2011-06-17 Joel Sherrill <joel.sherrill@oarcorp.com>

	PR 1819/cpukit
	* rtems/src/clocktick.c, score/Makefile.am,
	score/include/rtems/score/scheduler.h,
	score/include/rtems/score/schedulerpriority.h,
	score/include/rtems/score/schedulersimple.h,
	score/include/rtems/score/schedulersimplesmp.h,
	score/include/rtems/score/thread.h,
	score/inline/rtems/score/scheduler.inl: Add a scheduler entry point
	which is invoked at each clock tick. _Thread_Tickle_timeslice() is
	now a method owned by the Deterministic Priority Scheduler and shared
	by the Simple Priority Scheduler. The Simple SMP Scheduler has its
	own variation on this which does timeslicing bookkeeping on all
	cores.
	* score/src/schedulerprioritytick.c,
	score/src/schedulersimplesmptick.c: New files.
	* score/src/threadtickletimeslice.c: Removed.

2 files changed, 102 insertions, 30 deletions

diff --git a/cpukit/score/src/threadtickletimeslice.c b/cpukit/score/src/schedulerprioritytick.c
index 4c2772a2aa..6f49ab60c8 100644
--- a/cpukit/score/src/threadtickletimeslice.c
+++ b/cpukit/score/src/schedulerprioritytick.c
@@ -1,7 +1,4 @@
 /*
- *  Thread Handler
- *
- *
  *  COPYRIGHT (c) 1989-2009.
  *  On-Line Applications Research Corporation (OAR).
  *
@@ -17,34 +14,9 @@
 #endif
 
 #include <rtems/system.h>
-#include <rtems/score/apiext.h>
-#include <rtems/score/context.h>
-#include <rtems/score/interr.h>
-#include <rtems/score/isr.h>
-#include <rtems/score/object.h>
-#include <rtems/score/priority.h>
-#include <rtems/score/scheduler.h>
-#include <rtems/score/states.h>
-#include <rtems/score/sysstate.h>
-#include <rtems/score/thread.h>
-#include <rtems/score/threadq.h>
-#include <rtems/score/userext.h>
-#include <rtems/score/wkspace.h>
-
-/*PAGE
- *
- *  _Thread_Tickle_timeslice
- *
- *  This scheduler routine determines if timeslicing is enabled
- *  for the currently executing thread and, if so, updates the
- *  timeslice count and checks for timeslice expiration.
- *
- *  Input parameters:   NONE
- *
- *  Output parameters:  NONE
- */
+#include <rtems/score/schedulerpriority.h>
 
-void _Thread_Tickle_timeslice( void )
+void _Scheduler_priority_Tick( void )
 {
   Thread_Control *executing;
 
diff --git a/cpukit/score/src/schedulersimplesmptick.c b/cpukit/score/src/schedulersimplesmptick.c
new file mode 100644
index 0000000000..5577b5579b
--- /dev/null
+++ b/cpukit/score/src/schedulersimplesmptick.c
@@ -0,0 +1,100 @@
+/*
+ *  COPYRIGHT (c) 1989-2009.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/system.h>
+#include <rtems/score/schedulersimplesmp.h>
+
+static void _Scheduler_simple_smp_Tick_helper(
+  int cpu
+)
+{
+  Thread_Control *executing;
+
+  executing = _Per_CPU_Information[cpu].executing;
+
+  #ifdef __RTEMS_USE_TICKS_FOR_STATISTICS__
+    /*
+     *  Increment the number of ticks this thread has been executing
+     */
+    executing->cpu_time_used++;
+  #endif
+
+  /*
+   *  If the thread is not preemptible or is not ready, then
+   *  just return.
+   */
+
+  if ( !executing->is_preemptible )
+    return;
+
+  if ( !_States_Is_ready( executing->current_state ) )
+    return;
+
+  /*
+   *  The cpu budget algorithm determines what happens next.
+   */
+
+  switch ( executing->budget_algorithm ) {
+    case THREAD_CPU_BUDGET_ALGORITHM_NONE:
+      break;
+
+    case THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE:
+    #if defined(RTEMS_SCORE_THREAD_ENABLE_EXHAUST_TIMESLICE)
+      case THREAD_CPU_BUDGET_ALGORITHM_EXHAUST_TIMESLICE:
+    #endif
+      if ( (int)(--executing->cpu_time_budget) <= 0 ) {
+
+        /*
+         *  A yield performs the ready chain mechanics needed when
+         *  resetting a timeslice.  If no other thread's are ready
+         *  at the priority of the currently executing thread, then the
+         *  executing thread's timeslice is reset.  Otherwise, the
+         *  currently executing thread is placed at the rear of the
+         *  FIFO for this priority and a new heir is selected.
+         *
+         *  In the SMP case, we do the chain manipulation for every
+         *  CPU, then schedule after all CPUs have been evaluated.
+         */
+        _ISR_Disable( level );
+          _Scheduler_simple_Ready_queue_requeue( &_Scheduler, executing );
+        _ISR_Enable( level );
+
+        executing->cpu_time_budget = _Thread_Ticks_per_timeslice;
+      }
+      break;
+
+    #if defined(RTEMS_SCORE_THREAD_ENABLE_SCHEDULER_CALLOUT)
+      case THREAD_CPU_BUDGET_ALGORITHM_CALLOUT:
+	if ( --executing->cpu_time_budget == 0 )
+	  (*executing->budget_callout)( executing );
+	break;
+    #endif
+  }
+}
+
+void _Scheduler_simple_smp_Tick( void )
+{
+  uint32_t        cpu;
+
+  /*
+   *  Iterate over all cores, updating time slicing information
+   *  and logically performing a yield.  Then perform a schedule
+   *  operation to account for all the changes.
+   */
+  for ( cpu=0 ; cpu < _SMP_Processor_count ; cpu++ ) {
+    _Scheduler_simple_smp_Tick_helper( cpu );
+  }
+  _Scheduler_simple_smp_Schedule();
+}