Efficient Debugging of Parallel Programs

该项目致力于设计和实现并行程序调试系统的技术算法。 使用回流分析可以提供有关程序执行中事件之间因果关系的信息，而无需重新执行程序进行调试。 回流分析直接让程序员关注问题的原因。 解决了两个主要问题：（1）通过开发一种显着减少程序执行期间引起的开销的方法，使回流分析变得实用；（2）将回流分析的语义扩展到并行程序。 增量跟踪使用被调试程序的语义分析，使得回溯分析变得实用，并且在执行过程中仅生成少量跟踪。 回流分析已扩展到适用于并行程序、处理同步活动、进程之间的依赖关系以及共享内存访问。 还描述了一种检测协作进程的交互中的竞争条件的方法。 有效调试并行和顺序程序所需的技术和算法被纳入基于商用多处理器构建的原型系统中。

This project addresses techniques algorithms for design and implementation of a debugging system for parallel programs. The use of flowback analysis provides information on causal relationships between events in a program's execution, without having to re-execute the program for debugging. Flowback analysis directly focuses the programmer on the cause of a problem. Two major issues are addressed: (1) making flowback analysis practical by developing a method that significantly reduces the overhead induced during program execution, and (2) extending the semantics of flowback analysis to parallel programs. Incremental tracing, using semantic analyses of the debugged program, makes the folwback analysis practical with only a small amount of trace generated during execution. Flowback analysis is extended to apply to parallel programs, handling synchronization activities, dependencies between processes, and shared memory access. A method to detect race conditions in the interactions of the co-operating processes is also described. The techniques and algorithms necessary to efficiently debugging both parallel and sequential programs are incorporated in a prototype system built on a commercially available multiprocessor.