-- 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 1.3


-- | 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. For a simpler system that uses relative
--   times see Control.Event.Relative
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 -> UTCTime -> IO () -> IO EventId

-- | Atomic version of addEvent
addEventSTM :: EventSystem -> UTCTime -> 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 GHC.Show.Show Control.Event.TimerReset
instance GHC.Classes.Ord Control.Event.TimerReset
instance GHC.Classes.Eq Control.Event.TimerReset
instance GHC.Show.Show Control.Event.EventId
instance GHC.Classes.Ord Control.Event.EventId
instance GHC.Classes.Eq Control.Event.EventId
instance GHC.Exception.Type.Exception Control.Event.TimerReset


-- | This module uses Haskell concurrency libraries to build an extremely
--   simple event system that should perform better than the Control.Event
--   module but does not provide features such as STM action scheduling.
module Control.Event.Relative
type EventId = (ThreadId, MVar Bool)

-- | 'addEvent delay action' will delay for <tt>delay</tt> microseconds
--   then execute <tt>action</tt>. An EventId is returned, allowing the
--   event to be canceled.
addEvent :: Int -> IO () -> IO EventId

-- | 'delEvent eid' deletes the event and returns <a>True</a> if the event
--   was deleted. If <a>False</a> is returned then the time elapsed and the
--   action was forked off.
delEvent :: EventId -> IO Bool


-- | This module is a shim, providing the control-timeout api using
--   control-event to run the show. See the control-timeout package for
--   documentation. If you do not need compatability with the
--   control-timeout api then do not use this module!
module Control.Event.Timeout
addTimeout :: Float -> IO () -> IO TimeoutTag
addTimeoutAtomic :: Float -> IO (IO () -> IO (STM TimeoutTag))
cancelTimeout :: TimeoutTag -> STM Bool
data TimeoutTag