Each cell has a bit reserved for marking which is clear initially. During garbage collection all active cells are traced from the root and marked. Then all cells are examined. Unmarked cells are freed.

<programming> (GC) The process by which dynamically allocated storage is reclaimed during the execution of a program. The term usually refers to automatic periodic storage reclamation by the garbage collector (part of the run-time system), as opposed to explicit code to free specific blocks of memory. Automatic garbage collection is usually triggered during memory allocation when the amount free memory falls below some threshold or after a certain number of allocations. Normal execution is suspended and the garbage collector is run. There are many variations on this basic scheme. Languages like Lisp represent expressions as graphs built from cells which contain pointers and data. These languages use automatic dynamic storage allocation to build expressions. During the evaluation of an expression it is necessary to reclaim space which is used by subexpressions but which is no longer pointed to by anything. This reclaimed memory is returned to the free memory pool for subsequent reallocation. Without garbage collection the program's memory requirements would increase monotonically throughout execution, possibly exceeding system limits on virtual memory size. The three main methods are mark-sweep garbage collection, reference counting and copying garbage collection. See also the AI koan about garbage collection. (1997-08-25)

(garbage collectors)

Waste collection is a part of the process of waste management. It is the transfer of solid waste from the point of use and disposal to the point of treatment or landfill.

In computer programming, tracing garbage collection is a form of automatic memory management that consists of determining which objects should be deallocated ("garbage collected") by tracing which objects are reachable by a chain of references from certain "root" objects, and considering the rest as "garbage" and collecting them. Tracing garbage collection is the most common type of garbage collection – so much so that "garbage collection" often refers to tracing garbage collection, rather than other methods such as reference counting – and there are a large number of algorithms used in implementation.

Sweep rowing is one of two disciplines of the sport of rowing. In sweep rowing each rower has one oar, usually held with both hands.

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.

The Packers sweep, also known as the Lombardi sweep, is an American football play popularized by Green Bay Packers coach Vince Lombardi. The Packers sweep is based on the sweep, a football play that involves a back taking a handoff and running parallel to the line of scrimmage before turning upfield behind lead blockers.

Distributed garbage collection (DGC) in computing is a particular case of garbage collection where a remote client can hold references to an object.