Function poll

compat/poll/poll.c:306–610

#endif /* !MinGW */

int
poll (struct pollfd *pfd, nfds_t nfd, int timeout)
{
#ifndef WIN32_NATIVE
  fd_set rfds, wfds, efds;
  struct timeval tv;
  struct timeval *ptv;
  int maxfd, rc;
  nfds_t i;

# ifdef _SC_OPEN_MAX
  static int sc_open_max = -1;

  if (nfd < 0
      || (nfd > sc_open_max
	  && (sc_open_max != -1
	      || nfd > (sc_open_max = sysconf (_SC_OPEN_MAX)))))
    {
      errno = EINVAL;
      return -1;
    }
# else /* !_SC_OPEN_MAX */
#  ifdef OPEN_MAX
  if (nfd < 0 || nfd > OPEN_MAX)
    {
      errno = EINVAL;
      return -1;
    }
#  endif /* OPEN_MAX -- else, no check is needed */
# endif /* !_SC_OPEN_MAX */

  /* EFAULT is not necessary to implement, but let's do it in the
     simplest case. */
  if (!pfd && nfd)
    {
      errno = EFAULT;
      return -1;
    }

  /* convert timeout number into a timeval structure */
  if (timeout == 0)
    {
      ptv = &tv;
      ptv->tv_sec = 0;
      ptv->tv_usec = 0;
    }
  else if (timeout > 0)
    {
      ptv = &tv;
      ptv->tv_sec = timeout / 1000;
      ptv->tv_usec = (timeout % 1000) * 1000;
    }
  else if (timeout == INFTIM)
    /* wait forever */
    ptv = NULL;
  else
    {
      errno = EINVAL;