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authorJoel Sherrill <joel.sherrill@OARcorp.com>1999-05-17 20:41:13 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>1999-05-17 20:41:13 +0000
commit05df0a846f436295a490cc9ac19e5a4061c3a575 (patch)
tree886d4b9da28181bc0e7fe64a193b2642dcb3f5b2 /cpukit/score/src/threadyieldprocessor.c
parentPatch from D. V. Henkel-Wallace <gumby@zembu.com> to remove compiler (diff)
downloadrtems-05df0a846f436295a490cc9ac19e5a4061c3a575.tar.bz2
Thread Handler split into multiple files. Eventually, as RTEMS is
split into one function per file, this will decrease the size of executables.
Diffstat (limited to 'cpukit/score/src/threadyieldprocessor.c')
-rw-r--r--cpukit/score/src/threadyieldprocessor.c73
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 );
+}