static AutoCloseable dm_timerWithFieldSecondsInterval_startNow(S field, Runnable r) {
  class DaTimer implements Runnable {
    new Flag cancel;
    DynModule m = dm_current_mandatory();
    Long lastFired = null;
    
    run {
      while (licensed() && !cancel.isUp()) {
        if (lastFired != null) {
          long interval = toMS(toDouble(get(m, field)));
          if (interval <= 0) fail("Need delay > 0: " + field + " in " + m);
          sleepUntilSysTime(lastFired+interval);
        }
        lastFired = sysNow();
        if (licensed() && !cancel.isUp())
          callF(r);
      }
    }
  }
  new DaTimer t;
  startThread(t);
  ret dm_ownResource(flagAsAutoCloseable(t.cancel));
}