Every week for the last ten weeks I’ve thought “I should really write a dev blog post” and then…not done that. This isn’t because all is quiet on the Western front – on the contrary, everyone on the team has been really, really busy, and the dev blog is never the loudest thing shouting for attention. But now we have a new RC available, so here we are.

Mi Memory Es Tu Memory

11.53 fixes one bug, and it’s a rare bug, but it’s “exciting” when it happens. It turns out that if a Lua plugin requests a really huge amount of memory, instead of saying “no,” X-Plane gives the Lua program someone else’s memory. This is not good! If the bank gave you someone else’s money, that’d be a bad bookkeeping error. This bug is too, and the consequences of the bug are typically “really insane stuff happens later,” which is hard to sort out. The plugin that crashes may not be the plugin that requested the memory.

X-Plane 11.53 fixes this – large allocations that cannot be fulfilled are denied, which should cause the Lua plugin to halt the affected script without destabilizing the system.

Script authors, if you’re wondering “now can I allocate a lot of memory in my Lua script,” the short answer is “no.” The longer answer is: when your Lua plugin uses a new version of LuaJIT that can use 64-bit addressing, this limitation will go away via a new plugin, without a change to X-Plane. Since the limitation is in LuaJIT, it’s out of our hands.

G2 Controller Support

Since we were doing a bug fix release, we have included support for the HP Reverb G2. For reasons I don’t fully understand, controller support didn’t “just work” in 11.52, so we had to create a new profile.

G2 users should be able to use their controllers with X-Plane 11.53. However you should also read our KB article for any additional issues with controllers, especially with misalignment. This version also includes a CLI option to adjust this if needed.

Tyler Has Left the Building

After almost seven years, Tyler has joined the ranks of Laminar Research alumnae. You may know him from such hits as:

  • The X-Plane 11 User Interface
  • X-Plane Mobile’s global scenery
  • X-Plane Mobile’s mass multiplayer

He will be missed! It took several weeks just to figure out all the things he maintains.

We Need More Jims

A few weeks ago, we posted a developer opening – I am pleased to announce Jim Keir as the newest member of the X-Plane development team. Jim is already fixing our screwed up code contributing bug fixes and learning the insides and outs of X-Plane’s almost 1 million lines of code. Jim brings our count of Jims up to two, which is still less of a namespace collision than our three Dan*s.

Multicore and Plugins

Most of what we are working on is still in the lab and hasn’t escaped yet. A few weeks ago we did have a discussion with developers in our third party developer Slack channel about multi-core and plugins.

The short story is this: in X-Plane 11.50, Sidney added a widget to the plugin admin window that shows how much main thread time they’re consuming, which in turn reveals how much each add-on is impacting FPS.

Plugin authors responded! Lots of plugins moved their CPU processing time to a worker thread. This is mostly great – other cores tend to be underutilized on high-end machines so this gets us more FPS.

Here’s the concern: a lot of plugins are doing this, and they are each moving work to other cores in their own private way. There is no coordination between plugins, and one day we are going to wake up and X-Plane will stutter because plugins were (just for a frame) using all of the cores and leaving too few for X-Plane itself.

We are looking at a mechanism for plugins to use the background processing system that X-Plane has built in. The win would be that X-Plane could play traffic cop between plugins and the sim itself, and prevent background plugin loading from causing frame stutters.

I will write up a Request For Comments (RFC) as a future blog post, so that a wider audience can comment on this.

About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.

32 comments on “Departures and Arrivals, Lua Bug Fixes, G2 Controllers, and Stuff

  1. Thank you Tyler for your contributions to X-Plane and welcome Jim Keir. Hopefully all or most of those remaining X-Plane stutters will be addressed soon and we’ll enjoy the smoothest flight simulator experience available in the market. Can’t wait to see what’s next for X-Plane!

  2. Tyler thanks for your great contribution to X-Plane’s echo system, may the schwartz be with you.
    Jim, good luck with your new position.

    Glad to see the G2 fix in this built, waited for it for a long time. Happy to return and fly only in VR mode + controllers.
    It is good to be home.


  3. I am retired and was a PP and have been contributing to gateway since 2016. I am by no means computer savvy. I keep several iteration of X-Plane on my SSD and this latest one did stop lua from running and upped my FR, how ever it clobbered CPE4 Cambridge/Reid’s Field now awaiting approval. Suggestions to experiment with are welcome. I am going to start by removing the lua scripts to see if that makes a difference to CPE4 which is in custom scenery and still looks good in WED 2.3

    1. I removed the lua scripts it made no difference, found the exe file had not updated reloaded it no difference. I updated an other version on a different drive and it works fine with CPE4 so it is not a repeatable bug

      1. My X-Plane v11.52, Steam version, it was not updated. v11.53 is Beta or release?

  4. Ben Thank you for all these informations, Historically X Plane has always worked with plugins, I think it is positive that you set the memory usage rules and CPU resources for version 11 of the simulator and the future evolution of laminar X plane Next Gem…
    It is possible that this year we will know something about the future X Plane, in the X plane feature request & sugestion , Mr Tyler said that many things about the atmosphere, lights, and sceneries would be included in the future … please do not remain so silent, I understand that you are busy, but you must keep the flame alive of X plane, in these time … where many simmers have gone to the other side of the force … do not lose customers. simulation need an X plane Strong, Thx

  5. Good luck to Tyler. For me, X-Plane UI is the best ever created in a flight sim. It is simple, intuitive, effective. I hope this tradition continues. After flying this “other simulator” my appreciation level went up even more for XP UI, Camera control, and many other quality of life items.

    Looking forward to seeing Jim Keir and his amazing talent in XP.

  6. I assume that the announcement about getting the simulation to work with the HP Reverb G2 only applies to Windows users, since the MAC OS doesn’t support the Reverb. I unfortunately just bought one not knowing that the MAC OS doesn’t support it, so am sending it back and getting a HIVE.

  7. I welcome a traffic cop any day of the week! Frankly it is a gold diggers daydream to have so many different plugins to choose from, but it’s a double edged sword. I urge performance over variations any day of the week. A stable, well serviced and fully oiled X-Plane machine is a good platform to aim for and hopefully achieve. On that note, arguably then can you incrementally start to switch out functions and features in the sim. Getting that 60 fps stutter free goal as hardware minima starts to decrease, well that’s a day to look forward to. Wish you all the best on that feedback.

  8. Really enjoying VR with the Quest 2. However, 8gb of VRAM for x-plane and Oculus Direct Link doesn’t seem enough. Other than a new GPU (impossible at the moment), do you have any advice?
    Kind regards

  9. No difference regarding G2 controllers for me. They work, but have wrong “looks” and cant enter meny’s.

      1. To get the G2 controllers to work, I thought it would also be necessary to select the controller bindings by Sparker in SteamVR.

        Is this step not needed anymore?

        Thanks, Jörn

        1. Without Sparker’s bindings, not all buttons will work – for some reason SteamVR doesn’t map everything through to the app by default. But you’ll get some functionality. Custom 3-d models to match the g2 are _not_ coming any. time soon.

  10. Best wishes to Tyler on his new endeavors. He will be missed. I hope his departure doesn’t delay any work on bringing the multiplayer modules from Mobile to Desktop.

    And thanks for all the updates Ben. You always bring gainful insight into the workings of LR and we appreciate you so much.

  11. Best of luck Tyler! Thank you… and thanks Ben …. nice to see the focus on steady improvement !!

  12. We understand the x-plane platform is still getting performance tweaks and architectural redesigns and still maintain compatibility here and there to certain extent.

    Now Imagine you want to rewrite x-plane code from scratch.
    So, What are the key area of the code that would have the most radical changes – as delta from where x-plane 11.53 is at right now?

    Would you be ending up with a considerable different architecture altogether – or adopt many of the current methods and approaches of the sim engine.

  13. Woah.. Jim Keir:
    “Mission Editor for Microsoft FSX and Lockheed Martin Prepar3D, and XPForce for X-Plane).

    Contractor/developer for Dovetail Games who commissioned ongoing development on a custom version of the FSX Mission Editor for their Flight Sim World.”
    Finally a guy that could lift this sim somewhere!
    Now let’s see if LR will actually use that great knowledge for anything….. 🙂

  14. very interesting.
    but when areyou going to correct the bug / crash : Vulkan device loss error?
    so that we do not crash and receive always the same automated response?


    Device loss is a known crash error tracked as XPD-10830. The work around for device loss crashes is to turn off Vulkan and use OpenGL at this time.

    Jennifer Roberts

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