Description

Part I

1.  Explain what memory-mapped I/O is and how it works.
2.  Explain what DMA is and how it works.
3. Consider the following set of processes, with the length of the CPU-burst time given in milliseconds:

Process    Burst Time     Priority

P₁                           8                   4

P₂                           1                   1

P₃                           2                   3

P₄                           1                   5

P₅                           6                   2

The processes are assumed to have arrived in the order P₁, P₂, P₃, P₄, P₅, all at time 0.

•  Draw four Gantt charts illustrating the execution of these processes using FCFS, SJF, a nonpreemptive priority (a smaller priority number implies a higher priority), and RR (quantum = 1) scheduling.
•  What is the turnaround time of each process for each of the scheduling algorithms in part 3a?
• What is the waiting time of each process for each of the scheduling algorithms in part 3a?
•  Which of the schedulers in part 3a results in the minimal waiting time (over all processes)?

4.  A UNIX process has two parts—the user part and the kernel part. Is the kernel part like a subroutine and a coroutine? Why?

Part II

Write a monitor in C++ to simulate the dining philosopher problem mentioned in the textbook using the conditional variables provided by the Pthreads API. Make sure that your implementation is able to handle 5 philosophers and is free of the race condition.