How related is multi-threaded programming and multi-processor machines?

Is writing a program to be multi-threaded automatically a way to make that program perform optimally on a multi-processor machine?  Or are there other considerations that need to be programmed into multi-threaded applications?

Curious...

newbieweb
newbiewebSr. Software EngineerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Anil GolamariCommented:
Multiprocessing : Several jobs can run at the same time.

Multi-threading : Same job can be broken logically and executed simultaneously and the results are combined at the end of processing

http://forums.techarena.in/software-development/1131462.htm
http://www.jguru.com/faq/view.jsp?EID=211169

hope these links help you.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Vikram Singh SainiSoftware Engineer cum AD DeveloperCommented:
Hi,

To your first question answer is  true.

Let us try to understand the scene behind. For example, your application is multithreaded app. and when it executes different threads for making program optimize ( or in other words it can be say to utilize maximum resources for faster execution of code).

The programs which doesn't use threading are tend to using single processor generally. If the application is multithreaded (as already said), then it will execute threads two or more at a time, causing load on processor, and since processor needs to make threads in queue to handle them one by one.

In that case if there is one more processor then the other threads waiting in queue can be send to the next processor to execute and hence you are using your computer resources to max. Ultimately this will increase performance of your application and yes it makes it optimize too.

Considerations that need to be programmed into multithreaded application:

(1) Your application should have proper managements of Threads.
(2) Sometimes if both thread tries to access single resource or are waiting for each other to complete their operation respectively can cause problem in your program. Or it makes your program non-responsive for long time.
(3) Creating lot of threads in program unnecessary is also not recommended because it will increase load on processor unnecessary decreasing overall performance of system.

Hope it helps u to understand.

Regards,
V.S.Saini


0
TechnicallyMaybeCommented:
A program has to be coded to take advantage of multiple CPUs.  If not, it will only use 1. A multi-threaded app won't necessarily be multi-cpu.
An example of a multithreaded app is Firefox where each tab runs in it's own thread.  If one tab crashes, it doesn't cause the rest of the threads to crash.
0
newbiewebSr. Software EngineerAuthor Commented:
Thanks.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
.NET Programming

From novice to tech pro — start learning today.