ProcessPriorityClass

mowastengr · February 22nd, 2013, 05:07 AM

Hi everybody,
in VB 2010, I need to set the priority level of a process to a level that will not be interrupted by the operating system (Windows 7).
Could anyone please tell me how that is done?
Thanks for you assistance.
Best regards - Walter

Rod Stephens · February 23rd, 2013, 06:56 PM

I'm not sure you can do that reasonably in Windows. Here's an example that lets you set a thread's priority:

http://www.vb-helper.com/howto_net_thread_priority.html

But Windows is a task switching operating system. If you can make a process non-interruptable, then nothing else on the system including the system itself would be able to do anything.

If you really need that, then you may need to use some other real-time operating system.

mowastengr · February 24th, 2013, 05:40 AM

Thanks, Rod, for the info and the link.

VB in windows does provide a >ProcessPriorityClass.RealTime< - so maybe I can use that - being very careful to switch back to >ProcessPriorityClass.Normal< after the non-interruptable process is finished.

Don't you think that should work?

Take care - Walter

Rod Stephens · February 24th, 2013, 10:56 AM

That sounds promising, although I've never tried it.

Post again to tell us all if it works for you.

mowastengr · February 25th, 2013, 04:25 AM

Hi Rod,

the >ProcessPriorityClass.RealTime< seems to be some kind of joke: when I try to set the priorityClass to >RealTime< and then interrogate the process, asking for the status of the PriorityClass it gives back the status >High<.

I don't know what to make of it ????

Take care - Walter

Rod Stephens · February 25th, 2013, 11:49 AM

Sorry, I don't have any experience with this. It could be that you don't have privileges to elevate to the highest level. You could try running the program with the "As Administrator" option to see if there's any difference.

The documentation says RealTime gives the program the highest possible priority. Perhaps the operating system won't let you go higher than High.

I used to know some people who needed real time control for things like data acquisition. They used a real time operating system not windows. But that was a long time ago.

Sorry I don't have any more insight for you.