Data.Atomics.Counter.Reference

This reference version is implemented with atomicModifyIORef and can be a useful fallback if one of the other implementations needs to be debugged.

Documentation

newtype AtomicCounter

Constructors

AtomicCounter (IORef Int)

type CTicket = Int

newCounter :: IO AtomicCounter

Create a new counter initialized to zero.

readCounterForCAS :: AtomicCounter -> IO CTicket

Try repeatedly until we successfully increment the counter. incrCounter =

peekCTicket :: CTicket -> Int

readCounter :: AtomicCounter -> IO Int

writeCounter :: AtomicCounter -> Int -> IO ()

Make a non-atomic write to the counter. No memory-barrier.

casCounter :: AtomicCounter -> CTicket -> Int -> IO (Bool, CTicket)