Jointly-Owned Objects for Collaboration: Operating-System Support and Protection Model
Abstract
As real-time collaboration becomes more frequent, it is common for a group of users to create and own an object jointly. The use of multi-user tools makes the existence of jointly-owned objects a necessity: a participant who joins a multi-user tool written by others knows that the user agent executed in his name is not a Trojan horse if the multi-user tool is jointly owned by all the participants. In this paper, we discuss the requirements and issues behind jointly-owned objects. By generalizing these requirements we have implemented a conditionally jointly-owned object. The conditions take the form of a quorum or list of users who have the rights to access an object or to change its protection state. We sketch a design of conditionally jointly-owned objects, and apply the same concepts to subjects. Authority-and quorum-based objects are investigated as instances of conditionally jointly-owned objects. We show that conditionally jointly-owned objects can also be used to resolve the conflicts that may arise among joint owners. We generalize Graham and Denning's protection model to incorporate these jointly-owned entities. Operating system support for conditionally jointly-owned object is specified at the system-call level. Examples are provided to demonstrate the usefulness of conditionally jointly- owned objects. (kr)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA228493
Entities
People
- Hussein Abdel-wahab
- Peter Calingaert
- Sheng-uei Guan
Organizations
- University of North Carolina at Chapel Hill