OS Organization Chapter 6 Part I: Principals of Deadlock William Stallings

Principals of Deadlock: Deadlock (defn):

Principals of Deadlock: A set of processes is deadlocked when each process in the set is blocked awaiting an event that can only be triggered by another ______.
A. Blocked process in the set
B. Interrupt
C. Unblocked process in the set
D. A kernel level system call
E. None of the above

Principals of Deadlock: Joint Progress Diagram:



Path 1: O acquires B and then A and the releases B and A. When P resumes execution it will be able to to acquire both resources. (T/F)

Principals of Deadlock: Joint Progress Diagram:



Path 3: Q acquires B and then P acquires A. Deadlock isnevitable, because as execution proceeds, ___________.

A. Q will block on A and P will block on B.
B. P will release A but P will not release A.
C. P will block on A, and Q will release A.
D. None of the the above.

Principals of Deadlock: Joint Progress Diagram:
Path 4: P acquires A and then Q acquires B. Is deadlock inevitable, if so why?

Principals of Deadlock: In a joint progress diagram, what is the fatal region?

Principals of Deadlock: Two general categories of resources (?).

A.   Reusable and Consumable
B.   Reusable and Disposable
C. Consumable and Disposable
D.   Reusable and Non-Reusable
E.    None of the Above

Principals of Deadlock: Reusable Resource (defn'):

Principals of Deadlock: Reusable Resources: In the context of reusable resources, processes obtain resource units that they later release for reuse by other __________.

A. processes.
B. threads.
C. little monkeys.
D. kernel processes.
E. None of the above.

Principals of Deadlock: Consumable Resources (defn'):

Principals of Deadlock: In the context of consumable resources, typically there is no limit on the number of consumable resources of a particular type. An unblocked producing process may create any number of such resources. (T/F)

Principals of Deadlock: In the context of reusable resources, what is the best way to deal with the problem of Process Q holding resource A until B is released, and process P holding resource B until A is released?

A. imposing system design constraints concerning the order in which resources can be requested.
B. eliminate the possibility  of deadlock by using virtual memory.
C. calling a system level function to figure it out.
D. None of the above.

Principals of Deadlock: In the context of  reusable resources, what is the best way to handle requests for main memory?

A. eliminate the possibility of deadlock by using virtual memory.
B. imposing system design constraints concerning the order in which resources can be requested.
C. calling a system level function to figure it out.
D. None of the above.

Principals of Deadlock: Name some examples of consumable resources(?)

Principals of Deadlock: name some examples of reusable resources(?).

Principals of Deadlock: Name the 3 conditions of policy for deadlock to occur. Remember that these three conditions are necessary but not sufficient for a deadlock to exist.

Principals of Deadlock: Name the required condition for deadlock to occur (?)