1 files changed, 73 insertions, 0 deletions
diff --git a/cpukit/score/src/threadyieldprocessor.c b/cpukit/score/src/threadyieldprocessor.c
new file mode 100644
index 0000000000..0e9721c469
--- /dev/null
+++ b/cpukit/score/src/threadyieldprocessor.c
@@ -0,0 +1,73 @@
+/*
+ *  Thread Handler
+ *
+ *
+ *  COPYRIGHT (c) 1989-1998.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may be
+ *  found in found in the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#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/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_Yield_processor
+ *
+ *  This kernel routine will remove the running THREAD from the ready chain
+ *  and place it immediatly at the rear of this chain.  Reset timeslice
+ *  and yield the processor functions both use this routine, therefore if
+ *  reset is TRUE and this is the only thread on the chain then the
+ *  timeslice counter is reset.  The heir THREAD will be updated if the
+ *  running is also the currently the heir.
+ *
+ *  Input parameters:   NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  INTERRUPT LATENCY:
+ *    ready chain
+ *    select heir
+ */
+
+void _Thread_Yield_processor( void )
+{
+  ISR_Level       level;
+  Thread_Control *executing;
+  Chain_Control  *ready;
+
+  executing = _Thread_Executing;
+  ready     = executing->ready;
+  _ISR_Disable( level );
+    if ( !_Chain_Has_only_one_node( ready ) ) {
+      _Chain_Extract_unprotected( &executing->Object.Node );
+      _Chain_Append_unprotected( ready, &executing->Object.Node );
+
+      _ISR_Flash( level );
+
+      if ( _Thread_Is_heir( executing ) )
+        _Thread_Heir = (Thread_Control *) ready->first;
+      _Context_Switch_necessary = TRUE;
+    }
+    else if ( !_Thread_Is_heir( executing ) )
+      _Context_Switch_necessary = TRUE;
+
+  _ISR_Enable( level );
+}