summaryrefslogtreecommitdiffstats
path: root/cpukit/score/src/threadchangepriority.c
diff options
context:
space:
mode:
Diffstat (limited to 'cpukit/score/src/threadchangepriority.c')
-rw-r--r--cpukit/score/src/threadchangepriority.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/cpukit/score/src/threadchangepriority.c b/cpukit/score/src/threadchangepriority.c
new file mode 100644
index 0000000000..9a0e6936a2
--- /dev/null
+++ b/cpukit/score/src/threadchangepriority.c
@@ -0,0 +1,109 @@
+/*
+ * 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_Change_priority
+ *
+ * This kernel routine changes the priority of the thread. The
+ * thread chain is adjusted if necessary.
+ *
+ * Input parameters:
+ * the_thread - pointer to thread control block
+ * new_priority - ultimate priority
+ * prepend_it - TRUE if the thread should be prepended to the chain
+ *
+ * Output parameters: NONE
+ *
+ * INTERRUPT LATENCY:
+ * ready chain
+ * select heir
+ */
+
+void _Thread_Change_priority(
+ Thread_Control *the_thread,
+ Priority_Control new_priority,
+ boolean prepend_it
+)
+{
+ ISR_Level level;
+ /* boolean do_prepend = FALSE; */
+
+ /*
+ * If this is a case where prepending the task to its priority is
+ * potentially desired, then we need to consider whether to do it.
+ * This usually occurs when a task lowers its priority implcitly as
+ * the result of losing inherited priority. Normal explicit priority
+ * change calls (e.g. rtems_task_set_priority) should always do an
+ * append not a prepend.
+ */
+
+ /*
+ * Techically, the prepend should conditional on the thread lowering
+ * its priority but that does allow cxd2004 of the acvc 2.0.1 to
+ * pass with rtems 4.0.0. This should change when gnat redoes its
+ * priority scheme.
+ */
+/*
+ if ( prepend_it &&
+ _Thread_Is_executing( the_thread ) &&
+ new_priority >= the_thread->current_priority )
+ prepend_it = TRUE;
+*/
+
+ _Thread_Set_transient( the_thread );
+
+ if ( the_thread->current_priority != new_priority )
+ _Thread_Set_priority( the_thread, new_priority );
+
+ _ISR_Disable( level );
+
+ the_thread->current_state =
+ _States_Clear( STATES_TRANSIENT, the_thread->current_state );
+
+ if ( ! _States_Is_ready( the_thread->current_state ) ) {
+ _ISR_Enable( level );
+ return;
+ }
+
+ _Priority_Add_to_bit_map( &the_thread->Priority_map );
+ if ( prepend_it )
+ _Chain_Prepend_unprotected( the_thread->ready, &the_thread->Object.Node );
+ else
+ _Chain_Append_unprotected( the_thread->ready, &the_thread->Object.Node );
+
+ _ISR_Flash( level );
+
+ _Thread_Calculate_heir();
+
+ if ( !_Thread_Is_executing_also_the_heir() &&
+ _Thread_Executing->is_preemptible )
+ _Context_Switch_necessary = TRUE;
+ _ISR_Enable( level );
+}