Control.Distributed.Process.Internal.CQueue

Concurrent queue for single reader, single writer

Documentation

data CQueue a

data BlockSpec

Constructors

NonBlocking

Blocking

Timeout Int

data MatchOn m a

Constructors

MatchMsg (m -> Maybe a)

MatchChan (STM a)

Instances

Functor (MatchOn m)

Methods

fmap :: (a -> b) -> MatchOn m a -> MatchOn m b

(<$) :: a -> MatchOn m b -> MatchOn m a

newCQueue :: IO (CQueue a)

enqueue :: CQueue a -> a -> IO ()

Enqueue an element

Enqueue is strict.

enqueueSTM :: CQueue a -> a -> STM ()

Variant of enqueue for use in the STM monad.

dequeue

Arguments

:: CQueue m

Queue

-> BlockSpec

Blocking behaviour

-> [MatchOn m a]

List of matches

-> IO (Maybe a)

Nothing only on timeout

Dequeue an element

The timeout (if any) is applied only to waiting for incoming messages, not to checking messages that have already arrived

mkWeakCQueue :: CQueue a -> IO () -> IO (Weak (CQueue a))

Weak reference to a CQueue

queueSize :: CQueue a -> IO Int