score: PR2136: Fix _Thread_Change_priority()

Add call to _Scheduler_Schedule() in missing path after
_Thread_Set_transient() in _Thread_Change_priority().  See also
sptests/spintrcritical19.

Add thread parameter to _Scheduler_Schedule().  This parameter is
currently unused but may be used in future SMP schedulers.

Do heir selection in _Scheduler_Schedule().  Use
_Scheduler_Update_heir() for this in the particular scheduler
implementation.

Add and use _Scheduler_Generic_block().

1 files changed, 10 insertions, 4 deletions

diff --git a/cpukit/score/src/threadchangepriority.c b/cpukit/score/src/threadchangepriority.c
index b4437313a7..b3d79844c2 100644
--- a/cpukit/score/src/threadchangepriority.c
+++ b/cpukit/score/src/threadchangepriority.c
@@ -62,6 +62,15 @@ void _Thread_Change_priority(
     /* Only clear the transient state if it wasn't set already */
     if ( ! _States_Is_transient( original_state ) )
       the_thread->current_state = _States_Clear( STATES_TRANSIENT, state );
+
+    /*
+     * The thread may have new blocking states added by interrupt service
+     * routines after the change into the transient state.  This will not
+     * result in a _Scheduler_Block() operation.  Make sure we select an heir
+     * now.
+     */
+    _Scheduler_Schedule( the_thread );
+
     _ISR_Enable( level );
     if ( _States_Is_waiting_on_thread_queue( state ) ) {
       _Thread_queue_Requeue( the_thread->Wait.queue, the_thread );
@@ -91,10 +100,7 @@ void _Thread_Change_priority(
    *  We altered the set of thread priorities.  So let's figure out
    *  who is the heir and if we need to switch to them.
    */
-  _Scheduler_Schedule();
+  _Scheduler_Schedule( the_thread );
 
-  if ( !_Thread_Is_executing_also_the_heir() &&
-       _Thread_Executing->is_preemptible )
-    _Thread_Dispatch_necessary = true;
   _ISR_Enable( level );
 }