blob: 4285c0ec54073bf5b770ad8317b1fe10d2606aa2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
{- locking between threads
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.ThreadLock where
import Common
import System.Posix.Terminal
import Control.Concurrent.MVar
import System.Posix.Signals
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
{- Pauses the main thread, letting children run until program termination. -}
waitForTermination :: IO ()
waitForTermination = do
lock <- newEmptyMVar
check softwareTermination lock
whenM (queryTerminal stdInput) $
check keyboardSignal lock
takeMVar lock
where
check sig lock = void $
installHandler sig (CatchOnce $ putMVar lock ()) Nothing
|
