Strong APA Scheduler : First Draft

Gedare Bloom gedare at
Wed Jul 29 04:55:31 UTC 2020

On Tue, Jul 28, 2020 at 10:49 PM Sebastian Huber
<sebastian.huber at> wrote:
> On 27/07/2020 09:44, Richi Dubey wrote:
> >     Which compiler error do you get? Maybe there is a cyclic dependency.
> >
> > I assumed that the schedulersmp.h already includes the percpu.h which
> > was not the case. My bad. The error has been removed.
> >
> > I assumed this because schedulersmp.h uses
> > <> Per_CPU_Control
> > and does not show any compilation error, so it should have the
> > percpu.h included in one of its included header files right? If it
> > has, why did my schedulerstrongapa.h that had the schedulersmp.h
> > included give the following error:
> >
> > /home/richi/quick-start/src/rtems/cpukit/include/rtems/score/schedulerstrongapa.h:102:3:
> > error: unknown type name 'Per_CPU_Control'
> >    Per_CPU_Control cpu;
> We have two kinds of header files in the implementation of RTEMS.
> Firstly, some header files are included in API header files and are thus
> visible to application code. These header files should only define
> things which are strictly necessary for applications. Secondly, some
> header files are only included in implementation source files.
> The purpose of <rtems/score/schedulerstrongapa.h> is to enable the
> application to configure this scheduler and nothing more. Please note
> that <rtems/score/scheduler.h> uses
> struct Per_CPU_Control  *cpu
> and NOT
> Per_CPU_Control  *cpu
> You can use struct Per_CPU_Control with a forward declaration. This
> enables the use of this header file without having to include
> <rtems/score/percpu.h>. You should not include <rtems/score/percpu.h> in
> <rtems/score/schedulerstrongapa.h> and remove everything from this file
> which is not necessary to configure the scheduler.

I provided a (detailed) review on your PR. One of my comments is
related to creating a schedulerstrongapaimpl.h header file. That is
where you should include extra headers, to avoid "leaking" internal
details to the application.

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