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, 47 insertions, 0 deletions

diff --git a/cpukit/score/src/schedulersimpleunblock.c b/cpukit/score/src/schedulersimpleunblock.c
new file mode 100644
index 0000000000..5be5c16ad9
--- /dev/null
+++ b/cpukit/score/src/schedulersimpleunblock.c
@@ -0,0 +1,47 @@
+/*
+ *  Scheduler Simple Handler / Unblock
+ *
+ *  COPYRIGHT (c) 2011.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in 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/isr.h>
+#include <rtems/score/schedulersimple.h>
+#include <rtems/score/thread.h>
+
+void _Scheduler_simple_Unblock(
+  Thread_Control    *the_thread
+)
+{
+  _Scheduler_simple_Ready_queue_Enqueue(the_thread);
+
+  /*
+   *  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 ( the_thread->current_priority < _Thread_Heir->current_priority ) {
+    _Thread_Heir = the_thread;
+    if ( _Thread_Executing->is_preemptible ||
+        the_thread->current_priority == 0 )
+      _Thread_Dispatch_necessary = true;
+  }
+}