/** @brief Validate and fix-up tree properties for a new insert/colored node
*
* This routine checks and fixes the Red-Black Tree properties based on
* @a the_node being just added to the tree.
*
* @note It does NOT disable interrupts to ensure the atomicity of the
* append operation.
*/
void _RBTree_Validate_insert_unprotected(
RBTree_Node *the_node
)
{
RBTree_Node *u,*g;
/* note: the insert root case is handled already */
/* if the parent is black, nothing needs to be done
* otherwise may need to loop a few times */
while (_RBTree_Is_red(_RBTree_Parent(the_node))) {
u = _RBTree_Parent_sibling(the_node);
g = the_node->parent->parent;
/* if uncle is red, repaint uncle/parent black and grandparent red */
if(_RBTree_Is_red(u)) {
the_node->parent->color = RBT_BLACK;
u->color = RBT_BLACK;
g->color = RBT_RED;
the_node = g;
} else { /* if uncle is black */
RBTree_Direction dir = the_node != the_node->parent->child[0];
RBTree_Direction pdir = the_node->parent != g->child[0];
/* ensure node is on the same branch direction as parent */
if (dir != pdir) {
_RBTree_Rotate(the_node->parent, pdir);
the_node = the_node->child[pdir];
}
the_node->parent->color = RBT_BLACK;
g->color = RBT_RED;
/* now rotate grandparent in the other branch direction (toward uncle) */
_RBTree_Rotate(g, (1-pdir));
}
}
if(!the_node->parent->parent) the_node->color = RBT_BLACK;
}
rtems_task Init(
rtems_task_argument ignored
)
{
rtems_rbtree_control rbtree1;
rtems_rbtree_node *p;
test_node node1, node2;
test_node node_array[100];
test_node search_node;
int id;
int i;
puts( "\n\n*** TEST OF RTEMS RBTREE API ***" );
puts( "Init - Initialize rbtree empty" );
rtems_rbtree_initialize_empty( &rbtree1, &test_compare_function, true );
if ( !rtems_rbtree_is_unique( &rbtree1 ) )
puts( "INIT - FAILED IS UNIQUE CHECK" );
if ( rtems_rbtree_is_unique( NULL ) )
puts( "INIT - FAILED IS UNIQUE CHECK" );
/* verify that the rbtree insert work */
puts( "INIT - Verify rtems_rbtree_insert with two nodes" );
node1.id = 1;
node1.key = 1;
node2.id = 2;
node2.key = 2;
rtems_rbtree_insert( &rbtree1, &node1.Node );
rtems_rbtree_insert( &rbtree1, &node2.Node );
p = rtems_rbtree_insert( &rbtree1, NULL );
if (p != (void *)(-1))
puts( "INIT - FAILED NULL NODE INSERT" );
_RBTree_Rotate(NULL, RBT_LEFT);
i = (node1.Node.parent == &node2.Node);
_RBTree_Rotate( &node1.Node,
!node1.Node.child[RBT_LEFT] ? RBT_RIGHT : RBT_LEFT
);
if ( (node1.Node.parent == &node2.Node) != i )
puts( "INIT - FAILED FALSE ROTATION" );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 1 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 2 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if (id < 2) {
puts("INIT - NOT ENOUGH NODES ON RBTREE");
rtems_test_exit(0);
}
puts("INIT - Verify rtems_rbtree_insert with the same value twice");
node2.key = node1.key;
rtems_rbtree_insert(&rbtree1, &node1.Node);
p = rtems_rbtree_insert(&rbtree1, &node2.Node);
if (p != &node1.Node)
puts( "INIT - FAILED DUPLICATE INSERT" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 1 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 1 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if (id < 1) {
puts("INIT - NOT ENOUGH NODES ON RBTREE");
rtems_test_exit(0);
}
node2.key = 2;
/* verify that the rbtree is empty */
puts( "INIT - Verify rtems_rbtree_is_empty" );
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_XXX on an empty tree" );
if(rtems_rbtree_get_min(&rbtree1)) {
puts("INIT - get_min on empty returned non-NULL");
rtems_test_exit(0);
}
if(rtems_rbtree_get_max(&rbtree1)) {
puts("INIT - get_max on empty returned non-NULL");
rtems_test_exit(0);
}
if(rtems_rbtree_peek_min(&rbtree1)) {
puts("INIT - peek_min on empty returned non-NULL");
rtems_test_exit(0);
}
if(rtems_rbtree_peek_max(&rbtree1)) {
puts("INIT - peek_max on empty returned non-NULL");
rtems_test_exit(0);
}
/* verify that the rbtree insert works after a tree is emptied */
puts( "INIT - Verify rtems_rbtree_insert after empty tree" );
node1.id = 2;
node1.key = 2;
node2.id = 1;
node2.key = 1;
rtems_rbtree_insert( &rbtree1, &node1.Node );
rtems_rbtree_insert( &rbtree1, &node2.Node );
puts( "INIT - Verify rtems_rbtree_peek_max/min, rtems_rbtree_extract" );
test_node *t1 = rtems_rbtree_container_of(rtems_rbtree_peek_max(&rbtree1),
test_node,Node);
test_node *t2 = rtems_rbtree_container_of(rtems_rbtree_peek_min(&rbtree1),
test_node,Node);
if (t1->key - t2->key != 1) {
puts( "INIT - Peek Min - Max failed" );
rtems_test_exit(0);
}
p = rtems_rbtree_peek_max(&rbtree1);
rtems_rbtree_extract(&rbtree1, p);
t1 = rtems_rbtree_container_of(p,test_node,Node);
if (t1->key != 2) {
puts( "INIT - rtems_rbtree_extract failed");
rtems_test_exit(0);
}
rtems_rbtree_insert(&rbtree1, p);
for ( p = rtems_rbtree_get_min(&rbtree1), id = 1 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 2 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
}
puts( "INIT - Verify rtems_rbtree_insert with 100 nodes value [0,99]" );
for (i = 0; i < 100; i++) {
node_array[i].id = i;
node_array[i].key = i;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_rbtree_insert with 100 nodes value [99,0]" );
for (i = 0; i < 100; i++) {
node_array[i].id = 99-i;
node_array[i].key = 99-i;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
/* testing rbtree_extract by adding 100 nodes then removing the 20 with
* keys specified by the numbers array, then removing the rest */
puts( "INIT - Verify rtems_rbtree_extract with 100 nodes value [0,99]" );
for (i = 0; i < 100; i++) {
node_array[i].id = i;
node_array[i].key = i;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Extracting 20 random nodes" );
for (i = 0; i < 20; i++) {
id = numbers[i];
rtems_rbtree_extract( &rbtree1, &node_array[id].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Removing 80 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0, i = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p, test_node, Node);
while ( id == numbers_sorted[i] ) {
/* skip if expected minimum (id) is in the set of extracted numbers */
id++;
i++;
}
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
/* Additional rtems_rbtree_extract test which removes a node
* with two children while target node has a left child only. */
for ( i = 0; i < 7; i++ ) {
node_array[i].id = i;
node_array[i].key = i;
}
rtems_rbtree_insert( &rbtree1, &node_array[3].Node );
rtems_rbtree_insert( &rbtree1, &node_array[1].Node );
rtems_rbtree_insert( &rbtree1, &node_array[5].Node );
rtems_rbtree_insert( &rbtree1, &node_array[0].Node );
rtems_rbtree_insert( &rbtree1, &node_array[2].Node );
rtems_rbtree_insert( &rbtree1, &node_array[4].Node );
rtems_rbtree_insert( &rbtree1, &node_array[6].Node );
rtems_rbtree_extract( &rbtree1, &node_array[2].Node );
/* node_array[1] has now only a left child. */
if ( !node_array[1].Node.child[RBT_LEFT] ||
node_array[1].Node.child[RBT_RIGHT] )
puts( "INIT - LEFT CHILD ONLY NOT FOUND" );
rtems_rbtree_extract( &rbtree1, &node_array[3].Node );
while( (p = rtems_rbtree_get_max(&rbtree1)) );
puts( "INIT - Verify rtems_rbtree_get_max with 100 nodes value [99,0]" );
for (i = 0; i < 100; i++) {
node_array[i].id = 99-i;
node_array[i].key = 99-i;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_max(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_max(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != 99-id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_rbtree_get_max with 100 nodes value [0,99]" );
for (i = 0; i < 100; i++) {
node_array[i].id = i;
node_array[i].key = i;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Verify rtems_rbtree_find" );
search_node.key = 30;
p = rtems_rbtree_find(&rbtree1, &search_node.Node);
if(rtems_rbtree_container_of(p,test_node,Node)->id != 30) {
puts ("INIT - ERROR ON RBTREE ID MISMATCH");
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_rbtree_predecessor/successor");
p = rtems_rbtree_predecessor(&rbtree1, p);
if(p && rtems_rbtree_container_of(p,test_node,Node)->id != 29) {
puts ("INIT - ERROR ON RBTREE ID MISMATCH");
rtems_test_exit(0);
}
p = rtems_rbtree_find(&rbtree1, &search_node.Node);
p = rtems_rbtree_successor(&rbtree1, p);
if(p && rtems_rbtree_container_of(p,test_node,Node)->id != 31) {
puts ("INIT - ERROR ON RBTREE ID MISMATCH");
rtems_test_exit(0);
}
p = rtems_rbtree_find(&rbtree1, &search_node.Node);
puts( "INIT - Verify rtems_rbtree_find_header" );
if (rtems_rbtree_find_header(p) != &rbtree1) {
puts ("INIT - ERROR ON RBTREE HEADER MISMATCH");
rtems_test_exit(0);
}
if ( _RBTree_Sibling( NULL ) != NULL )
puts ( "INIT - ERROR ON RBTREE NULL SIBLING MISMATCH" );
if ( _RBTree_Sibling( rbtree1.root ) != NULL )
puts ( "INIT - ERROR ON RBTREE NULL SIBLING MISMATCH" );
if ( _RBTree_Grandparent( NULL ) != NULL )
puts ( "INIT - ERROR ON RBTREE NULL GRANDPARENT MISMATCH" );
if ( _RBTree_Is_red( NULL ) != 0 )
puts ( "INIT - ERROR ON RBTREE NULL IS RED MISMATCH" );
if ( _RBTree_Is_red( rbtree1.root ) != 0 )
puts ( "INIT - ERROR ON RBTREE NULL IS RED MISMATCH" );
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_max(&rbtree1), id = 99 ; p ;
p = rtems_rbtree_get_max(&rbtree1) , id-- ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id < 0 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
if (rtems_rbtree_find_header(&node_array[0].Node) != NULL) {
puts ("INIT - ERROR ON RBTREE HEADER MISMATCH");
rtems_test_exit(0);
}
if (rtems_rbtree_find_header(NULL) != NULL) {
puts ("INIT - ERROR ON RBTREE HEADER MISMATCH");
rtems_test_exit(0);
}
puts("INIT - Insert 20 random numbers");
for (i = 0; i < 20; i++) {
node_array[i].id = numbers[i];
node_array[i].key = numbers[i];
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Removing 20 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 19 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != numbers_sorted[id] ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_rbtree_initialize with 100 nodes value [0,99]" );
for (i = 0; i < 100; i++) {
node_array[i].id = i;
node_array[i].key = i;
}
rtems_rbtree_initialize( &rbtree1, &test_compare_function,
&node_array[0].Node, 100,
sizeof(test_node), true );
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != id ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
/* Initialize the tree for duplicate keys */
puts( "Init - Initialize duplicate rbtree empty" );
rtems_rbtree_initialize_empty( &rbtree1, &test_compare_function, false );
if ( rtems_rbtree_is_unique( &rbtree1 ) )
puts( "INIT - FAILED IS UNIQUE CHECK" );
if ( rtems_rbtree_is_unique( NULL ) )
puts( "INIT - FAILED IS UNIQUE CHECK" );
puts( "INIT - Verify rtems_rbtree_insert with 100 nodes value [0,99]" );
for (i = 0; i < 100; i++) {
node_array[i].id = i;
node_array[i].key = i%5;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Verify rtems_rbtree_find in a duplicate tree" );
search_node.key = 2;
p = rtems_rbtree_find(&rbtree1, &search_node.Node);
if(rtems_rbtree_container_of(p,test_node,Node)->id != 2) {
puts ("INIT - ERROR ON RBTREE ID MISMATCH");
rtems_test_exit(0);
}
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != ( ((id*5)%100) + (id/20) ) ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "INIT - Verify rtems_rbtree_insert with 100 nodes value [99,0]" );
for (i = 0; i < 100; i++) {
node_array[i].id = 99-i;
node_array[i].key = (99-i)%5;
rtems_rbtree_insert( &rbtree1, &node_array[i].Node );
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
puts( "INIT - Verify rtems_rbtree_find in a duplicate tree" );
search_node.key = 2;
p = rtems_rbtree_find(&rbtree1, &search_node.Node);
if(rtems_rbtree_container_of(p,test_node,Node)->id != 97) {
puts ("INIT - ERROR ON RBTREE ID MISMATCH");
rtems_test_exit(0);
}
puts( "INIT - Removing 100 nodes" );
for ( p = rtems_rbtree_get_min(&rbtree1), id = 0 ; p ;
p = rtems_rbtree_get_min(&rbtree1) , id++ ) {
test_node *t = rtems_rbtree_container_of(p,test_node,Node);
if ( id > 99 ) {
puts( "INIT - TOO MANY NODES ON RBTREE" );
rtems_test_exit(0);
}
if ( t->id != ( (((99-id)*5)%100) + (id/20) ) ) {
puts( "INIT - ERROR ON RBTREE ID MISMATCH" );
rtems_test_exit(0);
}
if (!rb_assert(rbtree1.root) )
puts( "INIT - FAILED TREE CHECK" );
}
if(!rtems_rbtree_is_empty(&rbtree1)) {
puts( "INIT - TREE NOT EMPTY" );
rtems_test_exit(0);
}
puts( "*** END OF RTEMS RBTREE API TEST ***" );
rtems_test_exit(0);
}
/** @brief Validate and fix-up tree properties after deleting a node
*
* This routine is called on a black node, @a the_node, after its deletion.
* This function maintains the properties of the red-black tree.
*
* @note It does NOT disable interrupts to ensure the atomicity
* of the extract operation.
*/
static void _RBTree_Extract_validate( RBTree_Node *the_node )
{
RBTree_Node *parent;
parent = the_node->parent;
if ( !parent->parent )
return;
/* continue to correct tree as long as the_node is black and not the root */
while ( !_RBTree_Is_red( the_node ) && parent->parent ) {
RBTree_Node *sibling = _RBTree_Sibling( the_node, parent );
/* if sibling is red, switch parent (black) and sibling colors,
* then rotate parent left, making the sibling be the_node's grandparent.
* Now the_node has a black sibling and red parent. After rotation,
* update sibling pointer.
*/
if ( _RBTree_Is_red( sibling ) ) {
RBTree_Direction dir = _RBTree_Direction( the_node, parent );
RBTree_Direction opp_dir = _RBTree_Opposite_direction( dir );
parent->color = RBT_RED;
sibling->color = RBT_BLACK;
_RBTree_Rotate( parent, dir );
sibling = parent->child[ opp_dir ];
}
/* sibling is black, see if both of its children are also black. */
if ( !_RBTree_Is_red( sibling->child[ RBT_RIGHT ] ) &&
!_RBTree_Is_red( sibling->child[ RBT_LEFT ] ) ) {
sibling->color = RBT_RED;
if ( _RBTree_Is_red( parent ) ) {
parent->color = RBT_BLACK;
break;
}
the_node = parent; /* done if parent is red */
parent = the_node->parent;
} else {
/* at least one of sibling's children is red. we now proceed in two
* cases, either the_node is to the left or the right of the parent.
* In both cases, first check if one of sibling's children is black,
* and if so rotate in the proper direction and update sibling pointer.
* Then switch the sibling and parent colors, and rotate through parent.
*/
RBTree_Direction dir = _RBTree_Direction( the_node, parent );
RBTree_Direction opp_dir = _RBTree_Opposite_direction( dir );
if (
!_RBTree_Is_red( sibling->child[ opp_dir ] )
) {
sibling->color = RBT_RED;
sibling->child[ dir ]->color = RBT_BLACK;
_RBTree_Rotate( sibling, opp_dir );
sibling = parent->child[ opp_dir ];
}
sibling->color = parent->color;
parent->color = RBT_BLACK;
sibling->child[ opp_dir ]->color = RBT_BLACK;
_RBTree_Rotate( parent, dir );
break; /* done */
}
} /* while */
if ( !the_node->parent->parent )
the_node->color = RBT_BLACK;
}