Rui Ribeiro
2128325237
- Added exercices: - Added process basics. - Added semaphores basics. - Added process communication - Added process termination - Added process_philosophers - Renamed and reordered philosophers_bonus
38 lines
1.8 KiB
Plaintext
38 lines
1.8 KiB
Plaintext
Assignment name: process_philosophers
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Expected files: process_philosophers.c
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Allowed functions: memset, printf, malloc, free, write, fork, kill, exit,
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pthread_create, pthread_detach, pthread_join, waitpid,
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sem_open, sem_close, sem_post, sem_wait, sem_unlink,
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usleep, gettimeofday
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-------------------------------------------------------------------------------
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Implement a simplified philosophers problem using processes and semaphores:
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1. Create N child processes (one per philosopher)
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2. Use a semaphore initialized to N to represent the forks in the middle of the table
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3. Each philosopher process:
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- Waits to acquire 2 forks (sem_wait called twice)
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- Eats for a specified time
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- Releases 2 forks (sem_post called twice)
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- Sleeps for a specified time
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- Repeats for a specified number of meals
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4. Each philosopher has a monitoring thread that checks if it's starving
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5. Parent process waits for all children; if any dies, kills all others
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Arguments: `number_of_philosophers time_to_die time_to_eat time_to_sleep number_of_meals`
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Output format:
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- "[timestamp] Philosopher <id>: has taken a fork"
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- "[timestamp] Philosopher <id>: is eating"
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- "[timestamp] Philosopher <id>: is sleeping"
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- "[timestamp] Philosopher <id>: is thinking"
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- "[timestamp] Philosopher <id>: died"
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Usage: `./process_philosophers 5 800 200 200 7`
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Hint: This combines everything: processes, semaphores, monitoring, and termination.
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Each philosopher is a process with its own monitoring thread (just like bonus).
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The semaphore represents all forks in the middle (different from mandatory version).
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Use pthread_create within each child process for the death monitor thread.
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Parent monitors children with waitpid(WNOHANG) and kills all if one dies.
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This is almost the complete philosophers_bonus, but simplified.
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