topic Re: get cpu usage programatically in LabWindows/CVI

get cpu usage programatically

test_man — Wed, 28 Feb 2007 14:45:29 GMT

Is there anyway to receive total CPU usuage and cpu usuage by a program programatically?

Re: get cpu usage programatically

Wim S — Thu, 01 Mar 2007 08:34:04 GMT

Hello Sheetal,

Take a look at the .NET example: c:\Program Files\National Instruments\CVI80\samples\dotnet\SimpleTaskMonitor

I never looked at the code, but it seems to me that this kinda does what you are looking for.

Good luck

Message Edited by Wim S on 03-01-2007 09:35 AM

Re: get cpu usage programatically

test_man — Thu, 01 Mar 2007 13:35:05 GMT

Hi,

Thanks for your reply. This is exactly what I need. Only problem is CPU activity is always 0!

Re: get cpu usage programatically

Brandon_V — Thu, 01 Mar 2007 20:42:05 GMT

Are you sure you have the .NET Framework installed? This example should give you CPU usage as long as it can make calls to .NET.

Re: get cpu usage programatically

test_man — Thu, 01 Mar 2007 20:53:07 GMT

i have framework 2.0 installed.

Re: get cpu usage programatically

test_man — Fri, 02 Mar 2007 03:17:18 GMT

I verified this on another PC and same results. CPU usuage is always 0. I do have framework 2.0 installed. CVI version 8.0.1.

Re: get cpu usage programatically

Patrick_P. — Mon, 05 Mar 2007 15:18:03 GMT

Do you see anything? Does the memory usage change at all and does it list the current processes? Are either of these machines dual core machines? Because it could be possible that the line that sets up the performance counter for the processor could be different if you have two processors. It is located in the Initialize funciton. Hope this helps!

Re: get cpu usage programatically

test_man — Mon, 05 Mar 2007 15:32:40 GMT

Thanks for the reply.

Yes. I see 0% CPU usuage and bar keep going from left to right.

No, Memory usuage does not change. (memory Usage tab)

No, it is not dual core machine.

I do see all applications listed in Process tab and memory Usage does change there after I click refresh button.

Re: get cpu usage programatically

test_man — Mon, 05 Mar 2007 15:37:24 GMT

When following called both gCPUCounter = NULL and gCommittedBytesCounter=NULL.

System_Diagnostics_PerformanceCounter__Create_2(&gCPUCounter, "Processor",
        "% Processor Time", "_Total", 0);
    System_Diagnostics_PerformanceCounter__Create_4(&gCommittedBytesCounter,
        "Memory", "Committed Bytes", 0);

Re: get cpu usage programatically

Patrick_P. — Mon, 05 Mar 2007 16:01:53 GMT

Hey Sheetal,

These counters are the same ones being used in performance monitor. We can check to make sure these are working properly. You should be able to go to Start>>Run and type in perfmon. This should open performance monitor. You can then right click on the graph and select to add a counter. These should directly correspond to what is in CVI (Performance Object = Processor, Counter = % Processor Time). You can test it here to make sure that you can see the CPU Usage. Also what operating system are you running, Win XP SP2?

Re: get cpu usage programatically

test_man — Mon, 05 Mar 2007 17:01:23 GMT

Yes XP SP2.

I tried % Processor Time and that graphs gives me value of higher 90%. Actual CPU usuage is less then 10%.

Re: get cpu usage programatically

test_man — Mon, 05 Mar 2007 21:28:05 GMT

From CVI example code,

status = Initialize_System(); //I added status

//status = 0 no error

     // Create .NET performance counter objects
    status = System_Diagnostics_PerformanceCounter__Create_2(&gCPUCounter, "Processor",
        "% Processor Time", "_Total", 0);//I added status

//status = -6571
error = CDotNetGetErrorDescription(status); //I added this

//error=Target invoked by Labwindows/CVI .net library threw an exception.

Any idea why?

Re: get cpu usage programatically

Patrick_P. — Wed, 07 Mar 2007 13:45:23 GMT

Hey Sheetal,
One thing I would recommend trying is to repair the CVI Run Time Engine. If you installed DotNET after installing CVI, this is necessary to do. You can go to Add Remove Programs, select National Instruments Software, select the CVI Run Time Engine for 8.0.1, and select repair.

Re: get cpu usage programatically

test_man — Wed, 07 Mar 2007 14:09:11 GMT

Thanks for suggestions.

It did not work. Same results.

I have CVI version 8.0.1 but my RTE is 8.1. Does it make any difference?

Re: get cpu usage programatically

JonathanN — Thu, 08 Mar 2007 20:03:17 GMT

Howdy Sheetal,

Do you have both the .NET 1.1 and 2.0 framework installed or just the 2.0 framework?

I am curious to see if the issue resides with LabWindows/CVI or rather with the .NET framework. I found and modified a small .NET example (found on www.codeproject.com) that uses the .NET performance monitor. Open and run this project to see if you also see a value of 0. This example is using the same assembly as the LabWindows/CVI example is.

If you don't have Visual Studio 2005 (which is what I created it in), then simply run the debug exe located in the bin\debug directory of the attached zip file.

Secondly, I see that you might now some LabVIEW. If you have LabVIEW installed, run the SimpleTaskMonitor.VI example to see if you see the same behavior. It also use the .NET assembly.

Let me know the findings.

Thanks and best regards,

Re: get cpu usage programatically

test_man — Thu, 08 Mar 2007 22:25:42 GMT

When I tried labview example I get error 1172. A Labview .net exception occured.

Re: get cpu usage programatically

JonathanN — Thu, 08 Mar 2007 23:06:51 GMT

Hi Sheetal,

What about the other example I sent that was built with VS2005. Does that work?

Re: get cpu usage programatically

test_man — Fri, 09 Mar 2007 02:26:23 GMT

When I run your program I get this error.

The thread 0x5f4 has exited with code 0 (0x0).

The thread '<No Name>' (0x828) has exited with code 0 (0x0).

'CpuUsageTest.vshost.exe' (Managed): Loaded 'C:\Documents and Settings\apatelsh\Desktop\Test CPU_Usage\Test CPU_Usage\CpuUsage\CpuUsageTest\bin\Debug\CpuUsageTest.exe', Symbols loaded.

A first chance exception of type 'System.InvalidOperationException' occurred in System.dll

An unhandled exception of type 'System.InvalidOperationException' occurred in System.dll

Additional information: Category does not exist.

'CpuUsageTest.vshost.exe' (Managed): Loaded 'C:\WINDOWS\assembly\GAC_MSIL\System.Configuration\2.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll', No symbols loaded.

The thread '<No Name>' (0xf6c) has exited with code 0 (0x0).

The program '[3324] CpuUsageTest.vshost.exe: Managed' has exited with code -532459699 (0xe0434f4d).

Re: get cpu usage programatically

JonathanN — Fri, 09 Mar 2007 15:54:19 GMT

Howdy Sheetal,

Hmmm.... that's a little weird that you are receiving errors issues in LabWindows/CVI, LabVIEW, and with Visual Studio executables.

What brought up a possibly light bulb in my head was the Visual Studio error that you posted which mentioned that the Category does not exist.

When you create a Performance Counter object in .NET, you must specify the Category to which you will be monitoring (in this case, the category was Processor). Thus, I found a Microsoft document entitled Some performance objects and counters are not available in the System Monitor tool on your Windows XP-based computer. Essentially, if you have paging turned off, you don't get access to those counters. I changed my virtual memory to no paging, and I receive the same Visual Studio error and CVI behavior you mentioned. That Microsoft document says to either contact Microsoft for the hotfix or gives you a workaround of basically changing your paging memory.

Anyway, this should fix your problem. Let me know what happens!

Best Regards,

Message Edited by Jonathan N on 03-09-2007 09:55 AM

Re: get cpu usage programatically

test_man — Fri, 09 Mar 2007 18:04:08 GMT

Hi Jon,

Thanks for your help. Yes I had page file off. I changed to system managed file. Restarted laptop and I tried CVI, labview and C sharp project but no success. I get same result.

Then I waited 10 minutes and tried again and it worked with all programs.. Interesting...Again thank you very much for help. This solves my problem.