Polysemy.Conc.Effect.Monitor

Documentation

data Restart

Marker type for the restarting action for Monitor.

Constructors

Restart

Instances

Show Restart

Defined in Polysemy.Conc.Effect.Monitor

Methods

showsPrec :: Int -> Restart -> ShowS

show :: Restart -> String

showList :: [Restart] -> ShowS

Eq Restart

Defined in Polysemy.Conc.Effect.Monitor

Methods

(==) :: Restart -> Restart -> Bool

(/=) :: Restart -> Restart -> Bool

data Monitor (action :: Type) :: Effect where

Mark a region as being subject to intervention by a monitoring program. This can mean that a thread is repeatedly checking a condition and cancelling this region when it is unmet. A use case could be checking whether a remote service is available, or whether the system was suspended and resumed. This should be used in a Scoped_ context, like withMonitor.

Constructors

Monitor :: m a -> Monitor action m a

monitor :: forall action r a. Member (Monitor action) r => Sem r a -> Sem r a

Mark a region as being subject to intervention by a monitoring program.

type ScopedMonitor (action :: Type) = Scoped_ (Monitor action)

Convenience alias for a Scoped_ Monitor.

type RestartingMonitor = ScopedMonitor Restart

Monitor specialized to the Restart action.

data MonitorCheck r

Resources for a Scoped_ Monitor.

Constructors

MonitorCheck

Fields

• interval :: NanoSeconds
• check :: MVar () -> Sem r ()

hoistMonitorCheck :: (forall x. Sem r x -> Sem r' x) -> MonitorCheck r -> MonitorCheck r'

Transform the stack of the check in a MonitorCheck.

withMonitor :: forall action r. Member (ScopedMonitor action) r => InterpreterFor (Monitor action) r

Start a region that can contain monitor-intervention regions.

restart :: Member (ScopedMonitor Restart) r => InterpreterFor (Monitor Restart) r

Variant of withMonitor that uses the Restart strategy.