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Re: SIGIO, siginfo
> On Jan 14, 1:24pm, yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi) wrote:
> -- Subject: Re: SIGIO, siginfo
> | "man siginfo|grep -i sigio" shows nothing.
> | i'm wondering why it's this different from linux.
> | see the attached code.
> I understand now.
> 1. We get the wrong fd (the original fd, and not the dupped one where FASYNC
> was set on), because in our current fd implementation the struct file is
> shared, and there is no way to tell the difference. Even when we ASYNC
> to the fd in the code, we already have lost the file descriptor index,
> since we pass struct file * directly. Is this a problem? What does POSIX
> say? I don't see an easy fix.
linux saves the descriptor number.
we can do the same if this interface is intended to be linux-compatibile.
it has a good side effect to remove an XXXSMP in kpsignal.
i don't think SIGIO and its fcntl/ioctl are in POSIX.
SIGPOLL is in POSIX, but it's for STREAMS which we don't have.
> 2. I don't know why we get the wrong direction. I think I added the
> notification and I might have gotten it backwards. The comments in the
> code indicate otherwise. I would expect poll to report backwards too then.
> Does it?
> Do you know why we have:
> #define POLLIN 0x0001
> #define POLLPRI 0x0002
> #define POLLOUT 0x0004
> #define POLLRDNORM 0x0040
> #define POLLWRNORM POLLOUT <--- and not a separate flag?
> #define POLLRDBAND 0x0080
> #define POLLWRBAND 0x0100
> | > | - siginfo.h and siginfo(2) mention SIGPOLL which actually does not
> | > | should they be just removed?
> | >
> | > I think we should alias SIGPOLL to SIGIO since it is a mentioned extension
> | > to POSIX.
> | isn't SIGPOLL something for STREAMS?
> | are they supposed to be same?
> It used to be, but now it is:
which part of the page are you reffering to?
"On Linux, SIGIO is a synonym for SIGPOLL." ?
> so I think we should just #define SIGPOLL SIGIO
> | thanks.
> | i think it's better to unifdef pipeselwakeup then.
> go for it!
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