Of late, I'm becoming more health oriented when constructing my program, I have observed that most of programs take 2 or 3 minutes to execute and when I check on the task scheduler, I see that they consume 100% of CPU usage, can I limit this usage programatically in code? This will certainly enable me to run multiple programs at a given time.
Thanks, Nidhi
That's not your concern... It's the job of the operating system to distribute processor time between running processes. If you'd like to give other processes first crack at getting their stuff done, then simply reduce the priority of your own process by modifying the Process.PriorityClass value for it.
You can run your program in a thread with a lower threadpriority, the rest is up to your operating system. Having a process eat up 100% of your CPU is not bad. My SETI is usually taking up all my remaining CPU time without bothering my other programs. It only gets a problem when your thread gets priority over more important programs.
According to MSDN, you can only set a thread priority, i.e.
var t1 = new Thread(() => doSomething());
t1.Priority = ThreadPriority.BelowNormal;
t1.Start();
where doSomething is the function you want to create a thead for. The priority can be one of the ThreadPriority enumeration members Lowest, BelowNormal, Normal, AboveNormal, Highest - for a description see the MSDN link above. Priority Normal is the default.
Note that CPU usage also depends on how many cores and logical processors your physical CPU has *) - and how the threads and processes are assigned to those cores (the assignment to a dedicated processor is called "processor affinity" - if you want to know more about that, see this StackOverflow question).
*) To find that out, open the task manager (via Ctrl+Alt+Delete - select "task manager"), go to Performance and select CPU there: Below the utilization graph you can see "Cores" and "Logical processors".
A core is a physical unit built into the CPU, while a logical processor is just an abstraction, which means the more cores your CPU consists of, the faster it can process parallel tasks.
I honestly think rather than worry about trying to limit CPU utilization by your app, you should focus more of your energies on profiling the application to uncover and correct bottlenecks and inefficiencies that may exist.
If you code is running at all, it is at 100%
I suppose slipping in some sleeps might have an effect.
I have to wonder about that 2-3 minute figure. I've seen it too, and I suppose it's loading and initializing lots of stuff I probably don't really need.
This is something I have come across a lot of times with complex integrations (for example a daily update of products, stock and pricing on an ecomm system).
Writing the integrations as efficiently as possible is always good, using DB server power where you can instead for iterating objects in the code but at the end of the day these things WILL take up processor time and you may want to run them on a server that is doing other things too.
Sharing is caring ;-)
A good approach to avoid coding a Governor or Throttling mechanism is to use the power of a web server. Expose the integration as a "local API call" and run it in IIS (for instance). There you have multiple throttling options and affinity masks you can apply to the application pool. This can then be easily adjusted "on the fly" to give a good balance and monitor closely.
If there is no other task running, is it wrong for your app to use all the cpu capacity that is available? It is available, as in it's there and it is free to use. So use it!
If you somehow limit the cpu usage of your task, it will take longer to complete. But it will still take the same number of cpu cycles, so you gain nothing. You just slow down your application.
Don't do it. Don't even try it. There's no reason why you should.
I think what you need to do is to understand the performance problem in your application instead of trying to put a cap on the CPU usage. You Can use Visual Studio Profiler to see why you application is taking 100% CPU for 2-3 minutes in the first place. This should reveal the hot spot in your app, and then you can be able to address this issue.
If you are asking in general regarding how to do resource throttling in windows, then you can look at the "Task" objects, Job objects allows you to set limits such as Working set, process priority...etc.
You can check out the Job objects documentation here http://msdn.microsoft.com/en-ca/library/ms684161(VS.85).aspx Hope this helps. Thanks