How to avoid Busy Waiting?

Hey everyone :)

I wish to know how can I translate a "busy waiting loop" approach into an event driven approach

Lets say I have a queue of tasks, whenever there are elements in the queue, a process has to treat these elements

Now I do it like this:

while(1){

if(MyQ.Size()>0){

My.Q.RemoveHead ....

}

}

This approach causes the cpu to work on full load, even if there are no elements in the queue.

Is there a way to avoid this loop and somehow to create an event driven approach. Something like OnQueueHasElements...

Thanks in advance :)

This is more a system specific problem than a language problem. Depends on what system you're on, but all systems have some sort of queue you can utilize.

, Espen

Delegate is a pointer to a function right

But who will monitor this evenet something has to check that my MyQueue.Size > 0 and trigger the event

As I understand it you don't want your infinitive loop to hug all the cpu time. You said this approach "causes the cpu to work on full load". Well, it's impossible to not have the cpu work on full load. It's designed to never stop. So what you have to do is to tell the system, for example Windows or Linux, that your program has nothing to do while it's waiting for something to enter your queue. So you'll free the cpu to do something usefull instead of running an infinitive loop, and useless as long as there's nothing in your queue.

This is system specific and has nothing to do with the language. I suggest that you look up whatever messagequeue the system you're running on utilize. If you're on Windows go search msdn for "GetMessage" to get you started.

, Espen

Marius Bancila wrote:

You have to give the other threads a chance to run by calling Sleep(). while(1) { if(MyQ.Size()>0) { My.Q.RemoveHead .... } Sleep(10); // let the OS run another thread }

Thanks its a good solution :) exactly what I needed