JPEGToLVImagePreflight threads causing major CPU load

[joergh]

Hi!

We have a major problem with a large built application (LabVIEW 8.6). Quite often the CPU load on the PCs goes up to 100% on one or more  cores, ultimatelz leading to an unusable system.

It seems, that the function JPEGToLVImagePreflight() in the lvrt.dll causes this problem (see attached screenshot). Can anyone sched some light on what this function does, and under which circumstances it might be called? Any hints on what to try to avoid this from happening or to further narrow it down?

Regards,

    Jörg

[rolfk]

This function preparses a JPG file to determine its properties such as the image rectangle and the size of the resulting uncompressed image datastream. It is therefore used if you happen to call something that does for some reason need to know the size of a JPG file. The LabVIEW VI to load a JPG file into a picture control could be one candidate. Other possibilities might be somewhere in the embedded WebServer in LabVIEW.

Do you use JPGs in your LabVIEW program? Can you check to disable the WebServer interface in your executable?

[joergh]

No, we don't use the LV WebServer, and no direct JPEG loading, either. We've already checked that. What we use heavily though is subpanels and .NET containers (and sometimes .NET containers inside subpanels ;-).

Are there any other cases besides WebServer and explicit JPEG loading, where this JPEGToLVImagePreflight might be involved?

[rolfk]

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joergh wrote:

No, we don't use the LV WebServer, and no direct JPEG loading, either. We've already checked that. What we use heavily though is subpanels and .NET containers (and sometimes .NET containers inside subpanels ;-).

Are there any other cases besides WebServer and explicit JPEG loading, where this JPEGToLVImagePreflight might be involved?

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I'll leave that to someone from NI as I can't think of anything right now.

[Ben]

Any jpgs used on the GUI ?

Could this be how over-lapping object show up when we chase it from the bottom up ?

Just brain-storming,

Ben