SHF: Small: Collaborative Research: Programming Interface And Runtime For Self-Tuning Scalable C/C++ Data Structures

在现代体系结构上开发多线程应用程序的一个关键挑战是正确同步线程之间共享的数据，同时避免过度的性能损失。不安全的低级同步机制很容易引入极难调试的错误(如争用条件和死锁)。同时，由于对共享数据的同步操作的实施效率低下，应用程序的性能和可伸缩性经常受到影响。本研究开发了一个具有相关编程接口和优化支持的高并发可伸缩数据容器库，以显著提高多核架构上的多线程C/C应用程序的生产率和性能。该库提供了一个类似于C标准模板库(STL)的易于使用和可组合的接口，并增强了每个容器类型对其数据访问的非阻塞同步的内部支持，从而通过消除死锁、活锁和优先级反转等危险以及高度可伸缩地支持大量线程来提供比传统阻塞同步更好的安全性和性能。与运行时相关联的预处理编译器支持类似于OpenMP的更高级编程接口，以简化现有的顺序或多线程C/C应用程序向使用非阻塞同步模板库的过渡，并为库抽象的使用提供优化和调整支持。开发的交付成果预计将演示开发人员输入、编译器优化和多核运行时的无缝集成，以支持将C/C应用程序系统地迁移到不断发展的体系结构。可扩展模板库以及相关的编程接口和调整支持预计将为高端科学和系统应用程序的开发人员提供巨大的生产力和性能提升，包括自主嵌入式系统中的分支和界限、图形分析、复杂场景渲染和目标传播。所开发的编程技术和工具可以实现将这种应用程序转换成比现有技术状态显著更可靠、更高效和可伸缩的软件。这些软件技术还有望被用作程序设计语言、编译器、系统软件和并行程序设计课程教学中的教育工具包。

A key challenge in developing multi-threaded applications on modern architectures is correctly synchronizing data shared among the threads while avoiding excessive performance penalties. Unsafe low-level synchronization mechanisms can easily introduce errors (e.g. race conditions and deadlock) that are extremely difficult to debug. At the same time, application performance and scalability are frequently compromised due to inefficient implementations of synchronous operations on shared data. This research develops a library of highly concurrent scalable data containers with associated programming interface and optimization support to significantly enhance the productivity and performance of multi-threaded C/C++ applications on multicore architectures. The library provides an easy to use and composable interface similar to that of C++ Standard Template Library (STL) and enhances each container type with internal support for non-blocking synchronization of their data accesses, thereby providing better safety and performance than traditional blocking synchronization by eliminating hazards such as deadlock, livelock, and priority inversion, and by being highly scalable in supporting large numbers of threads. A higher level programming interface, similar to that of OpenMP, is supported by a preprocessing compiler associated with the runtime to ease the transition of existing sequential or multi-threaded C/C++ applications to using the non-blocking synchronous template library and to provide optimization and tuning support for the use of the library abstractions. The developed deliverables are expected to demonstrate a seamless integration of developer input, compiler optimization, and multicore runtimes to support systematic migration of C/C++ applications to continuously evolving architectures. The scalable template library and the associated programming interface and tuning support is expected to provide an immense productivity and performance boost for developers of high-end scientific and systems applications, including branch and bound, graph analysis, complex scene rendering, and goal propagation in autonomous embedded systems. The developed programming techniques and tools can enable the transformation of such applications into software that is substantially more reliable, efficient, and scalable than existing state of the art. The software techniques is also expected to be employed as an educational toolkit in the teaching of programming languages, compilers, systems software, and parallel programming courses.