LanMountainDesktop/docs/LAUNCHER_COORDINATOR.md

Launcher Coordinator

LanMountainDesktop Launcher uses a per-user coordinator to prevent duplicate host startup.

Rules

• A Launcher reserves %LocalAppData%\LanMountainDesktop\.launcher\state\startup-attempt.json before starting the host.
• The active record stores coordinator pid, coordinator pipe name, heartbeat, host pid, Public IPC state, and shell status.
• Only the active coordinator may start the host process.
• Secondary Launchers attach to the coordinator and request desktop activation.
• A coordinator is considered live while its pid exists and its heartbeat is newer than 10s.
• Normal launch probes Host Public IPC first; if the host is already running, Launcher activates it and exits.

Tray And Taskbar

• Tray icon and tray menu are mandatory and are not controlled by user settings.
• Tray watchdog starts with the shell and runs until process exit.
• ShowInTaskbar=true affects only the main-window taskbar entry.
• When ShowInTaskbar=true, background mode uses a minimized taskbar entry while keeping tray visible.
• Pure TrayOnly is allowed only when ShowInTaskbar=false and tray is ready.

Public Shell IPC

Launcher and external callers can use:

• GetShellStatusAsync()
• ActivateMainWindowWithStatusAsync()
• EnsureTrayReadyAsync()
• EnsureTaskbarEntryAsync()

These APIs report process, shell, tray, taskbar, and activation state separately so callers do not infer health from window visibility alone.

Air APP Lifecycle

• Launcher is also the Air APP lifecycle manager.
• The desktop host requests Air APP operations through IAirAppLifecycleService on the dedicated LanMountainDesktop.Launcher.AirApp.v1 IPC pipe.
• When the dedicated pipe is unavailable, the desktop host starts LanMountainDesktop.Launcher.exe air-app-broker --requester-pid <pid> and retries the request.
• air-app-broker is a hidden internal command that starts only the Air APP lifecycle IPC host. It bypasses OOBE, Splash, debug preview windows, and normal desktop launch orchestration.
• Launcher creates, activates, tracks, and closes Air APP host processes by instance key: {appId}:{sourceComponentId}:{sourcePlacementId}.
• LanMountainDesktop.AirAppHost registers itself with Launcher after its window opens and unregisters on close; Launcher also prunes exited processes.
• Launcher remains alive while either the desktop host process or any Air APP process is alive.
• Broker mode remains alive while the requester process or any Air APP process is alive, then exits after both are gone.