SHF: Small: Precise Concurrency Exceptions: Architecture Support, Semantics and System Implications

如何普及并行编程是计算研究协会为系统社区提出的重大研究挑战之一。能够充分利用多核系统的潜力将使我们回到可用性能的指数级增长，并导致显著的电力节省。促进多线程程序的正确和有效执行将对IT行业产生变革性的影响，因为它解决了多处理器系统中可编程性问题的核心问题。随着无处不在的多核和新兴的并行程序的出现，IT行业现在正在处理更加困难的可靠性问题。并发性错误很难理解，通常是不确定的，并且在发生后很长一段时间才会出现。此外，它们对编程语言语义有重要的影响。最近在支持并发调试方面的工作取得了很好的进展，但通常侧重于在概率保证下进行bug检测的最佳努力技术。这项研究采用了一种直接的方法来解决这个问题：通过在错误出现之前交付异常来阻止并发错误。换句话说，系统检测到并发错误即将发生，并在允许执行带有错误的代码之前引发异常。研究人员称这种机制为并发异常。并发异常可以像除零和分段错误一样方便地处理并发错误。

How to popularize parallel programming is one of the Computing Research Association's Grand Research Challenges for the systems community. Being able to leverage the full potential of multi-core systems would put us back into exponential growth of usable performance, as well as lead to significant power savings. Facilitating correct and efficient execution of multithreaded programs would have a transformative effect in the IT industry, as it attacks a problem at the heart of the programmability issues in multiprocessor systems. With ubiquitous multicores and emerging parallel programs, the IT industry is now dealing with far harder reliability problems. Concurrency errors are hard to understand, are typically non-deterministic and manifest themselves way past the point of their occurrence. Moreover, they have major implications for programming language semantics. Recent work on support for concurrency debugging has made good progress, but has often focused on best-effort techniques for bug detection with probabilistic guarantees. This research takes a direct approach to the problem: making concurrency errors fail-stop by delivering an exception before the error manifests itself. In other words, the system detects that a concurrency error is about to happen and will raise an exception before the code with an error is allowed to execute. The investigators call this mechanism concurrency exceptions. Concurrency exceptions will allow concurrency errors to be handled as conveniently as division by zero and segmentation fault.