/Haskell 8


Copyright (c) The University of Glasgow 2001
License BSD-style (see the file libraries/base/LICENSE)
Maintainer [email protected]
Stability experimental
Portability non-portable (concurrency)
Safe Haskell Safe
Language Haskell2010


Quantity semaphores in which each thread may wait for an arbitrary "amount".

General Quantity Semaphores

data QSemN Source

QSemN is a quantity semaphore in which the resource is acquired and released in units of one. It provides guaranteed FIFO ordering for satisfying blocked waitQSemN calls.

The pattern

  bracket_ (waitQSemN n) (signalQSemN n) (...)

is safe; it never loses any of the resource.

newQSemN :: Int -> IO QSemN Source

Build a new QSemN with a supplied initial quantity. The initial quantity must be at least 0.

waitQSemN :: QSemN -> Int -> IO () Source

Wait for the specified quantity to become available

signalQSemN :: QSemN -> Int -> IO () Source

Signal that a given quantity is now available from the QSemN.

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).