High-performance concurrent programming

研究目标是通过编程语言、工具和运行时环境提供基本的使能技术，以利用共享内存多线程/核心/处理器计算机上的并发性。计算机科学已经进入了一个新时代，在这个时代，大多数计算设备都有多个处理器，未来的大多数程序都将是为运行在低成本、高性能、商用、并行计算机上的应用程序编写的。不幸的是，对于普通程序员来说，开发该应用程序领域的理解水平和必要的工具是完全不够的。如果没有进一步的发展，并发编程将仍然是一项深奥的技能，阻碍了商用并行硬件的充分利用和采用。我的研究考察并扩展了并发编程的5个关键领域的知识。1.异步调用隐含地引入了并发性，而期货用于从异步调用返回结果。我正在开发一种在同类和异类未来类型之间进行动态选择的机制，允许在选择器之间使用条件选择器和“与/或”运算符。2.异步异常传播是线程之间有用的替代通信，特别是在确保及时传播的情况下。但是，不可能对被阻止的线程进行及时传播。我正在开发一种解除线程阻塞的方法，以便快速开始传播异步终止和恢复异常。3.我已经确定了用于实现良好性能的7个基本内存分配器特性。每个特性都是单独检查的，以便更容易地推断内存分配器的设计，并为分配器的比较提供一个公共基础。4.我正在开发一个剖析工具，以帮助理解并行硬件上运行的并发程序的动态执行，以便于调试和性能分析。5.许多并发应用程序是I/O而不是CPU密集型(Web服务器)。我正在开发利用网络和CPU并行性来构建非常高性能的多线程Web服务器的方法。这项研究的潜在用户范围很广，因为并发应用程序在许多计算环境中变得至关重要。

The research objective is to provide basic and enabling technology, through programming languages, tools and the runtime environment, to exploit concurrency on shared-memory multi-threaded/core/processor computers. Computer Science has entered a new epoch where most computing devices have multiple processors, and most future programs will be written for applications running on low-cost, high-performance, commodity, parallel computers. Unfortunately, the level of understanding and necessary tools to develop this application domain is wholly inadequate for the average programmer. Without further advances, concurrent programming will remain an esoteric skill, inhibiting the full utilization and adoption of commodity parallel hardware. My research examines and extends knowledge in 5 critical areas of concurrent programming. 1. Asynchronous call implicitly introduces concurrency, and futures are used to return results from an asynchronous call. I am developing a mechanism for dynamically selecting among homogeneous and heterogeneous future types, allowing conditional selectors and "and/or" operators among selectors. 2. Asynchronous exception propagation is a useful alternative communication among threads, especially if timely propagation is ensured. However, timely propagation is impossible for blocked threads. I am developing an approach for unblocking threads to quickly begin propagation of asynchronous termination and resumption exceptions. 3. I have identified 7 fundamental memory-allocator features used to achieve good performance. Each feature is being examined in isolation to make it easier to reason about memory allocator design and provide a common base for comparison of allocators. 4. I am developing a profiling tool to aid in understanding the dynamic execution of concurrent programs running on parallel hardware to facilitate debugging and performance analysis. 5. Many concurrent applications are I/O rather that CPU intensive (web servers). I am developing approaches to utilize network and CPU parallelism to build very high-performance multi-threaded web-servers. Potential users of the research span a broad spectrum as concurrent applications are becoming crucial in many computing environments.