Copyright 1996-2003 John D. Polstra.
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* $Id: LockFile.i3.html,v 1.3 2010-04-29 17:20:02 wagner Exp $
The LockFile interface allows one to create and remove lock files.
It is probably not a good idea to put lock files on NFS-mounted
file systems.
INTERFACE LockFile;
IMPORT OSError, Pathname;
TYPE
T <: ROOT;
PROCEDURE Lock(name: Pathname.T): T
RAISES {OSError.E};
Creates and locks a file of the given name. Returns NIL if it was
already locked. Otherwise, writes the current process-ID into the
file, terminated by a newline. Returns a handle that can be used to
unlock the file later. The file is automatically unlocked and removed
at process termination.
PROCEDURE Unlock(lf: T)
RAISES {OSError.E};
Unlocks and removes the given lock file.
END LockFile.