This is the mail archive of the
ecos-discuss@sourceware.org
mailing list for the eCos project.
Re: Thread suspend when scheduler is locked.
Nick Garnett <nickg@calivar.com> writes:
> On 21/06/12 10:00, Sergei Organov wrote:
>> A few clarifications below.
>>
>> Sergei Organov <osv@javad.com> writes:
>>> Hello,
>>>
>>> In the following sequence:
>>>
>>> cyg_scheduler_lock();
>>> cyg_thread_suspend(thread);
>>>
>>> the second call returns immediately that is very surprising. Is it a bug
>>> or fature?
>>
>> 1. 'thread' is the current thread being executed so the suspend call asks
>> thread for suspending itself.
>>
>> 2. cyg_thread_delay(delay) returns immediately no matter what is 'delay'
>> value.
>>
>> 3. On the other hand, waiting on a primitive such as closed semaphore
>> works fine.
>>
>> Looks like a bug to me.
>
>
[...]
> Essentially locking the scheduler yourself is like running in a DSR,
> there is only a limited number of calls it makes sense to use, and their
> effects may be deferred until the scheduler lock returns to zero.
So, there is no way in eCos to just disable _preemption_? I.e.,
(temporarily) switch from preemptive to cooperative multi-threading?
-- Sergei.
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss