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counter ensures that the scheduler discards out-of-date priorities.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, 3 insertions, 2 deletions

diff --git a/cpukit/score/src/scheduleredfnodeinit.c b/cpukit/score/src/scheduleredfnodeinit.c
index ec6d9bae7c..6005fa0538 100644
--- a/cpukit/score/src/scheduleredfnodeinit.c
+++ b/cpukit/score/src/scheduleredfnodeinit.c
@@ -22,14 +22,15 @@
 
 void _Scheduler_EDF_Node_initialize(
   const Scheduler_Control *scheduler,
-  Thread_Control          *the_thread
+  Thread_Control          *the_thread,
+  Priority_Control         priority
 )
 {
   Scheduler_EDF_Node *node = _Scheduler_EDF_Thread_get_node( the_thread );
 
   (void) scheduler;
 
-  _Scheduler_Node_do_initialize( &node->Base, the_thread );
+  _Scheduler_Node_do_initialize( &node->Base, the_thread, priority );
 
   node->thread = the_thread;
 }