[ECOS] Re: Réf. : Twothreads.c without cyg_thread_delay

David Luca davidluca3000@yahoo.com
Fri Nov 24 16:08:00 GMT 2006

Timeslicing is enabled by default in eCos kernel.
This is what I'm interested, to see two threads of
same priority working. Using cyg_thread_delay doesn't
mean much advantage over infinite loops because the
tasks can be very long in working time before it
reaches cyg_thread_delay. Its just a cooperative
multitasking. Timeslicing is the reason I must use
RTOS. If timeslicing is not working, then eCos is not
a true RTOS. Anyone tested timeslicing?

--- Jean-Marc.Lopez@faiveleytransport.com wrote:

Hi David.

Excuse me but with your explanations, it's looks like
you did not manage properly  the threads priorities. 


It's just  a problem of Real time OS. 


If your 2 threads had the same priority, and Thread_1
never "give the hand" to the kernel, the Thread 2 will
never run. …Except if you configure the timeSlicing
option in your kernel. ( never done at this moment). 


By using a cyg_thread_delay function, we said to the 
kernel to stop the current Thread ( Thread 1 ) and to
run the Thread 2 ( or the thread who have the higtest
priority after the Thread1). 


By setting the timeslicing option, the kernel will
commute between the 2 threads every x ms ( depending
of your kernel configuration) even if threads have the
same priority. (but not experimented yet). 



-----David Luca <davidluca3000@yahoo.com> a écrit :

Pour : ecos-devel <ecos-devel@sourceware.org>,
ecos-discuss <ecos-discuss@sourceware.org>
De : David Luca <davidluca3000@yahoo.com>
Date : 24/11/2006 14:29
Objet : Twothreads.c without cyg_thread_delay

Today I started twothreads.c application, but I
replaced printf(not working yet on my platform) with
leds. My question is, without the cyg_thread_delay, is
it possible to run concurrently the two threads?
Because if I comment this function, only one task is
running, I can see that only one led is turn on and
Thank you in advance,
David Luca.


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