Reference counting, Operating System

Assignment Help:

The idea of reference counting is to maintain, for every object, the total number of references to that object, i.e. the number of "incoming" pointers. Whenever the number of references is zero we know that the object is not accessible through any pointers, and thus it is garbage. Also, whenever we choose to delete some useless object,we have to recursively check that object to see if it contains pointers to other objects; if so, we have decrement the reference counters for those objects as well. One problem of reference counting, though, is how to deal with cycles. Suppose object A points to B, and B points to A. If these objects can only be reached through each other, we have to free them too, even though their counters are not zero! Note that cycles can common inmany data structures; for example, consider a doubly-linked list. The commonly adopted solution to this problem is to run mark-sweep now and then, in order to remove cyclic references, and then run normal reference counting on the rest of the time.


Related Discussions:- Reference counting

Inter-process Communication !, My code it didn''t run properly ,i tried to ...

My code it didn''t run properly ,i tried to pass 2 parameter example : ./a.out ls -ll ,but it execute only the ls instead of the ls -ll ! plz help amd thank you ! #include #inclu

Describe paging technique used in unix systems, Describe paging technique u...

Describe paging technique used in UNIX systems. When a process begin in UNIX, not every its memory pages are read in from the disk at once. In its place, the kernel loads into

Explain worst fit algorithm, Worst Fit Algorithm Here we obtain the la...

Worst Fit Algorithm Here we obtain the largest space available for the smallest. Therefore after that process entered there will be much more space remaining. In this space we

#title:cs604, Consider a scenario of post mailbox, there are two processes ...

Consider a scenario of post mailbox, there are two processes named sender S and receiver R. Both processes can communicate with each other by name along with message. You need to I

Bounded and unbounded buffer, Ask question #Minimum 100 difference between ...

Ask question #Minimum 100 difference between bounded and unbounded buffer words accepted#

Dynamic memory management, Usually memory is allocated from a large pool of...

Usually memory is allocated from a large pool of unused memory area called the heap. In C++, dynamic allocation/deallocation must be manually performed using commands like malloc,

Define the main reason to encrypt a file, Define the Main reason to encrypt...

Define the Main reason to encrypt a file Major reason to encrypt a file is secure it for transmission.

Describe the actions of sun ultra sparc processor, Q. The Sun Ultra SPARC p...

Q. The Sun Ultra SPARC processor has numerous register sets that describe the actions of a context switch if the new context is previously loaded into one of the register sets. Wha

What do you mean by best fit, What do you mean by best fit? Best fit al...

What do you mean by best fit? Best fit allocates the smallest hole that is big sufficient. The entire list has to be searched, until it is sorted by size. This strategy creates

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