Threading and rendering architecture

[kaveh808]

Suggestions for how best to do threading?

[awolven]

I can comment on task-oriented threading, data oriented threading should be self explanatory. The main thread, and because of Cocoa restrictions, should run the render loop. The render loop should be dumb. You should not be able to run arbitrary code in the render thread. The render thread should just render draw lists, essentially. You can have a second thread that has an input queue for commands that are more complicated than can be done with a callback. Since glfwPollEvents must happen in the render thread, all callbacks should not ever enter the debugger. They can print a backtrace if necessary and let the render loop continue. Complex commands should be handled with a callback that places events in the input queue for the second thread to pick up. All code that can be compiled or executed at runtime should happen in the second thread or any other thread but not in the render thread. Commands that change the structure of a graphical object should enqueue the draw list from the graphical object to an update queue on the render thread, which are picked up and processed before the draw list is rendered. This architecture prevents random code from crashing the app. A secondary or tertiary thread can enter the debugger without stopping rendering. This means, with a graphical debugger the error can be handled in the graphics ui potentially instead of just in emacs, if you so desire.

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On Thu, Sep 1, 2022 at 2:05 PM Kaveh Kardan ***@***.***> wrote: Suggestions for how best to do threading? — Reply to this email directly, view it on GitHub <#80>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABGMMO7GARFGSTNOY5MOTLV4D467ANCNFSM6AAAAAAQCUKY4Q> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[kaveh808]

Sounds good.

[foretspaisibles]

So for instance a part of the scene that has still not be computed (in an interactive editing session) could be rendered as a wireframe or a box until other computation have been done and more details are available to the rendering loop?

[awolven]

if you want to do it that way, sure.

[kaveh808]

Updated the topic so we can discuss architecture related matters here.

[awolven]

this thread should be merged with the concurrency thread

[kaveh808]

I think this topic is important enough to have its own thread.

[awolven]

I guess I intended my post about the render thread and the input thread and tertiary threads to be in the more "concurrency" architecture discussions.

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On Wed, Sep 7, 2022 at 7:05 PM Kaveh Kardan ***@***.***> wrote: I think this topic is important enough to have its own thread. — Reply to this email directly, view it on GitHub <#80 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABGMMJVCFT25WSNV7F74YDV5EUUTANCNFSM6AAAAAAQCUKY4Q> . You are receiving this because you commented.Message ID: ***@***.***>

[kaveh808]

No worries. I don't know how to merge discussions. Why don't you post your comment above in the concurrency discussion and I'll close this one.