Stability | experimental |
---|---|

Maintainer | Bas van Dijk <v.dijk.bas@gmail.com> |

Safe Haskell | Safe-Infered |

This is a wrapped version of `Concurrent`

with types generalized
from `IO`

to all monads in either `MonadBase`

or `MonadBaseControl`

.

- data ThreadId
- myThreadId :: MonadBase IO m => m ThreadId
- fork :: MonadBaseControl IO m => m () -> m ThreadId
- forkWithUnmask :: MonadBaseControl IO m => ((forall α. m α -> m α) -> m ()) -> m ThreadId
- killThread :: MonadBase IO m => ThreadId -> m ()
- throwTo :: (MonadBase IO m, Exception e) => ThreadId -> e -> m ()
- forkOn :: MonadBaseControl IO m => Int -> m () -> m ThreadId
- forkOnWithUnmask :: MonadBaseControl IO m => Int -> ((forall α. m α -> m α) -> m ()) -> m ThreadId
- getNumCapabilities :: MonadBase IO m => m Int
- threadCapability :: MonadBase IO m => ThreadId -> m (Int, Bool)
- yield :: MonadBase IO m => m ()
- threadDelay :: MonadBase IO m => Int -> m ()
- threadWaitRead :: MonadBase IO m => Fd -> m ()
- threadWaitWrite :: MonadBase IO m => Fd -> m ()
- module Control.Concurrent.MVar.Lifted
- merge :: MonadBase IO m => [α] -> [α] -> m [α]
- nmerge :: MonadBase IO m => [[α]] -> m [α]
- forkOS :: MonadBaseControl IO m => m () -> m ThreadId
- isCurrentThreadBound :: MonadBase IO m => m Bool
- runInBoundThread :: MonadBaseControl IO m => m α -> m α
- runInUnboundThread :: MonadBaseControl IO m => m α -> m α

# 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
`ThreadId`

s. 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 will hopefully be corrected at a later date.

*Note*: Hugs does not provide any operations on other threads;
it defines `ThreadId`

as a synonym for ().

# Basic concurrency operations

myThreadId :: MonadBase IO m => m ThreadIdSource

Generalized version of `myThreadId`

.

forkWithUnmask :: MonadBaseControl IO m => ((forall α. m α -> m α) -> m ()) -> m ThreadIdSource

Generalized version of `forkIOWithUnmask`

.

Note that, while the forked computation `m ()`

has access to the captured
state, all its side-effects in `m`

are discarded. It is run only for its
side-effects in `IO`

.

killThread :: MonadBase IO m => ThreadId -> m ()Source

Generalized version of `killThread`

.

throwTo :: (MonadBase IO m, Exception e) => ThreadId -> e -> m ()Source

Generalized version of `throwTo`

.

## Threads with affinity

forkOnWithUnmask :: MonadBaseControl IO m => Int -> ((forall α. m α -> m α) -> m ()) -> m ThreadIdSource

Generalized version of `forkOnWithUnmask`

.

Note that, while the forked computation `m ()`

has access to the captured
state, all its side-effects in `m`

are discarded. It is run only for its
side-effects in `IO`

.

getNumCapabilities :: MonadBase IO m => m IntSource

Generalized version of `getNumCapabilities`

.

threadCapability :: MonadBase IO m => ThreadId -> m (Int, Bool)Source

Generalized version of `threadCapability`

.

# Scheduling

## Blocking

## Waiting

threadDelay :: MonadBase IO m => Int -> m ()Source

Generalized version of `threadDelay`

.

threadWaitRead :: MonadBase IO m => Fd -> m ()Source

Generalized version of `threadWaitRead`

.

threadWaitWrite :: MonadBase IO m => Fd -> m ()Source

Generalized version of `threadWaitWrite`

.

# Communication abstractions

# Merging of streams

# Bound Threads

isCurrentThreadBound :: MonadBase IO m => m BoolSource

Generalized version of `isCurrentThreadBound`

.

runInBoundThread :: MonadBaseControl IO m => m α -> m αSource

Generalized version of `runInBoundThread`

.

runInUnboundThread :: MonadBaseControl IO m => m α -> m αSource

Generalized version of `runInUnboundThread`

.