Development of an operating system that supports the distributed and persistent light-weight objects

我们设计并实现了一个支持轻量级对象的操作系统。在这一年里，我们开发了远程对象调用、全局命名和对象复制/迁移等分布式处理设施。我们设计了独立于位置的远程对象调用，这是分布式处理的基础。我们使用代理技术将本地对象调用转换为消息传递。我们的代理提供了全局命名、结果缓存和访问控制等功能.设计了用户自定义的复制对象一致性控制。一致性控制在方法调用级别执行。3.开发了资源管理设施。它们旨在作为用户级对象复制和迁移等的基础，我们定义了使用这些设施的接口，并使用该接口实现了一些简单的负载均衡策略.我们设计了将远程对象映射到虚拟地址空间的机制。当对象第一次被调用时，对象被映射到地址空间，并且访问检查由操作系统内核执行。但是，随后的对象调用完全在用户级别执行。5.该实现是通过修改自由软件操作系统之一NetBSD来实现的。

We designed and implemented an operating system that supports light-weight objects. In this year, we developed the destributed processing facilities such as remote object invocation, global naming, and object replication/migration, etc.1. We designed location-independent remote object invocation, which is a basis for distributed processing. We used the proxy technique for translating local object invocation to message passing. Our proxy provides the facilities of global naming, results caching and access control.2. We designed the user-defined consistency control for replicated objects. The consistency control is performed at the method invocation level.3. The resource management facilities were developed. They are intended to use as the basis ofuser-level object replication and migration, etc. We defined the interface for using the facilities, and implemented some simple load balancing policies using this interface.4. We designed the mechanism of mapping remote objects to a virtual addres space. When an object is first invoked, the object is mapped to an address space and the access check is performed by the operating system kernel. However, the subsequent object invocations are performed completely at the user level.5. The implemention was performed by modifying NetBSD,which is one of the free software operating systems.