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|
{- Pid locks, using lock pools.
-
- Copyright 2015 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
module Utility.LockPool.PidLock (
P.LockFile,
LockHandle,
waitLock,
tryLock,
checkLocked,
getLockStatus,
LockStatus(..),
dropLock,
checkSaneLock,
) where
import qualified Utility.LockFile.PidLock as F
import Utility.LockFile.LockStatus
import qualified Utility.LockPool.STM as P
import Utility.LockPool.STM (LockFile, LockMode(..))
import Utility.LockPool.LockHandle
import Utility.ThreadScheduler
import System.IO
import System.Posix
import Data.Maybe
import Control.Applicative
import Prelude
-- Takes a pid lock, blocking until the lock is available or the timeout.
waitLock :: Seconds -> LockFile -> IO LockHandle
waitLock timeout file = makeLockHandle P.lockPool file
-- LockShared for STM lock, because a pid lock can be the top-level
-- lock with various other STM level locks gated behind it.
(\p f -> P.waitTakeLock p f LockShared)
(\f -> mk <$> F.waitLock timeout f)
-- Tries to take a pid lock, but does not block.
tryLock :: LockFile -> IO (Maybe LockHandle)
tryLock file = tryMakeLockHandle P.lockPool file
(\p f -> P.tryTakeLock p f LockShared)
(\f -> fmap mk <$> F.tryLock f)
checkLocked :: LockFile -> IO (Maybe Bool)
checkLocked file = P.getLockStatus P.lockPool file
(pure (Just True))
(F.checkLocked file)
getLockStatus :: LockFile -> IO LockStatus
getLockStatus file = P.getLockStatus P.lockPool file
(StatusLockedBy <$> getProcessID)
(F.getLockStatus file)
mk :: F.LockHandle -> FileLockOps
mk h = FileLockOps
{ fDropLock = F.dropLock h
, fCheckSaneLock = \f -> F.checkSaneLock f h
}
|
