scheduler: Add start idle thread operation

Add and use _Scheduler_Start_idle().

cpukit/posix/src/pthreadcreate.c

@@ -203,7 +203,8 @@ int pthread_create(
     THREAD_START_POINTER,
     start_routine,
     arg,
-    0                     /* unused */
+    0,                    /* unused */
+    NULL
   );
 
   #if defined(RTEMS_DEBUG)

cpukit/rtems/src/taskstart.c

@@ -58,6 +58,7 @@ rtems_status_code rtems_task_start(
 {
   register Thread_Control *the_thread;
   Objects_Locations        location;
+  bool                     successfully_started;
 
   if ( entry_point == NULL )
     return RTEMS_INVALID_ADDRESS;
@@ -66,13 +67,22 @@ rtems_status_code rtems_task_start(
   switch ( location ) {
 
     case OBJECTS_LOCAL:
-      if ( _Thread_Start(
-             the_thread, THREAD_START_NUMERIC, entry_point, NULL, argument ) ) {
-        _Objects_Put( &the_thread->Object );
-        return RTEMS_SUCCESSFUL;
-      }
+      successfully_started = _Thread_Start(
+        the_thread,
+        THREAD_START_NUMERIC,
+        entry_point,
+        NULL,
+        argument,
+        NULL
+      );
+
       _Objects_Put( &the_thread->Object );
-      return RTEMS_INCORRECT_STATE;
+
+      if ( successfully_started ) {
+        return RTEMS_SUCCESSFUL;
+      } else {
+        return RTEMS_INCORRECT_STATE;
+      }
 
 #if defined(RTEMS_MULTIPROCESSING)
     case OBJECTS_REMOTE:

cpukit/score/Makefile.am

@@ -197,6 +197,7 @@ libscore_a_SOURCES += src/objectallocate.c src/objectclose.c \
 
 ## SCHEDULER_C_FILES
 libscore_a_SOURCES += src/scheduler.c
+libscore_a_SOURCES += src/schedulerdefaultstartidle.c
 
 ## SCHEDULERPRIORITY_C_FILES
 libscore_a_SOURCES += src/schedulerpriority.c \

cpukit/score/include/rtems/score/scheduler.h

@@ -89,6 +89,12 @@ typedef struct {
   /** perform scheduler update actions required at each clock tick */
   void ( *tick )(void);
 
+  /**
+   * @brief Starts the idle thread for a particular processor.
+   *
+   * @see _Scheduler_Start_idle().
+   */
+  void ( *start_idle )( Thread_Control *thread, Per_CPU_Control *processor );
 } Scheduler_Operations;
 
 /**
@@ -139,6 +145,17 @@ extern Scheduler_Control  _Scheduler;
  */
 void _Scheduler_Handler_initialization( void );
 
+/**
+ * @brief Unblocks the thread.
+ *
+ * @param[in/out] thread An idle thread.
+ * @param[in] processor This parameter is unused.
+ */
+void _Scheduler_default_Start_idle(
+  Thread_Control  *thread,
+  Per_CPU_Control *processor
+);
+
 #ifndef __RTEMS_APPLICATION__
 #include <rtems/score/scheduler.inl>
 #endif

cpukit/score/include/rtems/score/schedulercbs.h

@@ -60,7 +60,8 @@ extern "C" {
     _Scheduler_EDF_Extract,          /* extract entry point */ \
     _Scheduler_EDF_Priority_compare, /* compares two priorities */ \
     _Scheduler_CBS_Release_job,      /* new period of task */ \
-    _Scheduler_priority_Tick         /* tick entry point */ \
+    _Scheduler_priority_Tick,        /* tick entry point */ \
+    _Scheduler_default_Start_idle    /* start idle entry point */ \
   }
 
 /* Return values for CBS server. */

cpukit/score/include/rtems/score/scheduleredf.h

@@ -53,7 +53,8 @@ extern "C" {
     _Scheduler_EDF_Extract,          /* extract entry point */ \
     _Scheduler_EDF_Priority_compare, /* compares two priorities */ \
     _Scheduler_EDF_Release_job,      /* new period of task */ \
-    _Scheduler_priority_Tick         /* tick entry point */ \
+    _Scheduler_priority_Tick,        /* tick entry point */ \
+    _Scheduler_default_Start_idle    /* start idle entry point */ \
   }
 
 /**

cpukit/score/include/rtems/score/schedulerpriority.h

@@ -52,7 +52,8 @@ extern "C" {
     _Scheduler_priority_Extract,          /* extract entry point */ \
     _Scheduler_priority_Priority_compare, /* compares two priorities */ \
     _Scheduler_priority_Release_job,      /* new period of task */ \
-    _Scheduler_priority_Tick              /* tick entry point */ \
+    _Scheduler_priority_Tick,             /* tick entry point */ \
+    _Scheduler_default_Start_idle         /* start idle entry point */ \
   }
 
 /**

cpukit/score/include/rtems/score/schedulersimple.h

@@ -50,7 +50,8 @@ extern "C" {
     _Scheduler_simple_Extract,            /* extract entry point */ \
     _Scheduler_priority_Priority_compare, /* compares two priorities */ \
     _Scheduler_priority_Release_job,      /* new period of task */ \
-    _Scheduler_priority_Tick              /* tick entry point */ \
+    _Scheduler_priority_Tick,             /* tick entry point */ \
+    _Scheduler_default_Start_idle         /* start idle entry point */ \
   }
 
 /**

cpukit/score/include/rtems/score/thread.h

@@ -571,13 +571,17 @@ bool _Thread_Initialize(
  *  @param entry_point
  *  @param pointer_argument
  *  @param numeric_argument
+ *  @param[in/out] processor The processor if used to start an idle thread
+ *  during system initialization.  Must be set to @c NULL to start a normal
+ *  thread.
  */
 bool _Thread_Start(
   Thread_Control            *the_thread,
   Thread_Start_types         the_prototype,
   void                      *entry_point,
   void                      *pointer_argument,
-  Thread_Entry_numeric_type  numeric_argument
+  Thread_Entry_numeric_type  numeric_argument,
+  Per_CPU_Control           *processor
 );
 
 /**

cpukit/score/inline/rtems/score/scheduler.inl

@@ -208,6 +208,22 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Tick( void )
   _Scheduler.Operations.tick();
 }
 
+/**
+ * @brief Starts the idle thread for a particular processor.
+ *
+ * @param[in/out] thread The idle thread for the processor.
+ * @parma[in/out] processor The processor for the idle thread.
+ *
+ * @see _Thread_Create_idle().
+ */
+RTEMS_INLINE_ROUTINE void _Scheduler_Start_idle(
+  Thread_Control *thread,
+  Per_CPU_Control *processor
+)
+{
+  ( *_Scheduler.Operations.start_idle )( thread, processor );
+}
+
 /** @} */
 
 #endif

cpukit/score/src/schedulerdefaultstartidle.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2013 embedded brains GmbH
+ *
+ * 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.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/scheduler.h>
+
+void _Scheduler_default_Start_idle(
+  Thread_Control  *thread,
+  Per_CPU_Control *processor
+)
+{
+  (void) processor;
+  _Scheduler_Unblock( thread );
+}

cpukit/score/src/threadcreateidle.c

@@ -73,7 +73,8 @@ static void _Thread_Create_idle_for_cpu( Per_CPU_Control *per_cpu )
     THREAD_START_NUMERIC,
     rtems_configuration_get_idle_task(),
     NULL,
-    0
+    0,
+    per_cpu
   );
 }
 

cpukit/score/src/threadstart.c

@@ -38,7 +38,8 @@ bool _Thread_Start(
   Thread_Start_types         the_prototype,
   void                      *entry_point,
   void                      *pointer_argument,
-  Thread_Entry_numeric_type  numeric_argument
+  Thread_Entry_numeric_type  numeric_argument,
+  Per_CPU_Control           *processor
 )
 {
   if ( _States_Is_dormant( the_thread->current_state ) ) {
@@ -51,7 +52,12 @@ bool _Thread_Start(
 
     _Thread_Load_environment( the_thread );
 
-    _Thread_Ready( the_thread );
+    if ( processor == NULL ) {
+      _Thread_Ready( the_thread );
+    } else {
+      the_thread->current_state = STATES_READY;
+      _Scheduler_Start_idle( the_thread, processor );
+    }
 
     _User_extensions_Thread_start( the_thread );