dirCreateDirWindows

fn dirCreateDirWindows(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8, permissions: Dir.Permissions) Dir.CreateDirError!void {
    const t: *Threaded = @ptrCast(@alignCast(userdata));
    _ = t;
    _ = permissions; // TODO use this value

    const sub_path_w = try sliceToPrefixedFileW(dir.handle, sub_path, .{});
    const attr: windows.OBJECT.ATTRIBUTES = .{
        .RootDirectory = if (Dir.path.isAbsoluteWindowsWtf16(sub_path_w.span())) null else dir.handle,
        .Attributes = .{ .INHERIT = false },
        .ObjectName = @constCast(&windows.UNICODE_STRING.init(sub_path_w.span())),
        .SecurityDescriptor = null,
        .SecurityQualityOfService = null,
    };

    var sub_dir_handle: windows.HANDLE = undefined;
    var io_status_block: windows.IO_STATUS_BLOCK = undefined;
    var attempt: u5 = 0;
    var syscall: Syscall = try .start();
    while (true) switch (windows.ntdll.NtCreateFile(
        &sub_dir_handle,
        .{
            .GENERIC = .{ .READ = true },
            .STANDARD = .{ .SYNCHRONIZE = true },
        },
        &attr,
        &io_status_block,
        null,
        .{ .NORMAL = true },
        .VALID_FLAGS,
        .CREATE,
        .{
            .DIRECTORY_FILE = true,
            .NON_DIRECTORY_FILE = false,
            .IO = .SYNCHRONOUS_NONALERT,
            .OPEN_REPARSE_POINT = false,
        },
        null,
        0,
    )) {
        .SUCCESS => {
            syscall.finish();
            windows.CloseHandle(sub_dir_handle);
            return;
        },
        .CANCELLED => {
            try syscall.checkCancel();
            continue;
        },
        .SHARING_VIOLATION => {
            // This occurs if the file attempting to be opened is a running
            // executable. However, there's a kernel bug: the error may be
            // incorrectly returned for an indeterminate amount of time
            // after an executable file is closed. Here we work around the
            // kernel bug with retry attempts.
            syscall.finish();
            if (max_windows_kernel_bug_retries - attempt == 0) return error.Unexpected;
            try parking_sleep.sleep(.{ .duration = .{
                .raw = .fromMilliseconds((@as(u32, 1) << attempt) >> 1),
                .clock = .awake,
            } });
            attempt += 1;
            syscall = try .start();
            continue;
        },
        .DELETE_PENDING => {
            // This error means that there *was* a file in this location on
            // the file system, but it was deleted. However, the OS is not
            // finished with the deletion operation, and so this CreateFile
            // call has failed. There is not really a sane way to handle
            // this other than retrying the creation after the OS finishes
            // the deletion.
            syscall.finish();
            if (max_windows_kernel_bug_retries - attempt == 0) return error.Unexpected;
            try parking_sleep.sleep(.{ .duration = .{
                .raw = .fromMilliseconds((@as(u32, 1) << attempt) >> 1),
                .clock = .awake,
            } });
            attempt += 1;
            syscall = try .start();
            continue;
        },
        .OBJECT_NAME_INVALID => return syscall.fail(error.BadPathName),
        .OBJECT_NAME_NOT_FOUND => return syscall.fail(error.FileNotFound),
        .OBJECT_PATH_NOT_FOUND => return syscall.fail(error.FileNotFound),
        .BAD_NETWORK_PATH => return syscall.fail(error.NetworkNotFound), // \\server was not found
        .BAD_NETWORK_NAME => return syscall.fail(error.NetworkNotFound), // \\server was found but \\server\share wasn't
        .ACCESS_DENIED => return syscall.fail(error.AccessDenied),
        .OBJECT_NAME_COLLISION => return syscall.fail(error.PathAlreadyExists),
        .NOT_A_DIRECTORY => return syscall.fail(error.NotDir),
        .USER_MAPPED_FILE => return syscall.fail(error.AccessDenied),
        .INVALID_PARAMETER => |status| return syscall.ntstatusBug(status),
        .OBJECT_PATH_SYNTAX_BAD => |status| return syscall.ntstatusBug(status),
        .INVALID_HANDLE => |status| return syscall.ntstatusBug(status),
        else => |status| return syscall.unexpectedNtstatus(status),
    };
}