用于并行调试环境的改进的物理时钟算法

为满足并行调试需要,时钟模型必须既能保证事件之间的逻辑顺序,又能为性能调试提供时间戳。现有的基于事件的物理时钟同步算法在时间戳上可能存在较大误差,为了降低误差,对现有算法进行改进。改进的算法依次对时钟偏移误差最大的局部时钟进行调整,调整的依据是两个节点之间消息的发送和接收具有对等性,调整的时候考虑了该进程和其它所有进程之间的通信传输。模拟结果表明:该算法以较小的时间代价,减少了90%左右的误差。该算法可以解决并行调试环境中的时钟同步问题。

Algorithm for synchronizing physical clocks in a parallel debugging environment

In a parallel debugging environment,a synchronized clock is required to maintain the partial order among distributed events while keeping the local real time as the event timestamp.Currently used event-based physical clocks may distort the real times.The improved algorithm adjusts the local physical clock based on the time differenes using the fact that message sending and receiving between two nodes is equivalent.The algorithm also analyzes communications between local processes and all other processes.Simulation results show that the improved algorithm reduces the error by about 90%.The algorithm can be used to solve clock synchronizing problems in parallel debugging environments.