Hi, a few changes of the RTDM layer were committed to trunk recently. They make handling of RTDM file descriptors more handy: o rt_dev_close/POSIX-close now polls as long as the underlying device reports -EAGAIN. No more looping inside the application is required. This applies to the usual non-RT invocation of close, the corner case "close from RT context" can still return EAGAIN. o Automatic cleanup of open file descriptors has been implemented. This is not yet the perfect design (*), but a straightforward approach to ease the cleanup after application crashes or other unexpected terminations. The code is still young, so testers are welcome. Jan (*) Actually, I would like to see generic per-process file descriptor tables one day, used by both the POSIX and the RTDM skin. The FD table should be obtained via xnshadow_ppd_get(). But first this requires lock-less xnshadow_ppd_get() based on ipipe_get_ptd() to keep the overhead limited. Yet another story.