theparia/socket-programming

Implementation of a QA forum using socket-programming in a client-server architecture, Operating System Course (Fall 2021), University of Tehran

Socket-Programming

The goal of this project is to implement a question and answer system for different courses similar to Stackoverflow using socket programming and C language system calls.

In this project, we have a central server that can create rooms for asking questions for a number of fields of study. This server always listens on a certain port so that clients can connect to it. People can connect to the server as a client and give the server the number or name of the field they want to enter and ask questions. Note that the server is a process and each client is a separate process.

The capacity of each room is 3 people. As soon as the number of people in a room reaches the quorum, the server announces a new port to the people of that room so that they can broadcast messages on that port. Each client's connection with the server is of TCP type, and after a room is filled, the client's connection with each other will be of UDP broadcast type.

Each client has one minute to answer a question. To implement the timer, we use SIGALRM signal and alarm system call.

Also, in order to synchronize the server and the client without being blocked, we use the select system call. This system call can manage communication and I/O without blocking.