Job A, B and C share the same lock foo
Job A is running.
Job B and C are scheduled to start about the same time.
The plugin write a log "Collision with locks-and-latches/lock/foo(1)=1 and locks-and-latches/lock/foo(1)" twice every 2 seconds until job A is completed.

Functionally, the lock seems to handling the queue ok, but the fact that it writes to log twice every 2 seconds seems to create a performance issue for Jenkins.