🧠 Philosophers – 42 Project

This project is a simulation of the classic Dining Philosophers Problem, implemented in C using POSIX threads (pthreads).
It’s part of the common core at École 42 and focuses on multithreading, synchronization, and preventing race conditions and deadlocks.

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🧩 Project Goals

• Understand and use threads (via pthreads)
• Manage shared resources (forks) using mutexes
• Handle concurrency issues like deadlocks and starvation
• Simulate time, routines, and clean program termination

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🍽️ The Dining Philosophers Problem

Five philosophers sit at a table, each alternating between thinking, eating, and sleeping.
Each needs two forks (one on each side) to eat. But there are only five forks...

The challenge: allow all philosophers to eat without starving, deadlocking, or crashing the program.

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🛠 Implementation Details

• Language: C
• Concurrency: POSIX Threads
• Synchronization: Mutexes
• Precise timing: usleep, gettimeofday, time diff calculation
• Input parsing & error handling

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📦 Program Structure

philo/
├── philo.c              # Main program logic
├── utils.c              # Time & printing helpers
├── init.c               # Initialization of threads, mutexes, and data
├── routine.c            # Philosopher behavior loop
├── philo.h              # Headers and data structures
├── Makefile             # Compilation rules

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🧪 How to Compile & Run

✅ Compile:

make

🚀 Run:

./philo number_of_philosophers time_to_die time_to_eat time_to_sleep [number_of_times_each_philosopher_must_eat]

🧾 Example:

./philo 5 800 200 200

This runs the simulation with:

• 5 philosophers
• Each dies if they don’t eat within 800ms
• Eating takes 200ms
• Sleeping takes 200ms

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🧠 Bonus (If applicable)

If you did the philo_bonus version:

• Uses processes and semaphores instead of threads/mutexes
• Shows mastery of IPC (Interprocess Communication)

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🧯 Error Handling

Handles:

• Invalid argument count
• Non-numeric input
• Overflow/underflow
• System call failures

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📚 Useful References

• Dining Philosophers – Wikipedia
• man pthreads
• [42 Docs & peer reviews]

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👤 Author

42 Login: hsilverb
Contact: LinkedIn

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📝 License

This project was developed as part of the 42 School curriculum.
For educational and personal use only.