#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>        /* mnemonici in mode */
#include <fcntl.h>           /* mnemonici in oflag */
#include <semaphore.h>


int main (void)
{ 	
	int fd, i, pid, size=sizeof(int);
	int* buffer;
	sem_t* mutex1; 
	sem_t* barbiere;
	sem_t* cliente; 
	int* nr_clienti;
 
	mutex1=sem_open("mutex1",  O_EXCL, S_IRUSR | S_IWUSR, 1);	/* attacco i semafori */
	barbiere=sem_open("barb",  O_EXCL, S_IRUSR | S_IWUSR, 1);
	cliente=sem_open("clien",  O_EXCL, S_IRUSR | S_IWUSR, 0);

	fd = shm_open("mymem1",  O_EXCL |O_RDWR, S_IRUSR | S_IWUSR);    /* attacco la SHM */
 	ftruncate(fd,size);
 	buffer = mmap(NULL ,size,PROT_READ | PROT_WRITE, MAP_SHARED ,fd, 0);

	nr_clienti=buffer;
	
	printf("cliente: entro dal barbiere\n");
	sem_post(cliente);
	sem_wait(mutex1);
	*nr_clienti=*nr_clienti+1; 	
	sem_post(mutex1);
	sem_wait(barbiere);	
	sleep(1);
	printf("cliente %d: esco dal barbiere\n", *nr_clienti);
}