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Chandy–Misra–Haas Algorithm Resource Model
The Chandy–Misra–Haas algorithm resource model checks for deadlock (computer science), deadlock in a distributed system. It was developed by K. Mani Chandy, Jayadev Misra and Laura M. Haas. Locally dependent Consider the n processes ''P''''1'', ''P''''2'', ''P''''3'', ''P''''4'', ''P''''5,'', ... ,''P''''n'' which are performed in a single system (controller). ''P''''1'' is locally dependent on ''P''''n'', if ''P''''1'' depends on ''P''''2'', ''P''''2'' on ''P''''3,'' so on and ''P''''n−1'' on ''P''''n''. That is, if P_1 \rightarrow P_2 \rightarrow P_3 \rightarrow \ldots \rightarrow P_n , then P_1 is locally dependent on P_n. If ''P''''1'' is said to be locally dependent to itself if it is locally dependent on ''P''''n'' and ''P''''n'' depends on ''P''''1'': i.e. if P_1 \rightarrow P_2 \rightarrow P_3 \rightarrow \ldots \rightarrow P_n \rightarrow P_1, then P_1 is locally dependent on itself. Description The algorithm uses a message called probe(i,j,k) to transfer a mess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deadlock (computer Science)
In concurrent computing, deadlock is any situation in which no member of some group of entities can proceed because each waits for another member, including itself, to take action, such as sending a message or, more commonly, releasing a lock. Deadlocks are a common problem in multiprocessing systems, parallel computing, and distributed systems, because in these contexts systems often use software or hardware locks to arbitrate shared resources and implement process synchronization. In an operating system, a deadlock occurs when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process. If a process remains indefinitely unable to change its state because resources requested by it are being used by another process that itself is waiting, then the system is said to be in a deadlock. In a communications system, deadlocks occur mainly due to loss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed System
Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different networked computers. The components of a distributed system communicate and coordinate their actions by passing messages to one another in order to achieve a common goal. Three significant challenges of distributed systems are: maintaining concurrency of components, overcoming the lack of a global clock, and managing the independent failure of components. When a component of one system fails, the entire system does not fail. Examples of distributed systems vary from SOA-based systems to microservices to massively multiplayer online games to peer-to-peer applications. Distributed systems cost significantly more than monolithic architectures, primarily due to increased needs for additional hardware, servers, gateways, firewalls, new subnets, proxies, and so on. Also, distributed systems are prone to fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jayadev Misra
Jayadev Misra is an Indian-born computer scientist who has spent most of his professional career in the United States. He is the Schlumberger Centennial Chair Emeritus in computer science and a University Distinguished Teaching Professor Emeritus at the University of Texas at Austin. Professionally he is known for his contributions to the formal aspects of concurrent programming and for jointly spearheading, with Sir Tony Hoare, the project on Verified Software Initiative (VSI). Education and early career Misra received a B.Tech. in electrical engineering from IIT Kanpur, India in 1969 and a Ph.D. in electrical engineering and computer science from the Johns Hopkins University, Baltimore, Maryland in 1972. After a brief period working for IBM, he joined the University of Texas at Austin in 1974 where he has remained throughout his career, except for a sabbatical year spent at Stanford University during 1983–1984. He retired from active teaching in 2015. Major professional c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laura M
Laura may refer to: People and fictional characters * Laura (given name), including lists of people and fictional characters with the name * Laura, muse of Petrarch's poetry * Laura, the British code name for the World War I Belgian spy Marthe Cnockaert Places Australia * Laura, Queensland, a town on the Cape York Peninsula * Laura, South Australia, a town * Laura Bay, a bay on Eyre Peninsula * Laura River (Queensland) * Laura River (Western Australia) Italy * Laura (Capaccio), a village of the municipality of Capaccio, Campania * Laura, Crespina Lorenzana, a village in Tuscany United States * Laura, Illinois, an unincorporated community * Laura, Kentucky, an unincorporated community * Laura, Missouri, an unincorporated community * Laura, Ohio, a village Elsewhere * Laura, Saskatchewan, Canada, a hamlet * Laura, Marshall Islands, a town * Laura, Silesian Voivodeship, Poland, a village * Laura River (Romania) * 467 Laura, an asteroid Arts and entertainment Art * ''Laura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithm
In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use Conditional (computer programming), conditionals to divert the code execution through various routes (referred to as automated decision-making) and deduce valid inferences (referred to as automated reasoning). In contrast, a Heuristic (computer science), heuristic is an approach to solving problems without well-defined correct or optimal results.David A. Grossman, Ophir Frieder, ''Information Retrieval: Algorithms and Heuristics'', 2nd edition, 2004, For example, although social media recommender systems are commonly called "algorithms", they actually rely on heuristics as there is no truly "correct" recommendation. As an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudocode
In computer science, pseudocode is a description of the steps in an algorithm using a mix of conventions of programming languages (like assignment operator, conditional operator, loop) with informal, usually self-explanatory, notation of actions and conditions. Although pseudocode shares features with regular programming languages, it is intended for human reading rather than machine control. Pseudocode typically omits details that are essential for machine implementation of the algorithm, meaning that pseudocode can only be verified by hand. The programming language is augmented with natural language description details, where convenient, or with compact mathematical notation. The reasons for using pseudocode are that it is easier for people to understand than conventional programming language code and that it is an efficient and environment-independent description of the key principles of an algorithm. It is commonly used in textbooks and scientific publications to document ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Deadlock
In concurrent computing, deadlock is any situation in which no member of some group of entities can proceed because each waits for another member, including itself, to take action, such as sending a message or, more commonly, releasing a lock. Deadlocks are a common problem in multiprocessing systems, parallel computing, and distributed systems, because in these contexts systems often use software or hardware locks to arbitrate shared resources and implement process synchronization. In an operating system, a deadlock occurs when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process. If a process remains indefinitely unable to change its state because resources requested by it are being used by another process that itself is waiting, then the system is said to be in a deadlock. In a communications system, deadlocks occur mainly due to loss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
