@node pthread_sigmask
@subsection @code{pthread_sigmask}
@findex pthread_sigmask

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/pthread_sigmask.html}

Gnulib module: pthread_sigmask
@mindex pthread_sigmask

Portability problems fixed by Gnulib:
@itemize
@item
This function is missing on some platforms:
Minix 3.1.8, mingw, MSVC 14.
@item
This function is declared in @code{<pthread.h>} instead of @code{<signal.h>}
on some platforms:
FreeBSD 6.4, OpenBSD 3.8.
@item
This function does nothing and always returns 0 in programs that are not
linked with @code{-lpthread} on some platforms:
FreeBSD 14.0, MidnightBSD 1.1, HP-UX 11.31, Solaris 9.
@item
When it fails, this functions returns @minus{}1 instead of the error number on
some platforms:
Cygwin 1.7.5.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
On platforms that do not natively support this function,
it has unspecified behavior in a multi-threaded process.
@item
In case of failure, the return value is wrong on some platforms:
@c https://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=57214
NetBSD 9.3 when libpthread is not in use.
@end itemize
