An Object-Oriented Programming Model for Event-Based Actors

Universität Karlsruhe (TH) Fakultät für Informatik Institut für Programmstrukturen und Datenorganisation An Object-Oriented Programming Model for Event-Based Actors Diploma Thesis Philipp Haller May 2006 Referees: Prof. Martin Odersky, EPF Lausanne Prof. Gerhard Goos, Universität Karlsruhe Ich erkläre hiermit, dass ich die vorliegende Arbeit selbständig verfasst und keine anderen als die angegebenen Quellen und Hilfsmittel verwen-det habe. Lausanne, den 15. Mai 2006 Abstract Actors are concurrent processes which communicate through asyn-chronous message passing. Most existing actor languages and libraries implement actors using virtual machine or operating system threads. The resultingactorabstractionsareratherheavyweight,bothintermsofmem-ory consumption and synchronization. Consequently, their systems are not suited for resource-constrained devices or highly concurrent systems. Actor systems that do provide lightweight actors, rely on special runtime system implementations. Moreover, virtually all languages with a notion similar to actors support events or blocking operations only through inversion of control which leads to fragmentation of program logic and implicit control flow that is hard to track. We show how lightweight actors can be implemented on standard, un-modified virtual machines, such as the Java Virtual Machine. For this purpose, we propose an event-based computation model which does not require inversion of control. The presented actor abstractions are imple-mented as a library for Scala rather than as language extensions. The evaluation consists of two parts: In the first part we compare perfor-mance to an existing Java-based actor language. In the second part we report on experience implementing a distributed auction service as a case study. v ... - tailieumienphi.vn