Moduleunliftio-0.2.25.1Haskell2010

UnliftIO.QSemN

1 type
4 values

Packageunliftio-0.2.25.1
Exports5
LanguageHaskell2010
LicenceMIT
SourceQSemN.hs

datadata QSemN

QSemN is a quantity semaphore in which the resource is acquired and released in arbitrary amounts. 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.

valuenewQSemN :: MonadIO m => Int -> m QSemN

Lifted newQSemN.

valuewaitQSemN :: MonadIO m => QSemN -> Int -> m ()

Lifted waitQSemN.

valuesignalQSemN :: MonadIO m => QSemN -> Int -> m ()

Lifted signalQSemN.

valuewithQSemN :: MonadUnliftIO m => QSemN -> Int -> m a -> m a

withQSemN is an exception-safe wrapper for performing the provided operation while holding N unit of value from the semaphore. It ensures the semaphore cannot be leaked if there are exceptions.