On 5/21/2014 10:35 AM, Gedare Bloom wrote:
> On Wed, May 21, 2014 at 11:08 AM, Sebastian Huber
> <sebastian.hu...@embedded-brains.de> wrote:
>> On 2014-05-21 17:01, Gedare Bloom wrote:
>>>> if ( initially_locked ) {
>>>>> the_mutex->nest_count = 1;
>>>>> the_mutex->holder = executing;
>>>>> if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||
>>>>> _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ) {
>>>>>
>>>>> if ( executing->current_priority <
>>>>> the_mutex->Attributes.priority_ceiling )
>>>>> return CORE_MUTEX_STATUS_CEILING_VIOLATED;
>>> Looks like this check ensures the executing thread has got priority at
>>> least at the priority_ceiling. If it does not, the mutex is not
>>> initialized.
>>
>> Yes, this is the error case. In the good case the priority is not changed
>> to the ceiling priority like for a normal rtems_semaphore_obtain() (see
>> _CORE_mutex_Seize_interrupt_trylock_body()).
>>
> Ah. Then I think your suspicion is correct. Probably the executing
> thread should be given the priority_ceiling, otherwise there can be
> some priority inversion while the initial lock is held.
Good catch. Create a simple test case and verify it is broken.
This should have a PR with the test case and fix.
>> --
>> Sebastian Huber, embedded brains GmbH
>>
>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>> Phone : +49 89 189 47 41-16
>> Fax : +49 89 189 47 41-09
>> E-Mail : sebastian.hu...@embedded-brains.de
>> PGP : Public key available on request.
>>
>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
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joel.sherr...@oarcorp.com On-Line Applications Research
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