[Haskell-cafe] Re[2]: Parallel combinator, performance advice

[Bulat Ziganshin]

Hello Neil,

Tuesday, April 7, 2009, 6:13:29 PM, you wrote:

> Calls to System.Cmd.system, i.e. running external console processes.
> It's a make system I'm writing, so virtually all the time is spent in
> calls to ghc etc.

btw, if all that you need is to limit amount of simultaneous
System.Cmd.system calls, you may go from opposite side: wrap this call
into semaphore:

sem = unsafePerformIO$ newQSem numCapabilities

mysystem = bracket_ (waitQSem sem) (signalQSem sem) . system

and implement para as simple thread population:

para = mapM_ forkIO


-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com