• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* Convenience declarations when working with <signal.h>.
2 
3    Copyright (C) 2008-2012 Free Software Foundation, Inc.
4 
5    This program is free software: you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 3 of the License, or
8    (at your option) any later version.
9 
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14 
15    You should have received a copy of the GNU General Public License
16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17 
18 #ifndef _GL_SIG_HANDLER_H
19 #define _GL_SIG_HANDLER_H
20 
21 #include <signal.h>
22 
23 _GL_INLINE_HEADER_BEGIN
24 #ifndef SIG_HANDLER_INLINE
25 # define SIG_HANDLER_INLINE _GL_INLINE
26 #endif
27 
28 /* Convenience type when working with signal handlers.  */
29 typedef void (*sa_handler_t) (int);
30 
31 /* Return the handler of a signal, as a sa_handler_t value regardless
32    of its true type.  The resulting function can be compared to
33    special values like SIG_IGN but it is not portable to call it.  */
34 SIG_HANDLER_INLINE sa_handler_t
get_handler(struct sigaction const * a)35 get_handler (struct sigaction const *a)
36 {
37 #ifdef SA_SIGINFO
38   /* POSIX says that special values like SIG_IGN can only occur when
39      action.sa_flags does not contain SA_SIGINFO.  But in Linux 2.4,
40      for example, sa_sigaction and sa_handler are aliases and a signal
41      is ignored if sa_sigaction (after casting) equals SIG_IGN.  So
42      use (and cast) sa_sigaction in that case.  */
43   if (a->sa_flags & SA_SIGINFO)
44     return (sa_handler_t) a->sa_sigaction;
45 #endif
46   return a->sa_handler;
47 }
48 
49 _GL_INLINE_HEADER_END
50 
51 #endif /* _GL_SIG_HANDLER_H */
52