diff options
Diffstat (limited to 'Utility/LockFile/Posix.hs')
| -rw-r--r-- | Utility/LockFile/Posix.hs | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Utility/LockFile/Posix.hs b/Utility/LockFile/Posix.hs index a5775dba1..9013bd32c 100644 --- a/Utility/LockFile/Posix.hs +++ b/Utility/LockFile/Posix.hs @@ -16,6 +16,7 @@ module Utility.LockFile.Posix ( checkLocked, getLockStatus, dropLock, + checkSaneLock, ) where import Utility.Exception @@ -97,3 +98,17 @@ getLockStatus' lockfile = go =<< catchMaybeIO open dropLock :: LockHandle -> IO () dropLock (LockHandle fd) = closeFd fd + +-- Checks that the lock file still exists, and is the same file that was +-- locked to get the LockHandle. +-- +-- This check is useful if the lock file might get deleted by something +-- else. +checkSaneLock :: LockFile -> LockHandle -> IO Bool +checkSaneLock lockfile (LockHandle fd) = + go =<< catchMaybeIO (getFileStatus lockfile) + where + go Nothing = return False + go (Just st) = do + fdst <- getFdStatus fd + return $ deviceID fdst == deviceID st && fileID fdst == fileID st |