Control.Concurrent.MVar.WaitHandle

Documentation

data WaitHandle a

A WaitHandle is basically just an MVar that can only be put into once, and then never gets anything removed from it

Instances

Functor WaitHandle

Eq (WaitHandle a)

Show (WaitHandle a)

newWaitHandle :: IO (WaitHandle a, a -> IO ())

waitOnWaitHandle :: WaitHandle a -> IO a

mayWaitOnWaitHandle :: WaitHandle a -> IO Bool

Looks ahead to see if the caller is likely to have to wait on the wait handle. If this function returns True then they may or may not actually have to wait, but if the function returns False then they certainly won't have to wait.