Explain the concept of thread, Computer Engineering

Assignment Help:

The Concept of Thread

A thread is a sequential flow of control within a process. A process is able to have one or more threads. Threads have their own register-values and program-counter but they share memory space and other resources of the process. Every process begins with a single thread. Through the execution, other threads can be created as and when required. Similar to processes, every thread has an execution state (terminated, ready, blocked or running). A thread has right to use the memory address space and resources of its process. Threads have similar life cycles as processes do. A single processor system may support concurrency by switching execution among two or more threads. A multi processor system may support parallel concurrency by executing a separate thread on every processor. There are three fundamental techniques in concurrent programming languages for terminating and creating threads: 

  • Unsynchronised creation and termination - In this mode threads are created and terminated by means of library functions for example START_PROCESS, CREATE_PROCESS, START_THREAD, CREATE_THREAD and. Thus because of these function calls a new thread or process is created and starts executing independent of its parents.
  • Synchronized termination and unsynchronised creation: This manner uses two instructions: JOIN and FORK. The FORK instruction creates a new thread or process. When the parent needs the child's (thread or process) result, it calls JOIN instruction. At this junction two processes (threads) are synchronised.
  • Synchronised termination and creation: The most often system construct to implement synchronization is COBEGIN...COEND. The threads among the COBEGIN...COEND construct are implemented in parallel. The termination of parent-child is suspended till all child threads are terminated.

We can think of a thread as essentially a lightweight process. Though, threads propose a number of advantages over processes. The advantages are as follows:

a)  It does not take so much time to create and terminate a new thread than to create and terminate a process. The reason is that a newly created thread uses the current process address space.  

b)  It does not take so much time to switch between two threads within a common process, partly since the newly created thread uses current process address space. 

c)  Less communication overheads -- communicating between the threads of one process is simple since the threads share amongst other entities the address space. So, data generated by one thread is right away available to all other threads.


Related Discussions:- Explain the concept of thread

Illustrate about 8259, Illustrate about 8259 8259A adds 8 vectored pri...

Illustrate about 8259 8259A adds 8 vectored priority encoded interrupts to the microprocessor. We can expand it to 64 interrupt requests by using one master 8259A and 8 slave

Explain indirect cycle in control unit, Q. Explain Indirect Cycle in contro...

Q. Explain Indirect Cycle in control unit? Once an instruction is fetched the subsequent step is to fetch the operands. The instruction may have indirect and direct addressing

Tree strucred directory, what is the operations in atree structured directo...

what is the operations in atree structured directory.

Hrm, hrm digrams

hrm digrams

Expalin massively parallel system and scalability, Massively Parallel Syste...

Massively Parallel System Indicates to a "parallel computer system" involving a huge number of processors. The numbers in a huge number of processors keeps increasing and curre

Determine the indicator variables in a random forest, Given a dataset with ...

Given a dataset with 1000 rows and 25 predictors labeled x1, x2, ...,x25 to classify into two classes {a, b}. Consider the small random forest with 3 trees and one split in each tr

How do you pass basic types by reference, How do you pass basic types by re...

How do you pass basic types by reference?   In the case of basic types like bool, int, uint, etc. you can in fact choose among the two forms. If you prefix the method parameter

What is time slicing, What is time slicing? With this technique each pr...

What is time slicing? With this technique each program runs for a short period known as a time slice, and then another program runs for its time slice and so on.

Device drivers in unix, Device Drivers in UNIX, MS-DOS and Windows System ...

Device Drivers in UNIX, MS-DOS and Windows System Though device drivers are in effect add-on modules they are however considered to be part of system because they are closely i

What is static timing, What is Static timing a. Delays over all paths a...

What is Static timing a. Delays over all paths are added up. b. All possibilities, including false paths, verified without the need for test vectors. c. Faster than simul

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