Next Generation Software: A Computing Environment for Adaptively Parallel Multithreading

charles E. leiserson麻省理工学院自适应并行程序可以根据处理器资源的可用性增加和减少。自适应并行产生了许多系统问题，特别是当我们想要将程序员与变幻莫测的计算环境隔离开来时。如何由程序员指定并由系统实现自适应并行文件I/O ？自适应并行进程应该通过什么机制进行通信，这种通信应该如何在语言上指定？如何公平有效地调度多个自适应并行进程？自适应并行系统机制可以提供哪些性能保证？如何调试自适应并行代码？本研究调查了这些问题的实证和理论答案。Cape系统将为自适应并行多线程程序提供计算环境的原型实现。Cape将利用Cilk提供的多线程编程系统，Cilk是麻省理工学院开发的C编程语言的忠实扩展。Cape将允许Cilk程序以自适应并行的方式透明地运行，而无需任何程序员的干预。Cape将包含可证明的用于调度、文件I/O和进程间通信的良好算法，提供了效率的理论保证。自适应并行多线程计算环境将使灵活和不规则的应用程序能够充分利用下一代计算机系统。

EIA-9975036Charles E. LeisersonMassachusettes Institute of TechnologyAdaptively parallel programs can grow and shrink depending upon the availability of processor resources. Adaptive parallelism creates a host of system issues, especially if we want to insulate the programmer from the vagaries of his computing environment. How should adaptively parallel file I/O be specified by a programmer and implemented by the system? By what mechanisms should adaptively parallel processes communicate, and how should this communication be specified linguistically? How can multiple adaptively parallel processes be scheduled fairly and efficiently? What performance guarantees can adaptively parallel system mechanisms provide? How should adaptively parallel codes be debugged? This research investigates both empirical and theoretical answers to these questions.The Cape system will provide a prototype implementation of a computing environment for adaptively parallel multithreaded programs. Cape will leverage the multithreaded programming system provided by Cilk, a faithful extension of the C programming language, which has been developed at MIT. Cape will allow Cilk programs to run in an adaptively parallel fashion transparently without any programmer intervention. Cape will incorporate provably good algorithms for scheduling, file I/O, and interprocess communication, providing theoretical guarantees of efficiency.An adaptively parallel multithreaded computing environment will enable flexible and irregular applications to fully exploit the next generation of computer systems.