score: Improve scheduler helping protocol

Only register ask for help requests in the scheduler unblock and yield
operations.  The actual ask for help operation is carried out during
_Thread_Do_dispatch() on a processor related to the thread.  This yields
a better separation of scheduler instances.  A thread of one scheduler
instance should not be forced to carry out too much work for threads on
other scheduler instances.

Update #2556.

11 files changed, 21 insertions, 37 deletions

diff --git a/cpukit/score/src/schedulercbsunblock.c b/cpukit/score/src/schedulercbsunblock.c
index be9696eed8..403435eeb1 100644
--- a/cpukit/score/src/schedulercbsunblock.c
+++ b/cpukit/score/src/schedulercbsunblock.c
@@ -25,7 +25,7 @@
 #include <rtems/score/threadimpl.h>
 #include <rtems/score/watchdogimpl.h>
 
-Scheduler_Void_or_bool _Scheduler_CBS_Unblock(
+void _Scheduler_CBS_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -68,5 +68,4 @@ Scheduler_Void_or_bool _Scheduler_CBS_Unblock(
   }
 
   _Scheduler_EDF_Unblock( scheduler, the_thread, &the_node->Base.Base );
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/scheduleredfunblock.c b/cpukit/score/src/scheduleredfunblock.c
index 45653396af..29355d04fa 100644
--- a/cpukit/score/src/scheduleredfunblock.c
+++ b/cpukit/score/src/scheduleredfunblock.c
@@ -22,7 +22,7 @@
 #include <rtems/score/schedulerimpl.h>
 #include <rtems/score/thread.h>
 
-Scheduler_Void_or_bool _Scheduler_EDF_Unblock(
+void _Scheduler_EDF_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -59,6 +59,4 @@ Scheduler_Void_or_bool _Scheduler_EDF_Unblock(
       priority == ( SCHEDULER_EDF_PRIO_MSB | PRIORITY_PSEUDO_ISR )
     );
   }
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/scheduleredfyield.c b/cpukit/score/src/scheduleredfyield.c
index dfcb4d3569..4adb4f5121 100644
--- a/cpukit/score/src/scheduleredfyield.c
+++ b/cpukit/score/src/scheduleredfyield.c
@@ -21,7 +21,7 @@
 
 #include <rtems/score/scheduleredfimpl.h>
 
-Scheduler_Void_or_bool _Scheduler_EDF_Yield(
+void _Scheduler_EDF_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -36,6 +36,4 @@ Scheduler_Void_or_bool _Scheduler_EDF_Yield(
   _Scheduler_EDF_Extract( context, the_node );
   _Scheduler_EDF_Enqueue( context, the_node, the_node->priority );
   _Scheduler_EDF_Schedule_body( scheduler, the_thread, true );
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/schedulerpriorityaffinitysmp.c b/cpukit/score/src/schedulerpriorityaffinitysmp.c
index 7689469c54..8b54295122 100644
--- a/cpukit/score/src/schedulerpriorityaffinitysmp.c
+++ b/cpukit/score/src/schedulerpriorityaffinitysmp.c
@@ -352,16 +352,15 @@ static void _Scheduler_priority_affinity_SMP_Check_for_migrations(
 /*
  * This is the public scheduler specific Unblock operation.
  */
-bool _Scheduler_priority_affinity_SMP_Unblock(
+void _Scheduler_priority_affinity_SMP_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *thread,
   Scheduler_Node          *node
 )
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
-  bool               needs_help;
 
-  needs_help = _Scheduler_SMP_Unblock(
+  _Scheduler_SMP_Unblock(
     context,
     thread,
     node,
@@ -373,8 +372,6 @@ bool _Scheduler_priority_affinity_SMP_Unblock(
    * Perform any thread migrations that are needed due to these changes.
    */
   _Scheduler_priority_affinity_SMP_Check_for_migrations( context );
-
-  return needs_help;
 }
 
 /*
diff --git a/cpukit/score/src/schedulerprioritysmp.c b/cpukit/score/src/schedulerprioritysmp.c
index b4786ea872..5548ebf8e8 100644
--- a/cpukit/score/src/schedulerprioritysmp.c
+++ b/cpukit/score/src/schedulerprioritysmp.c
@@ -206,7 +206,7 @@ static bool _Scheduler_priority_SMP_Enqueue_scheduled_fifo(
   );
 }
 
-bool _Scheduler_priority_SMP_Unblock(
+void _Scheduler_priority_SMP_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *thread,
   Scheduler_Node          *node
@@ -214,7 +214,7 @@ bool _Scheduler_priority_SMP_Unblock(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Unblock(
+  _Scheduler_SMP_Unblock(
     context,
     thread,
     node,
@@ -342,7 +342,7 @@ Thread_Control *_Scheduler_priority_SMP_Remove_processor(
   );
 }
 
-bool _Scheduler_priority_SMP_Yield(
+void _Scheduler_priority_SMP_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *thread,
   Scheduler_Node          *node
@@ -350,7 +350,7 @@ bool _Scheduler_priority_SMP_Yield(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Yield(
+  _Scheduler_SMP_Yield(
     context,
     thread,
     node,
diff --git a/cpukit/score/src/schedulerpriorityunblock.c b/cpukit/score/src/schedulerpriorityunblock.c
index 405b83f350..42ba4de98f 100644
--- a/cpukit/score/src/schedulerpriorityunblock.c
+++ b/cpukit/score/src/schedulerpriorityunblock.c
@@ -22,7 +22,7 @@
 
 #include <rtems/score/schedulerpriorityimpl.h>
 
-Scheduler_Void_or_bool _Scheduler_priority_Unblock (
+void _Scheduler_priority_Unblock (
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -71,6 +71,4 @@ Scheduler_Void_or_bool _Scheduler_priority_Unblock (
   if ( priority < _Thread_Get_priority( _Thread_Heir ) ) {
     _Scheduler_Update_heir( the_thread, priority == PRIORITY_PSEUDO_ISR );
   }
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/schedulerpriorityyield.c b/cpukit/score/src/schedulerpriorityyield.c
index 439877d0ce..c12b759f83 100644
--- a/cpukit/score/src/schedulerpriorityyield.c
+++ b/cpukit/score/src/schedulerpriorityyield.c
@@ -21,7 +21,7 @@
 #include <rtems/score/schedulerpriorityimpl.h>
 #include <rtems/score/threadimpl.h>
 
-Scheduler_Void_or_bool _Scheduler_priority_Yield(
+void _Scheduler_priority_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -39,6 +39,4 @@ Scheduler_Void_or_bool _Scheduler_priority_Yield(
   }
 
   _Scheduler_priority_Schedule_body( scheduler, the_thread, true );
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/schedulersimplesmp.c b/cpukit/score/src/schedulersimplesmp.c
index 221fcc3df5..41eb491019 100644
--- a/cpukit/score/src/schedulersimplesmp.c
+++ b/cpukit/score/src/schedulersimplesmp.c
@@ -281,7 +281,7 @@ static bool _Scheduler_simple_SMP_Enqueue_scheduled_fifo(
   );
 }
 
-bool _Scheduler_simple_SMP_Unblock(
+void _Scheduler_simple_SMP_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *thread,
   Scheduler_Node          *node
@@ -289,7 +289,7 @@ bool _Scheduler_simple_SMP_Unblock(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Unblock(
+  _Scheduler_SMP_Unblock(
     context,
     thread,
     node,
@@ -417,7 +417,7 @@ Thread_Control *_Scheduler_simple_SMP_Remove_processor(
   );
 }
 
-bool _Scheduler_simple_SMP_Yield(
+void _Scheduler_simple_SMP_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *thread,
   Scheduler_Node          *node
@@ -425,7 +425,7 @@ bool _Scheduler_simple_SMP_Yield(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Yield(
+  _Scheduler_SMP_Yield(
     context,
     thread,
     node,
diff --git a/cpukit/score/src/schedulersimpleunblock.c b/cpukit/score/src/schedulersimpleunblock.c
index fe02ece5b2..5540e20e87 100644
--- a/cpukit/score/src/schedulersimpleunblock.c
+++ b/cpukit/score/src/schedulersimpleunblock.c
@@ -21,7 +21,7 @@
 #include <rtems/score/schedulersimpleimpl.h>
 #include <rtems/score/thread.h>
 
-Scheduler_Void_or_bool _Scheduler_simple_Unblock(
+void _Scheduler_simple_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -54,6 +54,4 @@ Scheduler_Void_or_bool _Scheduler_simple_Unblock(
       priority == PRIORITY_PSEUDO_ISR
     );
   }
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/schedulersimpleyield.c b/cpukit/score/src/schedulersimpleyield.c
index c84f571933..0c150d8b1f 100644
--- a/cpukit/score/src/schedulersimpleyield.c
+++ b/cpukit/score/src/schedulersimpleyield.c
@@ -20,7 +20,7 @@
 
 #include <rtems/score/schedulersimpleimpl.h>
 
-Scheduler_Void_or_bool _Scheduler_simple_Yield(
+void _Scheduler_simple_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -34,6 +34,4 @@ Scheduler_Void_or_bool _Scheduler_simple_Yield(
   _Chain_Extract_unprotected( &the_thread->Object.Node );
   _Scheduler_simple_Insert_priority_fifo( &context->Ready, the_thread );
   _Scheduler_simple_Schedule_body( scheduler, the_thread, false );
-
-  SCHEDULER_RETURN_VOID_OR_BOOL;
 }
diff --git a/cpukit/score/src/schedulerstrongapa.c b/cpukit/score/src/schedulerstrongapa.c
index 07d27e97b2..d8d3280ed9 100644
--- a/cpukit/score/src/schedulerstrongapa.c
+++ b/cpukit/score/src/schedulerstrongapa.c
@@ -340,7 +340,7 @@ static bool _Scheduler_strong_APA_Enqueue_scheduled_fifo(
   );
 }
 
-bool _Scheduler_strong_APA_Unblock(
+void _Scheduler_strong_APA_Unblock(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -348,7 +348,7 @@ bool _Scheduler_strong_APA_Unblock(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Unblock(
+  _Scheduler_SMP_Unblock(
     context,
     the_thread,
     node,
@@ -476,7 +476,7 @@ Thread_Control *_Scheduler_strong_APA_Remove_processor(
   );
 }
 
-bool _Scheduler_strong_APA_Yield(
+void _Scheduler_strong_APA_Yield(
   const Scheduler_Control *scheduler,
   Thread_Control          *the_thread,
   Scheduler_Node          *node
@@ -484,7 +484,7 @@ bool _Scheduler_strong_APA_Yield(
 {
   Scheduler_Context *context = _Scheduler_Get_context( scheduler );
 
-  return _Scheduler_SMP_Yield(
+  _Scheduler_SMP_Yield(
     context,
     the_thread,
     node,