2011-03-16 Jennifer Averett <jennifer.averett@OARcorp.com>

	PR 1743/cpu
	* sapi/include/confdefs.h, score/Makefile.am, score/preinstall.am: Add
	Simple Priority Scheduler as complement to existing Deterministic
	Priority Scheduler. This scheduler serves both as an example and as a
	lighter weight implementation for smaller systems.
	* score/include/rtems/score/schedulersimple.h,
	score/inline/rtems/score/schedulersimple.inl,
	score/src/schedulersimple.c, score/src/schedulersimpleblock.c,
	score/src/schedulersimpleenqueue.c,
	score/src/schedulersimpleenqueuefirst.c,
	score/src/schedulersimpleextract.c,
	score/src/schedulersimplereadyqueueenqueue.c,
	score/src/schedulersimplereadyqueueenqueuefirst.c,
	score/src/schedulersimpleschedule.c,
	score/src/schedulersimpleunblock.c, score/src/schedulersimpleyield.c:
	New files.

1 files changed, 199 insertions, 0 deletions

diff --git a/cpukit/score/include/rtems/score/schedulersimple.h b/cpukit/score/include/rtems/score/schedulersimple.h
new file mode 100644
index 0000000000..ea060ea59c
--- /dev/null
+++ b/cpukit/score/include/rtems/score/schedulersimple.h
@@ -0,0 +1,199 @@
+/**
+ *  @file  rtems/score/schedulersimple.h
+ *
+ *  This include file contains all the constants and structures associated
+ *  with the manipulation of threads on a simple-priority-based ready queue.
+ *
+ *
+ *  Copyright (C) 2011 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.
+ *
+ *  $Id$
+ */
+
+#ifndef _RTEMS_SCORE_SCHEDULERSIMPLE_H
+#define _RTEMS_SCORE_SCHEDULERSIMPLE_H
+
+/**
+ *  @addtogroup ScoreScheduler
+ *
+ */
+/**@{*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rtems/score/scheduler.h>
+
+/**
+ *  Entry points for Scheduler Simple
+ */
+#define SCHEDULER_SIMPLE_ENTRY_POINTS \
+  { \
+    _Scheduler_simple_Initialize,    /* initialize entry point */ \
+    _Scheduler_simple_Schedule,      /* schedule entry point */ \
+    _Scheduler_simple_Yield,         /* yield entry point */ \
+    _Scheduler_simple_Block,         /* block entry point */ \
+    _Scheduler_simple_Unblock,       /* unblock entry point */ \
+    _Scheduler_simple_Allocate,      /* allocate entry point */ \
+    _Scheduler_simple_Free,          /* free entry point */ \
+    _Scheduler_simple_Update,        /* update entry point */ \
+    _Scheduler_simple_Enqueue,       /* enqueue entry point */ \
+    _Scheduler_simple_Enqueue_first, /* enqueue_first entry point */ \
+    _Scheduler_simple_Extract        /* extract entry point */ \
+  }
+
+/**
+ * This routine initializes the simple scheduler.
+ */
+void _Scheduler_simple_Initialize( void );
+
+/**
+ *  This routine sets the heir thread to be the next ready thread 
+ *  on the ready queue by getting the first node in the scheduler
+ *  information.
+ */
+void _Scheduler_simple_Schedule( void );
+
+/**
+ *  This routine is invoked when a thread wishes to voluntarily
+ *  transfer control of the processor to another thread in the queue.
+ *  It will remove the running THREAD from the scheduler.informaiton 
+ *  (where the ready queue is stored) and place it immediately at the 
+ *  between the last entry of its priority and the next priority thread.  
+ *  Reset timeslice and yield the processor functions both use this routine, 
+ *  therefore if reset is true and this is the only thread on the queue then 
+ *  the timeslice counter is reset.  The heir THREAD will be updated if the
+ *  running is also the currently the heir.
+*/
+void _Scheduler_simple_Yield( void );
+
+/**
+ *  This routine removes @a the_thread from the scheduling decision, 
+ *  that is, removes it from the ready queue.  It performs
+ *  any necessary scheduling operations including the selection of
+ *  a new heir thread.
+ *
+ *  @param[in] the_thread is the thread that is to be blocked
+ */
+void _Scheduler_simple_Block( 
+  Thread_Control *the_thread 
+);
+
+/**
+ *  This routine adds @a the_thread to the scheduling decision, 
+ *  that is, adds it to the ready queue and 
+ *  updates any appropriate scheduling variables, for example the heir thread.
+ *
+ *  @param[in] the_thread is the thread that is to be unblocked
+ */
+void _Scheduler_simple_Unblock(
+  Thread_Control *the_thread 
+);
+
+/**
+ *  This routine removes a specific thread from the specified 
+ *  simple-based ready queue.
+ *
+ *  @param[in] the_thread is the thread to be blocked
+ */
+void _Scheduler_simple_Extract(
+  Thread_Control *the_thread
+);
+
+/**
+ *  This routine puts @a the_thread on to the ready queue.
+ *
+ *  @param[in] the_thread is the thread to be blocked
+ */
+void _Scheduler_simple_Enqueue(
+  Thread_Control *the_thread
+);
+
+/**
+ *  This routine puts @a the_thread to the head of the ready queue. 
+ *  The thread will be the first thread at its priority level.
+ *
+ *  @param[in] the_thread is the thread to be blocked
+ */
+void _Scheduler_simple_Enqueue_first(
+  Thread_Control *the_thread
+);
+
+/**
+ *  This routine is a place holder for any memeory allocation needed
+ *  by the scheduler.  For the simple scheduler the routine is an empty
+ *  place holder.
+ *
+ *  @param[in] the_thread is the thread the scheduler is allocating
+ *             management memory for
+ *
+ *  @return this routine returns -1 since this is just an empty placeholder
+ *  and the return value may be defined differently by each scheduler.
+ */
+void *_Scheduler_simple_Allocate( 
+  Thread_Control *the_thread
+);
+
+/**
+ * This routine does nothing, and is used as a stub for Schedule update
+ *
+ * The overhead of a function call will still be imposed.
+ *
+ *  @param[in] the_thread is the thread to be blocked
+ */
+void _Scheduler_simple_Update( 
+  Thread_Control *the_thread
+);
+
+/**
+ * This routine does nothing, and is used as a stub for Schedule free
+ *
+ * The overhead of a function call will still be imposed.
+ *
+ *  @param[in] the_thread is the thread to be blocked
+ */
+void _Scheduler_simple_Free( 
+  Thread_Control *the_thread
+);
+
+/**
+ *  _Scheduler_simple_Ready_queue_Enqueue
+ *
+ *  This routine puts @a the_thread on the ready queue
+ *  at the end of its priority group.
+ *  
+ *  @param[in] the_thread - pointer to a thread control block
+ */
+void _Scheduler_simple_Ready_queue_Enqueue(
+  Thread_Control    *the_thread
+);
+
+/**
+ *  _Scheduler_simple_Ready_queue_Enqueue_first
+ *
+ *  This routine puts @a the_thread on to the ready queue
+ *  at the beginning of its priority group.
+ *  
+ *  @param[in] the_thread - pointer to a thread control block
+ */
+void _Scheduler_simple_Ready_queue_Enqueue_first(
+  Thread_Control    *the_thread
+);
+
+#ifndef __RTEMS_APPLICATION__
+#include <rtems/score/schedulersimple.inl>
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+
+#endif
+/* end of include file */