[PATCH] posix: Ignore pshared for semaphores

Joel Sherrill joel at rtems.org
Tue Sep 12 15:07:57 UTC 2017


Sure. I still think it is wrong for an RTEMS application to set it to
shared since there isn't another process to share it with but it seems to
be compliant.

On Sep 12, 2017 10:03 AM, "Gedare Bloom" <gedare at rtems.org> wrote:

> On Tue, Sep 12, 2017 at 10:04 AM, Sebastian Huber
> <sebastian.huber at embedded-brains.de> wrote:
> > On 12/09/17 15:58, Gedare Bloom wrote:
> >
> >> On Tue, Sep 12, 2017 at 1:10 AM, Sebastian Huber
> >> <sebastian.huber at embedded-brains.de> wrote:
> >>>
> >>> On 11/09/17 16:03, Sebastian Huber wrote:
> >>>
> >>>> ----- Joel Sherrill <joel at rtems.org> schrieb:
> >>>>>
> >>>>> On Fri, Sep 8, 2017 at 1:51 PM, Sebastian Huber <
> >>>>> sebastian.huber at embedded-brains.de> wrote:
> >>>>>
> >>>>>> Ok,  but why do you think that this is an error?  We can share the
> >>>>>> synchronization objects among processes.
> >>>>>>
> >>>>> We don't have processes. How do you propose to share between
> >>>>> processes when RTEMS is fundamentally a single process system.
> >>>>
> >>>> Yes, its a single process system. So, it is very easy to support
> sharing
> >>>> between processes. Why should creating a process-shared
> synchronization
> >>>> object fail only because its impossible to create a second process?
> >>>>
> >>> I would like to remove this process-shared error also from the other
> >>> POSIX
> >>> synchronization objects:
> >>>
> >>> https://devel.rtems.org/ticket/3125
> >>> https://devel.rtems.org/ticket/3126
> >>>
> >> Do these process-shared synch objects work properly when used in a
> >> single process on *nix?
> >
> >
> > Yes, this is why I referred to the POSIX mutex documentation:
> >
> > http://pubs.opengroup.org/onlinepubs/9699919799/
> functions/pthread_mutexattr_getpshared.html
> >
> > See also follow up (2.9.9 Synchronization Object Copies and Alternative
> > Mappings):
> >
> > http://pubs.opengroup.org/onlinepubs/9699919799/
> functions/V2_chap02.html#tag_15_09_09
> >
> > Which explicitly mentions semaphores.
> >
> Then I think they are good to support from a compliance standpoint.
>
> >
> > --
> > Sebastian Huber, embedded brains GmbH
> >
> > Address : Dornierstr. 4, D-82178 Puchheim, Germany
> > Phone   : +49 89 189 47 41-16
> > Fax     : +49 89 189 47 41-09
> > E-Mail  : sebastian.huber at embedded-brains.de
> > PGP     : Public key available on request.
> >
> > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> >
>
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