Synchronized section in async map

Question

I have a big IO function that will continuesly load data from a folder, perform pure calculations on the data, and write it back.

I am running this function over multipl

Answer 1

The way you coordinate threads is via MVars or TVars if you want to use STM. You can read all about them in "Parallel and Concurrent Haskell". You could do something like:

do mutex <- newMVar ()
   let putStrLn' = withMVar mutex . const . putStrLn 
   mapConcurrently_ (iofunPrintingWith putStrLn') folderList