static struct binder_ref *binder_get_ref_for_node_olocked(
					struct binder_proc *proc,
					struct binder_node *node,
					struct binder_ref *new_ref)
{
	struct binder_context *context = proc->context;
	struct rb_node **p = &proc->refs_by_node.rb_node;
	struct rb_node *parent = NULL;
	struct binder_ref *ref;
	struct rb_node *n;

	while (*p) {
		parent = *p;
		ref = rb_entry(parent, struct binder_ref, rb_node_node);

		if (node < ref->node)
			p = &(*p)->rb_left;
		else if (node > ref->node)
			p = &(*p)->rb_right;
		else
			return ref;
	}
	if (!new_ref)
		return NULL;

	binder_stats_created(BINDER_STAT_REF);
	new_ref->data.debug_id = atomic_inc_return(&binder_last_id);
	new_ref->proc = proc;
	new_ref->node = node;
	rb_link_node(&new_ref->rb_node_node, parent, p);
	rb_insert_color(&new_ref->rb_node_node, &proc->refs_by_node);

	new_ref->data.desc = (node == context->binder_context_mgr_node) ? 0 : 1;
	for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) {
		ref = rb_entry(n, struct binder_ref, rb_node_desc);
		if (ref->data.desc > new_ref->data.desc)
			break;
		new_ref->data.desc = ref->data.desc + 1;
	}

	p = &proc->refs_by_desc.rb_node;
	while (*p) {
		parent = *p;
		ref = rb_entry(parent, struct binder_ref, rb_node_desc);

		if (new_ref->data.desc < ref->data.desc)
			p = &(*p)->rb_left;
		else if (new_ref->data.desc > ref->data.desc)
			p = &(*p)->rb_right;
		else
			BUG();
	}
	rb_link_node(&new_ref->rb_node_desc, parent, p);
	rb_insert_color(&new_ref->rb_node_desc, &proc->refs_by_desc);

	binder_node_lock(node);
	hlist_add_head(&new_ref->node_entry, &node->refs);

	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
		     "%d new ref %d desc %d for node %d\n",
		      proc->pid, new_ref->data.debug_id, new_ref->data.desc,
		      node->debug_id);
	binder_node_unlock(node);
	return new_ref;
}
Unknown