úÎZÃ  F locks the specified region of the file. It blocks the calling thread  until the lock is granted.  fd lm is equivalent to  fd  (lm,  , 0, 0)&. It locks the entire file, no matter  how big it is.  destroys the given lock.      colock-0.2.2System.IO.LockLockDescriptorLockMode LockWriteLockReadsetLock setLockAllunLockc_readc_lockLDbase GHC.IO.Device AbsoluteSeek