SHF: Small: Specifying and Verifying Essential Deterministic Behavior of Concurrent Programs

SHF：小：指定和验证并发程序的基本确定性行为

• 批准号: 1018730
• 负责人: Koushik Sen
• 金额: $ 47.54万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1018730&HistoricalAwards=false
• 关键词: SHF; Small; Specifying; Verifying; Essential

Parallel multi-threaded programs are more difficult to write than their sequential counterparts because while writing parallel programs programmers must consider all possible behaviors due to thread interleavings, in addition to the algorithmic correctness of the program. A widespread belief is that the only way to make multi-threaded programming accessible to a large number of programmers is to come up with programming paradigms and associated tools that explicitly separate reasoning about functional correctness from reasoning about additional behaviors arising due to parallelism.This project investigates strategies for separating the parallelization correctness aspect of a program from its functional correctness. First, for most parallel programs it is desired that the non-determinism introduced by the thread scheduler in a parallel program does not change the intended output of the program. This project will develop an assertion framework for specifying that regions of a parallel program behave deterministically despite non-deterministic thread interleaving.The second strategy is based on the observation that a natural step in the development of a parallel program is to first extend the sequential algorithm with a controlled amount of non-determinism, followed by the actual parallelization, when additional non-determinism is introduced by thread interleavings. This project will investigate the use of non-deterministic sequential programs as a specification mechanism, such that for each execution of a parallel program there exists an equivalent execution of the corresponding non-deterministic sequential program. Such non-deterministic sequential programs decouple parallelization correctness from functional correctness.

并行多线程程序比顺序程序更难编写，因为在编写并行程序时，除了程序的算法正确性之外，程序员还必须考虑由于线程交错而导致的所有可能行为。 人们普遍认为，让大量程序员能够使用多线程编程的唯一方法是提出编程范例和相关工具，将功能正确性的推理与并行性引起的其他行为的推理明确分开。该项目研究将程序的并行化正确性方面与其功能正确性分开的策略。首先，对于大多数并行程序来说，希望并行程序中线程调度程序引入的非确定性不会改变程序的预期输出。 该项目将开发一个断言框架，用于指定并行程序的区域在非确定性线程交错的情况下仍具有确定性行为。第二种策略基于以下观察：并行程序开发的自然步骤是首先使用受控量的非确定性扩展顺序算法，然后当线程交错引入额外的非确定性时，进行实际并行化。该项目将研究使用非确定性顺序程序作为规范机制，以便对于并行程序的每次执行，都存在相应非确定性顺序程序的等效执行。这种非确定性顺序程序将并行化正确性与功能正确性分离。