Principles
The basic principles of garbage collection are:
- Find data objects in a program that cannot be accessed in the future
- Reclaim the resources used by those objects
Many computer languages require garbage collection, either as part of the language specification (e.g., Java, C#, and most scripting languages) or effectively for practical implementation (e.g., formal languages like lambda calculus); these are said to be garbage collected languages. Other languages were designed for use with manual memory management, but have garbage collected implementations available (e.g., C, C++). Some languages, like Ada, Modula-3, and C++/CLI allow both garbage collection and manual memory management to co-exist in the same application by using separate heaps for collected and manually managed objects; others, like D, are garbage collected but allow the user to manually delete objects and also entirely disable garbage collection when speed is required. While integrating garbage collection into the language's compiler and runtime system enables a much wider choice of methods, post hoc GC systems exist, including some that do not require recompilation. (Post-hoc GC is sometimes distinguished as litter collection.) The garbage collector will almost always be closely integrated with the memory allocator.
Read more about this topic: Garbage Collection (computer Science)
Famous quotes containing the word principles:
“I cannot consent that my mortal body shall be laid in a repository prepared for an Emperor or a King—my republican feelings and principles forbid it—the simplicity of our system of government forbids it.”
—Andrew Jackson (1767–1845)
“I am not one of those who have the least anxiety about the triumph of the principles I have stood for. I have seen fools resist Providence before, and I have seen their destruction, as will come upon these again, utter destruction and contempt. That we shall prevail is as sure as that God reigns.”
—Woodrow Wilson (1856–1924)
“The proposition that Muslims are welcome in Britain if, and only if, they stop behaving like Muslims is a doctrine which is incompatible with the principles that guide a free society.”
—Roy Hattersley (b. 1932)