Pilot

Proceedings. The Sixth Workshop on Hot Topics in Operating Systems (Cat. No.97TB100133), 1997

We believe it is time to reexamine the operating system's role in computing. Operating systems exist to create an environment in which compelling applications come to life. They do that by providing abstractions built on the services provided by hardware. We argue that advances in hardware and networking technology enable a new kind of operating system to support tomorrow's applications. Such an operating system would raise the level of abstraction for developers and users, so that individual computers, file systems, and networks become unimportant to most computations in the same way that processor registers, disk sectors, and physical pages are today.

Software: Practice and Experience, 1980

This paper is an overview of the Trio system which enables users to simaltaneously develop and execute programs at three terminals. The system consists of an operating system written in Concurrent Pascal and a set of standard programs written in Sequential Pascal. The system has been used on a PDP 11/55 minicomputer since spring 1979. This work concludes 5 years of experience with the first abstract language for concurrent programming. KEY WORDS Concurrent Pascal Operating system Trio BACKGROUND This paper is an overview of the Trio operating system which enables users to simultaneously develop and execute programs at three terminals. The system consists of an operating system written in Concurrent Pascal and a set of standard programs written in Sequential Pascal. The system has been used on the PDP 11/55 minicomputer since spring 1979. This work is a continuation of earlier work that led to the development and implementation of the programming language Concurrent Pascal which includes processes, monitors and classes. The focus of this research has been the concept of an abstract data type-the combination of a data structure and all the possible operations on it into a single program module. This concept contributes to simplicity by locating details of data representation and transformation in modules instead of spreading them throughout a large program. It increases reliability by making it possible for a compiler to prevent data structures from being destroyed by arbitrary operations. So far Concurrent Pascal has been used to design a single-user operating system, a job stream system, a real-time scheduler, and a message passing system for a multicomputer It has also been used to build several, microcomputer operating systems. Each of these model systems has the following characteristics: * This research was supported by the Army Research Office under Contract No. DAAG-29-77-Gal92.

ACM SIGPLAN Notices, 1989

Technology -ESPRIT and it stems from the identified need of providing simpler and more integrated environments for application development in large distributed systems.

1972

This paper is a description of a simple operating system, which runs in a virtual machine (implemented on a real machine by an interpreter). OS6 copes with only one user at a time, and is not a multi-programming system: many major problems associated with large operating systems have therefore been avoided or considerably simplified. It nevertheless has several features of interest, including the fact that it is written almost entirely in the high-level language BCPL. The most important single feature, however, is the hierarchical nature of its control structure, which avoids the need for a special job-control language.

Digest of Papers. COMPCON Spring 89. Thirty-Fourth IEEE Computer Society International Conference: Intellectual Leverage, 1989

... reference net-work communication and extensible memory ob-jwts. transparcnt shared libraries to supply binary com. patibility and an object programming facility integrated with transparent network communication. Page 2. 2.1. ...

1994

Extensibility enables system services to be adapted to changing hardware and software trends. Providing extensible system services need not necessarily entail construction of new operating systems or inefficient implementations. Rather it can be effectively incorporated into existing commercial operating systems. We have incorporated the programming and run-time support necessary to build extensible system software into the AIX 3.2 kernel. Support for object-orientation within the kernel is provided though system call classes. Efficient crossdomain data transfer is facilitated by a shared object implementation. Loadable subclasses and flexible class objects enable dynamic composition and reconfiguration of system services. This paper describes the design and implementation of this support.

IEEE Transactions on Software Engineering, 1989

This paper presents a retrospective view of the Charlotte distributed operating system, a testbed for developing techniques and tools to solve computation-intensive problems with large-grain parallelism. The final version of Charlotte runs on the Crystal multicomputer, a collection of VAX-111750 computers connected by a local-area network. The kernellprocess interface is unique in its support for symmetric, bidirectional communication paths (called links), and synchronous nonblocking communication.

iii iv humorous style. Whether you find them useful, or humorous, well, that's another matter entirely.

1996

Orca is an object-based distributed shared memory system that is designed for writing portable and efficient parallel programs. Orca hides the communication substrate from the programmer by providing an abstract communication model based on shared objects. Mutual exclusion and condition synchronization are cleanly integrated in the model. Orca has been implemented using a layered system, consisting of a compiler, a runtime system, and a virtual machine (Panda). To implement shared objects efficiently on a distributed-memory machine, the Orca compiler generates regular expressions describing how shared objects are accessed. The runtime system uses this information together with runtime statistics to decide which objects to replicate and where to store nonreplicated objects. The Orca system has been implemented on a range of platforms (including Solaris, Amoeba, Parix, and the CM-5). Measurements of several benchmarks and applications across four platforms show that the new Orca system achieves portability with good performance. In addition, the measurements show that performance of the new system is as good as the previous implementation that was specialized for Amoeba.

This paper describes the philosophy and structure of a multiprogramming system that can be extended with a hierarchy of operating systems to suit diverse requirements of program scheduling and resource allocation. The system nucleus simulates an environment in which program execution and input/ output are handled uniformly as parallel, cooperating processes. A fundamental set of primitives allows the dynamic creation and control of a hierarchy of processes as well as the communication among them.