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

Explain about functions of operating system, Q. Explain about Functions of ...

Q. Explain about Functions of Operating System? Functions of Operating System Operating system performs 3 functions as follows: 1.  Convenience:   Operating System mak

Explain the demand paging system, Question : (a) In the demand paging ...

Question : (a) In the demand paging system, when a process tries to access a page that was not brought into memory, a page fault occurs that involves a series of actions. The

Multi user systems technology, describe main points of multiuser and multi ...

describe main points of multiuser and multi tasking operating systems.

Ipc, explain in detail about ipc in linux

explain in detail about ipc in linux

Explain the thread contextual data, Explain the Thread Contextual Data  ...

Explain the Thread Contextual Data  Threads in Net Ware carry additional context as well. Per-thread, stacks, errno, Net Ware Errno, t_errno and others are available to the ap

Shared stack is used for parameter passing, Q. What protection problems may...

Q. What protection problems may occur if a shared stack is used for parameter passing? Answer: The contents of the stack could be conciliation by other process(es) sharing th

Producer - consumer system, In this exercise we are going to use  pthread()...

In this exercise we are going to use  pthread()to simulate the dynamics between a warehouse, factory and retail. The factory produces product by using parts supplied by the warehou

Android, Which android version is available till now

Which android version is available till now

List ways to share directories in operating system, List ways to share file...

List ways to share files among directories in operating systems. a. Copy file from one account into another. b. Link directory entry of "copied" file to directory entry of o

Objectives and functions of an operating system, Question: a) What is ...

Question: a) What is an Input/Output module and what are the five categories their functions fall into? b) What is an Operating System? Briefly describe the two objectives

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