ST-CRTS: Collaborative: Delivering on Atomic Actions: Unlocking Concurrency for Ordinary Programmers

背景使用线程和锁编程的广泛公认的问题包括竞态条件、优先级反转和死锁，这些问题都是众所周知的难以避免和诊断的问题。解决锁问题的一个有希望的方向是各种形式的原子操作（AA）。AA是保证出现的计算操作的集合：无论是完全发生还是根本不发生，并且相对于其他AA有明确的顺序。类原子的概念在数据库应用中获得了巨大的成功。智力上的优点-一个精确的编程模型，为AA，重点是封闭和开放嵌套。在现有硬件上实现替代AA的开销。尽管会产生开销，但由于并行性的增加，AA的性能优势。AA的硬件辅助：硬件接口（API）和虚拟化以掩盖硬件限制。AAs与非事务性活动（如I/O、网络等）的对比- AA与运行时服务，如垃圾收集（GC），异常和陷阱。用于分析和调整AA性能的工具及其改进重新解决了瓶颈。更广泛的影响通过提高新商品硬件应用程序的健壮性和性能，交付AA将带来显著的经济和安全效益。AAs将使提高并发性成为可能，从而提高软件的性能，同时也提高了可靠性，简化了调优和维护。普通程序员将更容易利用桌面上的线程级并行性，编写他们以前无法编写的程序，并开始工作。该项目将通过利用他们的新产品而使硬件行业受益，通过增加并发软件的健壮性而使软件行业受益，同时也有助于经济和国家安全。所有项目成果和工具都将向公众开放，该项目将培训毕业生掌握重要的高需求技能，从而为技术劳动力做出贡献。

BackgroundWidely recognized problems of programming with threads and locks include race conditions,priority inversion, and deadlock, problems notoriously difficult both to avoid and to diagnose.We need better abstractions for ordinary programmers to use to exploit concurrency. A promisingdirection that solves the problems with locks is the various forms of atomic action (AA).An AA is a collection of computational actions that are guaranteed to appear to occur: eitherentirely or not at all, and in a definite order with respect to other AAs. Atom-like notionshave enjoyed great success in database applications.Intellectual Merit-A precise programming model for AAs, with a focus on closed and open nesting.- Overheads of alternative AA implementations on existing hardware.- Performance benefits of AAs resulting from increased parallelism, despite their overheads.- Hardware-assist for AAs: hardware interfaces (APIs) and virtualization to mask hardware limits.- AAs vis-a-vis non-transactional activities such as I/O, networking, etc.- AAs vis-a-vis run-time services such as garbage collection (GC), exceptions, and traps.- Tools for profiling and tuning performance of AAs, and their refinement re: bottlenecks.Broader ImpactDelivering on AAs will lead to significant economic and security benefitsthrough improved robustness and performance of applications for new commodity hardware. AAswill make it possible to increase concurrency, and thus performance, of software while also increasingreliability and simplifying tuning and maintenance. Ordinary programmers will more readily exploitthread-level parallelism on the desktop, writing programs they could not write, and get to work, before.The project will benefit the hardware industry by exploiting their new offerings, and the softwareindustry by increasing the robustness of concurrent software, while also contributing to economic andnational security. All project results and tools will be available to the public, and the project will traingraduates in important high-demand skills, and thus contribute to the technical work-force.