diff options
| author |  Joey Hess <joeyh@joeyh.name> | 2015-05-18 16:23:07 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2015-05-19 14:09:52 -0400 |
| commit | ae5433c4caf0ee57e3338df6dcd625f20ece7101 (patch) | |
| tree | 5bdab44419df36e7e5aab2e36cd6b221654de04e /Utility | |
| parent | 94a3e606fb31150c969d63790ec1ef870f413cc1 (diff) | |
use lock pools throughout git-annex
The one exception is in Utility.Daemon. As long as a process only
daemonizes once, which seems reasonable, and as long as it avoids calling
checkDaemon once it's already running as a daemon, the fcntl locking
gotchas won't be a problem there.
Annex.LockFile has it's own separate lock pool layer, which has been
renamed to LockCache. This is a persistent cache of locks that persist
until closed.
This is not quite done; lockContent stil needs to be converted.
Diffstat (limited to 'Utility')
| -rw-r--r-- | Utility/LockFile.hs | 3 | ||||
| -rw-r--r-- | Utility/LockPool/Posix.hs | 4 | ||||
| -rw-r--r-- | Utility/LockPool/STM.hs | 9 |
3 files changed, 8 insertions, 8 deletions
diff --git a/Utility/LockFile.hs b/Utility/LockFile.hs index f9a0e6783..1d924fc1e 100644 --- a/Utility/LockFile.hs +++ b/Utility/LockFile.hs @@ -4,6 +4,9 @@ - This module does *not* attempt to be a portability shim, it just exposes - the native locking of the OS. - + - Posix fcntl locks have some gotchas. So, consider using + - Utility.LockPool instead of using this module directly. + - - Copyright 2014 Joey Hess <id@joeyh.name> - - License: BSD-2-clause diff --git a/Utility/LockPool/Posix.hs b/Utility/LockPool/Posix.hs index e460272f2..e05ab9754 100644 --- a/Utility/LockPool/Posix.hs +++ b/Utility/LockPool/Posix.hs @@ -18,11 +18,9 @@ module Utility.LockPool.Posix ( import qualified Utility.LockFile.Posix as F import qualified Utility.LockPool.STM as P -import Utility.LockPool.STM (LockPool, LockFile, LockMode(..)) +import Utility.LockPool.STM (LockFile, LockMode(..)) import Utility.LockPool.LockHandle -import Utility.Monad -import Control.Concurrent.STM import System.IO import System.Posix import Data.Maybe diff --git a/Utility/LockPool/STM.hs b/Utility/LockPool/STM.hs index a60bbc7bf..f422c8a73 100644 --- a/Utility/LockPool/STM.hs +++ b/Utility/LockPool/STM.hs @@ -80,16 +80,15 @@ tryTakeLock pool file mode = -- -- Note that the lock pool is left empty while the checker action is run. -- This allows checker actions that open/close files, and so would be in --- danger of conflicting with existing locks. Since the lock pool is --- kept empty, anything that attempts to take a lock will block, --- avoiding that race. +-- danger of conflicting with locks created at the same time this is +-- running. With the lock pool empty, anything that attempts +-- to take a lock will block, avoiding that race. getLockStatus :: LockPool -> LockFile -> IO v -> IO (Maybe v) -> IO (Maybe v) getLockStatus pool file getdefault checker = do v <- atomically $ do m <- takeTMVar pool let threadlocked = case M.lookup file m of - Just (LockStatus _ n) - | n > 0 -> True + Just (LockStatus _ n) | n > 0 -> True _ -> False if threadlocked then do |