Operating Systems - AGH UST 🐧

A comprehensive collection of solutions and projects for the Operating Systems laboratory course, part of the Computer Science curriculum at the Faculty of Computer Science, AGH University of Science and Technology in Kraków.

The projects focus on low-level system programming in UNIX/Linux environments, utilizing the C programming language, strict adherence to the POSIX.1 standard, and robust build automation and testing methodologies.

📂 Repository Structure

Directory	Topic	Description
lab1/	Processes and Identifiers	Process creation (fork), exec functions, child process management (wait), and low-level file descriptors.
lab2/	Signals, IPC & Libraries	Advanced POSIX signal handling (sigaction, sigprocmask), Inter-Process Communication via sigqueue, modularization with Static/Shared/Dynamic libraries (dlopen), and automated CI testing.
lab3/	Pipes and FIFOs (IPC)	Inter-Process Communication using Unnamed Pipes (pipe) and Named Pipes/FIFOs (mkfifo), deadlock prevention, and client-server process synchronization.
lab4/	POSIX Message Queues (IPC)	A "hub and spoke" communication system where multiple independent terminal clients exchange text messages in real-time using /dev/mqueue. Features asynchronous I/O managed by duplicating processes via fork().
lab5/	POSIX Semaphores & Shared Memory	Implementation of the classic Producer-Consumer problem within a multi-process architecture. Leverages POSIX shared memory for zero-copy data transfer and POSIX semaphores for strict access synchronization, complete with a Manager daemon mitigating starvation via an aging algorithm.

⚙️ System Requirements

To successfully compile and run the code in this repository, a POSIX-compliant environment is required (e.g., native Linux distribution, WSL on Windows, or macOS).

Required tools:

• gcc (GNU Compiler Collection).
• make (required for multi-file projects and automated builds).
• bash (for executing the automated test suites and environment cleanup scripts).
• tmux (optional, heavily recommended for simulating multi-process execution in advanced IPC labs).

🚀 Compilation & Execution

Each laboratory folder contains a dedicated README.md file with highly specific compilation instructions, architectural details, and testing methodologies.

Unified Build Process: From Lab 2 onwards, all projects utilize a structured Makefile system. You can generally compile an entire laboratory module by navigating to its directory and executing:

make all

Automated Testing & Cleanup: Advanced labs dealing with persistent kernel resources (like FIFOs, Message Queues, and Shared Memory) include dedicated Bash utilities located in the scripts/ or tests/ directories. These scripts facilitate multi-terminal demonstrations and ensure safe environment cleanup:

# Example: Launching the automated tmux simulation for Lab 5
./scripts/test_tmux.sh

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Created by Wiktor Trybus