Editing Garbage collection (computer science) (section)

{{Short description|Form of automatic memory management}}
{{About|garbage collection in memory management|garbage collection in a solid-state drive|Garbage collection (SSD)}}
{{Use dmy dates|date=April 2019|cs1-dates=y}}
{{Use list-defined references|date=July 2022}}
[[File:Structure and Interpretation of Computer Programs p.764a.gif|thumb|400px|Stop-and-copy garbage collection in a [[Lisp (programming language)|Lisp architecture]]:<ref name="Abelson-Sussman_2016"/> Memory is divided into ''working'' and ''free'' memory; new objects are allocated in the former. When it is full (depicted), garbage collection is performed: All data structures still in use are located by pointer tracing and copied into consecutive locations in free memory.]]
[[File:Structure and Interpretation of Computer Programs p.764b.gif|thumb|400px|After that, the working memory contents is discarded in favor of the compressed copy, and the role of ''working'' and ''free'' memory are exchanged (depicted).]]

In [[computer science]], '''garbage collection''' ('''GC''') is a form of automatic [[memory management]].<ref name="techtarget">{{Cite web |title=What is garbage collection (GC) in programming? |url=https://www.techtarget.com/searchstorage/definition/garbage-collection |access-date=2024-06-21 |website=Storage |language=en}}</ref> The ''garbage collector'' attempts to reclaim memory that was allocated by the program, but is no longer referenced; such memory is called ''[[garbage (computer science)|garbage]]''. Garbage collection was invented by American computer scientist [[John McCarthy (computer scientist)|John McCarthy]] around 1959 to simplify manual memory management in [[Lisp (programming language)|Lisp]].<ref name="McCarthy_1960"/>

Garbage collection relieves the programmer from doing [[manual memory management]], where the programmer specifies what objects to de-allocate and return to the memory system and when to do so.<ref name="techtarget"/> Other, similar techniques include [[stack-based memory allocation|stack allocation]], [[region inference]], and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect [[computer performance|performance]] as a result.

Resources other than memory, such as [[network socket]]s, database [[Handle (computing)|handle]]s, [[Window (computing)|window]]s, [[File (computing)|file]] descriptors, and device descriptors, are not typically handled by garbage collection, but rather by other [[Method (computer programming)|method]]s (e.g. [[Destructor (computer programming)|destructor]]s). Some such methods de-allocate memory also.