score: Add thread priority to scheduler nodes

The thread priority is manifest in two independent areas.  One area is
the user visible thread priority along with a potential thread queue.
The other is the scheduler.  Currently, a thread priority update via
_Thread_Change_priority() first updates the user visble thread priority
and the thread queue, then the scheduler is notified if necessary.  The
priority is passed to the scheduler via a local variable.  A generation
counter ensures that the scheduler discards out-of-date priorities.

This use of a local variable ties the update in these two areas close
together.  For later enhancements and the OMIP locking protocol
implementation we need more flexibility.  Add a thread priority
information block to Scheduler_Node and synchronize priority value
updates via a sequence lock on SMP configurations.

Update #2556.

1 files changed, 5 insertions, 0 deletions

diff --git a/cpukit/score/include/rtems/score/threadimpl.h b/cpukit/score/include/rtems/score/threadimpl.h
index 164773ac2f..6bb78158e3 100644
--- a/cpukit/score/include/rtems/score/threadimpl.h
+++ b/cpukit/score/include/rtems/score/threadimpl.h
@@ -253,6 +253,11 @@ void _Thread_Cancel(
  */
 void _Thread_Close( Thread_Control *the_thread, Thread_Control *executing );
 
+RTEMS_INLINE_ROUTINE bool _Thread_Is_ready( const Thread_Control *the_thread )
+{
+  return _States_Is_ready( the_thread->current_state );
+}
+
 States_Control _Thread_Clear_state_locked(
   Thread_Control *the_thread,
   States_Control  state