Busy Waiting

[Daniel Kanev]

I have read many articles about 'Busy Waiting' prevention in thread synchronization. I am wondering if busy waiting is really a big problem with processors available nowadays. What is your opinion - is busy waiting just a theoretical problem or it really affects system performance? Thank you.

[CPallini]

Daniel Kanev wrote:

I am wondering if busy waiting is really a big problem with processors available nowadays.

IMHO wasting time is an issue regardless of processor speed. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke
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[Cedric Moonen]

Daniel Kanev wrote:

I am wondering if busy waiting is really a big problem with processors available nowadays

Suppose that you have a loop in which you constantly check the value of a variable (and do something if the variable is true), no sleep or wait, only an 'endless' loop. This loop will consume the maximum resources it can use on the processor on which it is running. So, even if you have a faster processor, you will only loop faster. But all other process will still be slowed down because of that. So, yes, busy waiting is bad, even if you have the fastest processor in the world.

Cédric Moonen Software developer
Charting control [v1.4] OpenGL game tutorial in C++

[Stephen Hewitt]

Yes, it's a big problem on a multitasking OS.

Steve