Garbage collection (computer science)

In <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, garbage collection (GC) is a form of automatic <a href="/facts/Memory_management/vthLkUpz">memory management</a>. The garbage collector attempts to reclaim memory that was allocated by the program, but is no longer referenced; such memory is called <a href="/facts/Garbage_(computer_science)/vnBYqx88">garbage</a>. Garbage collection was invented by American computer scientist <a href="/facts/John_McCarthy_(computer_scientist)/ajKU4SdD">John McCarthy</a> around 1959 to simplify manual memory management in <a href="/facts/Lisp_(programming_language)/xJHA3CrX">Lisp</a>.
Garbage collection relieves the programmer from doing <a href="/facts/Manual_memory_management/vLl0Qwdw">manual memory management</a>, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include <a href="/facts/Stack-based_memory_allocation/Wem3dQa6">stack allocation</a>, <a href="/facts/Region_inference/58t5AIVL">region inference</a>, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect <a href="/facts/Computer_performance/td1qKox4">performance</a> as a result.
Resources other than memory, such as <a href="/facts/Network_socket/r1ldfkb5">network sockets</a>, database <a href="/facts/Handle_(computing)/gKL1X2sX">handles</a>, <a href="/facts/Window_(computing)/g39X0vV3">windows</a>, <a href="/facts/File_(computing)/FjFH3Ufm">file</a> descriptors, and device descriptors, are not typically handled by garbage collection, but rather by other <a href="/facts/Method_(computer_programming)/8kAXxVYs">methods</a> (e.g. <a href="/facts/Destructor_(computer_programming)/gr4051ve">destructors</a>). Some such methods de-allocate memory also.

Garbage collection (computer science) open-in-new

Garbage collection (computer science)