In this project, you will use what you have studied in the chapter Memory Management & Operating Systems to emulate how operating systems manage memory paging, allocation, deallocation and replacement. Upon completion of this project you will be able to:
- Describe how operating systems manage memory
- Use simple codes to emulate basic functionalities of operating systems
Prompt
1) Show the memory state for the different scenarios in the tables below and analyze which choice is the best. Discuss the impact that Linux versus Windows might have on the ending memory state.
2) With that information in mind, run the following list of jobs:
- An interval is the number of seconds
- Total Memory size = 20 Kbyte
- Page size = 1 Kbyte
| Job ID | Start Time | Job required size | Execution interval | Job state at the end of the interval |
|---|---|---|---|---|
| 1 | 1 | 2 | 7 | End |
| 2 | 2 | 3 | 8 | Sleep |
| 3 | 3 | 4 | 6 | End |
| 4 | 4 | 3 | 6 | Sleep |
| 5 | 5 | 2 | 9 | Sleep |
| 6 | 6 | 3 | 6 | Sleep |
| 7 | 7 | 2 | 6 | Sleep |
3) Run three different scenarios in order to manage memory allocation
Run the program for the following scenarios:
- Best-Fit
- First-Fit
- Worst-Fit
Each should be run for the following jobs:
| Job ID | Start Time | Job required size | Execution interval | Job state at the end of the interval |
|---|---|---|---|---|
| 8 | 8 | 3 | 4 | Sleep |
| 9 | 9 | 5 | 5 | Sleep |
| 10 | 10 | 2 | 8 | Sleep |
| 11 | 11 | 4 | 6 | End |
| 12 | 12 | 6 | 5 | Sleep |
| 2 | 13 | 3 | 6 | End |
| 4 | 13 | 3 | 4 | Sleep |
| 13 | 13 | 5 | 3 | End |
| 7 | 13 | 2 | 3 | End |
| 9 | 17 | 4 | 4 | Sleep |
| 10 | 19 | 2 | 11 | End |
| 6 | 19 | 3 | 6 | End |
| 5 | 20 | 2 | 10 | Sleep |
| 4 | 21 | 3 | 12 | Sleep |
| 12 | 22 | 6 | 13 | End |
| 8 | 22 | 3 | 9 | End |
| 9 | 28 | 5 | 11 | End |
| 5 | 33 | 2 | 3 | Sleep |
| 4 | 34 | 3 | 10 | End |
| 5 | 38 | 2 | 10 | End |
Prompt Tips
Here are a couple tips for getting started with the assignment:
- You’ll want to write a program that will simulate the process an operating system follows when cycling jobs to make sure they are all completed quickly. C++ is a language that works well, but you can choose the language you prefer.
- Copy the data in the two tables from the prompt into a text file that you can use as input for a program.
- Write a program using Java, C++, Python, or the programming language of your choice that can take the input from your text file.
- In the same program, write a function that will queue up each job along with its start time, job size, execution interval, and state at the end of each interval.
- Continue building on this program so that you can execute each of these jobs according to their individual interval.
- Have this program return the state of each job at the end of each interval.
- Run the program until all jobs are complete.
You will need to use what you learned about allocation, deallocation, and replacement to build this program, and you’ll need to consider the total memory size and page size defined in the prompt. When asked to consider different scenarios, it means to consider running these jobs using the best-fit allocation scheme, the first-fit scheme, or others, and then determine which would be best.
