First Advisor

Andrew Tolmach

Date of Publication


Document Type


Degree Name

Master of Science (M.S.) in Computer Science


Computer Science




Programming languages (Electronic computers) -- Development, Systems programming (Computer science), Haskell (Computer program language)



Physical Description

1 online resource (viii, 89 p.) : col. ill.


This thesis presents Lighthouse, an experimental branch of the Haskell-based House operating system which integrates Li et al.'s Lightweight Concurrency framework. First and foremost, it improves House's viability as a "real operating system" by providing a new extensible scheduler framework which makes it easy to experiment with different scheduling policies. In particular, Lighthouse extends Concurrent Haskell with thread priority and implements a priority-based scheduler which significantly improves system responsiveness when compared with GHC's normal round-robin scheduler. Even while doing this, it improves on House's claim of being "written in Haskell" by moving a whole subsystem out of the complex C-based runtime system and into Haskell itself. In addition, Lighthouse also includes an alternate, simpler implementation of Lightweight Concurrency which takes advantage of House's unique setting (running directly on uniprocessor x86 hardware). This experience sheds light on areas that need further attention before the system can truly be viable---primarily interactions between blackholing and interrupt handling. In particular, this thesis uncovers a potential case of self-deadlock and suggests potential solutions. Finally, this work offers further insight into the viability of using high-level languages such as Haskell for systems programming. Although laziness and blackholing present unique problems, many parts of the system are still much easier to express in Haskell than traditional languages such as C.


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Portland State University. Dept. of Computer Science

Persistent Identifier