Transparently Mixing Undo Logs and Software Reversibility for State Recovery in Optimistic PDES
Transparently Mixing Undo Logs and Software Reversibility for State Recovery in Optimistic PDES
复制标题
透明地混合撤消日志和软件可逆性以实现乐观 PDES 中的状态恢复
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Quaglia
中科院分区：
文献类型：
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作者：
Davide Cingolani;Alessandro Pellegrini;F. Quaglia
回滚操作是支持基于时间扭曲的并行离散事件仿真正确执行的基本构件。在文献中，已经提出了几种解决方案，以减少此操作的执行成本，无论是基于先前的模拟状态图像的检查点的创建，或在能够撤销状态更新的模拟事件的负副本的执行。在本文中，我们探讨了实际的设计和实现的状态可恢复性技术，它允许恢复以前的模拟状态依赖于检查点或反向执行的状态更新，而在正向模式下处理事件。与其他提案不同，我们解决了以完全透明和事件粒度独立的方式执行向后更新的问题，依靠静态软件插装（针对x86架构和Linux系统）在运行时生成反向更新代码块（不要与反向事件混淆，正确的反向计算方法）。它们能够撤消正向执行的效果，同时最小化撤消操作的成本。我们还提出了与我们的实现，这是作为免费软件发布，并完全集成到开源的ROOT-Sim（罗马Optimistic模拟器）包的实验结果。实验数据支持我们的建议的可行性和有效性。
The rollback operation is a fundamental building block to support the correct execution of a speculative Time Warp-based Parallel Discrete Event Simulation. In the literature, several solutions to reduce the execution cost of this operation have been proposed, either based on the creation of a checkpoint of previous simulation state images, or on the execution of negative copies of simulation events which are able to undo the updates on the state. In this paper, we explore the practical design and implementation of a state recoverability technique which allows to restore a previous simulation state either relying on checkpointing or on the reverse execution of the state updates occurred while processing events in forward mode. Differently from other proposals, we address the issue of executing backward updates in a fully-transparent and event granularity-independent way, by relying on static software instrumentation (targeting the x86 architecture and Linux systems) to generate at runtime reverse update code blocks (not to be confused with reverse events, proper of the reverse computing approach). These are able to undo the effects of a forward execution while minimizing the cost of the undo operation. We also present experimental results related to our implementation, which is released as free software and fully integrated into the open source ROOT-Sim (ROme OpTimistic Simulator) package. The experimental data support the viability and effectiveness of our proposal.