Moduleconcurrency-1.11.0.3Haskell2010

Control.Concurrent.Classy.QSem

Simple quantity semaphores.

1 type
3 values

Packageconcurrency-1.11.0.3
Exports4
LanguageHaskell2010
LicenceMIT
SourceQSem.hs

Simple Quantity Semaphores

4 declarations

newtypenewtype QSem (m :: Type -> Type)

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

The pattern

bracket_ qaitQSem signalSSem (...)

is safe; it never loses a unit of the resource.

valuenewQSem :: (MonadConc m, MonadFail m) => Int -> m (QSem m)

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

valuewaitQSem :: MonadConc m => QSem m -> m ()

Wait for a unit to become available.

valuesignalQSem :: MonadConc m => QSem m -> m ()

Signal that a unit of the QSem is available.