[Bug 1817] Variable _Thread_Heir is not protected against interrupts

[bugzilla-daemon at rtems.org]

https://www.rtems.org/bugzilla/show_bug.cgi?id=1817

--- Comment #8 from Helder Silva <silvah15 at gmail.com> 2011-09-22 08:48:19 CDT ---
Yes, you are right, if you consider *a=b as atomic instruction, the 
_ISR_Disable
*a = b;
_ISR_Enable
… is unnecessary. Please just keep in mind the final assembly code, which is
not atomic.

In the patch there is one case more or less similar with the above:
+  _ISR_Disable(level);
   _Thread_Heir = (Thread_Control *) sched_info->thread;
+  _ISR_Enable(level);

The others are always more complex situations like for example:
+  _ISR_Disable(level);
   if ( _Scheduler_Is_priority_higher_than( the_thread->current_priority,
        _Thread_Heir->current_priority)) {
     _Thread_Heir = the_thread;
@@ -73,4 +76,5 @@
          the_thread->current_priority == 0 )
       _Thread_Dispatch_necessary = true;
   }
+  _ISR_Enable(level);

And
+  _ISR_Disable(level);
   _Thread_Heir = (Thread_Control *) _Chain_First(
     (Chain_Control *) _Scheduler.information
   );
+ _ISR_Enable(level);
In my idea these should be maintained.
The last update should be also removed since it is the initialization of the
Thread Initialization Handler.

-- 
Configure bugmail: https://www.rtems.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching all bug changes.