[ECOS] Re: how to implement EDF scheduling in eCos

[Nodir Kodirov <nodir dot qodirov at gmail dot com>]

Hello all!

I started EDF implementation to?eCos. I did basic works for it, such
as adding scheduler to eCosConfigTool, extending thread's structure
with properties needed for EDF (deadline, period and wcet), and
creating EDF scheduler files (edf.hxx and edf.cxx) in kernel folder
structure. I was able to build eCos library target from modified eCos
repository. But, I have problem with my application.

When I "make" my application (which creates eCos threads with extended
deadline, period and wcet) it gives me compile errors. Here is?excerpt
of common error and full error and my application code you can find in
attached files.

> /my_dev/ecos_edf_rep/ecos-3.0/packages/kernel/v3_0/src/common/thread.cxx:7
> 68: undefined reference to?`Cyg_Scheduler_Implementation::rem_thread?(Cyg_Thread*)'
> /my_dev/ecos_edf/install/lib/libtarget.a?(kernel_thread.o): In function `Cyg_Thread':
> /my_dev/ecos_edf_rep/ecos-3.0/packages/kernel/v3_0/src/common/thread.cxx:2
> 19: undefined reference to?`Cyg_Scheduler_Implementation::register_thread?(Cyg_Thread*)'
> ...

Last two days I am?struggling with them, if you have some idea to fix
it, please let me know.
Regards,
Nodir.

2010/1/8 Nodir Kodirov <nodir.qodirov@gmail.com>
>
> Hello all,
>
> I am going to implement EDF (Earliest Deadline First) scheduling
> algorithm in eCos. I had a survey of mailing list and I found very
> useful tips?here
> http://sourceware.org/ml/ecos-discuss/2005-10/msg00209.html and here
> http://sourceware.org/ml/ecos-discuss/2005-11/msg00059.html.?However,
> I did not find any evidence about successful completion of
> implementation.
>
> My approach is adding two more additional fields to thread's
> properties. Those are:
> cyg_tick_count_t wcet /*worst case execution time*/
> cyg_tick_count_t deadline /* absolute deadline thread to be finished */
>
> Currently, I don't need TCP/IP and I don't use POSIX. It has been 5
> years, since these question was aroused. So, my question to those
> people who has already tried implementation is: do you see any errors
> in my approach?
>
> Regards,
> Nodir.

Attachment: compile error.txt
Description: Text document

Attachment: twothreads.c
Description: Binary data

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