《操作系统教学资料》操作系统复习题-5.docVIP

Chapter 6 – Concurrency: Deadlock and Starvation 第六章 并发性： 死锁与饥饿 True / False Questions:（判断题） T / F – Deadlock can be defined as the periodic blocking of a set of processes that either compete for system resources or communicate with each other. 死锁是指一系列进程在相互竞争系统资源时发生的一种周期性.阶段性的阻塞。 ANS: F (permanent blocking) 错误。（应该是永久性的阻塞） T / F – All deadlocks involve conflicting needs for resources by two or more processes. 死锁都是由两个或两个以上进程对资源需求的冲突引起的。 ANS: T 正确。 T / F – A reusable resource is one that can be safely used by only one process at a time and is not depleted by that use. 可重复使用资源是指一次只能被一个进程使用，并且不会因使用而被耗尽的资源。 ANS: T 正确。 T / F – A consumable resource is one that can be safely used by only one process at a time and is not depleted by that use. 可消费资源是指一次只能被一个进程使用，并且不会因使用而被耗尽的资源 ANS: F (one that can be created (produced) and destroyed (consumed) 错误。可消费资源是指可以被创建和销毁的资源。 T / F – Although deadlock can potentially exist without it, the condition known as Circular Wait is required for deadlock to actually take place. 虽然死锁可能只是潜在性的存在，但循环等待必然导致死锁发生。 ANS: T 正确。 T / F – The strategy of deadlock prevention is to design a system in such a way that the possibility of deadlock is minimized. 死锁预防是指在设计系统时将死锁可能性降到最小。 ANS: F (possibility is excluded) 错误。死锁预防是指将死锁可能性排除。 T / F – The Deadlock Avoidance approach to solving the deadlock problem allows the three necessary conditions for deadlocks to exist. 死锁避免，允许死锁的三个必要条件存在，仍然可以解决死锁问题。 ANS: T 正确。 T / F – In the Resource Allocation Denial approach to Deadlock Avoidance, a safe state is defined as one in which all potential process sequences do not result in a deadlock. 资源拒绝分配解决死锁问题时，安全状态是指所有进程执行序列可以避免死锁的状态。 ANS: F (in which at least one does not) 错误。只要存在一个进程执行序列可以避免死锁即可。 T / F – Deadlock Detection strategies do not limit resource access or restrict process actions. 死锁检测不限制资源分配，也不限制进程的行为。 ANS: T 正确。死锁检测算法只负责检测，如果检测到死锁则要执行恢复策略。 T / F – One of the most common approaches for recovery from deadlocked processes is to abort all deadlocked proce