In computing, a file lock can be a mutex lock or a shared lock on a file. It is used to prevent more than one process from altering a file at the same time.
One use of file locking is in database maintenance where it can serialize access to the entire physical file underlying a database. While this prevents any other process from access the file it can actually be more efficient than locking a large number of regions in file by removing the overhead of achieving and releasing each lock.
Poor use of file locks, like any computer lock, can result in poor performance or deadlock.
