Method clear

Kernel/include/list.h:232–246

	}

	void clear() {
		acquireLock(&lock);

		ListNode<T>* node = front;
		while (node && node->next) {
			ListNode<T>* n = node->next;
			kfree(node);
			node = n;
		}
		front = NULL;
		back = NULL;
		num = 0;

		releaseLock(&lock);
	}

	void add_back(const T& obj) {
		acquireLock(&lock);