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

Explain the basic architecture of digital switching systems, Explain the ba...

Explain the basic architecture of digital switching systems. An easy N X N time division space switch is demonstrated in figure. The switch can be shown in an equivalence for

Two ways of converting a two input nand gate to an inverter, 1)      Short ...

1)      Short both I/Ps of NAND gate & use the gate as an inverter. 2)      Connect any one of the two I/Ps to VCC & use the remaining I/P & use the gate as an inverter.

To show - hide the ssi document in the page, Step 1: Click on Edit Step ...

Step 1: Click on Edit Step 2: Select reference Step 3: Select Translation Step 4: Click on SSI Step 5: For showing the SSI file; choose one of the following options:

Difference between static call and dynamic call, In the case of Static call...

In the case of Static call, the called program is a stand-alone program, it is an executable program. During run time we can call it in our called program. As about Dynamic call, t

What do you mean by interrupts, Q. What do you mean by Interrupts? The ...

Q. What do you mean by Interrupts? The term interrupt is an exceptional event which causes CPU to temporarily transfer its control from presently executing program to a separat

Interaction between the dynpro and the abap/4, How does the interaction bet...

How does the interaction between the Dynpro and the ABAP/4 Modules takes place? -A transaction is a collection os screens and ABAP/4 routines , controlled and implemented by a

why doesn''t c have nested functions, It's not trivial to execute nested f...

It's not trivial to execute nested functions such that they have the proper access to local variables in the having function(s), so they were deliberately left out of C as a simpli

Additions of numbers by using 2’s complement, Add +25 to -15 by using 2's c...

Add +25 to -15 by using 2's complement ? Ans. Firstly convert the numbers 25 and 15 in its 8-bit binary equivalent and determine the 2's complement of 15, after that add +25 to -

Standards for scan codes, Q. Standards for scan codes ? There are 3 sta...

Q. Standards for scan codes ? There are 3 standards for scan codes: Mode1 (83-key keyboard PC, PC-XT) and Mode2 (84-key AT keyboard) and Mode3 (101-key keyboard onwards). In Mo

What are various ids associated with a process, What are various IDs associ...

What are various IDs associated with a process? Unix identifies each process with a unique integer known as ProcessID. The process that implements the request for creation of 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