4d50958ed7
Also, rename lockContent to lockContentExclusive inAnnexSafe should perhaps be eliminated, and instead use `lockContentShared inAnnex`. However, I'm waiting on that, as there are only 2 call sites for inAnnexSafe and it's fiddly.
71 lines
2.1 KiB
Haskell
71 lines
2.1 KiB
Haskell
{- Posix lock files, using lock pools.
|
|
-
|
|
- Copyright 2015 Joey Hess <id@joeyh.name>
|
|
-
|
|
- License: BSD-2-clause
|
|
-}
|
|
|
|
module Utility.LockPool.Posix (
|
|
P.LockFile,
|
|
LockHandle,
|
|
lockShared,
|
|
lockExclusive,
|
|
tryLockShared,
|
|
tryLockExclusive,
|
|
checkLocked,
|
|
getLockStatus,
|
|
LockStatus(..),
|
|
dropLock,
|
|
checkSaneLock,
|
|
) where
|
|
|
|
import qualified Utility.LockFile.Posix as F
|
|
import Utility.LockFile.Posix (LockStatus(..))
|
|
import qualified Utility.LockPool.STM as P
|
|
import Utility.LockPool.STM (LockFile, LockMode(..))
|
|
import Utility.LockPool.LockHandle
|
|
|
|
import System.IO
|
|
import System.Posix
|
|
import Data.Maybe
|
|
import Control.Applicative
|
|
import Prelude
|
|
|
|
-- Takes a shared lock, blocking until the lock is available.
|
|
lockShared :: Maybe FileMode -> LockFile -> IO LockHandle
|
|
lockShared mode file = makeLockHandle
|
|
(P.waitTakeLock P.lockPool file LockShared)
|
|
(F.lockShared mode file)
|
|
|
|
-- Takes an exclusive lock, blocking until the lock is available.
|
|
lockExclusive :: Maybe FileMode -> LockFile -> IO LockHandle
|
|
lockExclusive mode file = makeLockHandle
|
|
(P.waitTakeLock P.lockPool file LockExclusive)
|
|
(F.lockExclusive mode file)
|
|
|
|
-- Tries to take a shared lock, but does not block.
|
|
tryLockShared :: Maybe FileMode -> LockFile -> IO (Maybe LockHandle)
|
|
tryLockShared mode file = tryMakeLockHandle
|
|
(P.tryTakeLock P.lockPool file LockShared)
|
|
(F.tryLockShared mode file)
|
|
|
|
-- Tries to take an exclusive lock, but does not block.
|
|
tryLockExclusive :: Maybe FileMode -> LockFile -> IO (Maybe LockHandle)
|
|
tryLockExclusive mode file = tryMakeLockHandle
|
|
(P.tryTakeLock P.lockPool file LockExclusive)
|
|
(F.tryLockExclusive mode file)
|
|
|
|
-- Returns Nothing when the file doesn't exist, for cases where
|
|
-- that is different from it not being locked.
|
|
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)
|
|
|
|
checkSaneLock :: LockFile -> LockHandle -> IO Bool
|
|
checkSaneLock lockfile (LockHandle _ fh) = F.checkSaneLock lockfile fh
|