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

What is the mfd, What is the MFD? UFD? How are they related? MFD is mas...

What is the MFD? UFD? How are they related? MFD is master-file directory, which points to the UFDs. UFD is user-file directory, which points to each of user's files.

Introduction to paging, We will brie?y introduce paging to ?nish off this l...

We will brie?y introduce paging to ?nish off this lecture. When a process is loaded, not all of the pages are immediately loaded, since it's possible that they will not all be need

Explain first fit allocation algorithm, Describe the following allocation a...

Describe the following allocation algorithms: a. First fit b. Best fit c. Worst fit   a. First-fit: search the list of available memory and all

Pages into physical memory, For reading, most operating systems use demand ...

For reading, most operating systems use demand paging. This means that pages are only read from the disk into physical memory when they are needed. In the page table, there is a re

Explain the reasons why an organisation fail to plan, Problem 1: (a) Wh...

Problem 1: (a) What are the likely benefits which an organisation may derive from the planning process? (b) Explain the main reasons why an organisation may fail to plan.

What is the main advantage of multiprogramming, What is the main advantage ...

What is the main advantage of multiprogramming? Multiprogramming makes efficient use of the CPU by overlapping the demands for the CPU and its I/O devices from various users. I

Evaluate the physical address, Compare between the one and two-dimensional ...

Compare between the one and two-dimensional memory organizations in terms of the  memory structure,  advantages, and disadvantages.  Which approach would better support the needs o

What is preallocation, What is preallocation? Why do it? Allocating spa...

What is preallocation? Why do it? Allocating space for a file before making the file to allow for expansion. This reserves space for a certain file so that other files can't gr

Search and print between two words/patterns, what if we need the portion fr...

what if we need the portion from a text based on some keyword. For eg. My file is like below, ------------------------------------------------ Order=[ 1 2 3 4 5 Order=[ 6 7 8 9

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