By Ryan Vallieu
I have seemingly found an issue with the shipping example code for Nested Malleable VIs. Another user has verified that he saw the same behavior in 2019.
I am working through the examples and the presentation from NIWeek 2019. In running the Lesson 2b code (C:\Program Files (x86)\National Instruments\LabVIEW 2019\examples\Malleable VIs\Nested Malleable VIs) I found the Equals.vi in the class was not being leveraged and the search failed. When I went to my LabVIEW 2018 machine and ran the Lesson 2b.vi the code worked to find the element by correctly leveraging the in-class Equals.vi.
One difference I see is that in the 2018 example the Equal.vi is in the example folder with the code, and in 2019 the Equal.vi has been moved to VI.lib - otherwise the code looks to be the same. The Equals.vi code looks identical, and the calling VIM look identical. I posted on the LabVIEW NI.com forum here:
I am trying to determine what may have broken or changed between the implementation in 2018 and 2019, visually the code looks the same.
I am programming with LabVIEW for around 2 years and was recently stumbled upon LVOOP.
I am required to write a communication protocol to work with a micro-controller, which later will be also used for ATP and debug purposes.
I want to build the program "correctly" from the beginning so it will be maintainable and flexible to additions and changes.
My natural way of building a program would have been a queued state machine, with several loops, each loop is in charge of a different module (one for GUI obviously), but as I stated in the beginning, I want to use LVOOP.
Does anyone have a LVOOP project I can use as reference? I've searched online and found some nice examples, but they are small and teach you the basic stuff.
For me it's important to see the how to use the project tree wisely, where to place the classes, see the managing loop and to learn as much as possible before I create one of my own.
Thanks in advance,
I have an array of classes, let's call the object TestPass, of size 1 (but it is an array because it can scale out to multiple test passes). In this class, there is one other nested class which is not too complex, then various numeric and string fields to hold some private data. There is also an array of clusters. In this cluster there is a string, two XY pair clusters, and an integer. Not very confusing.
This array of clusters gets fairly large, however, upwards of 80-100k elements. What I am finding is when I index the array of pass classes it is crazy slow. On the order of 30 ms. Doesn't seem like much, but we are indexing the array in our method to "Get Current Pass" which is used in various places throughout our code. This is adding potentially hours to our test time over the 80k devices we are testing.
So, I started digging. When I flatten the class to a string and get the length, it's 3 mb. But, when I run the function with the profiler is is allocating close to 20 mb of memory!
My gut feel was that the string is causing the issues. So I removed the string from the cluster and the index time went to 0 ms.
Luckily we can normalize a bit and pull the strings out of the cluster since a lot of them are duplicates. But it makes our data model a bit uglier.
Has anyone seen these kind of performance issues before? I saw them in 2013 and 2017.
I was browing through the actor framework discussions on the NI site yesterday and I came across a statement by AQ.
Never inherit a concrete class from another concrete class
I had to think about that for a second. The more I think about it, the more I realise that all of the LVOOP software I have been writing more or less adheres to this idea. But I had never seen it stated so succinctly before. Now that may just be down to me being a bit slow and all, but in the muddy and murky world of "correct" in OOP-land, this seems to be a pretty good rult to hold on to.
Are there others which can help wannabe plebs like me grasp the correct notions a bit better? How about only ever calling concrete methods from within the owning class, never from without? I'm learning for a long time now, but somehow, my expectations of LVOOP and the reality always seem a little disconnected. AQs statement above helped crystallise out some things which, up to that point, had been a bit nebulous in my mind. Well, I say I'm learning..... I'm certainly using my brain to investigate the subject, whether or not I'm actually LEARNING is a matter for discussion... The older I get, the less sure I am that I've actually properly grasped something. The old grey cells just seem to get more sceptical with time. Maybe that in itself is learning...