finally package:rebase

A specialised variant of bracket with just a computation to run afterward.

Fork a thread and call the supplied function when the thread is about to terminate, with an exception or a returned value. The function is called with asynchronous exceptions masked.

forkFinally action and_then =
mask $ \restore ->
forkIO $ try (restore action) >>= and_then

This function is useful for informing the parent when a child terminates, for example.