UI Server & Wayland

English

uiserver is RustOS's display server. It owns the framebuffer, draws the desktop chrome, hosts a Wayland compositor, and renders console-hosted sessions for Linux and Windows PE programs.

Boot Path

runtimed bootstrap_ui_server
  -> spawn uiserver with manifest args + env (RUSTOS_UI_PROFILE=1)
uiserver run()
  -> AppState::initialize (display_get_info + display_create_surface)
  -> render_boot_frame (single solid fill — no chrome yet)
  -> first present (boot frame stays on screen while runtime/Wayland init runs)
  -> open RuntimeClient (notify_ui_ready socket + sync socket)
  -> WaylandCompositor::initialize (creates /run/user/1000/wayland-0)
  -> notify_ui_ready -> runtimed unblocks autostart launches
  -> main loop:
       drain input, runtime poll, console poll, cursor blink,
       coalesce partial dirty rects, render & present

The synchronous critical path is intentionally short:

The first present uses a solid colour, not the full chrome. Chrome composition is deferred to the first idle frame so the user always sees pixels within a few frames of display_create_surface.
Console window surfaces are no longer "primed" during runtime polling; draw_console_window rebuilds the cached surface on the first draw, matching the same total work to the render budget instead of the runtime refresh budget.
The terminal cell loop in terminal.rs skips redundant per-cell background fills when the bulk render has already painted layout.bounds. Per-cell paint stays for single-cell repaints (cursor blink) only.

The chrome palette is a translucent monochrome blue. Glass and inner panels stack via fill_rect_alpha so the desktop band shows through the rails. Highlights and shadows are tuned to suggest frosted glass:

Rails draw an upper sheen half + a lower settled half + an inner elevated bloom, with a 1-pixel specular line at the top edge and a faint baseline shadow underneath.
Window title bars use the same two-layer technique with an extra accent overlay when focused.
Mouse cursor stays at the existing soft blue/white tone; do not change cursor_sprites.rs or the cursor colours in canvas.rs for theme recolours.

Wayland Surfaces

The compositor exposes the standard Wayland sockets via /run/user/1000/wayland-0. Surfaces, buffers, frame callbacks, and damage all use the canonical Wayland protocol — the in-tree Wayland clients (apps/wayclick, console hosts) and the planned external clients should not need special wrappers.

Console Hosting

Console-hosted programs (the shell, the PE demos) get a console session from runtimed and a window from uiserver. The terminal state lives in uiserver's TerminalState, parsing input bytes from the console output ring. Layout uses the terminal monospace atlas; chrome uses the UI atlas.

Profile Trace

Set RUSTOS_UI_PROFILE=1 (now applied automatically on the bootstrap launch) to enable profile::record_* paths. The summary lines tagged uiserver profile: ... get flushed to debugcon and are the primary tool for diagnosing slow refresh / slow present regressions. Use them before adding new diag prints.

한국어

uiserver는 RustOS의 display server입니다. framebuffer 소유, desktop chrome draw, Wayland compositor 운영, 그리고 Linux/Windows PE program의 console-hosted session rendering을 담당합니다.

Boot 경로

runtimed bootstrap_ui_server
  -> manifest args + env (RUSTOS_UI_PROFILE=1)로 uiserver spawn
uiserver run()
  -> AppState::initialize (display_get_info + display_create_surface)
  -> render_boot_frame (chrome 없이 단색 fill)
  -> first present (runtime/Wayland 초기화 동안 boot frame 유지)
  -> RuntimeClient open (notify_ui_ready socket + sync socket)
  -> WaylandCompositor::initialize (/run/user/1000/wayland-0 생성)
  -> notify_ui_ready -> runtimed가 autostart launch 해제
  -> main loop:
       input drain, runtime poll, console poll, cursor blink,
       partial dirty rect coalesce, render & present

동기 임계 경로는 의도적으로 짧습니다.

첫 present는 full chrome이 아니라 단색을 사용합니다. chrome 합성은 첫 idle frame으로 미뤄지므로, 사용자에게는 display_create_surface 직후 몇 frame 안에 항상 pixel이 보입니다.
console window surface는 runtime polling 중에 "prime" 하지 않습니다. draw_console_window가 첫 draw에서 cached surface를 rebuild하며, 동일한 총 작업량을 runtime refresh budget이 아닌 render budget으로 옮깁니다.
terminal.rs의 cell loop는 bulk render가 이미 layout.bounds를 채웠다면 cell별 background fill을 생략합니다. cell별 paint는 cursor blink 같은 single-cell repaint에서만 유지됩니다.

Translucent Aero Palette

chrome palette는 translucent monochrome blue입니다. glass / inner panel은 fill_rect_alpha로 쌓아서 desktop band가 rail을 통해 비치도록 합니다. hilight / shadow는 frosted glass 느낌을 내도록 tune 했습니다.

rail은 상단 sheen 반쪽 + 하단 settled 반쪽 + inner elevated bloom를 그리고, top edge에 1px specular line, base line에 옅은 그림자를 추가합니다.
window title bar는 같은 two-layer 기법을 쓰며 focus 상태에서 accent overlay 한 겹이 더 들어갑니다.
마우스 커서는 기존의 soft blue/white tone을 그대로 둡니다. theme recolor 시에 cursor_sprites.rs나 canvas.rs의 cursor color는 바꾸지 마세요.

Wayland Surface

compositor는 /run/user/1000/wayland-0로 standard Wayland socket을 노출합니다. surface, buffer, frame callback, damage는 canonical Wayland protocol을 사용합니다. tree 내의 Wayland client (apps/wayclick, console host)와 예정된 외부 client에 별도 wrapper가 필요하지 않습니다.

Console hosting

console-hosted program (shell, PE demo)은 runtimed에서 console session 을, uiserver에서 window를 받습니다. terminal state는 uiserver의 TerminalState 안에 있고 console output ring의 input byte를 parsing 합니다. layout은 terminal monospace atlas를, chrome은 UI atlas를 사용합니다.

Profile Trace

RUSTOS_UI_PROFILE=1 (이제 bootstrap launch에서 자동 적용)을 설정하면 profile::record_* 경로가 활성화됩니다. uiserver profile: ... summary line이 debugcon으로 flush 되며 slow refresh / slow present regression을 진단할 때 주된 도구입니다. 새 diag print를 추가하기 전에 이 경로를 먼저 사용하세요.

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