Notes

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<pthread.h>
#include<semaphore.h>

sem_t s1, s2, s3;

void *singer1(void *arg){
sem_wait(&s1);
printf("Forever trusting who we aren");
printf("And nothing else mattersn");
sem_post(&s2);
sem_wait(&s1);
printf("All these words I don't just sayn");
printf("And nothing else mattersn");
sem_post(&s2);
sem_wait(&s1);
printf("Open mind for a different viewn");
printf("And nothing else mattersn");
sem_post(&s3);
sem_wait(&s2);
return NULL;
}

void *singer2(void *args){
printf("So close, no matter how farn");
printf("Couldn't be much more from heartn");
sem_post(&s1);
sem_wait(&s2);
printf("Never opened myself this wayn");
printf("Life is ours, we live it our wayn");
sem_post(&s1);
sem_wait(&s2);
printf("Trust I seek and I find in youn");
printf("Every day for us something newn");
sem_post(&s1);
sem_wait(&s2);
return NULL;
}

void *chorus(void *args){
sem_wait(&s3);
printf("Never cared for what they don");
printf("Never cared for what they known");
printf("But I known");
return NULL;
}

int main(){
pthread_t tid1;
pthread_t tid2;
pthread_t tid3;

sem_init(&s1, 0, 0);
sem_init(&s2, 0, 0);
sem_init(&s3, 0, 0);

pthread_create(&tid1, NULL, singer1, NULL);
pthread_create(&tid2, NULL, singer2, NULL);
pthread_create(&tid3, NULL, chorus, NULL);

pthread_join(tid1, NULL);
pthread_join(tid2, NULL);
pthread_join(tid3,NULL);

sem_destroy(&s1);
sem_destroy(&s2);
sem_destroy(&s3);



}