In computer science, garbage collection (GC) is a form of automatic memory management. The garbage collector attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called garbage. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp.
John McCarthy was an American computer scientist and cognitive scientist. He was one of the founders of the discipline of artificial intelligence. He co-authored the document that coined the term "artificial intelligence" (AI), developed the programming language family Lisp, significantly influenced the design of the language ALGOL, popularized time-sharing, and invented garbage collection.
Peter John Landin was a British computer scientist. He was one of the first to realise that the lambda calculus could be used to model a programming language, an insight that is essential to the development of both functional programming and denotational semantics.
MultiLisp is a functional programming language, a dialect of the language Lisp, and of its dialect Scheme, extended with constructs for parallel computing execution and shared memory. These extensions involve side effects, rendering MultiLisp nondeterministic. Along with its parallel-programming extensions, MultiLisp also had some unusual garbage collection and task scheduling algorithms. Like Scheme, MultiLisp was optimized for symbolic computing. Unlike some parallel programming languages, MultiLisp incorporated constructs for causing side effects and for explicitly introducing parallelism.
The actor model in computer science is a mathematical model of concurrent computation that treats an actor as the basic building block of concurrent computation. In response to a message it receives, an actor can: make local decisions, create more actors, send more messages, and determine how to respond to the next message received. Actors may modify their own private state, but can only affect each other indirectly through messaging.
In theoretical computer science, Actor model theory concerns theoretical issues for the Actor model.
In computer science, the Actor model, first published in 1973, is a mathematical model of concurrent computation.
In computer science, unbounded nondeterminism or unbounded indeterminacy is a property of concurrency by which the amount of delay in servicing a request can become unbounded as a result of arbitration of contention for shared resources while still guaranteeing that the request will eventually be serviced. Unbounded nondeterminism became an important issue in the development of the denotational semantics of concurrency, and later became part of research into the theoretical concept of hypercomputation.
Indeterminacy in concurrent computation is concerned with the effects of indeterminacy in concurrent computation. Computation is an area in which indeterminacy is becoming increasingly important because of the massive increase in concurrency due to networking and the advent of many-core computer architectures. These computer systems make use of arbiters which gives rise to indeterminacy.
The actor model and process calculi share an interesting history and co-evolution.
In computer science, the Actor model, first published in 1973, is a mathematical model of concurrent computation. This article reports on the middle history of the Actor model in which major themes were initial implementations, initial applications, and development of the first proof theory and denotational model. It is the follow on article to Actor model early history which reports on the early history of the Actor model which concerned the basic development of the concepts. The article Actor model later history reports on developments after the ones reported in this article.
David Gries is an American computer scientist at Cornell University, United States mainly known for his books The Science of Programming (1981) and A Logical Approach to Discrete Math.
Carl Eddie Hewitt was an American computer scientist who designed the Planner programming language for automated planning and the actor model of concurrent computation, which have been influential in the development of logic, functional and object-oriented programming. Planner was the first programming language based on procedural plans invoked using pattern-directed invocation from assertions and goals. The actor model influenced the development of the Scheme programming language, the π-calculus, and served as an inspiration for several other programming languages.
In computer science, particularly in functional programming, hash consing is a technique used to share values that are structurally equal. When a value is constructed, such as a cons cell, the technique checks if such a value has been constructed before, and if so reuses the previous value, avoiding a new memory allocation. A useful property of hash consing is that two structures can be tested for equality in constant time via pointer equality, which in turn can improve efficiency of divide and conquer algorithms when data sets contain overlapping blocks. Hash consing has been shown to give dramatic performance improvements—both space and time—for symbolic and dynamic programming algorithms.
The history of the programming language Scheme begins with the development of earlier members of the Lisp family of languages during the second half of the twentieth century. During the design and development period of Scheme, language designers Guy L. Steele and Gerald Jay Sussman released an influential series of Massachusetts Institute of Technology (MIT) AI Memos known as the Lambda Papers (1975–1980). This resulted in the growth of popularity in the language and the era of standardization from 1990 onward. Much of the history of Scheme has been documented by the developers themselves.
Henry Lieberman is an American computer scientist at the MIT CSAIL in the fields of programming languages, artificial intelligence and human-computer interaction. He received the 2018 ACM Impact Award Intelligent User Interaction for work on mining affect from text and has been applied to the problem of prevention of cyberbullying. He has been a principal research scientist at the Media Lab and Director of the Software Agents Research group.
Conor McBride is a Reader in the department of Computer and Information Sciences at the University of Strathclyde. In 1999, he completed a Doctor of Philosophy (Ph.D.) in Dependently Typed Functional Programs and their Proofs at the University of Edinburgh for his work in type theory. He formerly worked at Durham University and briefly at Royal Holloway, University of London before joining the academic staff at the University of Strathclyde.
Alice Hartley (1937–2017) was an American computer scientist and business woman. Hartley worked on several dialects of Lisp, implementing multiple parts of Interlisp, maintaining Macintosh Common Lisp, and developing concepts in computer science and programming language design still in use today.
