score: Rework thread priority management

Add priority nodes which contribute to the overall thread priority.

The actual priority of a thread is now an aggregation of priority nodes.
The thread priority aggregation for the home scheduler instance of a
thread consists of at least one priority node, which is normally the
real priority of the thread.  The locking protocols (e.g. priority
ceiling and priority inheritance), rate-monotonic period objects and the
POSIX sporadic server add, change and remove priority nodes.

A thread changes its priority now immediately, e.g. priority changes are
not deferred until the thread releases its last resource.

Replace the _Thread_Change_priority() function with

 * _Thread_Priority_perform_actions(),
 * _Thread_Priority_add(),
 * _Thread_Priority_remove(),
 * _Thread_Priority_change(), and
 * _Thread_Priority_update().

Update #2412.
Update #2556.

1 files changed, 5 insertions, 2 deletions

diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index 90f58e646d..76b1dff6e4 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -198,12 +198,15 @@ bool _Thread_Initialize(
 
   the_thread->current_state           = STATES_DORMANT;
   the_thread->Wait.operations         = &_Thread_queue_Operations_default;
-  the_thread->current_priority        = priority;
-  the_thread->real_priority           = priority;
   the_thread->Start.initial_priority  = priority;
 
   RTEMS_STATIC_ASSERT( THREAD_WAIT_FLAGS_INITIAL == 0, Wait_flags );
 
+  _Priority_Node_initialize( &the_thread->Real_priority, priority );
+  _Priority_Initialize_one(
+    &scheduler_node->Wait.Priority,
+    &the_thread->Real_priority
+  );
   _Scheduler_Node_initialize( scheduler, scheduler_node, the_thread, priority );
   scheduler_node_initialized = true;