CAREER: Practical Language and System Support for Reliable Concurrent Software

职业：可靠并发软件的实用语言和系统支持

• 批准号: 1253703
• 负责人: Michael Bond
• 金额: $ 55.51万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253703&HistoricalAwards=false
• 关键词: CAREER; Practical; Language; System; Support

Over the past several decades, computer system performance has grown exponentially, enabling progress on key problems in science, engineering, health, and other areas. Owing to power, heat, and wire length limitations, however, microprocessors are now adding more, instead of faster, cores with each successive generation. As a result, general-purpose software must become more concurrent to see continued performance gains. Unfortunately, writing and debugging shared-memory concurrent software is notoriously difficult. A key problem is that most shared-memory programming languages and software systems do not provide good support for correct concurrent execution. They lack such support because all known approaches are impractical. This project aims to provide practical support for concurrency correctness in commodity systems. It develops low-overhead, software-only approaches that execute on existing commodity hardware. These approaches help programmers write and debug more reliable, scalable software, and to make software more reliable automatically by eliminating whole classes of errors. These benefits have the potential to enable society to continue to rely on software systems for increasingly complex, critical tasks. Furthermore, the project includes educational and outreach activities that help educate students in concurrent software systems, enhance dissemination of the ideas and outcomes, and broaden participation in computer science.The project develops practical, always-on dynamic checking and enforcement of key concurrency correctness properties: atomicity, sequential consistency, and multithreaded determinism. Existing approaches are impractical because custom hardware-based approaches are unrealistic, and software-based approaches slow programs unacceptably. The project builds on preliminary work on an efficient concurrency control mechanism that elides expensive synchronization from non-conflicting accesses, which are the vast majority of accesses. Developing new analyses and systems presents significant new challenges, both to apply the novel concurrency control mechanism and to make other aspects of these analyses and systems efficient enough for production systems. For example, precise conflict detection must track prior accesses and contend with imprecision inherent to the concurrency control mechanism. The project aims to make the analyses and systems both practical and flexible, which requires systematically investigating how to reduce the costs of conflicting and non-conflicting accesses. Expected contributions are the first practical always-on atomicity checker, the first practical multithreaded record & replay system, the first practical sequential consistency checker, and the first practical system providing multithreaded system determinism. In addition to broader impacts, the contributions have the potential to enable new research on efficient software-based analyses and systems that support concurrency correctness.

在过去的几十年里，计算机系统的性能呈指数级增长，使得科学、工程、健康和其他领域的关键问题取得了进展。然而，由于功率、热量和线长的限制，微处理器现在在每一代微处理器中都添加了更多的内核，而不是更快的内核。因此，通用软件必须变得更加并发才能获得持续的性能提升。不幸的是，编写和调试共享内存并发软件是出了名的困难。一个关键问题是大多数共享内存编程语言和软件系统都没有为正确的并发执行提供良好的支持。他们缺乏这样的支持，因为所有已知的方法都是不切实际的。该项目旨在为商品系统中的并发正确性提供实际支持。它开发了在现有商用硬件上执行的低开销、纯软件方法。这些方法帮助程序员编写和调试更可靠、可扩展的软件，并通过消除整类错误来自动提高软件的可靠性。 这些好处有可能使社会继续依赖软件系统来完成日益复杂、关键的任务。 此外，该项目还包括教育和推广活动，帮助学生了解并发软件系统，加强思想和成果的传播，并扩大对计算机科学的参与。该项目开发了实用的、始终在线的动态检查和关键并发正确性属性的执行：原子性、顺序一致性和多线程确定性。现有的方法是不切实际的，因为基于定制硬件的方法不切实际，并且基于软件的方法使程序速度慢得令人无法接受。 该项目建立在高效并发控制机制的初步工作基础上，该机制消除了非冲突访问（绝大多数访问）中昂贵的同步。 开发新的分析和系统提出了重大的新挑战，既要应用新颖的并发控制机制，又要使这些分析和系统的其他方面对于生产系统来说足够高效。例如，精确的冲突检测必须跟踪先前的访问并应对并发控制机制固有的不精确性。该项目旨在使分析和系统既实用又灵活，这需要系统地研究如何降低冲突和非冲突访问的成本。预期的贡献是第一个实用的始终在线原子性检查器、第一个实用的多线程记录和重放系统、第一个实用的顺序一致性检查器以及第一个提供多线程系统确定性的实用系统。除了更广泛的影响之外，这些贡献还有可能推动对支持并发正确性的高效基于软件的分析和系统的新研究。