From mboxrd@z Thu Jan  1 00:00:00 1970
From: Philippe Gerum <rpm@xenomai.org>
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Date: Mon, 04 May 2009 19:15:08 +0200
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Subject: Re: [Xenomai-help] rtdm_event_timedwait returns -EINTR
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To: Petr Cervenka <grugh@domain.hid>
Cc: xenomai@xenomai.org

On Mon, 2009-05-04 at 18:11 +0200, Petr Cervenka wrote:
> >
> >Read: it must interrupt Xenomai syscalls internally but the latter
> >should always be silently restarted, by properly setting the SA_RESTART
> >bit in the sigaction flags for that signal.
> >
> >Not allowing Linux to interrupt blocking Xenomai syscalls to process
> >pending signals would basically kill GDB support, and beyond this create
> >a very fragile situation wrt signal handling and Xenomai, which is the
> >last thing we would want to do.
> >
> >Philippe.
> >
> 
> I have found following problems / errors:
> --------------------------------------------------------------
> 1) rtdm_event_timedwait() in ioctl handler is not automatically internally restarted (driver: rtdm, app. tasks: native)
> 
> 2) computer hangs, when I call in ioctl handler something like:
> do {
>   res = rtdm_event_timedwait(&event, timeout, NULL);
> } while (res == -EINTR);

>>From any kernel space API called from userland syscalls:

   res = whatever_xenomai_skin_blocking_call(...);
   if (res == -EINTR)
	return -EINTR;

> this could have perhaps some relevance: https://mail.gna.org/public/xenomai-help/2008-11/msg00025.html
> 
> 3) rt_event_wait() in application is restarted always with the same relative timeout. it could run forever.
> 

As discussed earlier, using rt_event_wait_until() with an absolute
timeout spec would fix this (2.5 only though).

> problems with version 2.5-rc1:
> -----------------------------------------------
> 1) function rt_task_shadow always returns -EFAULT
> 

Are you passing a NULL task pointer?

> 2) when resizing window with latency test running, it prints out "Not SIGSHADOW !". But it should be SIGSHADOW (in my opinion).
> 
> Petr
> 
-- 
Philippe.