Fixed portability issues with union sigval. AIO support in nginx was originally developed against FreeBSD versions 4-6, where the sival_ptr field was named as sigval_ptr (seemingly by mistake[1]), which made nginx use the only name available then. The standard-complaint name was restored in 2005 (first appeared in FreeBSD 7.0, 2008), retaining compatibility with previous versions[2][3]. In DragonFly, similar changes were committed in 2009[4], with backward compatibility recently removed[5]. The change switches to the standard name, retaining compatibility with old FreeBSD versions. [1] https://svnweb.freebsd.org/changeset/base/48621 [2] https://svnweb.freebsd.org/changeset/base/152029 [3] https://svnweb.freebsd.org/changeset/base/174003 [4] https://gitweb.dragonflybsd.org/dragonfly.git/commit/3693401 [5] https://gitweb.dragonflybsd.org/dragonfly.git/commit/7875042

/
/ Copyright (C) Igor Sysoev
/ Copyright (C) Nginx, Inc.
/


/  "casa   [%o2] 0x80, %o1, %o0"  and
/  "casxa  [%o2] 0x80, %o1, %o0"  do the following:
/
/       if ([%o2] == %o1) {
/           swap(%o0, [%o2]);
/       } else {
/           %o0 = [%o2];
/       }


/ ngx_atomic_uint_t ngx_casa(ngx_atomic_uint_t set, ngx_atomic_uint_t old,
/      ngx_atomic_t *lock);
/
/ the arguments are passed in the %o0, %o1, %o2
/ the result is returned in the %o0

        .inline ngx_casa,0
        casa    [%o2] 0x80, %o1, %o0
        .end


/ ngx_atomic_uint_t ngx_casxa(ngx_atomic_uint_t set, ngx_atomic_uint_t old,
/      ngx_atomic_t *lock);
/
/ the arguments are passed in the %o0, %o1, %o2
/ the result is returned in the %o0

        .inline ngx_casxa,0
        casxa   [%o2] 0x80, %o1, %o0
        .end