|
Protected Procedure
In computer science, the concept of protected procedure, first introduced as protected service routine in 1965, is necessary when two computations ''A'' and ''B'' use the same routine ''S''; a protected procedure is such if makes not possible for a malfunction of one of the two computation to cause incorrect execution to the other.Dennis 66 One of the most important aspects of Dennis and Van Horn (hypothetical) system "supervisor" was the inclusion of a description of protected procedure.Levy 84, pp.46-6 In a global environment system (where there's some shared variable), the protected procedure mechanism allows the enforcement of the principle of least privilege and the avoidance of side effects In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ... in resources management (see Denn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subroutine
In computer programming, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of software logic that has a well-defined interface and behavior and can be invoked multiple times. Callable units provide a powerful programming tool. The primary purpose is to allow for the decomposition of a large and/or complicated problem into chunks that have relatively low cognitive load and to assign the chunks meaningful names (unless they are anonymous). Judicious application can reduce the cost of developing and maintaining software, while increasing its quality and reliability. Callable units are present at multiple levels of abstraction in the programming environment. For example, a programmer may write a function in source code that is compiled to machine code that implements similar semantics. There is a callable unit in the source code and an associated one in the machine code, but they are different kinds of callable units with different impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Environment
Global may refer to: General *Globe, a spherical model of celestial bodies *Earth, the third planet from the Sun Entertainment * ''Global'' (Paul van Dyk album), 2003 * ''Global'' (Bunji Garlin album), 2007 * ''Global'' (Humanoid album), 1989 * ''Global'' (Todd Rundgren album), 2015 * Bruno J. Global, a character in the anime series ''The Super Dimension Fortress Marcoss'' Companies and brands Television * Global Television Network, in Canada ** Canwest Global, former parent company of Global Television Network ** Global BC, on-air brand of CHAN-TV, a television station in Vancouver, British Columbia, Canada ** Global Calgary ** Global Edmonton ** Global Halifax ** Global Montreal ** Global News, the news division of the Global Television Network ** Global Okanagan, on-air brand of CHBC-TV, a television station in Kelowna, British Columbia, Canada ** Global Toronto, a television station in Toronto * Global TV (Venezuela), a regional channel in Venezuela * Global TV, the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Least Privilege
In information security, computer science, and other fields, the principle of least privilege (PoLP), also known as the principle of minimal privilege (PoMP) or the principle of least authority (PoLA), requires that in a particular abstraction layer of a computing environment, every module (such as a process, a user, or a program, depending on the subject) must be able to access only the information and resources that are necessary for its legitimate purpose. Details The principle means giving any user accounts or processes only those privileges which are essentially vital to perform its intended functions. For example, a user account for the sole purpose of creating backups does not need to install software: hence, it has rights only to run backup and backup-related applications. Any other privileges, such as installing new software, are blocked. The principle applies also to a personal computer user who usually does work in a normal user account, and opens a privileged, pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Side Effect (computer Science)
In computer science, an operation, function or expression is said to have a side effect if it has any observable effect other than its primary effect of reading the value of its arguments and returning a value to the invoker of the operation. Example side effects include modifying a non-local variable, a static local variable or a mutable argument passed by reference; raising errors or exceptions; performing I/O; or calling other functions with side-effects. In the presence of side effects, a program's behaviour may depend on history; that is, the order of evaluation matters. Understanding and debugging a function with side effects requires knowledge about the context and its possible histories. Side effects play an important role in the design and analysis of programming languages. The degree to which side effects are used depends on the programming paradigm. For example, imperative programming is commonly used to produce side effects, to update a system's state. By contrast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denning Principles
Peter James Denning (born January 6, 1942) is an American computer scientist and writer. He is best known for pioneering work in virtual memory, especially for inventing the working-set model for program behavior, which addressed thrashing in operating systems and became the reference standard for all memory management policies. He is also known for his works on principles of operating systems, operational analysis of queueing network systems, design and implementation of CSNET, the ACM digital library, and codifying the great principles of computing. He has written numerous influential articles and books, including an overview of fundamental computer science principles, computational thinking, and his thoughts on innovation as a set of learnable practices. Early life and education Denning was born January 6, 1942, in Queens, New York, and raised in Darien, Connecticut. He took an early interest in science, pursuing astronomy, botany, radio, and electronics while in grade sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Computing
Concurrent computing is a form of computing in which several computations are executed '' concurrently''—during overlapping time periods—instead of ''sequentially—''with one completing before the next starts. This is a property of a system—whether a program, computer, or a network—where there is a separate execution point or "thread of control" for each process. A ''concurrent system'' is one where a computation can advance without waiting for all other computations to complete. Concurrent computing is a form of modular programming. In its paradigm an overall computation is factored into subcomputations that may be executed concurrently. Pioneers in the field of concurrent computing include Edsger Dijkstra, Per Brinch Hansen, and C.A.R. Hoare. Introduction The concept of concurrent computing is frequently confused with the related but distinct concept of parallel computing, Pike, Rob (2012-01-11). "Concurrency is not Parallelism". ''Waza conference'', 11 Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
