File: ThreadLock.hs

package info (click to toggle)
git-annex 6.20170101-1%2Bdeb9u2
  • links: PTS
  • area: main
  • in suites: stretch
  • size: 50,088 kB
  • sloc: haskell: 53,116; sh: 1,582; ansic: 341; makefile: 292; perl: 144
file content (19 lines) | stat: -rw-r--r-- 385 bytes parent folder | download | duplicates (3) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
 
{- locking between threads
 -
 - Copyright 2012 Joey Hess <id@joeyh.name>
 -
 - License: BSD-2-clause
 -}

module Utility.ThreadLock where

import Control.Concurrent.MVar

type Lock = MVar ()

newLock :: IO Lock
newLock = newMVar ()

{- Runs an action with a lock held, so only one thread at a time can run it. -}
withLock :: Lock -> IO a -> IO a
withLock lock = withMVar lock . const