stm-2.5.3.1: Software Transactional Memory
Copyright(c) The University of Glasgow 2004
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilityexperimental
Portabilitynon-portable (requires STM)
Safe HaskellTrustworthy
LanguageHaskell2010

Control.Concurrent.STM.TVar

Contents

Description

 
Synopsis

TVars

data TVar a #

Instances

Instances details
Eq (TVar a) 
Instance details

Defined in GHC.Internal.Conc.Sync

Methods

(==) :: TVar a -> TVar a -> Bool #

(/=) :: TVar a -> TVar a -> Bool #

newTVar :: a -> STM (TVar a) #

newTVarIO :: a -> IO (TVar a) #

readTVar :: TVar a -> STM a #

readTVarIO :: TVar a -> IO a #

writeTVar :: TVar a -> a -> STM () #

modifyTVar :: TVar a -> (a -> a) -> STM () Source #

Mutate the contents of a TVar. N.B., this version is non-strict.

Since: stm-2.3

modifyTVar' :: TVar a -> (a -> a) -> STM () Source #

Strict version of modifyTVar.

Since: stm-2.3

stateTVar :: TVar s -> (s -> (a, s)) -> STM a Source #

Like modifyTVar' but the function is a simple state transition that can return a side value which is passed on as the result of the STM.

Since: stm-2.5.0

swapTVar :: TVar a -> a -> STM a Source #

Swap the contents of a TVar for a new value.

Since: stm-2.3

registerDelay :: Int -> IO (TVar Bool) #

mkWeakTVar :: TVar a -> IO () -> IO (Weak (TVar a)) Source #

Make a Weak pointer to a TVar, using the second argument as a finalizer to run when TVar is garbage-collected

Since: stm-2.4.3