Problem
1. Consider again. Suppose that the coordinator crashes. Does this always bring the system down? If not, under what circumstances does this happen? Is there any way to avoid the problem and make the system able to tolerate coordinator crashes?
2. Rican and Agrawala's algorithm has the problem that if a process has crashed and does not reply to a request from another process to enter a critical region, the lack of response will be interpreted as denial of permission. We suggested that all requests be answered immediately, to make it easy to detect crashed processes. Are there any circumstances where even this method is insufficient? Discuss.