CS 30200/ECE 46810 - Programming Assignment 4

This assignment makes use of files contained in this zip file. This assignment is due Wednesday, May 6.

For this assignment you are to write a program that performs virtual memory operations. You will run the program along with a virtual memory mapping program so that you can observe the virtual memory operations and answer some questions.

Complete the program that is outlined in the file VMdriver.c from the above zip file. Create a text file, called VMcmds.txt, with commands to exercise your virtual memory operations. The form of the command file is described in the comments of VMdriver.c. A very simple version of VMcmds.txt is contained in hw4.zip. Your command file should demonstrate all of the commands described in the comments of VMdriver.c. Run your program in a console window using a command of the form

   c:\VMdriver < VMcmds.txt

Your VMdriver.exe program should create a process from the program VMmapper.exe (its source code file, VMmapper.c, is included in the above zip file). The VMmapper.exe process will display a memory map of the VMdriver.exe process as it is running so that you can see the virtual memory operations take place in the VMdriver.exe virtual address space.

When you are done with your version of VMdriver.c, write a text file containing answers to the following questions. To answer these questions, you will need to use your version of VMdriver.exe, the VMmapper.exe program, and you may need to use other programs that let you observe virtual memory.

1) What happens if you try to reserve a huge amount of memory, say 1.5 gigabytes? (Be sure to find an unused area of virtual memory that is large enough.)
2) What happens if you try to commit a huge amount of memory, say 1.5 gigabytes?
3) What approximately is the largest amount of memory that you can reserve or commit? What determines these numbers?
4) After you have committed a block of pages, how can you observe the effect of the "Touch pages in a block" command? (Hint: You will need to use another program.)
5) What is the effect of committing and then touching as large a block of memory as you possibly can?
6) How can you observe the effect of the "Lock a block of pages" command? (Hint: Use one or two of the programs that we demonstrated in class.)
7) What is the effect of committing and then locking as large a block of memory as you possibly can?
8) What happens when you touch a reserved but noncommitted page of virtual memory?
9) What happens when you touch a guard page?
10) What happens when you write to a page with access code PAGE_READONLY? Explain how you tested this.

Turn in a zip file called CS302Hw4Surname.zip (where Surname is your last name) containing your version of VMdriver.c, your command file VMcmds.txt, and a text file containing answers to the above questions.

This assignment is due Wednesday, May 6.

Here are links to some Windows API documentation that you might need to use in this assignment.