void print_task_list()
{
int i = 0;
list_node_t *node = NULL;
list_foreach(task_list, node) {
task_t *task = node->key;
kprintf("task #%d:\n", i);
kprintf(" PID = %d\n", task->pid);
kprintf(" status = %d\n", task->status);
kprintf(" ustack = %x\n", task->mm->ustack);
kprintf(" kstack_start = %x\n", task->mm->kstack_start);
kprintf(" kstack_current = %x\n", task->mm->kstack_current);
kprintf(" page_directory = %x\n", task->mm->page_directory);
print_preorder(rbtree_root(task->mm->rb_vmallocs));
i++;
}
/*
* Returns the successor of node, or nil if there is none.
*/
static struct rbnode *rbsuccessor(struct rbtree *tree, struct rbnode *node)
{
struct rbnode *succ;
if ((succ = node->right) != rbnil(tree)) {
while (succ->left != rbnil(tree)) {
succ = succ->left;
}
} else {
/* No right child, move up until we find it or hit the root */
for (succ = node->parent; node == succ->right; succ = succ->parent) {
node = succ;
}
if (succ == rbtree_root(tree)) {
succ = rbnil(tree);
}
}
return (succ);
}
/*
* Delete node 'z' from the tree and return its data pointer.
*/
void *rbtree_delete(struct rbtree *tree, struct rbnode *z)
{
struct rbnode *x, *y;
void *data = z->data;
if (z->left == rbnil(tree) || z->right == rbnil(tree)) {
y = z;
} else {
y = rbsuccessor(tree, z);
}
x = (y->left == rbnil(tree)) ? y->right : y->left;
if ((x->parent = y->parent) == rbtree_root(tree)) {
rbtree_first(tree) = x;
} else {
if (y == y->parent->left) {
y->parent->left = x;
} else {
y->parent->right = x;
}
}
if (y->color == black) {
rbrepair(tree, x);
}
if (y != z) {
y->left = z->left;
y->right = z->right;
y->parent = z->parent;
y->color = z->color;
z->left->parent = z->right->parent = y;
if (z == z->parent->left) {
z->parent->left = y;
} else {
z->parent->right = y;
}
}
free(z);
tree->num_nodes--;
return (data);
}
/*
* If a node matching "data" already exists, a pointer to
* the existant node is returned. Otherwise we return NULL.
*/
struct rbnode *rbtree_insert(struct rbtree *tree, void *data)
{
struct rbnode *node = rbtree_first(tree);
struct rbnode *parent = rbtree_root(tree);
int res;
/* Find correct insertion point. */
while (node != rbnil(tree)) {
parent = node;
if ((res = tree->compar(data, node->data)) == 0) {
return (node);
}
node = res < 0 ? node->left : node->right;
}
node = (struct rbnode *) malloc(sizeof(*node));
node->data = data;
node->left = node->right = rbnil(tree);
node->parent = parent;
if (parent == rbtree_root(tree) || tree->compar(data, parent->data) < 0) {
parent->left = node;
} else {
parent->right = node;
}
node->color = red;
/*
* If the parent node is black we are all set, if it is red we have
* the following possible cases to deal with. We iterate through
* the rest of the tree to make sure none of the required properties
* is violated.
*
* 1) The uncle is red. We repaint both the parent and uncle black
* and repaint the grandparent node red.
*
* 2) The uncle is black and the new node is the right child of its
* parent, and the parent in turn is the left child of its parent.
* We do a left rotation to switch the roles of the parent and
* child, relying on further iterations to fixup the old parent.
*
* 3) The uncle is black and the new node is the left child of its
* parent, and the parent in turn is the left child of its parent.
* We switch the colors of the parent and grandparent and perform
* a right rotation around the grandparent. This makes the former
* parent the parent of the new node and the former grandparent.
*
* Note that because we use a sentinel for the root node we never
* need to worry about replacing the root.
*/
while (node->parent->color == red) {
struct rbnode *uncle;
if (node->parent == node->parent->parent->left) {
uncle = node->parent->parent->right;
if (uncle->color == red) {
node->parent->color = black;
uncle->color = black;
node->parent->parent->color = red;
node = node->parent->parent;
} else { /* if (uncle->color == black) */
if (node == node->parent->right) {
node = node->parent;
rotate_left(tree, node);
}
node->parent->color = black;
node->parent->parent->color = red;
rotate_right(tree, node->parent->parent);
}
} else { /* if (node->parent == node->parent->parent->right) */
uncle = node->parent->parent->left;
if (uncle->color == red) {
node->parent->color = black;
uncle->color = black;
node->parent->parent->color = red;
node = node->parent->parent;
} else { /* if (uncle->color == black) */
if (node == node->parent->left) {
node = node->parent;
rotate_right(tree, node);
}
node->parent->color = black;
node->parent->parent->color = red;
rotate_left(tree, node->parent->parent);
}
}
}
tree->num_nodes++;
rbtree_first(tree)->color = black; /* first node is always black */
return (NULL);
}