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

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

Linux, how to find ncr value in shell script

how to find ncr value in shell script

Case studies, Did Abhinav agree to the initial timeline requested by Rebecc...

Did Abhinav agree to the initial timeline requested by Rebecca

Explain the protection problems, Q. In some systems a subdirectory is able...

Q. In some systems a subdirectory is able to be read and written by an authorized user just as ordinary files can be. a. Explain the protection problems that could arise. b.

How does user specify block to be fetched in direct access, How does user s...

How does user specify block to be fetched in direct access? By specifying the relative block number, relative to first block in file, which is block 0.

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

Determine a processing that is not a part of synthesis phase, Determine a p...

Determine a processing that is not a part of Synthesis phase  Perform LC processing is not a part of Synthesis phase

Explain second-chance algorithm, Second-Chance algorithm When a page ha...

Second-Chance algorithm When a page has been selected, we inspect its reference bit. If the value is 0, we proceed to replace this page. If the reference bit is set to 1, thoug

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