
run ./sort SortingBenchmark

Main.ajava

home Home   up Up   ( Download )


public actor Main implements Entrypoint { // global clock private Clock clk; private Table table; public react (String[] args) { Stdout <-- "Dining Philosopher Problem" + "\n"; // create clock int speed = 1000; if (args.length > 0 && args[0].equalsIgnoreCase("fast")) { speed = 1; Stdout <-- "Fast Mode\n"; } clk = new Clock(speed); // create table, and start clock pulses table = new Table(clk, 10); clk.start(); } }