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Parallel loop doesn't work if called from quick drop

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I am making a quick drop tool and it appears that a for loop with parallel iterations turned on isn't actually running in parallel when called from quick drop.

 

I have also added it to the LabVIEW IDE Tools run time menu and it runs fine if called from there.

 

The symptoms when called from quick drop are:

- Much slower execution

- CPU usage only utilising one core

 

Anyone have any ideas? I am wondering if however quickdrop calls my VI is causing it run in the UI thread for some reason. I can't think why that would be.

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Several ideas.
File a service support request.

You haven't attached any code. You have not included your IDE tools.

I recommend using Jing to show a video of the exceptional behavior.

You may not get many posters willing to install your QD plugin as you suspect it is buggy. (Certainly, I won't risk my dev machine)

You may be fooling yourself with your loop. What is inside it? CAN it run parallel? What are the rest of the vi properties.

Even with all that, the problem might not reproduce after a save. Have you tried a force compile?

"Should be" isn't "Is" -Jay
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Solution
Accepted by topic author Niatross

Or the problem might be in the way QDs are invoked. If it is invoked as UI threaded top level VI you would see this since all the subVIs by default execute in that thread too. While there are likely reason why QDs are invoked as they are, you may get around it by putting the relevant code in a subVI and assign it explicitly another specific execution system than the default to execute in the callers execution system.

 

That all said I don’t feel that QDs are a good place to put parallel loops. The first letter in QD stands for quick and starting a function that makes a significant difference if execute with parallel loops or not, is anything but quick.

Rolf Kalbermatter
My Blog
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I had never noticed that you could se the preferred execution system of a VI but that has worked.

 

I guessed that it was been forced into the UI thread I just didn't know why that would be happening.

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