[Haskell-cafe] OS design & FP aesthetics

[Brandon S. Allbery KF8NH]

On Jun 18, 2007, at 19:51 , Creighton Hogg wrote:

> The hypothetical Haskell OS, especially if it were targeted toward 64
> bit machines, could keep processes from messing with each other by way
> of language based security, and run them all in a single memory
> space. (The first system to do this, I believe, was the MULTIPOP
> timesharing system, but there are other precedents, too.) This would
> eliminate or simplify lots of context switches and buffer copies and
> memory management and other nastiness that now goes into kernels.
>
> Okay, I remember seeing an example of this before , but I'm not  
> sure if I see what language based security Haskell's type system  
> could provide in protecting address spaces from each other.   
> Normally I've seen capabilities used so that you can't access  
> anything you can't name.  Can you elaborate a little?

He's saying that the language itself prevents programs from writing  
outside their address spaces or (via things like STM or runST)  
accessing resources they don't "own".  Which is a nice theory, but is  
dependent on the runtime not being buggy (I think some problems have  
been demonstrated with large arrays in GHC...).

-- 
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery at kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
electrical and computer engineering, carnegie mellon university    KF8NH