occwserv: An occam Web-Server

摘要

This paper presents 'occwserv', the Occam web-server. This is a highly concurrent web-server, written in the Occam multi-processing language, that supports the majority of the HTTP/1.1 protocol. Dynamic process and channel creation mechanisms are used to create scalable 'server-farms', each responsible for a particular webserver function - for example, reading client requests or running CGI processes. The design of the web-server is presented, along with some early performance benchmark results. Although performance may appear a limiting factor (when compared to other web-servers such as Apache), much is gained from the simplicity and security of occam. Extending the web-server with new functionality, for example, is intuitive and largely trivial - with the guarantees that code is free from race-hazard and aliasing errors. An experimental non-standard addition, the OGI (Occam Gateway Interface), is also presented. This provides a mechanism for dynamically loading and attaching pre-compiled occam processes to the running web-server, that can then handle one or multiple client connections. A text-based style adventure game is examined briefly, that allows multiple clients to interact within a "multi-user dungeon" (MUD) style environment.