Sunday, October 9, 2022

[SOLVED] Does endless While loop take up CPU resources?

Issue

From what I understand, you write your Linux Daemon that listens to a request in an endless loop.
Something like..

int main() {
    while(1) {
        //do something...
    }
}

ref: http://www.thegeekstuff.com/2012/02/c-daemon-process/

I read that sleeping a program makes it go into waiting mode so it doesn't eat up resources.

1.If I want my daemon to check for a request every 1 second, would the following be resource consuming?

int main() {
    while(1) {
        if (request) {
            //do something...
        }
        sleep(1)
    }
}

2.If I were to remove the sleep, does it mean the CPU consumption will go up 100%?

3.Is it possible to run an endless loop without eating resources? Say..if it does nothing but just loops itself. Or just sleep(1).

Endless loops and CPU resources is a mystery to me.


Solution

Is it possible to run an endless loop without eating resources? Say..if it does nothing but just loops itself. Or just sleep(1).

There ia a better option.
You can just use a semaphore, which remains blocked at the begining of loop and you can signal the semaphore whenever you want the loop to execute.
Note that this will not eat any resources.



Answered By - Alok Save
Answer Checked By - David Marino (WPSolving Volunteer)
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