feat: Implement Lab 6 - Real-Time Mobile Robot System Simulation

[Veexeq]

Description

This PR introduces the complete solution for Lab 6 (Operating Systems). It implements a highly concurrent, multi-threaded simulation of a mobile robot's internal operating system, scaling from basic synchronization to Real-Time Operating System (RTOS) concepts.

Key Changes & Features

The project was developed iteratively across three levels, adhering strictly to the DRY (Don't Repeat Yourself) principle using a shared common library.

• Architecture & Build System:

  • Implemented a structured project layout (src/, include/, obj/, bin/, output/, scripts/).
  • Added a dynamic Makefile for compiling specific simulation levels (make level1, make level2, make level3).
  • Added .gitignore to keep the repository clean from binaries and generated logs.

• Level 1 (program1.c): Basic Synchronization

  • Created 6 independent threads (Cameras, Synchronizer, Image Writer, Robot State, Logger) running at different frequencies (10Hz - 100Hz).
  • Used pthread_mutex_t and sem_t to prevent race conditions.

• Level 2 (program2.c): Advanced IPC & Graceful Shutdown

  • Implemented a 64-element Circular Buffer (FIFO) for lossless frame handling.
  • Replaced busy-waiting with Condition Variables (pthread_cond_t) for microsecond-level thread wake-ups.
  • Added robust SIGINT (CTRL+C) interception for graceful shutdown and memory cleanup.

• Level 3 (program3.c): RTOS & Lock-Free Monitoring

  • Applied Real-Time Scheduling (SCHED_FIFO) granting hardware-level priority to the robot state and camera threads.
  • Introduced a Watchdog Thread to monitor deadline misses.
  • Replaced standard mutex-based counters with C11 Atomics (stdatomic.h) for lock-free performance monitoring.

• Automated Testing:

  • Added bash scripts (scripts/run_levelX.sh) to automatically compile, run, simulate SIGINT, and analyze outputs.

How to Test

1. Pull the branch and navigate to the root directory.
2. Ensure scripts have execution permissions: chmod +x scripts/*.sh
3. Run the automated tests:

   ./scripts/run_level1.sh
   ./scripts/run_level2.sh
   sudo ./scripts/run_level3.sh # 'sudo' is required to grant SCHED_FIFO real-time priorities

4. Verify that the output/ directory contains simulated .jpg files and the robot_state.txt log without memory leaks or race conditions.

Checklist:

• Code compiles without warnings (-Wall -Wextra)
• No busy-waiting utilized
• Graceful shutdown handles pthread_join and resource destruction
• README.md updated with project documentation