[PATCH 1/2] rbtree: Simplify off-tree handling

[Sebastian Huber]

Only use the parent pointer, since this pointer is never NULL for nodes
which are part of a tree.

Rename functions from *_off_rbtree() to *_off_tree().
---
 cpukit/sapi/include/rtems/rbtree.h        |  8 +++----
 cpukit/score/include/rtems/score/rbtree.h | 37 +++++++++++++++++--------------
 testsuites/sptests/sprbtree01/init.c      |  8 +++----
 3 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/cpukit/sapi/include/rtems/rbtree.h b/cpukit/sapi/include/rtems/rbtree.h
index 2005b36..dbc6d20 100644
--- a/cpukit/sapi/include/rtems/rbtree.h
+++ b/cpukit/sapi/include/rtems/rbtree.h
@@ -121,11 +121,11 @@ RTEMS_INLINE_ROUTINE void rtems_rbtree_initialize_empty(
  * This function sets the next and previous fields of the @a node to NULL
  * indicating the @a node is not part of any rbtree.
  */
-RTEMS_INLINE_ROUTINE void rtems_rbtree_set_off_rbtree(
+RTEMS_INLINE_ROUTINE void rtems_rbtree_set_off_tree(
   rtems_rbtree_node *node
 )
 {
-  _RBTree_Set_off_rbtree( node );
+  _RBTree_Set_off_tree( node );
 }
 
 /**
@@ -134,11 +134,11 @@ RTEMS_INLINE_ROUTINE void rtems_rbtree_set_off_rbtree(
  * This function returns true if the @a node is not on a rbtree. A @a node is
  * off rbtree if the next and previous fields are set to NULL.
  */
-RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_node_off_rbtree(
+RTEMS_INLINE_ROUTINE bool rtems_rbtree_is_node_off_tree(
   const rtems_rbtree_node *node
 )
 {
-  return _RBTree_Is_node_off_rbtree( node );
+  return _RBTree_Is_node_off_tree( node );
 }
 
 /**
diff --git a/cpukit/score/include/rtems/score/rbtree.h b/cpukit/score/include/rtems/score/rbtree.h
index 2ec77ea..94c8ee5 100644
--- a/cpukit/score/include/rtems/score/rbtree.h
+++ b/cpukit/score/include/rtems/score/rbtree.h
@@ -245,7 +245,7 @@ RBTree_Node *_RBTree_Insert(
  * @brief Extracts (removes) the node from the red-black tree.
  *
  * This function does not set the node off-tree.  In case this is desired, then
- * call _RBTree_Set_off_rbtree() after the extraction.
+ * call _RBTree_Set_off_tree() after the extraction.
  *
  * In case the node to extract is not a node of the tree, then this function
  * yields unpredictable results.
@@ -273,32 +273,35 @@ RBTree_Node *_RBTree_Next(
 );
 
 /**
- * @brief Set off RBtree.
+ * @brief Sets a red-black tree node as off-tree.
  *
- * This function sets the parent and child fields of the @a node to NULL
- * indicating the @a node is not part of a rbtree.
+ * Do not use this function on nodes which are a part of a tree.
  *
+ * @param[in] the_node The node to set off-tree.
+ *
+ * @see _RBTree_Is_node_off_tree().
  */
-RTEMS_INLINE_ROUTINE void _RBTree_Set_off_rbtree(
-    RBTree_Node *node
-    )
+RTEMS_INLINE_ROUTINE void _RBTree_Set_off_tree( RBTree_Node *the_node )
 {
-  node->parent = node->child[RBT_LEFT] = node->child[RBT_RIGHT] = NULL;
+  the_node->parent = NULL;
 }
 
 /**
- * @brief Is the node off RBTree.
+ * @brief Returns true, if this red-black tree node is off-tree, and false
+ * otherwise.
+ *
+ * @param[in] the_node The node to test.
+ *
+ * @retval true The node is not a part of a tree (off-tree).
+ * @retval false Otherwise.
  *
- * This function returns true if the @a node is not on a rbtree. A @a node is
- * off rbtree if the parent and child fields are set to NULL.
+ * @see _RBTree_Set_off_tree().
  */
-RTEMS_INLINE_ROUTINE bool _RBTree_Is_node_off_rbtree(
-    const RBTree_Node *node
-    )
+RTEMS_INLINE_ROUTINE bool _RBTree_Is_node_off_tree(
+  const RBTree_Node *the_node
+)
 {
-  return (node->parent == NULL) &&
-         (node->child[RBT_LEFT] == NULL) &&
-         (node->child[RBT_RIGHT] == NULL);
+  return the_node->parent == NULL;
 }
 
 /**
diff --git a/testsuites/sptests/sprbtree01/init.c b/testsuites/sptests/sprbtree01/init.c
index 2c62d12..68b2c92 100644
--- a/testsuites/sptests/sprbtree01/init.c
+++ b/testsuites/sptests/sprbtree01/init.c
@@ -235,8 +235,8 @@ rtems_task Init( rtems_task_argument ignored )
   puts( "Init - Initialize rbtree empty" );
   rtems_rbtree_initialize_empty( &rbtree1 );
 
-  rtems_rbtree_set_off_rbtree( &node1.Node );
-  rtems_test_assert( rtems_rbtree_is_node_off_rbtree( &node1.Node ) );
+  rtems_rbtree_set_off_tree( &node1.Node );
+  rtems_test_assert( rtems_rbtree_is_node_off_tree( &node1.Node ) );
 
   /* verify that the rbtree insert work */
   puts( "INIT - Verify rtems_rbtree_insert with two nodes" );
@@ -247,7 +247,7 @@ rtems_task Init( rtems_task_argument ignored )
   rb_insert_unique( &rbtree1, &node1.Node );
   rb_insert_unique( &rbtree1, &node2.Node );
 
-  rtems_test_assert( !rtems_rbtree_is_node_off_rbtree( &node1.Node ) );
+  rtems_test_assert( !rtems_rbtree_is_node_off_tree( &node1.Node ) );
 
   _RBTree_Rotate(NULL, RBT_LEFT);
   i = (node1.Node.parent == &node2.Node);
@@ -360,7 +360,7 @@ rtems_task Init( rtems_task_argument ignored )
     puts( "INIT - rtems_rbtree_extract failed");
     rtems_test_exit(0);
   }
-  rtems_test_assert( !rtems_rbtree_is_node_off_rbtree( p ) );
+  rtems_test_assert( !rtems_rbtree_is_node_off_tree( p ) );
   rb_insert_unique(&rbtree1, p);
 
   for ( p = rtems_rbtree_get_min(&rbtree1), id = 1 ; p ;
-- 
1.8.1.4