import Control.Monad
import Control.Concurrent
import Control.Concurrent.STM

main = do
    ops <- atomically $ newTVar 0
    forM_ [0..49] $ \_ -> do
        forkIO . forever $ do
            atomically $ modifyTVar ops (+1)
            threadDelay 100

    threadDelay 1000000
    opsFinal <- atomically $ readTVar ops
    putStrLn $ "ops: " ++ show opsFinal
