Re: [Haskell-cafe] scheduling an alarm

Brian Denheyer wrote:

On Mon, 25 Jan 2010 23:19:53 -0800 Thomas DuBuisson wrote:

...

1) Don't use System.Posix.Signals It isn't necessary and makes your code less portable

2) The POSIX SIGALRM is used/caught by the RTS and that is why you are seeing strange behavior.

3) Consider using Haskell exceptions from Control.Concurrent (throwTo). Not sure what you want to do but you can always "myThreadId >>= \tid -> forkIO $ threadDelay someDelayTime >> (throwTo tid someExceptionVal)"

I just want a routine to run every 15 min.

You can still use Control.Concurrent:

import Control.Concurrent

doEvent f usDelay = forkIO $ threadDelay usDelay doEvent f usDelay f

Or a wrapper around Control.Concurrent - Ex: The Control-Event package.

I'm not clear on why the throwTo is in you example.

It will give you an exception just like you were expecting from SIGALRM. Thomas