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Software Transactional Memory
In computer science, software transactional memory (STM) is a concurrency control mechanism analogous to database transactions for controlling access to shared memory in concurrent computing. It is an alternative to lock-based synchronization. STM is a strategy implemented in software, rather than as a hardware component. A transaction in this context occurs when a piece of code executes a series of reads and writes to shared memory. These reads and writes logically occur at a single instant in time; intermediate states are not visible to other (successful) transactions. The idea of providing hardware support for transactions originated in a 1986 paper by Tom Knight.Tom Knight. An architecture for mostly functional languages.' Proceedings of the 1986 ACM conference on Lisp and functional programming. The idea was popularized by Maurice Herlihy and J. Eliot B. Moss.Maurice Herlihy and J. Eliot B. Moss. ''Transactional memory: architectural support for lock-free data structures.'' ... [...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] |
Idempotence
Idempotence (, ) is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application. The concept of idempotence arises in a number of places in abstract algebra (in particular, in the theory of projectors and closure operators) and functional programming (in which it is connected to the property of referential transparency). The term was introduced by American mathematician Benjamin Peirce in 1870 in the context of elements of algebras that remain invariant when raised to a positive integer power, and literally means "(the quality of having) the same power", from + '' potence'' (same + power). Definition An element x of a set S equipped with a binary operator \cdot is said to be ''idempotent'' under \cdot if : . The ''binary operation'' \cdot is said to be ''idempotent'' if : . Examples * In the monoid (\mathbb, \times) of the natural numbers with multiplication, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntax (programming Languages)
In computer science, the syntax of a computer language is the rules that define the combinations of symbols that are considered to be correctly structured Statement (computer science), statements or Expression (computer science), expressions in that language. This applies both to programming languages, where the document represents source code, and to markup languages, where the document represents data. The syntax of a language defines its surface form. Text-based user interface, Text-based computer languages are based on sequences of Character (computing), characters, while visual programming languages are based on the spatial layout and connections between symbols (which may be textual or graphical). Documents that are syntactically invalid are said to have a syntax error. When designing the syntax of a language, a designer might start by writing down examples of both legal and illegal String (computer science), strings, before trying to figure out the general rules from these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glasgow Haskell Compiler
The Glasgow Haskell Compiler (GHC) is a native or machine code compiler for the functional programming language Haskell. It provides a cross-platform software environment for writing and testing Haskell code and supports many extensions, libraries, and optimisations that streamline the process of generating and executing code. GHC is the most commonly used Haskell compiler. It is free and open-source software released under a BSD license. History GHC originally begun in 1989 as a prototype, written in Lazy ML (LML) by Kevin Hammond at the University of Glasgow. Later that year, the prototype was completely rewritten in Haskell, except for its parser, by Cordelia Hall, Will Partain, and Simon Peyton Jones. Its first beta release was on 1 April 1991. Later releases added a strictness analyzer and language extensions such as monadic I/O, mutable arrays, unboxed data types, concurrent and parallel programming models (such as software transactional memory and data parallelism) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with command line shells and utility interfaces, for software compatibility (portability) with variants of Unix and other operating systems. POSIX is also a trademark of the IEEE. POSIX is intended to be used by both application and system developers. As of POSIX 2024, the standard is aligned with the C17 language standard. Name Originally, the name "POSIX" referred to IEEE Std 1003.1-1988, released in 1988. The family of POSIX standards is formally designated as IEEE 1003 and the ISO/IEC standard number is ISO/ IEC 9945. The standards emerged from a project that began in 1984 building on work from related activity in the ''/usr/group'' association. Richard Stallman suggested the name ''POSIX'' to the IEEE instead of the former ''IEEE-IX''. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linearizability
In concurrent programming, an operation (or set of operations) is linearizable if it consists of an ordered list of invocation and response events, that may be extended by adding response events such that: # The extended list can be re-expressed as a sequential history (is serializable). # That sequential history is a subset of the original unextended list. Informally, this means that the unmodified list of events is linearizable if and only if its invocations were serializable, but some of the responses of the serial schedule have yet to return. In a concurrent system, processes can access a shared object at the same time. Because multiple processes are accessing a single object, a situation may arise in which while one process is accessing the object, another process changes its contents. Making a system linearizable is one solution to this problem. In a linearizable system, although operations overlap on a shared object, each operation appears to take place instantaneousl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Haskell
Concurrent Haskell (also Control.Concurrent, or Concurrent and Parallel Haskell) is an extension to the functional programming language Haskell, which adds explicit primitive data types for concurrency. It was first added to Haskell 98, and has since become a library named Control.Concurrent included as part of the Glasgow Haskell Compiler. Its two main underlying concepts are: * A primitive data type MVar α implementing a bounded/single-place asynchronous channel, which is either empty or holds a value of type α. * The ability to spawn a concurrent thread via the forkIO primitive. Built on this is a set of useful concurrency and synchronizing abstractions such as unbounded channels, semaphores and sample variables. Haskell threads have very low overhead: creating, context-switching, and scheduling are all internal to the Haskell runtime system. These Haskell-level threads are mapped onto a configurable number of operating system (OS) level threads, usually one per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simon Peyton Jones
Simon Peyton Jones (born 18 January 1958) is a British computer scientist who researches the implementation and applications of functional programming languages, particularly lazy functional programming. Education Peyton Jones graduated from the University of Cambridge with a Bachelor of Science degree in Electrical Sciences in 1979. During this time he was an undergraduate student of Trinity College, Cambridge, and subsequently went on to complete the Cambridge Diploma in Computer Science in 1980. He never did a PhD. Career and research Peyton Jones worked in industry for two years before serving as a lecturer at University College London and, from 1990 to 1998, as a professor at the University of Glasgow. From 1998 to 2021 he worked as a researcher at Microsoft Research in Cambridge, England. Since 2021 he has worked at Epic Games as an engineering fellow. He is a major contributor to the design of the Haskell programming language, and a lead developer of the Glasgow H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simon Marlow
Simon Marlow is a British computer scientist, programmer, author, and co-developer of the Glasgow Haskell Compiler (GHC) for the programming language Haskell. He and Simon Peyton Jones won the SIGPLAN Programming Languages Software Award in 2011 for their work on GHC. Marlow's book ''Parallel and Concurrent Programming in Haskell'' was published in July 2013. Formerly of Microsoft Research, Marlow has worked at Facebook since March 2013. The "noted Haskell guru" is part of the team behind Facebook's open source Haxl project, a Haskell library that simplifies access to remote data. Honours and awards In 2011, he and Simon Peyton Jones Simon Peyton Jones (born 18 January 1958) is a British computer scientist who researches the implementation and applications of functional programming languages, particularly lazy functional programming. Education Peyton Jones graduated fro ... were awarded the SIGPLAN Programming Languages Software Award for their work on GHC. In 2019 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type System
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a ''type'' (for example, integer, floating point, string) to every '' term'' (a word, phrase, or other set of symbols). Usually the terms are various language constructs of a computer program, such as variables, expressions, functions, or modules. A type system dictates the operations that can be performed on a term. For variables, the type system determines the allowed values of that term. Type systems formalize and enforce the otherwise implicit categories the programmer uses for algebraic data types, data structures, or other data types, such as "string", "array of float", "function returning boolean". Type systems are often specified as part of programming languages and built into interpreters and compilers, although the type system of a language can be extended by optional tools that perform added checks using the language's original type synta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compile Time
In computer science, compile time (or compile-time) describes the time window during which a language's statements are converted into binary instructions for the processor to execute. The term is used as an adjective to describe concepts related to the context of program compilation, as opposed to concepts related to the context of program execution ( run time). For example, ''compile-time requirements'' are programming language requirements that must be met by source code before compilation and ''compile-time properties'' are properties of the program that can be reasoned about during compilation. The actual length of time it takes to compile a program is usually referred to as ''compilation time''. Overview Most compilers have at least the following compiler phases (which therefore occur at compile-time): syntax analysis, semantic analysis, and code generation. During optimization phases, constant expressions in the source code can also be evaluated at compile-time usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haskell
Haskell () is a general-purpose, statically typed, purely functional programming language with type inference and lazy evaluation. Designed for teaching, research, and industrial applications, Haskell pioneered several programming language features such as type classes, which enable type-safe operator overloading, and monadic input/output (IO). It is named after logician Haskell Curry. Haskell's main implementation is the Glasgow Haskell Compiler (GHC). Haskell's semantics are historically based on those of the Miranda programming language, which served to focus the efforts of the initial Haskell working group. The last formal specification of the language was made in July 2010, while the development of GHC continues to expand Haskell via language extensions. Haskell is used in academia and industry. , Haskell was the 28th most popular programming language by Google searches for tutorials, and made up less than 1% of active users on the GitHub source code repository ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
