[Haskell-cafe] Concurrency strategy for 2 threads and rare events

[JP Moresmau]

Hello, I'm wondering what's the best strategy to use in the following scenario:
- 2 threads
  - One perform some work that will take time, possibly go on forever
  - Another waits for user input (like commands from the keyboard)
that affects thread 1 (causing it to stop, in the simplest case)

I've read a bit on MVar and channels, but they seem to be a lot for
cases where the reading thread block for input. In my case, I expect
to have "something" that thread 2 updates when an event occur, and
thread 1 checks it regularly. So thread 1 should not block, but should
check "is there something" and there is, act on it, otherwise continue
doing what it was currently doing. I suppose I could just tryTakeMVar
on a MVar, but is there something more adapted to my needs?

Thanks!

-- 
JP Moresmau
http://jpmoresmau.blogspot.com/