61 lines
1.7 KiB
Haskell
61 lines
1.7 KiB
Haskell
{- Posix lock files, using lock pools.
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-
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- Copyright 2015 Joey Hess <id@joeyh.name>
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-
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- License: BSD-2-clause
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-}
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module Utility.LockPool.Posix (
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LockHandle,
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lockShared,
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lockExclusive,
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tryLockExclusive,
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checkLocked,
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getLockStatus,
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LockStatus(..),
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dropLock,
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checkSaneLock,
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) where
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import qualified Utility.LockFile.Posix as F
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import Utility.LockFile.Posix (LockStatus(..))
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import qualified Utility.LockPool.STM as P
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import Utility.LockPool.STM (LockFile, LockMode(..))
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import Utility.LockPool.LockHandle
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import System.IO
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import System.Posix
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import Data.Maybe
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import Control.Applicative
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import Prelude
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-- Takes a shared lock, blocking until the lock is available.
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lockShared :: Maybe FileMode -> LockFile -> IO LockHandle
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lockShared mode file = makeLockHandle
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(P.waitTakeLock P.lockPool file LockShared)
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(F.lockShared mode file)
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lockExclusive :: Maybe FileMode -> LockFile -> IO LockHandle
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lockExclusive mode file = makeLockHandle
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(P.waitTakeLock P.lockPool file LockExclusive)
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(F.lockExclusive mode file)
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tryLockExclusive :: Maybe FileMode -> LockFile -> IO (Maybe LockHandle)
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tryLockExclusive mode file = tryMakeLockHandle
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(P.tryTakeLock P.lockPool file LockExclusive)
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(F.tryLockExclusive mode file)
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-- Returns Nothing when the file doesn't exist, for cases where
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-- that is different from it not being locked.
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checkLocked :: LockFile -> IO (Maybe Bool)
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checkLocked file = P.getLockStatus P.lockPool file
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(pure (Just True))
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(F.checkLocked file)
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getLockStatus :: LockFile -> IO LockStatus
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getLockStatus file = P.getLockStatus P.lockPool file
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(StatusLockedBy <$> getProcessID)
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(F.getLockStatus file)
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checkSaneLock :: LockFile -> LockHandle -> IO Bool
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checkSaneLock lockfile (LockHandle _ fh) = F.checkSaneLock lockfile fh
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