Copyright	(c) Sergey Vinokurov 2022
License	Apache-2.0 (see LICENSE)
Maintainer	serg.foo@gmail.com
Safe Haskell	None
Language	Haskell2010

Control.Concurrent.Counter.Lifted.IO

Contents

Create
Read/write
Arithmetic operations
Bitwise operations

Description

Lifted Counter specialized to operate in the IO monad.

Synopsis

data Counter
new :: Int -> IO Counter
get :: Counter -> IO Int
set :: Counter -> Int -> IO ()
cas :: Counter -> Int -> Int -> IO Int
add :: Counter -> Int -> IO Int
sub :: Counter -> Int -> IO Int
and :: Counter -> Int -> IO Int
or :: Counter -> Int -> IO Int
xor :: Counter -> Int -> IO Int
nand :: Counter -> Int -> IO Int

Documentation

data Counter #

Memory location that supports select few atomic operations.

Isomorphic to IORef Int.

Instances

Instances details

Eq Counter #	Pointer equality
Instance details Defined in Control.Concurrent.Counter.Lifted.IO Methods (==) :: Counter -> Counter -> Bool # (/=) :: Counter -> Counter -> Bool #

Create

new :: Int -> IO Counter #

Create new counter with initial value.

Read/write

get :: Counter -> IO Int #

Atomically read the counter's value.

set :: Counter -> Int -> IO () #

Atomically assign new value to the counter.

cas #

Arguments

:: Counter
-> Int	Expected old value
-> Int	New value
-> IO Int

Atomic compare and swap, i.e. write the new value if the current value matches the provided old value. Returns the value of the element before the operation

Arithmetic operations

add :: Counter -> Int -> IO Int #

Atomically add an amount to the counter and return its old value.

sub :: Counter -> Int -> IO Int #

Atomically subtract an amount from the counter and return its old value.

Bitwise operations

and :: Counter -> Int -> IO Int #

Atomically combine old value with a new one via bitwise and. Returns old counter value.

or :: Counter -> Int -> IO Int #

Atomically combine old value with a new one via bitwise or. Returns old counter value.

xor :: Counter -> Int -> IO Int #

Atomically combine old value with a new one via bitwise xor. Returns old counter value.

nand :: Counter -> Int -> IO Int #

Atomically combine old value with a new one via bitwise nand. Returns old counter value.