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

In JavaScript, Ask quesIn JavaScript, what is event handling tion #Minimum ...

Ask quesIn JavaScript, what is event handling tion #Minimum 100 words accepted#

Illustrate different ways that threads could be implemented, Q. Multithread...

Q. Multithreading is a commonly utilized programming technique. Illustrate three different ways that threads could be implemented. Describe how these ways compare to the Linux clon

What are the system components of an operating system, What are the system ...

What are the system components of an operating system and explain them? a) Process management b) Main-memory management c) I/O management d) File management e) Seco

How program execute in operating system, Q. How Program execute in operatin...

Q. How Program execute in operating system? Program execution: Operating system loads a program in memory and executes the program. The program should be able to end its exec

Explain the procedure for handling the page fault, The procedure for handli...

The procedure for handling the page fault is as follows 1. We check the internal table to verify whether the reference was valid or invalid. 2. If the reference was invalid,

Explain kernel activity for ults, KERNEL ACTIVITY FOR ULTS: The kernel...

KERNEL ACTIVITY FOR ULTS: The kernel isn't aware of thread activity but it is still managing process activity. When a thread compose a system call the whole process will be bl

Explain independent process and a cooperating process, Question: a) Ea...

Question: a) Each process is represented in the operating system by a process control block (PCB). The PCB contains many pieces of information associated with a specific proce

Demand-paging system, Consider a demand-paging system with the following ti...

Consider a demand-paging system with the following time-measured utilizations: CPU utilization: 10%, Paging disk: 98%, Other I/O devices: 5%. What does this imply? How to improv

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