-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Event scheduling system.
--   
--   Allows scheduling and canceling of IO actions to be executed at a
--   specified future time.
@package control-event
@version 0.3.0


-- | This module can execute events at specified time. It uses a two thread
--   system that allows the STM adding and deleting of new threads without
--   requiring later IO actions.
--   
--   This differs from control-timeout in that control-event is: * More
--   complex * Requires initilization * Allows pure STM adding and removing
--   of events (no post STM IO action) * Allows user control over event
--   systems (can have more than one) * Allows events to run in event
--   handler thread (advisable if thread spark is too expensive /
--   computation is cheap) * No possible duplication of EventId
--   (theoretical! no real advantage)
--   
--   A shim has been made providing control-timeout API with Control.Event
--   running under the hood (called Control.Event.Timeout).
module Control.Event

-- | IDs useful for canceling previously scheduled events.
data EventId

-- | The event system must be initilized using initEventSystem. More than
--   one event system can be instantiated at once (eg. for
--   non-interference).
data EventSystem

-- | A value indicating there is no such event. Canceling this event
--   returns True and has no other effect.
noEvent :: EventId

-- | The only way to get an event system is to initilize one
initEventSystem :: IO EventSystem

-- | Add an *action* to be performed at *time* by *system*. Returns a
--   unique ID.
addEvent :: EventSystem -> ClockTime -> IO () -> IO EventId

-- | Atomic version of addEvent
addEventSTM :: EventSystem -> ClockTime -> IO () -> STM EventId

-- | Cancel an event from the system, returning True on success.
cancelEvent :: EventSystem -> EventId -> IO Bool

-- | Atomic version of cancelEvent
cancelEventSTM :: EventSystem -> EventId -> STM Bool

-- | Returns the number of pending events.
evtSystemSize :: EventSystem -> STM Int
instance Typeable TimerReset
instance Eq TimerReset
instance Ord TimerReset
instance Show TimerReset
instance Eq EventId
instance Ord EventId
instance Show EventId


-- | This module is a shim, providing the control-timeout api using
--   control-event to run the show
module Control.Event.Timeout
addTimeout :: Float -> (IO ()) -> IO TimeoutTag
addTimeoutAtomic :: Float -> IO () -> IO (STM TimeoutTag)
cancelTimeout :: TimeoutTag -> STM Bool
data TimeoutTag