SOS: An Object-Oriented Operating System ―- Assessment and Perspectives

International audienceSOS (SOMIW Operating System) is the result of a four-year effort at INRIA to define an object-oriented operating system. SOS provides support for arbitrary, user-defrned, typed objects. The system implements object migration; this mechanism is generic, but can be tailored to specific object semantics thanks to the prerequisite and upcall concepts. SOS also supports Fragmented Objects (FOs), i.e. objects the representation of which spreads across multiple address spaces. Fragments of a single FO are objects that enjoy mutual communication privileges. A fragment acts as a proxy, i.e. a local interface to the FO. All the other mechanisms of SOS are built upon these basic abstractions. Thanks to prerequisites, migration of data may cause the migration and dynamic type-checking and linking of the corresponding code. A distributed object manager, an object storage service, a naming service, as well as a protocol toolbox and some applications, have been built as FOs. This paper gives a detailed account of the architecture and design decisions of the SOS prototype on UNIX. rùy'e examine both good decisions and problems. The basic good decision is our simple object model, and its ability to map user-defrned semantics (policy decisions) on system-implemented mechanisms. The most important problem is the dynamic nature of Fragmented Objects, and inadequate support for them

A simple object storage system

International audienceNo abstrac

Persistence and Migration for C++ Objects

International audienceWe describe the support to object management of the distributed object-oriented operating system SOS. We discuss the integration of object migration and storage into C++ programs, a language not designed for that purpose. The necessary support is split between the compiler and a run-time object management system. Migration and storage preserve the type and structure of the objects, which may be user-defined and arbitrarily complex. Our mechanisms are simple, generic, and require little programmer intervention. The key elements are dynamic classes, a generalized pointer type which allows to efficiently refer to an object, pre-requisite objects, and a mechanism for object re-initialization

COOL: Kernel Support for Object-Oriented Environments

The Chorus Object-Oriented Layer (COOL) is an extension of the facilities provided by the Chorus distributed operating system with additional functionality for the support of object-oriented environments. This functionality is realized by a layer built on top of the Chorus V3 Nucleus, which extends the Chorus interface with generic functions for object management: creation, deletion, storage, remote invocation and migration. One major goal of this approach was to explore the feasibility of general object management at the kernel level, with support of multiple object models at a higher level. We present the implementation of COOL and a first evaluation of this approach with a C++ environment using the COOL mechanisms

SOS: An Object-Oriented Operating System - Assessment and Perspectives

SOS (SOMIW Operating System) is the result of a four-year effort at INRIA to define an object-oriented operating system. SOS provides support for arbitrary, user-defined, typed objects. The system implements object migration; this mechanism is generic, but can be tailored to specific object semantics thanks to the prerequisite and upcall concepts. SOS also supports Fragmented Objects (FOs), i.e. objects the representation of which spreads across multiple address spaces. Fragments of a single FO are objects that enjoy mutual communication privileges. A fragment acts as a proxy, i.e. a local interface to the FO. All the other mechansisms of SOS are built upon these basic abstractions. Thanks to prerequisites, migration of data may cause the migration and dynamic type-checking and linking of the corresponding code. A distributed object manager, an object storage service, a naming service, as well as a protocol toolbox and some applications, have been built as FOs. This paper gives a detai..

Un Bilan du système rèparti à objets SOS

International audienceNo abstrac

COOL : Kernel support for object-oriented environments

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 14802 E, issue : a.1990 n.1211 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Un bilan du systheme reparti a objets SOS

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 14802 E, issue : a.1990 n.1242 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc