Fork.hs

module Fork (
    main
) where

import Control.Concurrent (forkIO, ThreadId, threadDelay)
import Control.Concurrent.STM
import Control.Monad
import Control.Monad.IO.Class (liftIO)
import System.Random

second :: Int
second = 1000000 --microseconds

action :: String -> IO ()
action message = do
    delay <- getStdRandom (randomR (0, 5*second))
    threadDelay delay
    putStrLn $ (show delay) ++ " * " ++ message

z1 messages = forkIO ((void . (mapM (forkIO . action)) . (take 10000)) messages)
z2          =                 (mapM (forkIO . action)) . (take 10000)


main = do
    let messages = map (("M" ++) . show) [1..]
    p <- (z2 messages)
    print p
    --threadDelay (3*second)