| Safe Haskell | Trustworthy |
|---|
GHC.Event
Contents
Description
This module provides scalable event notification for file descriptors and timeouts.
This module should be considered GHC internal.
- ---------------------------------------------------------------------------
- data EventManager
- new :: IO EventManager
- getSystemEventManager :: IO (Maybe EventManager)
- loop :: EventManager -> IO ()
- step :: EventManager -> TimeoutQueue -> IO (Bool, TimeoutQueue)
- shutdown :: EventManager -> IO ()
- data Event
- evtRead :: Event
- evtWrite :: Event
- type IOCallback = FdKey -> Event -> IO ()
- data FdKey
- registerFd :: EventManager -> IOCallback -> Fd -> Event -> IO FdKey
- registerFd_ :: EventManager -> IOCallback -> Fd -> Event -> IO (FdKey, Bool)
- unregisterFd :: EventManager -> FdKey -> IO ()
- unregisterFd_ :: EventManager -> FdKey -> IO Bool
- closeFd :: EventManager -> (Fd -> IO ()) -> Fd -> IO ()
- type TimeoutCallback = IO ()
- data TimeoutKey
- registerTimeout :: EventManager -> Int -> TimeoutCallback -> IO TimeoutKey
- updateTimeout :: EventManager -> TimeoutKey -> Int -> IO ()
- unregisterTimeout :: EventManager -> TimeoutKey -> IO ()
Types
data EventManager Source
The event manager state.
Creation
Create a new event manager.
Running
loop :: EventManager -> IO ()Source
Start handling events. This function loops until told to stop,
using shutdown.
Note: This loop can only be run once per EventManager, as it
closes all of its control resources when it finishes.
Stepwise running
step :: EventManager -> TimeoutQueue -> IO (Bool, TimeoutQueue)Source
shutdown :: EventManager -> IO ()Source
Asynchronously shuts down the event manager, if running.
Registering interest in I/O events
registerFd :: EventManager -> IOCallback -> Fd -> Event -> IO FdKeySource
registerFd mgr cb fd evs registers interest in the events evs
on the file descriptor fd. cb is called for each event that
occurs. Returns a cookie that can be handed to unregisterFd.
registerFd_ :: EventManager -> IOCallback -> Fd -> Event -> IO (FdKey, Bool)Source
Register interest in the given events, without waking the event
manager thread. The Bool return value indicates whether the
event manager ought to be woken.
unregisterFd :: EventManager -> FdKey -> IO ()Source
Drop a previous file descriptor registration.
unregisterFd_ :: EventManager -> FdKey -> IO BoolSource
Drop a previous file descriptor registration, without waking the event manager thread. The return value indicates whether the event manager ought to be woken.
closeFd :: EventManager -> (Fd -> IO ()) -> Fd -> IO ()Source
Close a file descriptor in a race-safe way.
Registering interest in timeout events
type TimeoutCallback = IO ()Source
Callback invoked on timeout events.
registerTimeout :: EventManager -> Int -> TimeoutCallback -> IO TimeoutKeySource
Register a timeout in the given number of microseconds. The
returned TimeoutKey can be used to later unregister or update the
timeout. The timeout is automatically unregistered after the given
time has passed.
updateTimeout :: EventManager -> TimeoutKey -> Int -> IO ()Source
Update an active timeout to fire in the given number of microseconds.
unregisterTimeout :: EventManager -> TimeoutKey -> IO ()Source
Unregister an active timeout.