Defining TEVENT_NUM_SIGNALS as (2 * SIGRTMIN) so that SIGNAL-based AIO handling on FreeBSD works

[Jeremy Allison]

On Mon, Dec 03, 2012 at 11:55:03AM -0800, Richard Sharpe wrote:
> On Mon, Dec 3, 2012 at 11:41 AM, Jeremy Allison <jra at samba.org> wrote:
> > On Fri, Nov 30, 2012 at 03:06:18PM -0800, Richard Sharpe wrote:
> >> Hi folks,
> >>
> >> I am canvassing opinions on whether there is a better way to do this.
> >>
> >> Currently, the default AIO stuff in Samba does not work on FreeBSD
> >> because TEVENT_NUM_SIGNALS is set to 64 and there is a check to see
> >> that the signal number used by the AIO stuff does not exceed this
> >> number.
> >>
> >> However, if RT_SIGNAL_AIO Is not set, then:
> >>
> >> /* The signal we'll use to signify aio done. */
> >> #ifndef RT_SIGNAL_AIO
> >> #define RT_SIGNAL_AIO   (SIGRTMIN+3)
> >> #endif
> >>
> >> in source3/smbd/aio.c but on FreeBSD
> >>
> >> /usr/include/sys/signal.h:#define       SIGRTMIN        65
> >>
> >> So, things do not work.
> >>
> >> One solution is to define TEVENT_NUM_SIGNALS as 2 * SIGRTMIN ...
> >>
> >> On Linux SIGRTMIN is 32.
> >>
> >> Can anyone suggest a better fix?
> >
> > Took a quick look at this and at least on Linux there's
> >
> > #define SIGRTMAX
> >
> > which looks like it might be part of the POSIX-RT standard.
> >
> > Is this defined on *BSD ? If so, what is it defined to ?
> 
> /usr/include/sys/signal.h
> ...
> #define SIGRTMIN        65
> #define SIGRTMAX        126

Actually looks like using that instead of the hard-coded 64
is the right decision (IMHO).

Jeremy.