usr/src/lib/libast/common/misc/signal.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23
  24 /*
  25  * signal that disables syscall restart on interrupt with clear signal mask
  26  * fun==SIG_DFL also unblocks signal
  27  */
  28
  29 #if !_UWIN
  30
  31 #undef  signal
  32 #define signal          ______signal
  33
  34 #endif
  35
  36 #include <ast.h>
  37 #include <sig.h>
  38
  39 #if !_UWIN
  40
  41 #undef  signal
  42
  43 #undef  _def_map_ast
  44 #include <ast_map.h>
  45
  46 #if defined(__EXPORT__)
  47 #define extern  __EXPORT__
  48 #endif
  49
  50 #endif
  51
  52 #if defined(SV_ABORT)
  53 #undef  SV_INTERRUPT
  54 #define SV_INTERRUPT    SV_ABORT
  55 #endif
  56
  57 #if !_std_signal && (_lib_sigaction && defined(SA_NOCLDSTOP) || _lib_sigvec && defined(SV_INTERRUPT))
  58
  59 #if !defined(SA_NOCLDSTOP) || !defined(SA_INTERRUPT) && defined(SV_INTERRUPT)
  60 #undef  SA_INTERRUPT
  61 #define SA_INTERRUPT    SV_INTERRUPT
  62 #undef  sigaction
  63 #define sigaction       sigvec
  64 #undef  sigemptyset
  65 #define sigemptyset(p)  (*(p)=0)
  66 #undef  sa_flags
  67 #define sa_flags        sv_flags
  68 #undef  sa_handler
  69 #define sa_handler      sv_handler
  70 #undef  sa_mask
  71 #define sa_mask         sv_mask
  72 #endif
  73
  74 extern Sig_handler_t
  75 signal(int sig, Sig_handler_t fun)
  76 {
  77         struct sigaction        na;
  78         struct sigaction        oa;
  79         int                     unblock;
  80 #ifdef SIGNO_MASK
  81         unsigned int            flags;
  82 #endif
  83
  84         if (sig < 0)
  85         {
  86                 sig = -sig;
  87                 unblock = 0;
  88         }
  89         else
  90                 unblock = fun == SIG_DFL;
  91 #ifdef SIGNO_MASK
  92         flags = sig & ~SIGNO_MASK;
  93         sig &= SIGNO_MASK;
  94 #endif
  95         memzero(&na, sizeof(na));
  96         na.sa_handler = fun;
  97 #if defined(SA_INTERRUPT) || defined(SA_RESTART)
  98         switch (sig)
  99         {
 100 #if defined(SIGIO) || defined(SIGTSTP) || defined(SIGTTIN) || defined(SIGTTOU)
 101 #if defined(SIGIO)
 102         case SIGIO:
 103 #endif
 104 #if defined(SIGTSTP)
 105         case SIGTSTP:
 106 #endif
 107 #if defined(SIGTTIN)
 108         case SIGTTIN:
 109 #endif
 110 #if defined(SIGTTOU)
 111         case SIGTTOU:
 112 #endif
 113 #if defined(SA_RESTART)
 114                 na.sa_flags = SA_RESTART;
 115 #endif
 116                 break;
 117 #endif
 118         default:
 119 #if defined(SA_INTERRUPT)
 120                 na.sa_flags = SA_INTERRUPT;
 121 #endif
 122                 break;
 123         }
 124 #endif
 125         if (sigaction(sig, &na, &oa))
 126                 return 0;
 127         if (unblock)
 128                 sigunblock(sig);
 129         return oa.sa_handler;
 130 }
 131
 132 #else
 133
 134 NoN(signal)
 135
 136 #endif