getNamedPipeDevice

fn getNamedPipeDevice(t: *Threaded) !windows.HANDLE {
    {
        mutexLock(&t.mutex);
        defer mutexUnlock(&t.mutex);
        if (t.pipe_file.handle) |handle| return handle;
    }

    var fresh_handle: windows.HANDLE = undefined;
    var io_status_block: windows.IO_STATUS_BLOCK = undefined;
    var syscall: Syscall = try .start();
    while (true) switch (windows.ntdll.NtOpenFile(
        &fresh_handle,
        .{ .STANDARD = .{ .SYNCHRONIZE = true } },
        &.{
            .ObjectName = @constCast(&windows.UNICODE_STRING.init(
                &.{ '\\', 'D', 'e', 'v', 'i', 'c', 'e', '\\', 'N', 'a', 'm', 'e', 'd', 'P', 'i', 'p', 'e', '\\' },
            )),
        },
        &io_status_block,
        .VALID_FLAGS,
        .{ .IO = .SYNCHRONOUS_NONALERT },
    )) {
        .SUCCESS => {
            syscall.finish();
            mutexLock(&t.mutex); // Another thread might have won the race.
            defer mutexUnlock(&t.mutex);
            if (t.pipe_file.handle) |prev_handle| {
                windows.CloseHandle(fresh_handle);
                return prev_handle;
            } else {
                t.pipe_file.handle = fresh_handle;
                return fresh_handle;
            }
        },
        .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();
            try parking_sleep.sleep(.{ .duration = .{
                .raw = .fromMilliseconds(1),
                .clock = .awake,
            } });
            syscall = try .start();
            continue;
        },
        .CANCELLED => {
            try syscall.checkCancel();
            continue;
        },
        .INVALID_PARAMETER => |status| return syscall.ntstatusBug(status),
        .OBJECT_PATH_SYNTAX_BAD => |status| return syscall.ntstatusBug(status),
        .INVALID_HANDLE => |status| return syscall.ntstatusBug(status),
        .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),
        .NO_MEDIA_IN_DEVICE => return syscall.fail(error.NoDevice),
        .SHARING_VIOLATION => return syscall.fail(error.AccessDenied),
        .ACCESS_DENIED => return syscall.fail(error.AccessDenied),
        .PIPE_NOT_AVAILABLE => return syscall.fail(error.NoDevice),
        .FILE_IS_A_DIRECTORY => return syscall.fail(error.IsDir),
        .NOT_A_DIRECTORY => return syscall.fail(error.NotDir),
        .USER_MAPPED_FILE => return syscall.fail(error.AccessDenied),
        else => |status| return syscall.unexpectedNtstatus(status),
    };
}