Dining philosophers problem with mutexes
In the problem as I have seen it, the philosophers only take one fork at a time and can hang on to it (but they only eat when they have 2 forks). You have simplified it by having them take both or none.

There shouldn't be any deadlocks as the philosopher only has 0 or 2 forks, but there is still potential for starvation if the 2 neighbouring philosophers start eating again before the philosopher has finished thinking.