#include <stdlib.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <time.h>


int main (int argc, char **argv)
{
 struct sockaddr_un address;
 int socket_fd;
 socklen_t address_length;
 unsigned char buffer[512];
 struct timeval now, msg;
 int cnt = 0;
 long *diffs;
 int num_diffs;

 if (argc != 2)
 {
   printf("Usage:\n");
   printf("  unixdomain_server <num_samples_to_collect>\n");
   return 0;
 }
 num_diffs = atoi(argv[1]);
 if (num_diffs <= 0)
 {
   printf("Number of samples to collect must be >0\n");
   return 1;
 }
 fprintf(stderr, "Number of samples to collect: %d\n", num_diffs);
 diffs = malloc(sizeof(*diffs)*num_diffs);

 socket_fd = socket (PF_UNIX, SOCK_DGRAM, 0);
 if (socket_fd < 0)
 {
   printf ("socket() failed\n");
   return 1;
 }

 /* start with a clean address structure */
 memset (&address, 0, sizeof (struct sockaddr_un));

 address.sun_family = AF_UNIX;
 snprintf (address.sun_path, FILENAME_MAX, "./demo_socket");
 unlink (address.sun_path);

 if (bind (socket_fd,
       (struct sockaddr *) &address, sizeof (struct sockaddr_un)) != 0)
 {
   perror ("bind() failed");
   return 1;
 }
 while (read (socket_fd, &msg, sizeof (msg)) >= sizeof (msg))
 {
   long long t1, t2;

   t1 = msg.tv_sec * 1000000;
   t1 += msg.tv_usec;

   gettimeofday (&now, NULL);
   t2 = now.tv_sec * 1000000;
   t2 += now.tv_usec;
   diffs[cnt] = t2 - t1;

   cnt++;
   if (cnt > num_diffs)
   {
     cnt = 0;

     for (int j = 0; j<num_diffs; j++)
       printf("%ld\n", diffs[j]);
     
     return 0;
   }
 }


 close (socket_fd);
 unlink ("./demo_socket");
 
 free(diffs);
 
 return 0;
}