CCF: Medium: Routine Parallelism Enabled by Speculation

并行编程是出了名的困难，但对计算的未来是必不可少的。很大一部分困难源于需要提前保证并行计算不会相互冲突。受赞助的研究旨在使线程和进程级推测成为未来编程系统的基本特征，并将其用于多种形式和多种目的：自动或半自动地并行化顺序应用程序；动态地检查显式并行计算的独立性；隔离语义原子函数的执行；使不总是安全的优化成为可能；利用每次一个线程的语义并行化脚本语言；并并行分析应用程序，以实现反馈驱动的优化。该项目采用分层方法，使使用简单编程习惯用法的用户不必了解更复杂的备选方案。在实现级别，它强调共享内存和集群级别分布、基于编译器和二进制翻译器的软件插装、虚拟内存和硬件推测/事务(如果有)的无缝集成。项目的后期阶段主要侧重于分析工具，以识别潜在的独立程序区域，然后可以在未来的运行中安全地并行执行(通过推测)。

Parallel programming is notoriously difficult, but essential to the future of computing. Much of the difficulty stems from the need to guarantee, in advance, that parallel computations will not conflict with one another.Speculation provides an attractive alternative. By monitoring behavior at run time, and retrying computations that conflict, speculation can expose significant amounts of otherwise unexploitable parallelism, while imposing little or no conceptual burden on the programmer.The sponsored research aims to make thread- and process-level speculation a fundamental feature of future programming systems, and to employ it in multiple forms and for multiple purposes: to automatically or semi-automatically parallelize sequential applications; to check, dynamically, the independence of explicitly parallel computations; to isolate the execution of semantically atomic functions; to enable optimizations that are not always safe; to parallelize scripting languages with one-thread-at-a-time semantics; and to profile applications in parallel, for feedback-driven optimization.The project adopts a tiered approach that isolates the users of simpler programming idioms from the need to understand more complex alternatives.At the implementation level, it stresses the seamless integration of shared memory and cluster-level distribution, compiler- and binary translator-based software instrumentation, virtual memory, and hardware speculation/transactions where available. Latter phases of the project place major emphasis on profiling tools to identify potentially independent program regions, which can then safely be executed in parallel (via speculation) in future runs.