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

[Gary Thomas]

Michele Portolan wrote:
> 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,

   CYGNUM_HAL_INTERRUPT_RTC

> 
> 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.
>>
>>
> 
> 


-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

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