Control.Concurrent.QSem

Simple quantity semaphores.

Simple Quantity Semaphores

data QSem

A QSem is a simple quantity semaphore, in which the available "quantity" is always dealt with in units of one.

Instances

Eq QSem

Typeable QSem

newQSem :: Int -> IO QSem

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

waitQSem :: QSem -> IO ()

Wait for a unit to become available

signalQSem :: QSem -> IO ()

Signal that a unit of the QSem is available