1 files changed, 66 insertions, 0 deletions
diff --git a/cpukit/score/include/rtems/score/schedulersmp.h b/cpukit/score/include/rtems/score/schedulersmp.h
index 778a1fb832..ee1b087ff8 100644
--- a/cpukit/score/include/rtems/score/schedulersmp.h
+++ b/cpukit/score/include/rtems/score/schedulersmp.h
@@ -38,15 +38,81 @@ extern "C" {
  * @{
  */
 
+/**
+ * @brief Scheduler context specialization for SMP schedulers.
+ */
 typedef struct {
   /**
    * @brief Basic scheduler context.
    */
   Scheduler_Context Base;
 
+  /**
+   * @brief The chain of scheduled nodes.
+   */
   Chain_Control Scheduled;
 } Scheduler_SMP_Context;
 
+/**
+ * @brief SMP scheduler node states.
+ */
+typedef enum {
+  /**
+   * @brief This scheduler node is blocked.
+   *
+   * A scheduler node is blocked if the corresponding thread is not ready.
+   */
+  SCHEDULER_SMP_NODE_BLOCKED,
+
+  /**
+   * @brief The scheduler node is scheduled.
+   *
+   * A scheduler node is scheduled if the corresponding thread is ready and the
+   * scheduler allocated a processor for it.  A scheduled node is assigned to
+   * exactly one processor.  The sum of scheduled and in the air nodes equals
+   * the processor count owned by a scheduler instance.
+   */
+  SCHEDULER_SMP_NODE_SCHEDULED,
+
+  /**
+   * @brief This scheduler node is ready.
+   *
+   * A scheduler node is ready if the corresponding thread is ready and the
+   * scheduler did not allocate a processor for it.
+   */
+  SCHEDULER_SMP_NODE_READY,
+
+  /**
+   * @brief This scheduler node is in the air.
+   *
+   * A scheduled node is in the air if it has an allocated processor and the
+   * corresponding thread is in a transient state.  Such a node is not an
+   * element of the set of scheduled nodes.  The extract operation on a
+   * scheduled node will produce a scheduler node in the air (see also
+   * _Thread_Set_transient()).  The next enqueue or schedule operation will
+   * decide what to do based on this state indication.  It can either place the
+   * scheduler node back on the set of scheduled nodes and the thread can keep
+   * its allocated processor, or it can take the processor away from the thread
+   * and give the processor to another thread of higher priority.
+   */
+  SCHEDULER_SMP_NODE_IN_THE_AIR
+} Scheduler_SMP_Node_state;
+
+/**
+ * @brief Scheduler node specialization for SMP schedulers.
+ */
+typedef struct {
+  /**
+   * @brief Basic scheduler node.
+   */
+  Scheduler_Node Base;
+
+  /**
+   * @brief The state of this node.
+   */
+  Scheduler_SMP_Node_state state;
+} Scheduler_SMP_Node;
+
 /** @} */
 
 #ifdef __cplusplus