XPS: FP: DeCoP: Deterministic Cooperative Parallelism

大多数现代计算机系统都有多个计算核心，需要并行应用程序。不幸的是，开发可靠而高效的并行应用程序是出了名的困难，部分原因是不确定的调度，它可以在任意程序点的并行线程之间切换上下文。由此产生的不可预测性和不确定性给开发可靠的并行软件带来了极大的困难，本项目提出将简单协作并发扩展到确定性协作并行，研究并开发一种更好的并行编程模型。协作并发是一种简单的非抢占式模型，只需要最低限度的同步，在这种模式下，即使是有错误或错误的抢占式程序也经常正确执行。这有效地降低了设计的复杂性。协作并发很简单，但不会带来任何加速。该方案利用软件事务存储来提取并行性。该方案解决了三个紧密耦合的问题：提供更简单的并行语义，提供高效的并行执行的新技术，以及与自动并行化和线程级推测等现有补充技术的集成。研究生和本科生研究人员将参与这项研究，其中一些人来自代表性不足的群体。总体而言，该项目旨在使并行应用程序的编程变得更简单，这是一个根本性的进步，不仅对计算机科学界产生影响，而且对移动系统等其他领域也有影响。

Most modern computer systems have multiple computational cores that require parallel applications. Unfortunately, developing reliable and efficient parallel applications is notoriously difficult, in part due to nondeterministic scheduling, which can context-switch between parallel threads at any arbitrary program point. The resulting unpredictability and nondeterminism makes it extremely difficult to develop reliable parallel software.This project proposes to investigate and develop a better model for parallel programming based on extending simple cooperative concurrency to deterministic cooperative parallelism. Cooperative concurrency is a simple non-preemptive model requires minimal synchronization, and under which even buggy or incorrect preemptive programs often execute correctly. This effectively reduces the design complexity. Cooperative concurrency is simple but it does not yield any speedup. This proposal leverages software transactional memory to extract parallelism. The proposal addresses three tightly coupled problems: provide simpler parallel semantics, novel techniques to provide efficient parallel execution, and integrate with existing complementary techniques like automatic parallelization and thread level speculation. Graduate and undergraduate researchers some from under-represented groups will be involved in the research. Overall, the project aims to make a fundamental advanced toward simpler to program parallel applications, with impacts not only in the computer science community but also in other fields like mobile systems.