score: Simplify _Thread_Change_priority()

The function to change a thread priority was too complex.  Simplify it
with a new scheduler operation.  This increases the average case
performance due to the simplified logic.  The interrupt disabled
critical section is a bit prolonged since now the extract, update and
enqueue steps are executed atomically.  This should however not impact
the worst-case interrupt latency since at least for the Deterministic
Priority Scheduler this sequence can be carried out with a wee bit of
instructions and no loops.

Add _Scheduler_Change_priority() to replace the sequence of
  - _Thread_Set_transient(),
  - _Scheduler_Extract(),
  - _Scheduler_Enqueue(), and
  - _Scheduler_Enqueue_first().

Delete STATES_TRANSIENT, _States_Is_transient() and
_Thread_Set_transient() since this state is now superfluous.

With this change it is possible to get rid of the
SCHEDULER_SMP_NODE_IN_THE_AIR state.  This considerably simplifies the
implementation of the new SMP locking protocols.

1 files changed, 1 insertions, 2 deletions

diff --git a/cpukit/libmisc/capture/capture.c b/cpukit/libmisc/capture/capture.c
index da9d785f77..118e4ff5b3 100644
--- a/cpukit/libmisc/capture/capture.c
+++ b/cpukit/libmisc/capture/capture.c
@@ -913,8 +913,7 @@ rtems_capture_switch_task (rtems_tcb* current_task,
     rtems_capture_task_t* ht;
 
 
-    if (_States_Is_transient (current_task->current_state)
-     || _States_Is_dormant (current_task->current_state))
+    if (_States_Is_dormant (current_task->current_state))
     {
       rtems_id ct_id = current_task->Object.id;