ricardofares / ribabari

:desktop_computer: College project for an operating system simulator

Troque para Português Brasileiro 🇧🇷.

🖋️ About

Ribabari is an operating system simulator focused on hardware resource management among different processes. Our operating system simulator provides management for these following resources, CPU, Memory, I/O and Disk.

🎓 A college Project

Ribabari operating system simulator project is a requirement for the Operating Systems course.

📖 Brief

Our simulator provides a interative terminal for users run its processes and see the processes execution among different views, being each view for a different resource.

❓ Have you not understood what is a view?

A view is basically a window in the simulator terminal that shows under the hood the operating system managing a hardware resource. In each view, a different hardware resource is being managed (e.g., there are views showing the OS managing the disk and semaphores).

❓ How can I execute my own process?

Oh, wait a minute, following sections is going to detail how to write a synthetic program file 🗒️ in which specifies the process instruction, the segment size, semaphores to be used, and so more.

🛠️ Compiling

First of all, it is a good way to start to compile the simulator first. Therefore, we suggest to follow the next steps.

1. Installing the gcc.

Install the gcc the C compiler executing the following line.

sudo apt install gcc

🔔 Note: If you already have the gcc installed, then you can jump to the next step.

2. Installing the make.

Install the make easies the compilation of our simulator enabling compile the entire project using just one command.

sudo apt install make

🔔 Note: If you already have the make installed, then you can jump to the next step.

3. Installing the ncurses.

Install the ncurses is the library used by our simulator for create the terminal interface.

sudo apt install libncurses-dev

🔔 Note: If you already have the ncurses installed, then you are ready. Hence, go to the next section.

🚀 Running

If you already followed the steps provided in the previous section, thne you are ready to run our operating system simulator, for that run the following line (in the same directory in which the Makefile is).

make run

After that, take a good taste of our simulator!

🔎 Terminal Menu Options

If is this the first time you are running our simulator, then is essential that you read this section. The terminal menu provides three options, being them

1. Process Create

Allow the user to create a process and execute its instructions. Pressing it, opens a window on the center of the window asking for the synthetic program file path.

2. Toggle Resource Acquisition View

It shows/hide the resource acquisition view.

3. Exit

It closes the operating system simulator.

🎬 How can I run my own process?

All of the process executed by the operating system simulato are inputted using a special file called synthetic program file. This file has a specific format that specifies process metadata and the process' instructions that the CPU is going to execute.

📜 Synthetic Program File

The file format is given blow

program name
segment id
process start priority
segment size
semaphore list (each semaphore name separated by a blank space)
<blank line>
sequence of instructions separated by line

Each file specifier is going to be detailed below.

• program name: The process name. There is no need to be unique.
• segment id: The memory segment id that is going to bee allocate to the process the segment identifier MUST BE unique. Otherwise, unexpected behvaior may occur along the simulation.
• process start priority: It indicates in which CPU scheduling queue the process must start, being 0 for highest priority and 1 for lowest priority.
• segment size: It indicates the segment size that is going to be allocated to the process.
• semaphore list: The semaphore list that may be used by the process along the simulation.

An example of such synthetic program file is

process1
50
0
24
s

exec 20
exec 80
P(s)
read 110
print 50
exec 40
write 150
V(s)
exec 30

🔔 Note 1: The synthetic program file given above specifies a process with the name process1, with segment identifier 50, having initial cpu priority set to 0 (highest priority), with segment size set to 24 kbytes and s as the semaphore to be used.

🔔 Note 2: The synthetic program file does not need to have any file extesion or any special name. Therefore, you can give any name you would like to.

❓ Wait a minute, what are the available instructions? Of course, we already know you'd ask that. Please, go to the next subsection where we present the available instructions.

🖥️ Available Instructions

The available instructions listed below are all instructions that can be insert into the sequence of instructions part of the synthetic program file. Therefore, the available instructions are

• exec k: Indicate that the program is going to execute (something) for k units of time.
• read k: Indicate that the program is going to read (something) from the k disk's track.
• write k: Indicate that the progra mis going to write (something) to the k disk's track.
• print t: Indicate that the program is going to print (something) for k units of time.
• P(s): Indicate that the program is going to access the critical region bounded by the semaphore s.
• V(s): Indicate that the program is going to release the critical region bounded by the semaphore s.

After that, have fun!