Topic is Operating Systems.

Some questions could have multiple correct answers.

Choose all correct answers.

a point for each correct answer selected.

a half-point off for each incorrect answer selected.

QUESTION 16 Preventing one of the three necessary conditions for deadlock is OA. a direct prevention strategy. OB. an indirect prevention strategy Hint: you are controlling the environment necessary for deadlock to exist - not deadlock itself. QUESTION 17 In the Banker's algorithm an unsafe state is one in which DA. all sequences of resource allocation from that state result in deadlock. UB. one sequence of resource allocation from that state results in deadlock. Hint: an unsafe state is one in which there is no safe way home; 1.e., no sequence of transitions from that state to completion will prevent deadlock. QUESTION 18 A form of fully asynchronous interprocess communication in UNIX is a OA. pipe. OB. SysV message queue. OC. signal. OD. Syst semaphore. Hint: a pipe is a unidirectional data channel used for fully synchronous interprocess communication: SyaV message queues are not fully asynchronous since the sender always blocks on full and the receiver can block on empty, semaphores are synchronous on D and -1 senops. QUESTION 19 The use of Resource Classes is an integrated approach to dealing with deadlock. OA. True OB. False Hint: shared resources are put into resource classes so that the same strategy can be applied to a set of resources. QUESTION 20 Assume two or more processes are sharing a resource. You can prevent deadlock it ... DA. you eliminate circular wait among the processes. OB. the shared resource does not require exclusive use. OC. you eliminate starvation on that resource. OD. one process can be preempted from waiting on/holding the shared resou source. Hint: mutual exclusion is not something you can generally omit from the requirements but if you could it would prevent deadlock; circular wait and the other three necessary conditions are sufficient for deadlock - removing any of the 4 will eliminate deadlock but circular wait is often hard to predict and control so typically you work on the other three. QUESTION 21 One fail-safe approach to deadlock recovery is to abort all involved processes. OA. True OB. False A hint for you