AW: question about posix timer expiration

Gabriel.Moyano at Gabriel.Moyano at
Fri May 21 09:44:33 UTC 2021

Hi Chris,

Did you compile ptpd with kqueue only? I’ve tried with posix timer, which are implemented in rtems, but it seems that the handler with siginfo_t is not called correctly. I’ve managed to get it working using a workaround but I’ll continue with kqueue, thx!.


Von: Chris Johns <chrisj at>
Gesendet: Mittwoch, 19. Mai 2021 10:30
An: Moyano Heredia, Victor Gabriel <Gabriel.Moyano at>
Cc: devel at
Betreff: Re: question about posix timer expiration

On 18 May 2021, at 10:02 pm, Gabriel.Moyano at<mailto:Gabriel.Moyano at> wrote:

From further investigation I’ve found that when a timer expires, _POSIX_Timer_TSR() is called and this uses pthread_kill() to send a signal. Shouldn’t ptimer->inf.sigev_value be used here in order to create a siginfo_t object with the right value?

Did anyone have to deal with this while using posix timers?


Von: devel <devel-bounces at<mailto:devel-bounces at>> Im Auftrag von Gabriel.Moyano at<mailto:Gabriel.Moyano at>
Gesendet: Mittwoch, 12. Mai 2021 14:37
An: devel at<mailto:devel at>
Betreff: question about posix timer expiration

Hello everyone,

Currently I am trying to get running ptpd on rtems (following the Chris’ work, thx btw).

Ptpd uses posix timers and when a timer expires a handler with this signature void(int sig, siginfo_t *info, void *ucontext) is called.

Is this on libbsd? If it is I would have expected kqueue being used so I am not sure where this is happening.


 Unfortunately (*info) doesn’t have the right values, eg. info->si_code should be SI_TIMER but it is SI_USER and also info->si_signo should be the same as sig but it’s not.

Diving into the code I’ve found where the handler is called (also where *info is created). This is done in the function _POSIX_signals_Check_signal() in the file psignalunblockthread.c. It doesn’t seems that info is updated with the values (I guess) should take from object ptimer, which was created by create_timer().

My question is: is this handler fully supported? Or maybe I’m missing something else.

Thanks in advance,


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Gabriel Moyano | Research Scientist in Onboard Software Systems group
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