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Re: Re: Réf. : Twothreads.c without cyg_thread_delay


I have the same problems for eCos working on Leon2: I have no context switches if the process is not suspended....
Which interrupt whoudl I check? Thanks,

Michele

Gary Thomas wrote:
David Luca wrote:
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?

Of course!


I just tried it.  I changed the thread function to simply
put a unique value into the platform LEDs - no delays:

/* this is a simple program which runs in a thread */
void simple_program(cyg_addrword_t data)
{
  int message = (int) data;

  printf("Beginning execution; thread data is %d\n", message);
  while (true) {
      HAL_SET_LEDS(1<<data);
  }
}

Using the default scheduler (MLQUEUE), I changed the timeslice count
to be something that I can see (500 ticks = 5 seconds).  Running this,
I see first one value in the LEDS then a different value 5 seconds later.
The pattern repeats, ad nauseum.

Timeslicing definitely works, as do eCos' other scheduling mechanisms.

I believe that you're having trouble with your platform - interrupts aren't
working for your system clock.  Have you tried running the various kernel
tests?


--- 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).


LPZ

-----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





Hello,
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
off.
Thank you in advance,
David Luca.




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