/**
* binary_tree_delete - deletes an entire binary tree
* @tree: binary tree to delete
* Return: nothing
*/
void binary_tree_delete(binary_tree_t *tree)
{
if (tree == NULL)
return;
binary_tree_delete(tree->right);
binary_tree_delete(tree->left);
free(tree);
}
int bus_detatch(struct bus_t *self_p,
struct bus_listener_t *listener_p)
{
ASSERTN(self_p != NULL, EINVAL);
ASSERTN(listener_p != NULL, EINVAL);
int res = 0;
struct bus_listener_t *head_p, *curr_p, *prev_p;
rwlock_writer_take(&self_p->rwlock);
head_p = (struct bus_listener_t *)binary_tree_search(
&self_p->listeners, listener_p->id);
if (head_p == NULL) {
res = -1;
} else if (head_p == listener_p) {
res = binary_tree_delete(&self_p->listeners, listener_p->id);
if (listener_p->next_p != NULL) {
binary_tree_insert(&self_p->listeners,
&listener_p->next_p->base);
}
} else {
curr_p = head_p->next_p;
prev_p = head_p;
res = -1;
while (curr_p != NULL) {
if (curr_p == listener_p) {
prev_p->next_p = listener_p->next_p;
res = 0;
break;
}
prev_p = curr_p;
curr_p = curr_p->next_p;
}
}
rwlock_writer_give(&self_p->rwlock);
return (res);
}
static void rb_delete(qrb_tree *tree_p, qrb_node *n_p )
{
qrb_node *c_p; // the single non-leaf child
qrb_node *parent;
tree_p->node_count --;
if( tree_p->node_count == 0 ){
assert( IS_ROOT_NODE(n_p) );
givbuf(n_p);
tree_p->root = NULL;
return;
}
if( n_p->left != NULL && n_p->right != NULL ){
//fprintf(stderr,"before calling binary_tree_delete:\n");
//dump_rb_node(n_p);
n_p = binary_tree_delete(n_p);
//fprintf(stderr,"after calling binary_tree_delete:\n");
//dump_rb_node(n_p);
} else if( IS_ROOT_NODE(n_p) ){
// we are deleting a root node with only one child
if( n_p->left != NULL ){
set_root_node(tree_p,n_p->left);
} else {
set_root_node(tree_p,n_p->right);
}
givbuf(n_p);
return;
}
assert( n_p->left == NULL || n_p->right == NULL );
if( n_p->left != NULL )
c_p = n_p->left;
else c_p = n_p->right; // may be NULL
// if c_p is null, then we need to keep a reference to the parent...
parent=n_p->parent;
replace_node(tree_p,n_p,c_p);
if( IS_RED(n_p) ){
givbuf(n_p);
return;
}
// Now we can free n_p
givbuf(n_p);
if( IS_RED(c_p) ){
MAKE_BLACK(c_p);
return;
}
// Now we know the node in question is black and has no red child
//assert( n_p->left != NULL && n_p->right != NULL );
// Now we know that both n_p and c_p are black
rebalance(tree_p,c_p,parent);
}
