C. A. Ellis
Abstract
Groupware systems are computer-based systems that support two or more users engaged in a common task, and that provide an interface to a shared environment. These systems frequently require fine-granularity sharing of data and fast response times. This paper distinguishes real-time groupware systems from other multi-user systems and discusses their concurrency control requirements. An algorithm for concurrency control in real-time groupware systems is then presented. The advantages of this algorithm are its simplicity of use and its responsiveness: users can operate directly on the data without obtaining locks. The algorithm must know some semantics of the operations. However the algorithm's overall structure is independent of the semantic information, allowing the algorithm to be adapted to many situations. An example application of the algorithm to group text editing is given, along with a sketch of its proof of correctness in this particular case. We note that the behavior desired in many of these systems is non-serializable.
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Index Terms
- Concurrency control in groupware systems
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Concurrency control in groupware systems
SIGMOD '89: Proceedings of the 1989 ACM SIGMOD international conference on Management of dataGroupware systems are computer-based systems that support two or more users engaged in a common task, and that provide an interface to a shared environment. These systems frequently require fine-granularity sharing of data and fast response times. This ...
Semantics-based concurrency control: beyond commutativity
The concurrency of transactions executing on atomic data types can be enhanced through the use of semantic information about operations defined on these types. Hitherto, commutativity of operations has been exploited to provide enchanced concurrency ...
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