bug#9010: sigprocmask -> pthread_sigmask for Emacs

[Eli Zaretskii]

> Date: Fri, 08 Jul 2011 02:58:55 -0700
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: 9010@debbugs.gnu.org
> 
> On 07/08/11 00:17, Eli Zaretskii wrote:
> > After your patch, will there be any code in Emacs that still uses
> > sigprocmask?  If not, we could just rename the w32.c sigprocmask stub
> > to pthread_sigmask.  If sigprocmask will still be used, then your
> > suggestion for pthread_sigmask to call sigprocmask is TRT.
> 
> There will still be some code in lib-src/emacsclient.c that uses sigprocmask,
> because emacsclient is single-threaded and does not need pthread_sigmask.
> pthread_sigmask sometimes needs extra libraries, such as -lpthread;
> these libraries are ordinarily linked into Emacs anyway, so it's no
> big deal for Emacs to call pthread_sigmask, but I'd rather not have
> single-threaded apps link to -lpthread if they don't need it.
> 
> Does emacsclient run on w32 and/or msdos?

emacsclient works on w32, but it doesn't use the part that calls
sigprocmask (NO_SOCKETS_IN_FILE_SYSTEM is defined on w32).  So this is
not an issue for w32.

The MSDOS port doesn't support emacsclient at all.

IIUC, using sigprocmask in Emacs proper will never be TRT.  If so, we
can simply rename the sigprocmask stub in w32 to be a pthread_sigmask
stub.