score: Remove PRIORITY_PSEUDO_ISR thread priority

The uniprocessor schedulers had some special case logic for the
PRIORITY_PSEUDO_ISR priority.  Tasks with a priority of PRIORITY_PSEUDO_ISR
were allowed to preempt a not preemptible task.  If other higher priority task
are made ready while a PRIORITY_PSEUDO_ISR task preempts a not preemptible
task, then the other tasks run before the not preemptible task.  This made the
RTEMS_NO_PREEMPT mode ineffective.

Remove the PRIORITY_PSEUDO_ISR special case logic.  This simplifies the
uniprocessor schedulers.  Move the uniprocessor-specific scheduler support to
the new header file <rtems/score/scheduleruniimpl.h>.

Close #2365.

1 files changed, 1 insertions, 19 deletions

diff --git a/cpukit/score/src/schedulersimpleunblock.c b/cpukit/score/src/schedulersimpleunblock.c
index 7791503d7a..436f20ac38 100644
--- a/cpukit/score/src/schedulersimpleunblock.c
+++ b/cpukit/score/src/schedulersimpleunblock.c
@@ -58,23 +58,5 @@ void _Scheduler_simple_Unblock(
   priority = _Thread_Get_priority( the_thread );
   insert_priority = SCHEDULER_PRIORITY_APPEND( priority );
   _Scheduler_simple_Insert( &context->Ready, the_thread, insert_priority );
-
-  /*
-   *  If the thread that was unblocked is more important than the heir,
-   *  then we have a new heir.  This may or may not result in a
-   *  context switch.
-   *
-   *  Normal case:
-   *    If the current thread is preemptible, then we need to do
-   *    a context switch.
-   *  Pseudo-ISR case:
-   *    Even if the thread isn't preemptible, if the new heir is
-   *    a pseudo-ISR system task, we need to do a context switch.
-   */
-  if ( priority < _Thread_Get_priority( _Thread_Heir ) ) {
-    _Scheduler_Update_heir(
-      the_thread,
-      priority == PRIORITY_PSEUDO_ISR
-    );
-  }
+  _Scheduler_uniprocessor_Unblock( scheduler, the_thread, priority );
 }