Most people learn Operating Systems from textbooks. I decided to learn it by building a music streaming service from scratch.

My goal was simple: Create a system where a Python Server streams raw audio to a C Client in real-time, played entirely inside the terminal.

No high-level audio libraries. No frameworks. Just raw bytes, TCP sockets, and the chaos of multithreading.

THE CHALLENGE

Streaming music sounds easy: Download file

Play sound.

But if you do this in a single loop, the UI freezes while downloading. If you try to do both at once without safeguards, you get a Race Condition—the audio glitches, memory corrupts, and the app crashes.

To make this work, I had to engineer a manual Producer-Consumer Architecture.

How It Works under the Hood

The system relies on two distinct threads fighting over a single piece of shared memory.

1. The Producer (Network Thread): Grabs data from the internet.

2. The Consumer (Audio Thread): Feeds that data to the speakers.

The "Ring Buffer" Strategy

I couldn't load the whole song into RAM. Instead, I built a Circular Buffer. Imagine a bucket that holds 1MB of audio. The downloader fills it, and the player empties it. When they reach the end, they wrap back around to the start continuously.

The Traffic Light (Mutexes)

This was the hardest part. If the Downloader tries to write to memory at the exact same nanosecond the Player tries to read from it, the system crashes.

I implemented Mutex Locks, which act like a traffic light. They force one thread to wait while the other touches the memory, ensuring perfectly synchronized, glitch-free audio.

The Tech Stack

• Language: C (Client) & Python (Server)

• Networking: Raw Linux TCP Sockets

• Concurrency: POSIX Threads (pthreads)

• Audio: SDL2 (PCM Output)

What's Next?

This project handles the Operating System layer. In future posts, I plan to expand this into a full distributed system:

1. The Cloud: Moving the server to AWS for real remote streaming.

2. The AI: Building a Neural Network to recommend the next song.

Try It Yourself

I made this open source so you can run it on your Mac or Linux machine.

https://github.com/fairuzanika-11/spotify-terminal-clone.git