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/Haskell 8

GHC.Conc.IO

Copyright (c) The University of Glasgow 1994-2002
License see libraries/base/LICENSE
Maintainer [email protected]
Stability internal
Portability non-portable (GHC extensions)
Safe Haskell Trustworthy
Language Haskell2010

Contents

Description

Basic concurrency stuff.

ensureIOManagerIsRunning :: IO () Source

ioManagerCapabilitiesChanged :: IO () Source

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

Switch the value of returned TVar from initial value False 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.

threadWaitReadSTM :: Fd -> IO (STM (), IO ()) Source

Returns an STM action that can be used to wait for data to read from a file descriptor. The second returned value is an IO action that can be used to deregister interest in the file descriptor.

threadWaitWriteSTM :: Fd -> IO (STM (), IO ()) Source

Returns an STM action that can be used to wait until data can be written to a file descriptor. The second returned value is an IO action that can be used to deregister interest in the file descriptor.

closeFdWith Source

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.

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.6.1/docs/html/libraries/base-4.12.0.0/GHC-Conc-IO.html