Compilation and Automatic Optimization of Network Protocol Implementations

网络软件很难设计、实现、调试和维护。异构性和对高性能的需求加剧了这一基本问题。异构性导致必须开发和维护的网络软件数量成倍增加。为了提高性能，网络软件通常是在操作系统内核中手工制作的，在操作系统内核中，软件特别难调试和维护。新兴的高速网络技术，加上下一代多媒体应用，导致对高性能和极其灵活的网络软件的需求不断增加。这项提议的一个基本主题是，网络软件的进步只能通过同时考虑编程简易性、平台多样性和性能的方法来实现。该方案研究了如何使用编译器技术来快速构建复杂协议软件的原型并自动进行优化。其结果是网络软件更易于编写、更易于移植和更易于维护。然而，通过适当的自动优化，这样的实现的性能应该可以与手工制作的实现的性能相媲美。我们建议的第一部分涉及自动优化网络软件以实现千兆链路速度的技术。这涉及发明新的优化技术(例如，将单独的消息解复用定义融合到有效的解复用代码中)，自动化现有的优化范例(例如，报头预测和地址高速缓存)，以及扩展关于自动化优化技术的现有工作。我们的计划呼吁建立在优化编译器基础上的现有理论，以统一各种特殊技术，并为产生新的优化技术提供一个出发点。我们提案的第二部分涉及一个框架，该框架集成了我们的优化技术，以支持高效网络软件的快速原型制作。我们允许开发协议代码，而无需过度关注低级有线数据格式；用于多路分解、同步或错误处理的操作系统特定机制。这允许非常紧凑的协议描述，然后由我们的框架针对广泛的目标环境进行编译和优化。这些环境包括模拟器、应用级网络接口和共享内存多处理器平台。

Network software is hard to design, implement, debug, and maintain. This basic problem is compounded by heterogeneity and the need for high performance. Heterogeneity results in multiplying the amount of networking software that must be developed and maintained. To improve performance, networking software is often hand-crafted in an operating system kernel, where software is particularly hard to debug and maintain. Emerging high-speed networking technology, coupled with next generation multimedia applications, is resulting in increased demand for high performance and extremely flexible networking software. A fundamental theme of this proposal is that advances in network software can only be achieved by an approach that simultaneously considers programming ease, platform diversity, and performance. This proposal investigates the use of compiler technology to rapidly prototype and automatically optimize complex protocol software. The result is network software that is easier to write, more portable, and more maintainable. Yet, with the appropriate automatic optimizations, the performance of such implementations should compare favorably to the performance of hand-crafted implementations. The first part of our proposal concerns techniques for automatically optimizing network software to achieve Gigabit link speeds. This involves inventing new optimization techniques (e.g., fusing together individual message demultiplexing definitions into efficient demultiplexing code), automating existing optimization paradigms (e.g., header prediction and address caching), and extending existing work on automated optimization techniques. Our plans call for building on the existing theory underlying optimizing compilers to unify various ad hoc techniques, and to provide a point of departure for producing new optimization techniques. The second part of our proposal involves a framework that integrates our optimization techniques to support rapid prototyping of efficient ne tworking software. We enable protocol code to be developed without undue attention paid to low-level wire data formats; operating system specific mechanisms for demultiplexing, synchronization, or error handling. This allows an extremely compact protocol description that is then compiled and optimized by our framework to a wide range of target environments. These environments include a simulator, application-level network interfaces, and shared-memory multiprocessor platforms.