Reference no: EM132253824

Question 1:

In this question, you are required to simulate the starving problem that a process may suffer if all other processes in the system have higher priority than its priority.

It is required to create at least two processes (P1 and P2) with priorities 40 and 35 for example. You should create a third process (Pstav) with less priority such as 25.

You may need to put P1 and P2 in the sleep state every couple of seconds to simulate a context switch between P1 and P2. When P1 sleeps, P2 will run and when P2 sleeps, P1 will run. Until now, Pstarv will not be able to run since its priority is the lowest priority. You need to fix that. You are required to change/update/increase the priority of Pstarv each time a context switch occurs.

So, after a number of context switches, Pstarv will finally be able to run to print its ID and print a celebration message that it is finally running and celebrate that you will get a good grade as well.

Feel free to assume any missing information such as should you have a flag or an argument to decide which process you are interested to avoid starvation, should you use shell commands or not, should you increase the Pstarv priority by 1 or by 5........ etc. P1 and P2 should not know anything about the Pstarv process. Do not hardcode it inside P1 or P2. So, you should not include the code of increasing the Pstarv priority in P1 nor P2.

Question 2:

Xinu can work on the BBB hardware board or via the virtual machine. One of the main differences of the Xinu OS that is designed for the hardware is that it has a dedicated clock handler function (clkhandler.c). Our version of Xinuthat is designed for the virtual machine(VM) does not have this clock handler. Attached is the "clkhandler.c". Study the clkhandler.c file.

Explain how our version of xinu that runs on the virtual machine can achieve the functions in the clkhandler.c file.

Attached:clkhandler.c for the BBB, clkinit for the BBB, and the clkinit for the VM.

Write a program in Xinu to show that the clkhandler.c for the BBB and clkinit for the BBB can be replaced by only the clkinit for the VM.

You can think of the starvation problem but instead of incrementing the priority of the Pstarv every time a context switch occurs, the priority increment of Pstarv should occur every two seconds the Pstarv process is in the ready queue without getting the CPU while another CPU bound process should reduce its priority by dividing its priority by two each second. CPU bound process is the process that uses up its quantum completely. Whenever we find that we are at the end of a timeslice, we should set the cpu usage flag for the current process to CPU ALL to represent CPU bound process. By using this technique and after a few seconds, Pstarv priority will increase and other CPU bound processes priority will decrease to the point that Pstarv will be able to run.

Submission: PLEASE, READ CAREFULLY. Note: Any change in the submission format will cause deduction of points.

One single zipped (.zip) file that includes the following:

1. A video file for Question 1 explaining the code and showing the results. Do not include the make clean, make, ./upload.sh, sudominicom, and opening the back end in your video to reduce the video file size.

2. A video file for Question 2 explaining the task you are doing, the code and showing the results. Do not include the make clean, make, ./upload.sh, sudominicom, and opening the back end in your video to reduce the video file size.

3. A single pdf file that includes the following:

3.1 Codes of every file you edited highlighting in yellow the change for Question 1 and 2

3.2 Answer to Question 2 explaining how our version of xinu that runs on the virtual machine can achieve the functions in the clkhandler.c file.

4. The files that you changed/edited (such as .c and .h files) for both questions.

5. A tar file of xinu includes all files (changed or not changed) for both questions.

Attachment:- Final Exam.zip