This paper describes the Time Warp Operating System, under development for three years at the Jet Propulsion Laboratory for the Caltech Mark III Hypercube multiprocessor. Its primary goal is concurrent execution of la...
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The proceedings contain 29 papers. The topics discussed include: environments as first class objects;semantic parallelization : a practical exercise in abstract interpretation;a logic for partially specified data stru...
ISBN:
(纸本)0897912152
The proceedings contain 29 papers. The topics discussed include: environments as first class objects;semantic parallelization : a practical exercise in abstract interpretation;a logic for partially specified data structures;axioms for concurrent objects;the concurrent logic programming language CP: definition and operational semantics;on strictness and its analysis;macro-by-example: deriving syntactic transformations from their specifications;automatic decomposition of scientific programs for parallel execution;binding performance at language design time;strictness analysis and denotational abstract interpretation;compiling strictness into streams;completeness and incompleteness of trace-based network proof systems;computable values can be classical;full abstraction of a real-time denotational semantics for an OCCAM-like language;concurrent transition system semantics of process networks;semantics for concurrency without powerdomains;and appraising fairness in languages for distributed programming.
We have developed a unified model, called the precedence-assignment model (PAM), of concurrency control algorithms in distributed database. It is shown that two-phase locking, timestamp-ordering and other existing con...
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ISBN:
(纸本)0897912233
We have developed a unified model, called the precedence-assignment model (PAM), of concurrency control algorithms in distributed database. It is shown that two-phase locking, timestamp-ordering and other existing concurrency control algorithms may be modeled by PAM. We have also developed a new concurrency control algorithm under the PAM modeling framework, which is free from deadlocks and transaction restarts. Finally, a unified concurrency control subsystem for precedence-assignment algorithms is developed. By using this subsystem, different transactions may be executed under different concurrency control algorithms simultaneously.
Let DB be a database and let U//1, . . . , u//n be a collection of users each having at his or her disposal a query sublanguage L//u//i generated by some view predicate. Each of these users knows only as much as he ca...
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ISBN:
(纸本)0897912233
Let DB be a database and let U//1, . . . , u//n be a collection of users each having at his or her disposal a query sublanguage L//u//i generated by some view predicate. Each of these users knows only as much as he can learn from the database using his or her query sublanguage. Such a knowledge is called relative knowledge in the paper and its various properties including the model and proof theory are investigated. The applications of relative knowledge in the database security and integrity are also discussed.
Some of the techniques used to replicate objects for resilience in distributed operating systems are reviewed. The problems associated with the replication of objects are discussed, and a scheme of replicated actions ...
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ISBN:
(纸本)0818607378
Some of the techniques used to replicate objects for resilience in distributed operating systems are reviewed. The problems associated with the replication of objects are discussed, and a scheme of replicated actions and replicated objects, using a paradigm called PETs (parallel execution threads) is presented. The PET scheme not only utilizes the high availability of replicated objects, but also tolerates site failures that happen while an action is executing. It is shown how this scheme can be implemented in a distributed object-based system, and the Clouds operating system is used as an example testbed.
The authors propose a reliable distributed environment (RDE) based on an efficient and reliable extension to datagram communications that provides reliable communication and configuration services. They introduce the ...
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ISBN:
(纸本)0818607823
The authors propose a reliable distributed environment (RDE) based on an efficient and reliable extension to datagram communications that provides reliable communication and configuration services. They introduce the coupled relation to measure the degree of reliability of distributed environments. They also present view sections, which protect against changes in node status (available or unavailable) in the same sense that critical sections protect against changes to shared memory, as support for distributed communications tasks. Simulation results are given for coupled relations based on different algorithms, node failure rates, recovery times, and message arrival rates. The behavior of distributed systems constructed using the authors' view section model on top of RDE is illustrated.
We have developed a unified model, called the precedence-assignment model (PAM), of concurrency control algorithms in distributed database. It is shown that two-phase locking timestamp-ordering and other existing conc...
ISBN:
(纸本)9780897912235
We have developed a unified model, called the precedence-assignment model (PAM), of concurrency control algorithms in distributed database. It is shown that two-phase locking timestamp-ordering and other existing concurrency control algorithms may be modeled by PAM. We have also developed a new concurrency control algorithm under the PAM modeling framework, which is free from deadlocks and transaction restarts. Finally, a unified concurrency control subsystem for precedence-assignment algorithms is developed. By using this subsystem, different transactions may be executed under different concurrency control algorithms simultaneously.
Let DB be a database and let u1, um be a collection of users each having at his or her disposal a query sublanguage Lu1 generated by some view predicate Each of these users knows only as much as he can learn from the ...
ISBN:
(纸本)9780897912235
Let DB be a database and let u1, um be a collection of users each having at his or her disposal a query sublanguage Lu1 generated by some view predicate Each of these users knows only as much as he can learn from the database using his or her query sublanguage. Such a knowledge is called relative knowledge in the paper and its various properties including the model and proof theory are investigated. The applications of relative knowledge in the database security and integrity are also discussed.
作者：
K. R. AptN. FrancezS. KatzLITP
Universite Paris 7 2 Place Jussieu 75251 Paris France and Laboratoire d'Informatique Ecole Normale Superieure 45 Rue d'Ulm 75230 Paris France Department of Computer Science
The Technion- Israel Institute of Technology Haifa Israel
The relations among various languages and models for distributed computation and various possible definitions of fairness are considered. Natural semantic criteria are presented which an acceptable notion of fairness ...
ISBN:
(纸本)9780897912150
The relations among various languages and models for distributed computation and various possible definitions of fairness are considered. Natural semantic criteria are presented which an acceptable notion of fairness should satisfy. These are then used to demonstrate differences among the basic models, the added power of the fairness notion, and the sensitivity of the fairness notion to irrelevant semantic interleavings of independent operations. These results are used to show that from the considerable variety of commonly used possibilities, only strong process fairness is appropriate for CSP if these criteria are adopted. We also show that under these criteria, none of the commonly used notions of fairness are fully acceptable for a model with an n-way synchronization mechanism. Finally, the notion of fairness most often mentioned for Ada is shown to be fully acceptable.
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