MVar package:unliftio

An MVar (pronounced "em-var") is a synchronising variable, used for communication between concurrent threads. It can be thought of as a box, which may be empty or full.
Lifted isEmptyMVar.
Unlifted mkWeakMVar.
Unlifted modifyMVar.
Unlifted modifyMVarMasked.
Unlifted modifyMVar_.
Lifted newEmptyMVar.
Lifted newMVar.
Lifted putMVar.
Lifted readMVar.
Lifted swapMVar.
Lifted takeMVar.
Lifted tryPutMVar.
Lifted tryReadMVar.
Lifted tryTakeMVar.
Unlifted withMVar.
Unlifted withMVarMasked.
Same as memoizeRef, but uses an MVar to ensure that an action is only run once, even in a multithreaded application.
A TMVar is a synchronising variable, used for communication between concurrent threads. It can be thought of as a box, which may be empty or full.
Check whether a given TMVar is empty.
Lifted version of mkWeakTMVar
Create a TMVar which is initially empty.
Lifted version of newEmptyTMVarIO