topic Re: Parallel read from .NET in .NET Forum

Parallel read from .NET

Anonymous — Wed, 22 Jun 2016 00:49:56 GMT

How do I read all objects in modelspace using parallel.foreach() in .NET? I use Visual Basic .NET, but a C# answer is ok. I tried some methods, but the code hangs, and it may be that Autocad needs some specific way to read the objects in parallel, so that's why I ask. I do not need to make any modifications to modelspace objects. Just read their properties (like cordinates and layer names objects names). I have an autocad 2013 file with hundred of thousands of objects in modelspace, and I need to find all polylines from a specific layer, to get their coordinates. A single threaded code works, but is unbearably slow, and I have many processors idling, so I want to use parallel code.

Re: Parallel read from .NET

dgorsman — Wed, 22 Jun 2016 14:52:20 GMT

There is no parallel processing in AutoCAD. For better performance I would first suggest better data management ie. more drawings with fewer objects per drawing - that's better for both automation and users. Maybe there is some loop optimization that can be done as well, but without knowing how you are looping over the model space objects its hard to tell.

Re: Parallel read from .NET

jabowabo — Thu, 23 Jun 2016 03:22:26 GMT

As dgorsman states, it's hard to diagnose without seeing your code. From the example you give (finding polylines on a specific layer), it would be much faster to use selection filters rather than looping every object.
https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2016/ENU/AutoCAD-NET/files/GUID-BE8B5EE4-9B5A-4D1F-B2D8-7DC013BFC6C0-htm.html

Re: Parallel read from .NET

Anonymous — Sun, 26 Jun 2016 03:18:15 GMT

That's so depressing. Multicore desktop processors are more than a decade old.

Autodesk released more than 10 versions of Autocad in between. Is time to get up to the times, Autodesk!

Re: Parallel read from .NET

Anonymous — Sun, 26 Jun 2016 03:20:08 GMT

Thanks Jabowabo. I will try this way.

Re: Parallel read from .NET

dgorsman — Mon, 27 Jun 2016 16:02:30 GMT

That would require changing the entire drawing database structure, as well as everything that interfaces with it. Effectively that's a ground-up redesign of the entire program (short of the UI layer, anyways). That's a huge investment for not much return, as most either don't have to deal with that much data and the few who do structure it in a more efficient manner.

That would also render all existing DWG files unreadable from the updated version and vice-versa. That goes against one the strongest points of AutoCAD - the forward, (and to a certain extend, backwards) compatibility of DWG file content.

Re: Parallel read from .NET

kerry_w_brown — Tue, 28 Jun 2016 01:49:14 GMT

You may find that investing a little time in LINQ to access and mine into the database will be worth your while ...

particularly for something a simple as this

[quote] ...

I need to find all polylines from a specific layer ... [/quote]

Regards,

added:

http://aucache.autodesk.com/au2012/sessionsFiles/1923/2638/handout_1923_CP1923.pdf

http://through-the-interface.typepad.com/through_the_interface/2016/02/sorting-lists-of-autocad-objects-using-linq-part-3.html

http://drive-cad-with-code.blogspot.com.au/2011/04/tips-of-using-linq-in-autocad-net.html

or preferably, look for any of the AutoDesk AU lectures by Scott McFarlane.

http://au.autodesk.com/au-online/classes-on-demand/search?full-text=Scott+McFarlane

Re: Parallel read from .NET

Anonymous — Wed, 29 Jun 2016 12:20:01 GMT

Tanks KerryBrown

Re: Parallel read from .NET

kerry_w_brown — Thu, 30 Jun 2016 01:10:05 GMT

You're welcome, and I appreciate the comment.

Regards,

Re: Parallel read from .NET

Anonymous — Thu, 30 Jun 2016 12:34:16 GMT

@dgorsman

As a programmer, I understand. I had been there before.

Yet, it will need to be done soon or later. The code shouldn't depend on a specific implementation of a database.

Last processor I bought for my home (not work) was an i7-920. Is already an antique. I didn't updated because the faster desktop processor sold today is barely 30% faster per thread (i7-6950X). But it has 10 cores instead of 4.

The number of cores rises slowly, but much faster than single threaded performance.If Autocad does not embrace multicore, his performance will freeze in time.

Re: Parallel read from .NET

MGO-Norsyn — Fri, 05 Nov 2021 08:56:38 GMT

Hello from the future! Guess what? Autocad is still as it was back then! That is singlethreaded. And I guess it will stay that way untill it comes up against a much better competitor. Which isn't happening in foreseeable future.

The sad reality is that outdated, underperforming, loaded with technical debt, architecture is weighting down the WHOLE world, is using more electricity and hampering progress overall.

And Autodesk is not interested in changing this situation!