Wait-Free Dining Under Eventual Weak Exclusion

We present a wait-free solution to the generalized dining philosophers problem under eventual weak exclusion in environments subject to crash faults. Wait-free dining guarantees that every correct hungry process eventually eats, regardless of process crashes. Eventual weak exclusion (3WX ) actually allows scheduling mistakes, whereby mutual exclusion may be violated finitely-many times; for each run, however, there must exist a convergence point after which live neighbors never eat simultaneously. Wait-free dining under 3WX is particularly useful for synchronization tasks where eventual safety is sufficient for correctness (e.g., duty-cycle scheduling, self-stabilizing daemons, and contention managers). Unfortunately, wait-free dining is unsolvable in asynchronous systems. As such, we characterize sufficient conditions for solvability under partial synchrony by presenting a wait-free dining algorithm for 3WX using a local refinement of the eventually perfect failure detector 3P1.