Safe Haskell	Safe-Inferred
Language	Haskell2010

Control.Concurrent.Class.MonadSTM.Strict.TVar

Contents

StrictTVar
- Low-level API
MonadLabelSTM
MonadTraceSTM

Description

This module corresponds to TVar in "stm" package

Synopsis

data StrictTVar m a
type LazyTVar m = TVar m
toLazyTVar :: StrictTVar m a -> LazyTVar m a
fromLazyTVar :: LazyTVar m a -> StrictTVar m a
castStrictTVar :: LazyTVar m ~ LazyTVar n => StrictTVar m a -> StrictTVar n a
newTVar :: MonadSTM m => a -> STM m (StrictTVar m a)
newTVarIO :: MonadSTM m => a -> m (StrictTVar m a)
newTVarWithInvariant :: (MonadSTM m, HasCallStack) => (a -> Maybe String) -> a -> STM m (StrictTVar m a)
newTVarWithInvariantIO :: (MonadSTM m, HasCallStack) => (a -> Maybe String) -> a -> m (StrictTVar m a)
readTVar :: MonadSTM m => StrictTVar m a -> STM m a
readTVarIO :: MonadSTM m => StrictTVar m a -> m a
writeTVar :: (MonadSTM m, HasCallStack) => StrictTVar m a -> a -> STM m ()
modifyTVar :: MonadSTM m => StrictTVar m a -> (a -> a) -> STM m ()
stateTVar :: MonadSTM m => StrictTVar m s -> (s -> (a, s)) -> STM m a
swapTVar :: MonadSTM m => StrictTVar m a -> a -> STM m a
check :: MonadSTM m => Bool -> STM m ()
checkInvariant :: HasCallStack => Maybe String -> a -> a
labelTVar :: MonadLabelledSTM m => StrictTVar m a -> String -> STM m ()
labelTVarIO :: MonadLabelledSTM m => StrictTVar m a -> String -> m ()
traceTVar :: MonadTraceSTM m => proxy m -> StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> STM m ()
traceTVarIO :: MonadTraceSTM m => StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> m ()

StrictTVar

data StrictTVar m a Source #

type LazyTVar m = TVar m Source #

toLazyTVar :: StrictTVar m a -> LazyTVar m a Source #

Get the underlying TVar

Since we obviously cannot guarantee that updates to this LazyTVar will be strict, this should be used with caution.

fromLazyTVar :: LazyTVar m a -> StrictTVar m a Source #

castStrictTVar :: LazyTVar m ~ LazyTVar n => StrictTVar m a -> StrictTVar n a Source #

newTVar :: MonadSTM m => a -> STM m (StrictTVar m a) Source #

newTVarIO :: MonadSTM m => a -> m (StrictTVar m a) Source #

newTVarWithInvariant Source #

Arguments

:: (MonadSTM m, HasCallStack)
=> (a -> Maybe String)	Invariant (expect `Nothing`)
-> a
-> STM m (StrictTVar m a)

newTVarWithInvariantIO Source #

Arguments

:: (MonadSTM m, HasCallStack)
=> (a -> Maybe String)	Invariant (expect `Nothing`)
-> a
-> m (StrictTVar m a)

readTVar :: MonadSTM m => StrictTVar m a -> STM m a Source #

readTVarIO :: MonadSTM m => StrictTVar m a -> m a Source #

writeTVar :: (MonadSTM m, HasCallStack) => StrictTVar m a -> a -> STM m () Source #

modifyTVar :: MonadSTM m => StrictTVar m a -> (a -> a) -> STM m () Source #

stateTVar :: MonadSTM m => StrictTVar m s -> (s -> (a, s)) -> STM m a Source #

swapTVar :: MonadSTM m => StrictTVar m a -> a -> STM m a Source #

check :: MonadSTM m => Bool -> STM m () #

See check.

Low-level API

checkInvariant :: HasCallStack => Maybe String -> a -> a Source #

Check invariant (if enabled) before continuing

checkInvariant mErr x is equal to x if mErr == Nothing, and throws an error err if mErr == Just err.

This is exported so that other code that wants to conditionally check invariants can reuse the same logic, rather than having to introduce new per-package flags.

MonadLabelSTM

labelTVar :: MonadLabelledSTM m => StrictTVar m a -> String -> STM m () Source #

labelTVarIO :: MonadLabelledSTM m => StrictTVar m a -> String -> m () Source #

MonadTraceSTM

traceTVar :: MonadTraceSTM m => proxy m -> StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> STM m () Source #

traceTVarIO :: MonadTraceSTM m => StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> m () Source #