#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>
//syncro10.c
int main (void)
{ 	
	int fd,i, pid,size=5*sizeof(float); 
	float* shared_memory; 
	float* p; 
	float* q; 
	sem_t * sem1_id;
	sem_t * sem2_id;

	fd = shm_open("mymem",  O_EXCL |O_RDWR, S_IRUSR | S_IWUSR);
	shared_memory = mmap(NULL ,size,PROT_READ | PROT_WRITE, MAP_SHARED ,fd, 0);
 
 	sem1_id = sem_open("/mysem1", O_CREAT, S_IRUSR | S_IWUSR, 1);
	sem2_id = sem_open("/mysem2", O_CREAT, S_IRUSR | S_IWUSR, 0);

	p=shared_memory;
	sem_post(sem2_id);
	for(i=0;i<10;i++){
		sem_wait(sem1_id); 
		printf("\tB *p = %f\n", (*p)++);
		sem_post(sem1_id);
	}

	shm_unlink("mymem");
}