1. [syn: garbage collection, garbage pickup, trash collection, trash pickup]
WordNet (r) 3.0 (2006):
n 1: the collection and removal of garbage [syn: garbage
collection, garbage pickup, trash collection, trash
The Free On-line Dictionary of Computing (18 March 2015):
(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
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.