distributed-process-0.7.5: Cloud Haskell: Erlang-style concurrency in Haskell

Safe Haskell	None
Language	Haskell2010

Control.Distributed.Process.Internal.CQueue

Description

Concurrent queue for single reader, single writer

Synopsis

data CQueue a
data BlockSpec
- = NonBlocking
- | Blocking
- | Timeout Int
data MatchOn m a
- = MatchMsg (m -> Maybe a)
- | MatchChan (STM a)
newCQueue :: IO (CQueue a)
enqueue :: CQueue a -> a -> IO ()
enqueueSTM :: CQueue a -> a -> STM ()
dequeue :: CQueue m -> BlockSpec -> [MatchOn m a] -> IO (Maybe a)
mkWeakCQueue :: CQueue a -> IO () -> IO (Weak (CQueue a))
queueSize :: CQueue a -> IO Int

Documentation

data CQueue a Source #

data BlockSpec Source #

Constructors

NonBlocking
Blocking
Timeout Int

data MatchOn m a Source #

Constructors

MatchMsg (m -> Maybe a)
MatchChan (STM a)

Instances

Instances details

Functor (MatchOn m) Source #
Instance details Defined in Control.Distributed.Process.Internal.CQueue Methods fmap :: (a -> b) -> MatchOn m a -> MatchOn m b # (<$) :: a -> MatchOn m b -> MatchOn m a #

newCQueue :: IO (CQueue a) Source #

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

Enqueue an element

Enqueue is strict.

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

Variant of enqueue for use in the STM monad.

dequeue Source #

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)) Source #

Weak reference to a CQueue

queueSize :: CQueue a -> IO Int Source #