[PATCH v2 2/5] score: Simplify _Thread_queue_Boost_priority()

[Sebastian Huber]

Raise the priority under thread queue lock protection and omit the
superfluous thread queue priority change, since the thread is extracted
anyway.  The unblock operation will pick up the new priority.

Update #2412.
Update #2556.
Update #2765.
---
 cpukit/score/src/coremutexsurrender.c | 14 +++++++-------
 cpukit/score/src/mutex.c              |  2 +-
 cpukit/score/src/threadqops.c         | 26 +++++++++++++++-----------
 3 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/cpukit/score/src/coremutexsurrender.c b/cpukit/score/src/coremutexsurrender.c
index 6604be8..aed17ab 100644
--- a/cpukit/score/src/coremutexsurrender.c
+++ b/cpukit/score/src/coremutexsurrender.c
@@ -38,13 +38,6 @@ Status_Control _CORE_mutex_Surrender_slow(
 
     _CORE_mutex_Set_owner( the_mutex, new_owner );
 
-    unblock = _Thread_queue_Extract_locked(
-      &the_mutex->Wait_queue.Queue,
-      operations,
-      new_owner,
-      queue_context
-    );
-
 #if defined(RTEMS_MULTIPROCESSING)
     if ( _Objects_Is_local_id( new_owner->Object.id ) )
 #endif
@@ -53,6 +46,13 @@ Status_Control _CORE_mutex_Surrender_slow(
       _Thread_queue_Boost_priority( &the_mutex->Wait_queue.Queue, new_owner );
     }
 
+    unblock = _Thread_queue_Extract_locked(
+      &the_mutex->Wait_queue.Queue,
+      operations,
+      new_owner,
+      queue_context
+    );
+
     _Thread_queue_Unblock_critical(
       unblock,
       &the_mutex->Wait_queue.Queue,
diff --git a/cpukit/score/src/mutex.c b/cpukit/score/src/mutex.c
index 525992a..4b95262 100644
--- a/cpukit/score/src/mutex.c
+++ b/cpukit/score/src/mutex.c
@@ -136,13 +136,13 @@ static void _Mutex_Release_slow(
 
     mutex->Queue.Queue.owner = first;
     ++first->resource_count;
+    _Thread_queue_Boost_priority( &mutex->Queue.Queue, first );
     unblock = _Thread_queue_Extract_locked(
       &mutex->Queue.Queue,
       operations,
       first,
       queue_context
     );
-    _Thread_queue_Boost_priority( &mutex->Queue.Queue, first );
     _Thread_queue_Unblock_critical(
       unblock,
       &mutex->Queue.Queue,
diff --git a/cpukit/score/src/threadqops.c b/cpukit/score/src/threadqops.c
index 5a00ee6..83abf0d 100644
--- a/cpukit/score/src/threadqops.c
+++ b/cpukit/score/src/threadqops.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2015, 2016 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -318,16 +318,20 @@ void _Thread_queue_Boost_priority(
 {
   Thread_queue_Heads *heads = queue->heads;
 
-  if (
-    heads != NULL
-      && (
-        !_Chain_Has_only_one_node( &heads->Heads.Fifo )
-          || _RBTree_Is_empty(
-            &_Thread_queue_Priority_queue( heads, the_thread )->Queue
-          )
-      )
-  ) {
-    _Thread_Raise_priority( the_thread, PRIORITY_PSEUDO_ISR );
+  if ( !_Chain_Has_only_one_node( &heads->Heads.Fifo ) ) {
+    const Scheduler_Control *scheduler;
+    Scheduler_Node          *own_node;
+    Priority_Control         boost_priority;
+
+    the_thread->priority_restore_hint = true;
+    _Atomic_Fence( ATOMIC_ORDER_ACQ_REL );
+
+    scheduler = _Scheduler_Get_own( the_thread );
+    own_node = _Scheduler_Thread_get_own_node( the_thread );
+    boost_priority = _Scheduler_Map_priority( scheduler, PRIORITY_PSEUDO_ISR );
+    _Scheduler_Node_set_priority( own_node, boost_priority, false );
+
+    the_thread->current_priority = boost_priority;
   }
 }
 #endif
-- 
1.8.4.5