Locket implements a lock that can be used by multiple processes provided they
use the same path.
Locks largely behave as (non-reentrant) Lock instances from the threading
module in the standard library. Specifically, their behaviour is:
* Locks are uniquely identified by the file being locked, both in the same
process and across different processes.
* Locks are either in a locked or unlocked state.
* When the lock is unlocked, calling acquire() returns immediately and
changes the lock state to locked.
* When the lock is locked, calling acquire() will block until the lock state
changes to unlocked, or until the timeout expires.
* If a process holds a lock, any thread in that process can call release()
to change the state to unlocked.
* Behaviour of locks after fork is undefined.
Provides
Requires