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

Explain lru approximation page replacement, LRU approximation page replacem...

LRU approximation page replacement In this we are able to use the reference bit associated with the page entry to choose a page to be removed. The various algorithms used for

Explain schemes for defining the logical structure, What are the most commo...

What are the most common schemes for defining the logical structure of a directory? The most common schemes for explaining the logical structure of a directory Single-L

Benefits and drawbacks of batch system, Q. Benefits and Drawbacks of Batch ...

Q. Benefits and Drawbacks of Batch System? Benefits of Batch System: Move much of the work of operator to computer. Increased performance as it was possible for j

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

Explain the spawnlp functions used in the netware, Explain the Spawnlp Func...

Explain the Spawnlp Functions Used in the NetWare Spawnlp(flags, execName, arg0,...)  The Spawnlp function is used to load  a NetWare executable file (NLM) specified by exec

What is a buddy system?, What is a buddy system? We are dividing the me...

What is a buddy system? We are dividing the memory as powers of two therefore the division will be 2, 4, 8, 16, 32, 64, 128, 256...i.e. in powers of 2 as well as we are selecti

Comparison of disk scheduling algorithms, COMPARISON OF DISK SCHEDULING ALG...

COMPARISON OF DISK SCHEDULING ALGORITHMS Name      Description                  Remarks      (Selection according to requestor)   RSS        Random scheduling     fo

What is demand paging, What is Demand paging? Virtual memory is commonl...

What is Demand paging? Virtual memory is commonly executed by demand paging. In demand paging, the pager brings only those essential pages into memory instead of swapping in a

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