PrioritySync.Internal.Room

Documentation

data Room u

A resource pool, parameterized against arbitrary user data.

Instances

Eq (Room u)

Ord (Room u)

RoomGroup (Room u)

Occupancy (Room u)

newRoom :: u -> IO (Room u)

Create a new Room with some arbitrary user data.

userData :: Room u -> u

Get the user data associated with a Room.

inUse :: Room u -> STM (Set ThreadId)

Get all ThreadIds that are currently claiming this Room.

data Claim u

A Claim, or attempt to acquire or release a Room.

claimedRoom :: Claim u -> Room u

Get the Room target of a Claim.

claimedThread :: Claim u -> ThreadId

Get the thread attempting a Claim.

data ClaimMode

Constructors

Acquire

Release

Instances

Eq ClaimMode

claim :: (RoomGroup c, ClaimContext c) => ClaimMode -> c -> IO a -> IO a

Temporarily Acquire, and then release, or Release, and then acquire, some Rooms for the duration of a critical section. A simple example where a room might be used to prevent interleaving of stdout:

 room <- newRoom (MaxThreads 1)
 forkIO $ claim Acquire (Default,room) $ putStrLn "Hello World!"
 forkIO $ claim Acquire (Default,room) $ putStrLn "Foo!  Bar!"

approveClaims :: RoomConstraint u => [Claim u] -> STM ()

approve some claims according to their constraints.

approve :: Claim u -> STM ()

Approve a claim. This actually acquires or releases a Room.

isEmpty :: Room u -> STM Bool

True iff a Room is empty.