base-4.5.1.0: Basic libraries

Portabilitynon-portable (GHC extensions)
Stabilityinternal
Maintainer[email protected]
Safe HaskellTrustworthy

GHC.Conc.IO

Contents

Description

Basic concurrency stuff.

Synopsis

Documentation

Waiting

threadDelay :: Int -> IO ()Source

Suspends the current thread for a given number of microseconds (GHC only).

There is no guarantee that the thread will be rescheduled promptly when the delay has expired, but the thread will never continue to run earlier than specified.

registerDelay :: Int -> IO (TVar Bool)Source

Set the value of returned TVar to True after a given number of microseconds. The caveats associated with threadDelay also apply.

threadWaitRead :: Fd -> IO ()Source

Block the current thread until data is available to read on the given file descriptor (GHC only).

This will throw an IOError if the file descriptor was closed while this thread was blocked. To safely close a file descriptor that has been used with threadWaitRead, use closeFdWith.

threadWaitWrite :: Fd -> IO ()Source

Block the current thread until data can be written to the given file descriptor (GHC only).

This will throw an IOError if the file descriptor was closed while this thread was blocked. To safely close a file descriptor that has been used with threadWaitWrite, use closeFdWith.

closeFdWithSource

Arguments

:: (Fd -> IO ())

Low-level action that performs the real close.

-> Fd

File descriptor to close.

-> IO () 

Close a file descriptor in a concurrency-safe way (GHC only). If you are using threadWaitRead or threadWaitWrite to perform blocking I/O, you must use this function to close file descriptors, or blocked threads may not be woken.

Any threads that are blocked on the file descriptor via threadWaitRead or threadWaitWrite will be unblocked by having IO exceptions thrown.