Mark-sweep, Operating System

Assignment Help:

The objects that a program can access directly are those objects which are referenced by local vari-ables on the processor stack, or by any global/static variables that refer to objects, or by variables in CPU registers. In the context of garbage collection, these variables are called the roots. An object is indirectly accessible if it is referenced by a ?eld in some other (directly or indirectly) accessible object. An accessible object is said to be live. Conversely, an object which is not live is garbage.

Note that heap objects which are live are indirectly accessible from the roots or other heap objects. The idea of mark-sweep is relatively straightforward. We start at the roots, and recursively visit every object accessible through pointers, marking them as live. At the end of the process, every thing not marked is considered garbage and will be deleted. Notice that mark-sweep can perform lazy garbage collection, in the sense that it does not necessarily need to remove the garbage immediately.

Note thatmark-sweep does not clean upmemory which is allocated, but simply never used. Also, periodically we have to visit all objects recursively, starting from the roots. For a large program, this will be slow. This is a problem with the traditional mark-sweep algorithm.


Related Discussions:- Mark-sweep

Briefly explain the process management in unix., Briefly explain the proces...

Briefly explain the process management in UNIX. UNIX makes use of the easy but powerful process facility that is visible to the user. UNIX follows the model in which the majori

Components of an operating system-control programs, CONTROL PROGRAMS Co...

CONTROL PROGRAMS Control Programs are those programs which control & maintain the operation of computer. They provide basic facilities. Control program are further divided into

Batch oriented and interactive operating system., properies of Batch orient...

properies of Batch oriented and interactive operating system.

Backup and recovery, what is it all about? why do we need? what are the typ...

what is it all about? why do we need? what are the types of backup? how is it done in unix?

Explain single-user systems, We have stressed the need for an operating sys...

We have stressed the need for an operating system to make efficient use of the computing hardware. When is it appropriate for the operating system to forsake this principle and to

Implementation of modern memory management system , Central to implementati...

Central to implementation of a modern memory management system is the page replacement algorithm. Modern virtual memory systems break memory up into pages and map (via a page table

Explain chaining to handle collision, Explain Chaining to Handle Collision ...

Explain Chaining to Handle Collision Chaining:  One easy scheme is to chain all collisions in lists attached to the suitable slot. This permits an unlimited number of collision

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd