Rob, I'm not better than you at C, but I did have to dig deep into this for my `bc', so I thought I would offer my 2 cents.
First off, sigaction() is complex, but it is better in every other way. It gives you a lot more options, has better ways of querying the current signal handlers, has better behavior, etc. For multithreaded programs on Linux, the man page (http://man7.org/linux/man-pages/man2/signal.2.html) says that the behavior of signal() is unspecified. It also encourages the use of sigaction(). Second, the GNU page for glibc's signal() and sigaction() (http://www.gnu.org/software/libc/manual/html_node/Signal-and-Sigaction.html) says that they discourage the use of both signal() and sigaction() in the same program. There is one more wrinkle, but I don't think it will be a problem for toybox: signal() is more widely available. However, sigaction() has been defined in POSIX since at least 2001, and you told me that you generally require POSIX 2008, so I don't think that availability will be a problem at all. Also, my `bc' already uses sigaction(). Thus, I suggest you use xsignal()/sigaction(). I can send you a patch for that. Would you want me to do that? And if so, would you want it before or after the next release? Gavin Howard On Fri, Sep 21, 2018 at 5:30 PM Rob Landley <r...@landley.net> wrote: > > signal() defaults to SA_RESTART, xsignal() uses sigaction() which does not. > I'm > not sure which is correct? (It's currently using signal() and things seem ok > with what?) > > *shrug* The readall() code assumes no SA_RESTART. The main downside of signal > by > default I'm aware of is having to poll before read() when you want a timeout > via > alarm() (unless you siglongjmp)... > > Just wondering if anybody out there better than me at C has an opinion. :) > > Rob > _______________________________________________ > Toybox mailing list > Toybox@lists.landley.net > http://lists.landley.net/listinfo.cgi/toybox-landley.net _______________________________________________ Toybox mailing list Toybox@lists.landley.net http://lists.landley.net/listinfo.cgi/toybox-landley.net
