The new structure of an operating system

Urbana, 1996

This article offers our solution to the problem of building customizable operating systems and describes the results achieved in implementing a customizable operating system. We have built an object-oriented, customizable operating system, Choices [3, 4]. ...

1993

To respond to continuing hardware advances and changing application demands, operating systems must be flexible. Recently developed metacomputation techniques can provide the desired flexibility. The p architecture investigates the use of metaobject protocols to tailor subsystems of operating systems. It allows effective utilization of events and resources through interfaces for tailorable object implementations. Its main contributions are flexible event management, scope reification and change management. The challenges and possible solutions are described in the context of a distributed shared object subsystem. Keywords: Operating systems, distribution, resources, events, interfaces, reification, metacomputation, scope, distributed shared objects p: Effective Use of Metacomputation for Structuring Operating Systems Dinesh C. Kulkarni, Arindam Banerji, David L. Cohn 1. Introduction There is an emerging need for operating systems to be flexible and it is caused by two key factors: ...

1994

Abstract Advanced future applications require to exploit new types of objects such as continuous media objects and distributed objects. Such new requirements stress operating systems to support variable levels of responsiveness and reliability. One computational model and resource management policy cannot cover the various requirements from all users so a exible structure is important when building future distributed systems to ensure such requirements.

Software components as reusable building blocks for software are becoming widely used in software engineering. However, so far there has been little attempt to apply this programming and design paradigm in the domain of general-purpose operating systems. This paper analyze several nice properties of component systems which might be beneficial in operating system design, the obstacles which emerge when we want to use components as a building blocks of an operating system, proposes a component model which targets these obstacles, metrics to determine the rate of success of this approach and concludes with current work in this field.

… Conference on Parallel …

The design of an object-oriented operating system involves the design of a model that governs the execution of the tasks. In this paper we show the design goals to build a computational model for an object-oriented operating system based in an object-oriented abstract machine. We propose to adopt an active object model and we consider features like uniformity, homogeneity or selfcontained are essential for objects. Finally, our proposal is to achieve the above using reflectivity as a key characteristic of the system.

1993

To respond to continuing hardware advances and changing application demands, operating systems must be flexible. Recently developed metacomputation techniques can provide the desired flexibility. The πarchitecture investigates the use of metaobject protocols to tailor subsystems of operating systems. It allows effective utilization of events and resources through interfaces for tailorable object implementations. Its main contributions are flexible event management, scope reification and change management. The challenges and possible solutions are described in the context of a distributed shared object subsystem.

1987

: Elmwood is an object-oriented, multiprocessor operating system designed and implemented as a group project at the University of Rochester. An Elmwood object, consisting of code and data, represents an instance of an abstracts data type. Only the code associated with an object may access its data; interaction between objects is via remote procedure call. Access to an object requires that the caller provide an appropriate logical object name, which denotes a kernel-protected pair containing an object reference and a context value. Elmwood provides only basic mechanisms for protection and synchronization; the object itself supplies and interprets the context value, thereby implementing its own policies for protection and synchronization. We describe the Elmwood design, and multiprocessor implementation for the BBN Butterfly Parallel Processor, and our experiences in building a functionally-complete operating system as a group project in four months.

Oops Messenger, 1993

Modern computer hardware technology allows a single architecture to be used for a range of machines from supercomputers to toasters. Hardware designers have recognized that an architecture should be scalable and system software developers must address the same issue. Scalability means that the architecture must be flexible enough to satisfy diverse hardware and application needs. The key to operating system flexibility is to base the architecture on a high-level graph model and to use the generalized object model and metacomputing. The resulting framework is a uniform object model for application and system software. Classically, operating system flexibility means that the architecture must handle various processor capabilities, differing memory and disk sizes and a vast range of peripheral devices. Today, it also includes dealing with multiprocessor systems, diverse network topologies and multimedia input/output. In the future, as radio-based networking becomes common, changes will be dynamic, requiring the flexible operating system to adapt as elements of a distributed system move into and out of range. Different classes of applications have different requirements. The valuable data managed by an OODB must be maintained over long periods of time while a multimedia application requires guaranteed bandwidth. The necessary services and the relative emphasis on different functionalities vary drastically.

Over the past several years, a number of trends affecting operating system design are witnessed and foremost among them is a move towards modularity. Operating systems such as Microsofts Windows, IBMs OS/2, C-DACs PARAS and others are splintered into discrete components, each having a small, well defined interface, and each communicating with others via inter-task message interface. The lowest level is the microkernel, which provides only essential OS services, such as context switching. Windows NT, for example, also includes a hardware abstraction layer (HAL) beneath its microkernel which enables the rest of the OS to perform irrespective of the processor underneath. This high level of OS portability is a primary driving force behind the modular, microkernel-based push.