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

What is the cache coherency problem, Question: (a) Modern processors op...

Question: (a) Modern processors operate in one of two modes: one for the operating system and one for applications. What is the purpose of having these two modes? What are

Calculate the average waiting time, Calculate the Average Waiting Time ...

Calculate the Average Waiting Time CPU burst time points out the time, the process needs the CPU. The subsequent are the set of processes with their respective CPU burst time (

Explain process termination - operating system, Process termination A p...

Process termination A process terminates when it finishes implementing its final statement and asks the operating system to delete it by using the exit system call. At that tim

Define file permission in unix, The permission function is used to calculat...

The permission function is used to calculate what, if any access each class or level of user has to each file on a Unix machine. The permission task is one of the data components s

Facility location, What is the essence of facility location in production o...

What is the essence of facility location in production operation management

Explain swapping technique used in pre-3bsd unix systems?, What are the dis...

What are the disadvantages of swapping technique used in pre-3BSD UNIX systems? If there is excessively much memory contention, processes are swapped out until sufficient

What are the different accessing methods of a file, What are the different ...

What are the different accessing methods of a file? The different types of accessing a file are: Sequential access: Information in the file is accessed sequentially

Bind a real-time thread to an lwp, Q. Suppose an operating system maps user...

Q. Suppose an operating system maps user-level threads to the kernel utilizing the many-to-many model where the mapping is done through the use of LWPs. In addition the system allo

Explain disadvantages of the two-level directory, How do we overcome the di...

How do we overcome the disadvantages of the two-level directory? Give links from one user directory to another, creating path names; system files become available by letting th

Why high level languages need compiler, Q. Why High level languages need Co...

Q. Why High level languages need Compiler? High level languages - illustrations are COBOL, FORTRAN, PL/I andALGOL - are processed by interpreters andcompilers. A compilers is 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