Blocking locks, Operating System

Assignment Help:

We have talked about blocking locks, which voluntarily yield, and spinlocks, which just spin until they acquire the lock. At ?rst, it seems like spinlocks are verywasteful, and that one should always use blocking locks. But this question is a bit more complicated than that. In well-written code, locks are only held around small pieces of code, so they should not be held for very long. On a multi-processor system, it often makes sense to use spinlocks, since the thread holding the lock will likely release the lock soon, and may be running simultaneously on another processor, about to release the lock.

This question is further complicated, however, by the possibility of pagefaults (see virtual mem- ory, later in this course). Pagefaults or similar hard-to-predict delays couldmake evenwell-written multi-threaded code hold locks for longer than anticipated. A hybrid type of lock, called spin-then-yield locks, will spin for some amount of time, and if it still hasn't acquired the lock, yield. A spin-then-yield lock can be adaptive in the amount of time it spins before yielding.


Related Discussions:- Blocking locks

Define virtual memory, Define Virtual memory Virtual memory is employe...

Define Virtual memory Virtual memory is employed in all major commercial operating systems

Explain the fork function, Explain the Fork Function Fork function caus...

Explain the Fork Function Fork function causes a new process to be created. The calling progress is duplicated as an exact copy (called the child process) that differs only in

What is the use of system calls, Q. What is the use of system calls? A...

Q. What is the use of system calls? Answer: System calls permit user-level processes to request services of the operating system.

What is spooling, What is spooling? Spooling overlaps the I/O of single...

What is spooling? Spooling overlaps the I/O of single job with the computation of other jobs.

Paging, ___paging fecthces a page only when needed

___paging fecthces a page only when needed

Explain direct communication and indirect communication, Direct communicati...

Direct communication With direct communication each process that requires to communicate must explicitly name the recipient or sender of the communication. The send and receive

Deadlock-avoidance algorithm, Regard as a computer system that runs 5000 jo...

Regard as a computer system that runs 5000 jobs per month with no deadlock-prevention or deadlock-avoidance scheme. Deadlocks take place about twice per month and the operator must

Explain activities of an os in regard to file management, What are the five...

What are the five major activities of an operating system in regard to file management? The creation and deletion of files The creation and deletion of directories The s

What is multiprogramming, What is Multiprogramming? Multiprogramming is...

What is Multiprogramming? Multiprogramming is the capability of am operating system to support multiple applications running concurrently. Multiprogramming simply means that an

Write a short note on memory management, Write a short note on Memory manag...

Write a short note on Memory management. Memory management includes reallocating and allocating the memory space. The kinds of allocation of memory FIXED PARTITIONING

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