Function try_rebuild_channel 

fn try_rebuild_channel(
    conn: &mut RustConnection,
    root: &mut u32,
    rsettings: &CaptureSettings,
    cap_x: &mut i16,
    cap_y: &mut i16,
    cap_w: &mut u16,
    cap_h: &mut u16,
    root_w: &mut u16,
    root_h: &mut u16,
    pool_n: usize,
    pool: &FramePool,
    surfaces: &mut Vec<ShmSurface>,
    stop: &AtomicBool,
) -> Result<(), String>

Rebuild the X channel + capture surfaces after a connection-level failure (Xorg restart, VT switch), refreshing the offset/dims state against the live root. The pool is drained first so the encode thread can never be reading a surface as it is destroyed, and its generation is bumped so the encoder rebuilds against the new layout. Every fallible step completes before the swap, and the old channel/surfaces are destroyed best-effort after it (their server is likely gone; the local detaches still run, and the kernel frees each old segment once nothing maps it).