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An Asymmetric Stream Communication System Computing Equipment and Technical Support Are Provided in Part under a Cooperative Research Agreement with Digital Equipment Corporation. O. Introduction
| Content Provider | Semantic Scholar |
|---|---|
| Author | Black, Andrew P. |
| Abstract | Input and output are often viewed as complementary operations, and it is certainly true that the direction of data flow during input is the reverse of that during output. However, in a conventional operating system, the direction of control flow is the same for both input and output: the program plays the active role, while the operating system transput primitives are always passive. Thus there are four primitive transput operations, not two: the corresponding pairs are passive input and active output, and active input and passive output. This paper explores ~he implications of this idea in the context of an object oriented operating system. In most operating systems the primitives for transput (i.e. input and output) appear as system calls. Programs almost always take the initiative in interactions with the system. The most notable exception to this generalisa-lion is that usually there exists some kind of primitive interrupt facility whereby the operating system kernel can notify a program that a certain event has occurred. The Eden system currently under construction at the University of Washington is radically different from this norm. In Eden it is quite usual for one program to ask another for a service, via a mechanism called /nvo-vab~on. This design naturally leads to a system in which most services are provided by "programs" rather than by the system itself, and each program is a provider as well as a consumer of services. One of the consequences of this design is that each program is prepared to receive invocations as welt as to send them. Communication with the outside world is no longer the perogative of the program; the "outside world" is able to take the initiative in communication. This capability allows a transput system for Eden to be built in a rather novel way, which this paper explores. However, before continuing it is necessary to provide some background about Eden itself. The Eden Project [11] (currently in its third year) is a five-year experiment in the design, construction and use of an integrated, distributed computing environment. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, … |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://web.cecs.pdx.edu/~black/publications/AsymmetricStreams.pdf |
| Alternate Webpage(s) | http://www.cs.pdx.edu/~black/publications/AsymmetricStreams.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
