Editing Dining philosophers problem (section)

=== Arbitrator solution ===
Another approach is to guarantee that a philosopher can only pick up both forks or none by introducing an arbitrator to replace circular waiting, e.g., a waiter. In order to pick up the forks, a philosopher must ask permission of the waiter. The waiter gives permission to only one philosopher at a time until the philosopher has picked up both of his forks. Putting down a fork is always allowed. The waiter can be implemented as a mutex.
In addition to introducing a new central entity (the waiter), this approach can result in reduced parallelism: if a philosopher is eating and one of his neighbors is requesting the forks, all other philosophers must wait until this request has been fulfilled even if forks for them are still available.
[[File:Deadlocks and the Dining Philosophers Problem.webm|thumb|Concurrent algorithm design]]