Dynamic Deadlock Avoidance in Concurrent Software via Discrete Control

提案编号0819882TITLE：通过离散控制在并发软件中避免动态死锁PI：Stephane LaFortieCo-PI：Scott Mahle确保并发程序的无死锁执行是一个日益重要的问题，因为多核处理器迫使注重性能的软件开发人员将应用程序并行化。提出了一种动态控制并发软件执行以避免死锁的新方法。它解决了当今占主导地位的并发编程范例，即使用锁的多线程程序。在这种方法中，避免死锁的责任被放在一个反馈控制器上，该控制器是从应用软件源代码自动合成的。源代码的模型将根据编译时获得的全程序控制流程图自动构建。反馈控制器将使用离散控制理论中的技术从模型离线合成，并用于检测代码。在运行时，控制器将通过仔细管理锁获取和释放来操作，以确保永远不会进入潜在的死锁状态。这项建议的研究计划为这一新方法的开发、实施、绩效评估和课堂部署提供了一种系统的方法。通过自动反馈控制允许程序无死锁执行，未经修改的遗留代码的全部价值将被保留，程序员将被授权以更高的安全性、信心和生产率编写代码。

Proposal Number 0819882TITLE: Dynamic Deadlock Avoidance in Concurrent Software via Discrete ControlPI: Stephane LafortuneCo-PI: Scott MahlkeEnsuring deadlock-free execution of concurrent programs is an increasingly important problem as multi-core processors compel performance-conscious software developers to parallelize applications. A novel methodology for dynamically controlling the execution of concurrent software in order to provably avoid deadlocks is proposed. It addresses today's dominant concurrent programming paradigm, multi-threaded programs that employ locks. In this approach, the responsibilities for deadlock avoidance are placed upon a feedback controller that is automatically synthesized from application software source code. A model of the source code will automatically be constructed from a whole-program control flow graph obtained at compile time. The feedback controller will be synthesized offline from the model using techniques from discrete control theory and used to instrument the code. At run-time, the controller will operate by carefully managing lock acquisition and release to ensure that potential deadlock states are never entered. The research plan of this proposal presents a systematic approach for the development, implementation, performance evaluation, and classroom deployment of this novel methodology. By allowing deadlock-free execution of programs via automated feedback control, the full value of unmodified legacy code will be preserved and programmers will be empowered to write code with increased safety, confidence, and productivity.