timerfd_create fails with CLOCK_BOOTTIME

[jbeich]

FreeBSD >= 13.1 added CLOCK_BOOTTIME but it appears to work differently from what consumers expect.

$ pkg install git meson pkgconf libepoll-shim json-glib
$ git clone https://gitlab.gnome.org/guidog/gmobile.git
$ git -C gmobile fetch origin merge-requests/11/head
$ git -C gmobile merge FETCH_HEAD
$ meson setup gmobile_build gmobile
$ meson compile -C gmobile_build
$ meson test -C gmobile_build timeout
[...]
1/1 timeout        TIMEOUT        30.02s   killed by signal 15 SIGTERM

$ gmobile_build/examples/gm-timeout -s 1
** Message: 19:01:38.768: Arming timer with 1 seconds
** Message: 19:01:38.769: Now 19:01:38
^T
load: 0.08  cmd: gm-timeout 9389 [select] 40.63r 0.00u 0.00s 0% 6152k

[jbeich]

Neither feedbackd nor phoc use gm_timeout_add_seconds_*, so it's not critical to get right in ports/ because gmobile doesn't support system-wide installation.

[valpackett]

hmm:

epoll-shim/src/timerfd.c

Lines 121 to 123 in 702e845

	if (clockid != CLOCK_MONOTONIC && clockid != CLOCK_REALTIME) {
	return EINVAL;
	}

does that consumer check the returned error?

[jbeich]

From gmobile/src/gm-timeout.c:

static GSource *
gm_timeout_source_once_new (gulong timeout_ms)
{
...
  timer->fd = timerfd_create (CLOCK_BOOTTIME, 0);
  if (timer->fd == -1)
    return (GSource*)timer;
...
static gboolean
gm_timeout_once_prepare (GSource *source, gint *timeout)
{
...
  if (timer->fd == -1)
    return FALSE;

[jbeich]

Native timerfd on NetBSD and FreeBSD is also limited to CLOCK_REALTIME and CLOCK_MONOTONIC.

[jbeich]

Looking at illumos/illumos-gate@6a72db4a7fa1 I can't find what it does with unsupported clocks.