CSR: Small: Multi-Version Concurrency Control (MVCC) for Main Memory and its Implications for Deterministic Concurrency

CSR：小：主内存的多版本并发控制 (MVCC) 及其对确定性并发的影响

• 批准号: 1320235
• 负责人: Jakob Eriksson
• 金额: $ 45.37万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1320235&HistoricalAwards=false
• 关键词: CSR; Small; Multi; Version; Concurrency

The objective of this project is to investigate version consistency, a new concurrent programming consistency model, as a means of enhancing the performance and scalability of concurrent systems. Under version consistency, which can be seen as a relaxation of release consistency, processes are guaranteed to see the same memory contents (only) if they are accessing the same version of the memory. Such versions are created, retrieved and/or merged through calls analogous with version control systems for source code.An important class of applications that benefits substantially from version consistency is deterministic concurrency runtimes, where the goal is to ensure that a program produces the same output given the same input, independent of any non-deterministic timing effects. In prior work, the PI achieved up to 50% performance gain for the deterministic runtime DThreads, using version consistency. In this project, one of the goals is to achieve ``pthreads parity" for a deterministic runtime, where enforcing determinism incurs only negligible performance impact. When and if this is achieved, ``determinism by default'' becomes a feasible option for mainstream computer systems.As computer processors continue to evolve from a centralized single ``core'' architecture to highly distributed and parallel ``multi-core systems'', writing correct programs that make efficient use of this extremely powerful hardware is becoming increasingly difficult. This results in a number of detrimental effects ranging from poor resource utilization, to seriously flawed programs where loss of data, or even loss of life may result. This project investigates (a) a means of reducing the complexity of programming highly parallel systems to combat these problems, and (b) a means of guaranteeing that even an incorrect parallel program produces the same result every time. This latter part will help programmers write correct programs, and to fix software flaws that may otherwise be intermittent and difficult to identify.

该项目的目的是调查版本一致性，即一种新的并发编程一致性模型，以增强并发系统的性能和可扩展性。在版本的一致性下，可以看作是放宽释放一致性的放宽，可以保证，当它们访问相同版本的内存时，可以看到相同的内存内容（仅）。创建，检索和/或通过呼叫与源代码的版本控制系统合并。一种重要的应用程序类别。从版本一致性中获得基本上受益的一类应用程序是确定性的并发运行时间，在这种应用程序中，目标是确保程序在给定相同输入的相同输出中产生相同的输出，而与任何非确定性时序效应无关。在先前的工作中，使用版本一致性，确定性运行时DThreads的PI最多可实现50％的性能增益。在这个项目中，目标之一是在确定性的运行时实现````pthreads perit'''，在这种情况下，执行确定性只会造成可忽略的绩效影响。何时和如果实现这一目标，则``'默认情况下的确定性''成为可行的计算机系统的可行选择。撰写正确利用这种非常有力的硬件的系统越来越困难。后一部分将帮助程序员编写正确的程序，并修复否则可能是间歇性且难以识别的软件缺陷。