Re: [Haskell-cafe] Parallel executing of actions

I may be talking out of my other end here, but... if you want something like parMap to calculate all the pixels in parallel, then... can't you use parMap itself? Something like: weirdParMap action = sequence_ . map action . parMap (id $!) This evaluates all the elements of the list using parMap (the expensive part, right?), and then sequentially applies the action on the current thread. JCAB On Sun, 15 Apr 2007 12:56:02 -0700, Mitar wrote:

Hi!

On 4/15/07, Spencer Janssen wrote:

...

This version will fork a new thread for each action:

\begin{code} import Control.Concurrent import Control.Monad

parSequence_ xs = do m <- newEmptyMVar mapM_ (\x -> forkIO x >> putMVar m ()) xs replicateM_ (length xs) (takeMVar m)

parMapM_ f xs = parSequence_ $ map f xs \end{code}

OpenGL bindings successfully crash. The functional calculations in f should be done in parallel, but those few OpenGL actions should still be done sequentially. I am attaching the code in question. It is a simple voxel raycasting engine.

(Any suggestions on other memory/performance improvements are more than welcome.)

Mitar