In the following options about a process and a program, which one is not correct?

computer science


1.      In the following options about a process and a program, which one is not correct?

A.     A program is permanent, but a process is temporary

B.     A program is dynamic, but a process is static

C.     A process is just an executing program.

D.     A process has a program, input, output, and a state


2.      In the following goals, which one is not the goal of batch systems? (  )

A.     Throughout

B.     Turnaround time

C.     CPU utilization

D.     Response time


3.      The operating system manages the process with (  )

A.     PCB

B.     Semaphore

C.     FAT

D.     Page Table


4.      In the following situations of the process states, (  ) is impossible.

A.     running ® ready

B.     running ® blocked

C.     ready ® running

D.     blocked ® running


5.      At a period of time, the resources that only allows one process to access is called (  )

A.     Sharing resource

B.     Critical region

C.     Critical resource

D.     Sharing region


6.      A soft real- time system has three periodic events with periods of 60, 200 and 100 msec each. Suppose that the three events require 30, 50, and x msec of CPU time, respectively. What is the largest value of x for which the system is schedulable?


7.      Why would a thread ever voluntarily give up the CPU by calling thread_yield?


8.      What is the biggest advantage of implementing threads in user space? What is the biggest disadvantage?


9.      Five batch jobs. A through E, arrive at a computer center at almost the same time.

They have estimated running times of 10, 6, 2, 4, and 8 minutes. Their (externally determined) priorities are 3, 5, 2, 1, and 4, respectively, with 5 being the highest priority.

For each of the following scheduling algorithms, determine the mean process turnaround time. Ignore process switching overhead.

(a)    Round robin.

(b)    Priority scheduling.

(c) First-come, first-served (run in order 10, 6, 2, 4, 8).

(d) Shortest job first.

For (a), assume that the system is multiprogrammed, and that each job gets its fair share of the CPU. For (b) through (d), assume that only one job at a time runs, until it finishes. All jobs are completely CPU bound.


10.   Simply introduce the definition and function of semaphores.


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