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

Operating System, my Operating System is windows trust but when the windows...

my Operating System is windows trust but when the windows start say its windows xp. help pleaes

Perform alpha-beta pruning on the following tree, Perform alpha-beta prunin...

Perform alpha-beta pruning on the following tree. Put an "X" over each node that is pruned. Put the final value next to all other nodes. Indicate which action MAX should take: to B

Software Support (Introducing Operating Systems), The questions ask List fo...

The questions ask List four major functions of an OS. My answer: Function 1: Provide a user interface Function 2: Manage files Function 3: Manage hardware Function 4: Manage appli

Determine the syntax of the fork and join primitive, Determine the syntax o...

Determine the syntax of the Fork and Join Primitive  Answer: Syntax of the Fork and Join Primitive is as follow: Fork Join

Virtual memory, In modern operating systems, applications do not directly a...

In modern operating systems, applications do not directly access the physical memory. Instead, they use so-called virtual memory, where each virtual address is translated to a phys

Can page tables be set up to replicate base registers, Q. We have an OS (o...

Q. We have an OS (operating system) for a machine that uses base and limit registers however we have modified the machine to provide a page table. Can the page tables be set up to

What is a path name, What is a path name? A pathname is the path from t...

What is a path name? A pathname is the path from the root by all subdirectories to a specified file. In a two-level directory structure a user name and a file name explain a pa

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

properies of Batch oriented and interactive operating system.

Activities of operating system-secondary-storage management, Q. What are th...

Q. What are the three main activities of an operating system in regard to secondary-storage management? Answer: 1) Free-space management 2) Storage allocation 3) Disk

Define process? what is meant by state of a process?, Define process? What ...

Define process? What is meant by state of a process? Process is a program in implementation. A process in general includes the process stack, which consists temporary data and

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