Question

Chapter 5 Process Synchronization 7. Consider a system with 14 dedicated devices of the same type. All jobs cur- a maximum of five devices to complete rently running on this system require a mi their execution, but they each run for long periods of time with just three devices, and request the remaining two only at the very end of the run. Assume that the job stream is endless and that your operating system's device allocation policy is a very conservative one: no job will be started unless all the required drives have been allocated to it for the entire duration of its run. a. What is the maximum number of jobs that can be active at once? Explain your answer. b. What are the minimum and maximum number of devices that may be idle as a result of this policy? Under what circumstances would an additional job be started? tom is identical to the one described in the previous

I need answer of 10th question.

Answer 1

10. Total number of devices in the system=16
  Total number of allocated devices is 5+3+4+2=14
So, number of free devices=16-14=2
Number of devices needed by Job1=8-5=3
  Number of devices needed by Job2=9-3=6
  Number of devices needed by Job3=8-4=4
  Number of devices needed by Job1=5-2=3

So, we can see that none of the above jobs can be completed using the free devices because the no. of free devices is less than the number of devices needed by any of the above jobs.

Therefore, the above situation is in a Deadlock and none of the jobs can proceed further.

If the answer helped then please upvote.And for any queries,please comment.