[RTEMS Project] #4690: CLOCK_REALTIME thread queue no updated as part of clock_settime call

[RTEMS trac]

#4690: CLOCK_REALTIME thread queue no updated as part of clock_settime call
--------------------------+--------------------
  Reporter:  Chris Johns  |      Owner:  (none)
      Type:  defect       |     Status:  new
  Priority:  normal       |  Milestone:  6.1
 Component:  score        |    Version:  6
  Severity:  normal       |   Keywords:
Blocked By:               |   Blocking:
--------------------------+--------------------
 Setting the `CLOCK_REALTIME` clock using `clock_settime(CLOCK_REALTIME, ,
 )` clock does not update thread relative period entries on the watchdog
 timer queue.

 A system's stability is effected if a user calls `clock_settime` on the
 `CLOCK_REALTIME` clock. The watchdog's REALTIME clock queue is references
 against the realtime clock and movement of the time means

 The effected parts are:

 1. User C code that calls `nanosleep`, `usleep`, `sleep` or
 `clock_nanosleep(CLOCK_REALTIME, , )`.
 2. User C++ code that uses `std::this_thread::sleep_for()` as GCC uses the
 `nanosleep()` call.
 3. LibBSD uses `CLOCK_REALTIME`.

 The
 [https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanosleep.html
 nanosleep] call is explained in more detail in the
 [https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_nanosleep.html
 clock_nanosleep] rational. The `nanosleep` clock must be `CLOCK_REALTIME`.
 The
 [https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_settime.html
 clock_settime] standard says:

  Setting the value of the CLOCK_REALTIME clock via clock_settime() shall
 have no effect on threads that are blocked waiting for a relative time
 service based upon this clock, including the nanosleep() function; nor on
 the expiration of relative timers based upon this clock. Consequently,
 these time services shall expire when the requested relative interval
 elapses, independently of the new or old value of the clock.

--
Ticket URL: <http://devel.rtems.org/ticket/4690>
RTEMS Project <http://www.rtems.org/>
RTEMS Project