Starvation freedom

For acquisition of a mutex, the guarantee that every persistent requester eventually succeeds, under specified scheduling assumptions and with owners eventually releasing. Some software threads repeatedly succeeding while another waits forever violates starvation freedom without violating mutual exclusion. A finite bound on the wait, and service in arrival order, are additional requirements.

With a LIFO stack of waiting requests, an old request may remain at the bottom while a new request arrives before each completion and is served next. Every service can finish in finite time while the old request waits forever. A FIFO queue prevents this overtaking within one priority class. Nonpreemptive strict-priority arbitration can separately starve a lower-priority class; using a LIFO stack adds potential starvation even among requests of equal priority.