Книга: Distributed operating systems

PROBLEMS

PROBLEMS

1. Capabilities in Chorus use epoch numbers in their UIs. Why?

2. What is the difference between a region and a segment?

3. The Chorus supervisor is machine dependent, whereas the real-time executive is machine independent. Explain.

4. Why does Chorus need system processes in addition to user processes and kernel processes?

5. What is the difference between a thread being SUSPENDED and it being STOPPED? After all, in both cases it cannot run.

6. Briefly describe how exceptions and interrupts are handled in Chorus, and tell why they are handled differently.

7. Chorus supports both semaphores and mutexes. Is this strictly necessary? Would it not be sufficient to support only semaphores?

8. What is the function of a mapper?

9. Briefly describe what MpPullIn and MpPushOut are used for.

10. Chorus supports both RPC and an asynchronous send. What is the essential difference between these two?

11. Give a possible use of port migration in Chorus.

12. It is possible to send a message to a port group in Chorus. Does the message go to all the ports in the group, or to a randomly selected port?

13. Chorus has explicit calls to create and delete ports, but only a call for creating port groups (grpAllocate). Make an educated guess as to why there is no grpDelete.

14. Why were miniports introduced? Do they do anything that regular ports do not do?

15. Why does Chorus support both preemptive and nonpreemptive scheduling?

16. Name one way in which Chorus is like Amoeba. Name one way in which it is like Mach.

17. How does Chorus' use of port groups differ from group communication in Amoeba?

18. Why did Chorus extend the semantics of UNIX signals?

Оглавление книги