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

[Timur I. Bakeyev]

Jeremy, in FreeBSD port we fix it with following patch. That make us sure
that we have sane SIGRTMIN/MAX later on for the usage in tevent. And this
patch is somewhat 3 years old. I've sent it to the list, but it never went
through...

--- ./lib/replace/system/wait.h.orig    2010-04-01 15:26:22.000000000 +0200
+++ ./lib/replace/system/wait.h 2010-04-23 01:08:35.000000000 +0200
@@ -32,6 +32,18 @@

 #include <signal.h>

+#ifndef SIGRTMIN
+#      ifdef NSIG
+#              define SIGRTMIN (NSIG+1)
+#      else
+#              define SIGRTMIN 33
+#      endif
+#endif
+
+#ifndef SIGRTMAX
+#define SIGRTMAX (SIGRTMIN+64)
+#endif
+
 #ifndef SIGCLD
 #define SIGCLD SIGCHLD
 #endif



On Tue, Dec 4, 2012 at 6:10 PM, Jeremy Allison <jra at samba.org> wrote:

> On Tue, Dec 04, 2012 at 08:20:11AM +0100, Stefan (metze) Metzmacher wrote:
> > Am 03.12.2012 20:41, schrieb Jeremy Allison:
> > > 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 ?
> >
> > At least this doesn't work on Linux.
> >
> >
> https://gitweb.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=9a92ca3b637d41709ded56a5161ff9ff7505f677
> >
> > As SIGRTMAX is not a const value.
>
> Yes, I already discovered that :-). I'm still thinking
> about how to fix this..
>
> Jeremy.
>