A deadlock in a packet switching network is a state in which one or more messages have not yet reached their target, yet cannot progress any further. We formalize three different notions of deadlock in the context of packet switching networks, to which we refer as global, local and weak deadlock. We establish the precise relations between these notions, and prove they characterize different sets of deadlocks. Moreover, we implement checking of deadlock freedom of packet switching networks using the symbolic model checker nuXmv. We show experimentally that the implementation is effective at finding subtle deadlock situations in packet switching networks.

中文翻译：

---

分组交换网络中的死锁

分组交换网络中的死锁是一种状态，其中一个或多个消息尚未到达其目标，但无法进一步进行。在分组交换网络的上下文中，我们将死锁的三种概念形式化，我们将其称为全局，局部和弱死锁。我们在这些概念之间建立了精确的关系，并证明它们具有不同的僵局特征。此外，我们使用符号模型检查器nuXmv实现了分组交换网络的死锁自由性检查。我们通过实验表明，该实现有效地发现了分组交换网络中的细微死锁情况。