Study on operating system architectures for supporting application-specific resource management

我们研究了用于特定于应用程序的资源管理的操作系统架构。传统上，资源管理策略已经在操作系统内核内实现。本研究探讨了新的操作系统支持用户级资源管理。我们设计并实现了一种灵活的高效轻量级线程机制，该机制与操作系统内核合作在用户级实现。由于大多数线程操作都是在用户级别执行的，因此可以通过使用应用程序特定的策略来有效地执行线程。它的突出特点是内核级和用户级编译器的一致集成，以及有效的远程过程调用机制，消除了额外的用户-内核交互.我们提出了一个有效的服务开发应用程序框架。它提供了基于线程迁移的过程间通信。进程间通信采用基本优先级继承协议。该框架简化了微内核与用户级服务之间的交互，保证了响应的实时性.我们设计了一种新的路径名评估算法。与传统的方法不同，该算法合并所有的方式下分层的目录树到一个名称空间，每个分层的目录可以有不同的目录树结构，并允许修改不仅在前layr的文件系统，但也在layrs后面的文件系统。我们介绍了主要规则，用于评估路径名在一个层次的名称空间组成的联合挂载，并实现这些规则在一个实际的操作系统。

We investigated operating system architectures for application specific resource management. Traditionally, resource management policies have been implemented inside the operating system kernel. This study explores new operating system support for user-level resource management.1. We designed and implemented a flexible mechanism for efficient lightweight threads which is implemented at the user-level in cooperation with the operating system kernel. Since most thread operations are performed at the user-level, threads can be executed efficiently by using application specific policies. The distinguished features are the coherent integration of kernel and user-level schedulers and the efficient remote procedure call mechanism which eliminates extra user-kernel interactions.2. We proposed an effective application framework for service developments. It provides the peocedural interprocess communication based on the thread migration. Basic priority inheritance protocol is applied to the interprosess communication. The proposed framework simplifies the interaction between the micro-kernel and user-level services, and ensures real-time response.3. We designed a new pathname evaluation algorithm for union mount. Unlike the conventional method, the proposed algorithm merges all the way down the layred directory trees into a name space ; each of the layred directories can have different directory tree structures ; and modifications are allowed on not only the file-systems in the front layr but also the file-systems in the layrs behind. We introduced principal rules to be used for evaluating pathnames in a hierarchcal name space composed of union mounts, and implemented these rules in a practical operating system.