Data.Pool

A simple resource pool implementation.

Use newPool to construct a resource Pool of a certain size and use withResource to acquire and release resources.

A simple resource pool and its configuration

data Pool a

a simple resource pool

Use newPool to construct a Pool

Constructors

UnsafeMkPool

Fields

• poolConfig :: !(PoolConfig a)

  the config of the Pool

• poolSem :: QSem

  the quantity semaphore managing the available resources

data PoolConfig a

a simple resource pool config

Constructors

MkPoolConfig

Fields

• createResource :: IO a

  the action that creates a resource of type a

• destroyResource :: a -> IO ()

  the action that destorys a resource of type a

• maxResources :: !Int

  the maximum amount of used resources. It needs to be at least 0

creating a pool

defaultPoolConfig

Arguments

:: IO a

the action that creates a resource of type a

-> (a -> IO ())

the action that destroys a resource of type a

-> Int

the maximum amount of used resources. It needs to be at lest 0

-> PoolConfig a

constructing a default PoolConfig

newPool :: MonadIO m => PoolConfig a -> m (Pool a)

given a PoolConfig, create a new Pool

using a resource from a pool

withResource :: MonadUnliftIO m => Pool a -> (a -> m r) -> m r

acquire a resource from a pool and run an action on it