#include <semaphore.h>
#include <signal.h>
#include <unistd.h>

static int failed;
static pid_t pid;
static uid_t uid;
static sem_t sem;
static int is_kill;

#define THESIG SIGRTMIN

static void
sh (int sig, siginfo_t *si, void *ctx)
{
  if (sig != si->si_signo)
    {
      printf ("sig != si->si_signo: %d vs %d\n", sig, (int) si->si_signo);
      failed = 1;
    }
  if (si->si_code != is_kill ? SI_USER : SI_QUEUE)
    {
      printf ("si->si_code wrong: %d\n", si->si_code);
      failed = 1;
    }
  if (si->si_pid != pid)
    {
      printf ("si->si_pid wrong: %d vs %d\n", (int) si->si_pid, (int) pid);
      failed = 1;
    }
  if (si->si_uid != uid)
    {
      printf ("si->si_uid wrong: %d vs %d\n", (int) si->si_uid, (int) uid);
      failed = 1;
    }
  sem_post (&sem);
}


static void *
tf (void *arg)
{
  puts ("trying kill");
  is_kill = 1;
  kill (pid, THESIG);
  sem_wait (&sem);

  puts ("trying sigqueue");
  sigval_t sv;
  sv.sival_int = 42;
  is_kill = 0;
  sigqueue (pid, THESIG, sv);
  sem_wait (&sem);
}


int
main (void)
{
  pid = getpid ();
  uid = getuid ();

  struct sigaction sa;
  sa.sa_sigaction = sh;
  sa.sa_flags = SA_SIGINFO;
  sigemptyset (&sa.sa_mask);
  sigaction (THESIG, &sa, NULL);

  sem_init (&sem, 0, 0);

  pthread_t th;
  puts ("starting 1st thread");
  pthread_create (&th, NULL, tf, NULL);
  pthread_join (th, NULL);
  puts ("starting 2nd thread");
  pthread_create (&th, NULL, tf, NULL);
  pthread_join (th, NULL);

  return failed;
}