c program for dining philosophers problem semaphore struct code example

Example: dining philosophers problem solution using semaphores in c

#include<stdio.h>#include<stdlib.h>#include<pthread.h>#include<semaphore.h>#include<unistd.h>sem_t room;sem_t chopstick[5];void * philosopher(void *);void eat(int);int main(){	int i,a[5];	pthread_t tid[5];		sem_init(&room,0,4);		for(i=0;i<5;i++)		sem_init(&chopstick[i],0,1);			for(i=0;i<5;i++){		a[i]=i;		pthread_create(&tid[i],NULL,philosopher,(void *)&a[i]);	}	for(i=0;i<5;i++)		pthread_join(tid[i],NULL);}void * philosopher(void * num){	int phil=*(int *)num;	sem_wait(&room);	printf("\nPhilosopher %d has entered room",phil);	sem_wait(&chopstick[phil]);	sem_wait(&chopstick[(phil+1)%5]);	eat(phil);	sleep(2);	printf("\nPhilosopher %d has finished eating",phil);	sem_post(&chopstick[(phil+1)%5]);	sem_post(&chopstick[phil]);	sem_post(&room);}void eat(int phil){	printf("\nPhilosopher %d is eating",phil);}/* BY - ANUSHKA DESHPANDE */