2019: Time to make Unity8 great again?



  • @alan_g said in 2019: Time to make Unity8 great again?:

    Once Mir has a Mir-on-Wayland platform it will be possible to retain that architecture and use Wayland instead of the mirclient API.

    Naive question alert, sorry:
    is it possible to estimate/ quantify the amount of work for that task in any way? E.g, how many skilled developers will need to work on this problem fulltime in order to have a solution in one year? 50, 100, 4...?



  • @fossMan said in 2019: Time to make Unity8 great again?:

    @alan_g said in 2019: Time to make Unity8 great again?:

    Once Mir has a Mir-on-Wayland platform it will be possible to retain that architecture and use Wayland instead of the mirclient API.

    Naive question alert, sorry:
    is it possible to estimate/ quantify the amount of work for that task in any way? E.g, how many skilled developers will need to work on this problem fulltime in order to have a solution in one year? 50, 100, 4...?

    Almost all the code concerned is here:

    $ wc -l src/server/graphics/nested/*
       253 src/server/graphics/nested/buffer.cpp
        64 src/server/graphics/nested/buffer.h
        20 src/server/graphics/nested/CMakeLists.txt
        54 src/server/graphics/nested/cursor.cpp
        51 src/server/graphics/nested/cursor.h
       225 src/server/graphics/nested/display_buffer.cpp
       105 src/server/graphics/nested/display_buffer.h
       442 src/server/graphics/nested/display.cpp
       178 src/server/graphics/nested/display.h
       183 src/server/graphics/nested/host_buffer.cpp
        73 src/server/graphics/nested/host_buffer.h
        54 src/server/graphics/nested/host_chain.h
        95 src/server/graphics/nested/host_connection.h
        50 src/server/graphics/nested/host_stream.h
        52 src/server/graphics/nested/host_surface.h
        49 src/server/graphics/nested/host_surface_spec.h
       528 src/server/graphics/nested/input_platform.cpp
        84 src/server/graphics/nested/input_platform.h
        92 src/server/graphics/nested/ipc_operations.cpp
        48 src/server/graphics/nested/ipc_operations.h
       825 src/server/graphics/nested/mir_client_host_connection.cpp
       134 src/server/graphics/nested/mir_client_host_connection.h
        74 src/server/graphics/nested/native_buffer.h
       234 src/server/graphics/nested/nested_display_configuration.cpp
        78 src/server/graphics/nested/nested_display_configuration.h
        35 src/server/graphics/nested/passthrough_option.h
       227 src/server/graphics/nested/platform.cpp
       117 src/server/graphics/nested/platform.h
      4424 total
    

    That needs re-implementing to use Wayland protocol extensions instead of the mirclient API.

    It isn't a lot of code, and not a lot of work. But it does need someone that can read mirclient code and write Wayland code. I've done that a few times (for the "internal" clients in the example shells) and the concepts correspond well.

    There are few other parts of the system that would need touching (e.g. the configuration to set it up) but that is less of a problem.

    I think it would take me a couple of days (but the unexpected could happen). However, that's probably the fastest it could be: there are not many that know the Mir codebase as well as I do.

    tl;dr: Depending on the developer's background, anywhere from a few days to a month.



  • Thanks @alan_g.
    What exactly is the "mirclient API", is that an abstraction or a specific set of files? Could you give a small example e.g a line of code showing dependence on that API, and perhaps how a Wayland extension could replace it?



  • @fossMan said in 2019: Time to make Unity8 great again?:

    What exactly is the "mirclient API", is that an abstraction or a specific set of files? Could you give a small example e.g a line of code showing dependence on that API, and perhaps how a Wayland extension could replace it?

    The mirclient API is the API provided by libmirclient.so. It is the API through which Mir proposed to support "Convergent" application toolkits. There are various bits of UBports relying on this API that need rework to Wayland (so learning to do that will remain useful after this exercise).

    Here's some mirclient API code:

                Surface surface{mir_connection_create_render_surface_sync(DecorationProvider::connection, width, height)};
    
                auto const buffer_stream =
                    mir_render_surface_get_buffer_stream(surface, width, height, mir_pixel_format_xrgb_8888);
    
                auto window = WindowSpec::for_gloss(DecorationProvider::connection, width, height)
                    .set_fullscreen_on_output(output_id)
                    .set_event_handler(&handle_event_for_background, this)
                    .add_surface(surface, width, height, 0, 0)
                    .set_name(wallpaper_name).create_window();
    

    and some equivalent Wayland code:

            ctx.surface = wl_compositor_create_surface(globals.compositor);
    ...
            ctx.shell_surface = wl_shell_get_shell_surface(globals.shell, ctx.surface);
            wl_shell_surface_set_fullscreen(
                ctx.shell_surface,
                WL_SHELL_SURFACE_FULLSCREEN_METHOD_DEFAULT,
                0,
                ctx.output.output);
    ...
            auto const shm_pool = make_scoped(
                make_shm_pool(globals.shm, stride * height, &ctx.content_area),
                &wl_shm_pool_destroy);
    
            ctx.buffer = wl_shm_pool_create_buffer(
                    shm_pool.get(),
                    0,
                    width, height, stride,
                    WL_SHM_FORMAT_ARGB8888);
    

    https://github.com/MirServer/mir/pull/669/files#diff-ea35a63c157fb0d09e5713c6ee0b1dbe



  • @alan_g said in 2019: Time to make Unity8 great again?:

    The mirclient API is the API provided by libmirclient.so.

    Thanks for the example. Is there any way to download an example of a libmirclient.so file without installing anything? The closest I got was a mention on this Ubuntu package

    EDIT: or perhaps there is some documentation of the libmirclient API in order to understand better exactly what parts of the code is addressing the API?





  • I would like to look at these issues but can't spare the focus time until start of June.



  • @fossMan said in 2019: Time to make Unity8 great again?:

    I would like to look at these issues but can't spare the focus time until start of June.

    I imagine there will still be issues left for you when you have the time. 😎



  • @alan_g I see in the Mir 1.4.0 release discourse mention of the layer-shell extension. If I understand correctly how this extension works, we should be able to use it for re-implementing the trusted overlays, no?

    If we could do that, and get it done soon, that would be a huge step forward in being able to use unity8 on wayland.



  • @dobey said in 2019: Time to make Unity8 great again?:

    @alan_g I see in the Mir 1.4.0 release discourse mention of the layer-shell extension. If I understand correctly how this extension works, we should be able to use it for re-implementing the trusted overlays, no?

    I agree we should map out Wayland protocols that can help replace mirclient functionality. But in this specific case, I don't think layer-shell addresses the same concerns as trusted prompts, so I don't immediately see how you imagine using it.

    I'll have a closer look at this idea after the holiday weekend to see what I've missed.


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