fn randomSecure(userdata: ?*anyopaque, buffer: []u8) Io.RandomSecureError!void
fn randomSecure(userdata: ?*anyopaque, buffer: []u8) Io.RandomSecureError!void { const ev: *Evented = @ptrCast(@alignCast(userdata)); if (buffer.len == 0) return; var cancel_region: CancelRegion = .init(); defer cancel_region.deinit(); ev.urandomReadAll(&cancel_region, buffer) catch |err| switch (err) { error.Canceled => |e| return e, else => return error.EntropyUnavailable, }; }