Safe Haskell	None
Language	Haskell2010

UnliftIO.Concurrent

Contents

Concurrent Haskell
Basic concurrency operations
- Threads with affinity
Scheduling
- Waiting
Communication abstractions
Bound Threads
Weak references to ThreadIds

Description

Unlifted Control.Concurrent.

This module is not reexported by UnliftIO, use it only if UnliftIO.Async is not enough.

Since: 0.1.1.0

Synopsis

data ThreadId
myThreadId :: MonadIO m => m ThreadId
forkIO :: MonadUnliftIO m => m () -> m ThreadId
forkWithUnmask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m ()) -> m ThreadId
forkIOWithUnmask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m ()) -> m ThreadId
forkFinally :: MonadUnliftIO m => m a -> (Either SomeException a -> m ()) -> m ThreadId
killThread :: MonadIO m => ThreadId -> m ()
throwTo :: (Exception e, MonadIO m) => ThreadId -> e -> m ()
forkOn :: MonadUnliftIO m => Int -> m () -> m ThreadId
forkOnWithUnmask :: MonadUnliftIO m => Int -> ((forall a. m a -> m a) -> m ()) -> m ThreadId
getNumCapabilities :: MonadIO m => m Int
setNumCapabilities :: MonadIO m => Int -> m ()
threadCapability :: MonadIO m => ThreadId -> m (Int, Bool)
yield :: MonadIO m => m ()
threadDelay :: MonadIO m => Int -> m ()
threadWaitRead :: MonadIO m => Fd -> m ()
threadWaitWrite :: MonadIO m => Fd -> m ()
module UnliftIO.MVar
module UnliftIO.Chan
rtsSupportsBoundThreads :: Bool
forkOS :: MonadUnliftIO m => m () -> m ThreadId
isCurrentThreadBound :: MonadIO m => m Bool
runInBoundThread :: MonadUnliftIO m => m a -> m a
runInUnboundThread :: MonadUnliftIO m => m a -> m a
mkWeakThreadId :: MonadIO m => ThreadId -> m (Weak ThreadId)

Concurrent Haskell

data ThreadId #

A ThreadId is an abstract type representing a handle to a thread. ThreadId is an instance of Eq, Ord and Show, where the Ord instance implements an arbitrary total ordering over ThreadIds. The Show instance lets you convert an arbitrary-valued ThreadId to string form; showing a ThreadId value is occasionally useful when debugging or diagnosing the behaviour of a concurrent program.

Note: in GHC, if you have a ThreadId, you essentially have a pointer to the thread itself. This means the thread itself can't be garbage collected until you drop the ThreadId. This misfeature would be difficult to correct while continuing to support threadStatus.

Instances

Instances details

Show ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods showsPrec :: Int -> ThreadId -> ShowS # show :: ThreadId -> String # showList :: [ThreadId] -> ShowS #
NFData ThreadId	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: ThreadId -> () #
Eq ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: ThreadId -> ThreadId -> Bool # (/=) :: ThreadId -> ThreadId -> Bool #
Ord ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods compare :: ThreadId -> ThreadId -> Ordering # (<) :: ThreadId -> ThreadId -> Bool # (<=) :: ThreadId -> ThreadId -> Bool # (>) :: ThreadId -> ThreadId -> Bool # (>=) :: ThreadId -> ThreadId -> Bool # max :: ThreadId -> ThreadId -> ThreadId # min :: ThreadId -> ThreadId -> ThreadId #
Hashable ThreadId
Instance details Defined in Data.Hashable.Class Methods hashWithSalt :: Int -> ThreadId -> Int Source # hash :: ThreadId -> Int Source #

Basic concurrency operations

myThreadId :: MonadIO m => m ThreadId Source #

Lifted version of myThreadId.

Since: 0.1.1.0

forkIO :: MonadUnliftIO m => m () -> m ThreadId Source #

Unlifted version of forkIO.

Since: 0.1.1.0

forkWithUnmask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m ()) -> m ThreadId Source #

Deprecated: forkWithUnmask has been renamed to forkIOWithUnmask

Please use forkIOWithUnmask instead. This function has been deprecated in release 0.2.11 and will be removed in the next major release.

Since: 0.1.1.0

forkIOWithUnmask :: MonadUnliftIO m => ((forall a. m a -> m a) -> m ()) -> m ThreadId Source #

Unlifted version of forkIOWithUnmask.

Since: 0.2.11

forkFinally :: MonadUnliftIO m => m a -> (Either SomeException a -> m ()) -> m ThreadId Source #

Unlifted version of forkFinally.

Since: 0.1.1.0

killThread :: MonadIO m => ThreadId -> m () Source #

Lifted version of killThread.

Since: 0.1.1.0

throwTo :: (Exception e, MonadIO m) => ThreadId -> e -> m () Source #

Throw an asynchronous exception to another thread.

Synchronously typed exceptions will be wrapped into an AsyncExceptionWrapper, see https://github.com/fpco/safe-exceptions#determining-sync-vs-async.

It's usually a better idea to use the UnliftIO.Async module, see https://github.com/fpco/safe-exceptions#quickstart.

Since: 0.1.0.0

Threads with affinity

forkOn :: MonadUnliftIO m => Int -> m () -> m ThreadId Source #

Unlifted version of forkOn.

Since: 0.1.1.0

forkOnWithUnmask :: MonadUnliftIO m => Int -> ((forall a. m a -> m a) -> m ()) -> m ThreadId Source #

Unlifted version of forkOnWithUnmask.

Since: 0.1.1.0

getNumCapabilities :: MonadIO m => m Int Source #

Lifted version of getNumCapabilities.

Since: 0.1.1.0

setNumCapabilities :: MonadIO m => Int -> m () Source #

Lifted version of setNumCapabilities.

Since: 0.1.1.0

threadCapability :: MonadIO m => ThreadId -> m (Int, Bool) Source #

Lifted version of threadCapability.

Since: 0.1.1.0

Scheduling

yield :: MonadIO m => m () Source #

Lifted version of yield.

Since: 0.1.1.0

Waiting

threadDelay :: MonadIO m => Int -> m () Source #

Lifted version of threadDelay.

Since: 0.1.1.0

threadWaitRead :: MonadIO m => Fd -> m () Source #

Lifted version of threadWaitRead.

Since: 0.1.1.0

threadWaitWrite :: MonadIO m => Fd -> m () Source #

Lifted version of threadWaitWrite.

Since: 0.1.1.0

Communication abstractions

module UnliftIO.MVar

module UnliftIO.Chan

Bound Threads

rtsSupportsBoundThreads :: Bool #

True if bound threads are supported. If rtsSupportsBoundThreads is False, isCurrentThreadBound will always return False and both forkOS and runInBoundThread will fail.

forkOS :: MonadUnliftIO m => m () -> m ThreadId Source #

Unflifted version of forkOS.

Since: 0.1.1.0

isCurrentThreadBound :: MonadIO m => m Bool Source #

Lifted version of isCurrentThreadBound.

Since: 0.1.1.0

runInBoundThread :: MonadUnliftIO m => m a -> m a Source #

Unlifted version of runInBoundThread.

Since: 0.1.1.0

runInUnboundThread :: MonadUnliftIO m => m a -> m a Source #

Unlifted version of runInUnboundThread.

Since: 0.1.1.0

Weak references to ThreadIds

mkWeakThreadId :: MonadIO m => ThreadId -> m (Weak ThreadId) Source #

Lifted version of mkWeakThreadId.

Since: 0.1.1.0