Safe Haskell	Trustworthy
Language	Haskell2010

GHC.Event

Contents

Types
Creation
Registering interest in I/O events
Registering interest in timeout events

Description

This module provides scalable event notification for file descriptors and timeouts.

This module should be considered GHC internal.

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Synopsis

data EventManager
data TimerManager
getSystemEventManager :: IO (Maybe EventManager)
new :: IO EventManager
getSystemTimerManager :: IO TimerManager
data Event
evtRead :: Event
evtWrite :: Event
type IOCallback = FdKey -> Event -> IO ()
data FdKey
data Lifetime
- = OneShot
- | MultiShot
registerFd :: EventManager -> IOCallback -> Fd -> Event -> Lifetime -> IO FdKey
unregisterFd :: EventManager -> FdKey -> IO ()
unregisterFd_ :: EventManager -> FdKey -> IO Bool
closeFd :: EventManager -> (Fd -> IO ()) -> Fd -> IO ()
type TimeoutCallback = IO ()
data TimeoutKey
registerTimeout :: TimerManager -> Int -> TimeoutCallback -> IO TimeoutKey
updateTimeout :: TimerManager -> TimeoutKey -> Int -> IO ()
unregisterTimeout :: TimerManager -> TimeoutKey -> IO ()

Types

data EventManager Source #

The event manager state.

data TimerManager Source #

The event manager state.

Creation

getSystemEventManager :: IO (Maybe EventManager) Source #

Retrieve the system event manager for the capability on which the calling thread is running.

This function always returns Just the current thread's event manager when using the threaded RTS and Nothing otherwise.

new :: IO EventManager Source #

Create a new event manager.

getSystemTimerManager :: IO TimerManager Source #

Registering interest in I/O events

data Event Source #

An I/O event.

Instances

Eq Event #	Since: base-4.4.0.0
Instance details Defined in GHC.Event.Internal Methods (==) :: Event -> Event -> Bool Source # (/=) :: Event -> Event -> Bool Source #
Show Event #	Since: base-4.4.0.0
Instance details Defined in GHC.Event.Internal Methods showsPrec :: Int -> Event -> ShowS Source # show :: Event -> String Source # showList :: [Event] -> ShowS Source #
Semigroup Event #	Since: base-4.10.0.0
Instance details Defined in GHC.Event.Internal Methods (<>) :: Event -> Event -> Event Source # sconcat :: NonEmpty Event -> Event Source # stimes :: Integral b => b -> Event -> Event Source #
Monoid Event #	Since: base-4.4.0.0
Instance details Defined in GHC.Event.Internal Methods mempty :: Event Source # mappend :: Event -> Event -> Event Source # mconcat :: [Event] -> Event Source #

evtRead :: Event Source #

Data is available to be read.

evtWrite :: Event Source #

The file descriptor is ready to accept a write.

type IOCallback = FdKey -> Event -> IO () Source #

Callback invoked on I/O events.

data FdKey Source #

A file descriptor registration cookie.

Instances

Eq FdKey #	Since: base-4.4.0.0
Instance details Defined in GHC.Event.Manager Methods (==) :: FdKey -> FdKey -> Bool Source # (/=) :: FdKey -> FdKey -> Bool Source #
Show FdKey #	Since: base-4.4.0.0
Instance details Defined in GHC.Event.Manager Methods showsPrec :: Int -> FdKey -> ShowS Source # show :: FdKey -> String Source # showList :: [FdKey] -> ShowS Source #

data Lifetime Source #

The lifetime of an event registration.

Since: base-4.8.1.0

Constructors

OneShot	the registration will be active for only one event
MultiShot	the registration will trigger multiple times

Instances

Eq Lifetime #	Since: base-4.8.1.0
Instance details Defined in GHC.Event.Internal Methods (==) :: Lifetime -> Lifetime -> Bool Source # (/=) :: Lifetime -> Lifetime -> Bool Source #
Show Lifetime #	Since: base-4.8.1.0
Instance details Defined in GHC.Event.Internal Methods showsPrec :: Int -> Lifetime -> ShowS Source # show :: Lifetime -> String Source # showList :: [Lifetime] -> ShowS Source #
Semigroup Lifetime #	Since: base-4.10.0.0
Instance details Defined in GHC.Event.Internal Methods (<>) :: Lifetime -> Lifetime -> Lifetime Source # sconcat :: NonEmpty Lifetime -> Lifetime Source # stimes :: Integral b => b -> Lifetime -> Lifetime Source #
Monoid Lifetime #	`mappend` takes the longer of two lifetimes. Since: base-4.8.0.0
Instance details Defined in GHC.Event.Internal Methods mempty :: Lifetime Source # mappend :: Lifetime -> Lifetime -> Lifetime Source # mconcat :: [Lifetime] -> Lifetime Source #

registerFd :: EventManager -> IOCallback -> Fd -> Event -> Lifetime -> IO FdKey Source #

registerFd mgr cb fd evs lt registers interest in the events evs on the file descriptor fd for lifetime lt. cb is called for each event that occurs. Returns a cookie that can be handed to unregisterFd.

unregisterFd :: EventManager -> FdKey -> IO () Source #

Drop a previous file descriptor registration.

unregisterFd_ :: EventManager -> FdKey -> IO Bool Source #

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.

data TimeoutKey Source #

A timeout registration cookie.

Instances

Eq TimeoutKey #	Since: base-4.7.0.0
Instance details Defined in GHC.Event.TimerManager Methods (==) :: TimeoutKey -> TimeoutKey -> Bool Source # (/=) :: TimeoutKey -> TimeoutKey -> Bool Source #

registerTimeout :: TimerManager -> Int -> TimeoutCallback -> IO TimeoutKey Source #

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 :: TimerManager -> TimeoutKey -> Int -> IO () Source #

Update an active timeout to fire in the given number of microseconds.

unregisterTimeout :: TimerManager -> TimeoutKey -> IO () Source #

Unregister an active timeout.