Explain the per thread scoping, Operating System

Assignment Help:

Explain the Per Thread Scoping

Thread-level programming introduces new twists for application-level variable scoping. Threads are commonly used in one of two ways.

  • To execute independent parts of the application program
  • To execute similar application functions on a per-user basis

 

In the latter case, any global variables used by the threads may be subject to modification by more than one thread at a time. Disastrous results may occur if this is left unchecked.

Since threads are potentially executing  the same procedures within an application. Or accessing similar data, per-thread data items may be required.

A common practice in a multithreaded program is  to repentantly call application functions on a per-user or per-function basis. In order to make a function reentrant, variables within the function must either be local or have sterilized access to global data. When executing functions on be half of a user, however, these functions may need access to some user contextual data.

The application developer has one of two choices to make:

  • A variable could be passed to the functions representing an index into a user data structure or a pointer to user data. This is cumbersome, however, because that same variable will need to be passed to each subsequent function so that its scope is visible to application components down the line.
  • The developer can set up a similar variable with the global application scope but with per-threads access. The user data must be unique for each thread and be globally addressable by application functions.

Related Discussions:- Explain the per thread scoping

Paging, protection in paging

protection in paging

What is a semaphore, What is a semaphore? A semaphore 'S' is a synchron...

What is a semaphore? A semaphore 'S' is a synchronization tool which is  an integer value that, apart from initialization, is accessed only by two standard atomic operations; w

What are the advantages of multi threading?, What are the advantages of mul...

What are the advantages of multi threading?  Multithreading a code can have several advantages. Improve application responsiveness --Any program in which var

What are the necessary conditions for deadlocks?, What are the necessary co...

What are the necessary conditions for deadlocks? 1. Mutual exclusion :  Only one process at a time is able to use the resource. 2. Hold and wait :  A process should be holdi

Explain message passing among systems, Q. Explain Message passing among sys...

Q. Explain Message passing among systems? Communications- Message passing among systems requires messages to be turned into packets of information and sent to the network contr

Cycle time, when demand is 24000 units/year, production rate is 48000 units...

when demand is 24000 units/year, production rate is 48000 units/year, setup cost is rs 200 per setup, carring cost is rs 20 per units/year, and economic batch quantity is 692.8203

What are the advantages of using unequal- size partitions, In fixed portion...

In fixed portioning scheme, what are the advantages of using unequal- size partitions? With unequal-size partitions there are two probable ways to assign process to partitions.

Write an equation for this seek time, Q. The accelerating search for descr...

Q. The accelerating search for described in subsequent exercise is typical of hard-disk drives. By contrast floppy disks and several hard disks manufactured before the mid-1980s t

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