Possible error in coremutex.c

[Manuel Coutinho]

Hi

 

Was seeing the differences between using and not using
__RTEMS_STRICT_ORDER_MUTEX__ and stumbled in what (I) find to be a possible
bug.

 

The coremutex.c has the following:

 

  if ( initial_lock == CORE_MUTEX_LOCKED ) {

    the_mutex->nest_count = 1;

    the_mutex->holder     = _Thread_Executing;

    the_mutex->holder_id  = _Thread_Executing->Object.id;

    if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||

         _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) )

      

#ifdef __RTEMS_STRICT_ORDER_MUTEX__

       _Chain_Prepend_unprotected( &_Thread_Executing->lock_mutex,

                                   &the_mutex->queue.lock_queue );

       the_mutex->queue.priority_before =
_Thread_Executing->current_priority;

#endif

 

      _Thread_Executing->resource_count++;

  } else {

    the_mutex->nest_count = 0;

    the_mutex->holder     = NULL;

    the_mutex->holder_id  = 0;

  }

 

 

 

In the older RTEMS versions, the 

 

_Thread_Executing->resource_count++; 

 

operation was inside the "if"

 

if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||

         _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) )

 

and now, if the strict order is defined, it is not.

 

 

 

My guess is that the 2 operations of the strict order mutex and the
resource_count++ operation must be inside the "if", because it makes sense
to do those operations with priority ceiling or inherence protocols.

Like:

 

  if ( initial_lock == CORE_MUTEX_LOCKED ) {

    the_mutex->nest_count = 1;

    the_mutex->holder     = _Thread_Executing;

    the_mutex->holder_id  = _Thread_Executing->Object.id;

    if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||

         _CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ){
<<<---- added bracket

      

#ifdef __RTEMS_STRICT_ORDER_MUTEX__

         _Chain_Prepend_unprotected( &_Thread_Executing->lock_mutex,

                                   &the_mutex->queue.lock_queue );

         the_mutex->queue.priority_before =
_Thread_Executing->current_priority;

#endif

 

        _Thread_Executing->resource_count++;

      }  <<<---- added bracket

  } else {

    the_mutex->nest_count = 0;

    the_mutex->holder     = NULL;

    the_mutex->holder_id  = 0;

  }

 

 

That is, add the missing brackets.

 

Should the brackets be added?

 

Kind regards

Manuel Coutinho

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/users/attachments/20090515/65585f85/attachment.html>