src/syssignal.h

   1 /* syssignal.h - System-dependent definitions for signals.
   2    Copyright (C) 1993, 1999, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 extern void init_signals P_ ((void));
  23
  24 #if defined (HAVE_GTK_AND_PTHREAD) || (defined (HAVE_CARBON) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1020)
  25 #include <pthread.h>
  26 /* If defined, asynchronous signals delivered to a non-main thread are
  27    forwarded to the main thread.  */
  28 #define FORWARD_SIGNAL_TO_MAIN_THREAD
  29 #endif
  30
  31 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
  32 extern pthread_t main_thread;
  33 #endif
  34
  35 #ifdef POSIX_SIGNALS
  36
  37 /* Don't #include <signal.h>.  That header should always be #included
  38    before "config.h", because some configuration files (like s/hpux.h)
  39    indicate that SIGIO doesn't work by #undef-ing SIGIO.  If this file
  40    #includes <signal.h>, then that will re-#define SIGIO and confuse
  41    things.  */
  42 /* XXX This is not correct anymore, there is a BROKEN_SIGIO macro. */
  43
  44 #define SIGMASKTYPE sigset_t
  45
  46 #define SIGEMPTYMASK (empty_mask)
  47 #define SIGFULLMASK (full_mask)
  48 extern sigset_t empty_mask, full_mask;
  49
  50 /* POSIX pretty much destroys any possibility of writing sigmask as a
  51    macro in standard C.  We always define our own version because the
  52    predefined macro in Glibc 2.1 is only provided for compatility for old
  53    programs that use int as signal mask type.  */
  54 #undef sigmask
  55 #ifdef __GNUC__
  56 #define sigmask(SIG)                            \
  57   ({                                            \
  58     sigset_t _mask;                             \
  59     sigemptyset (&_mask);                       \
  60     sigaddset (&_mask, SIG);                    \
  61     _mask;                                      \
  62   })
  63 #else /* ! defined (__GNUC__) */
  64 extern sigset_t sys_sigmask ();
  65 #define sigmask(SIG) (sys_sigmask (SIG))
  66 #endif /* ! defined (__GNUC__) */
  67
  68 #undef sigpause
  69 #define sigpause(MASK)    sigsuspend (&(MASK))
  70
  71 #define sigblock(SIG)    sys_sigblock (SIG)
  72 #define sigunblock(SIG)  sys_sigunblock (SIG)
  73 #ifndef sigsetmask
  74 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  75 #endif
  76 #define sighold(SIG)     ONLY_USED_IN_BSD_4_1
  77 #define sigrelse(SIG)    ONLY_USED_IN_BSD_4_1
  78 #undef signal
  79 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  80
  81 /* Whether this is what all systems want or not, this is what
  82    appears to be assumed in the source, for example data.c:arith_error.  */
  83 typedef RETSIGTYPE (*signal_handler_t) (/*int*/);
  84
  85 signal_handler_t sys_signal P_ ((int signal_number, signal_handler_t action));
  86 sigset_t sys_sigblock   P_ ((sigset_t new_mask));
  87 sigset_t sys_sigunblock P_ ((sigset_t new_mask));
  88 sigset_t sys_sigsetmask P_ ((sigset_t new_mask));
  89
  90 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  91
  92 #else /* ! defined (POSIX_SIGNALS) */
  93 #ifdef USG5_4
  94
  95 extern SIGMASKTYPE sigprocmask_set;
  96
  97 #ifndef sigblock
  98 #define sigblock(sig)                                   \
  99      (sigprocmask_set = SIGEMPTYMASK | (sig),           \
 100       sigprocmask (SIG_BLOCK, &sigprocmask_set, NULL))
 101 #endif
 102
 103 #ifndef sigunblock
 104 #define sigunblock(sig)                                         \
 105      (sigprocmask_set = SIGFULLMASK & ~(sig),                   \
 106       sigprocmask (SIG_SETMASK, &sigprocmask_set, NULL))
 107 #endif
 108
 109 #else
 110 #ifdef USG
 111
 112 #ifndef sigunblock
 113 #define sigunblock(sig)
 114 #endif
 115
 116 #else
 117
 118 #ifndef sigunblock
 119 #define sigunblock(SIG) \
 120 { SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }
 121 #endif
 122
 123 #endif /* ! defined (USG) */
 124 #endif /* ! defined (USG5_4) */
 125 #endif /* ! defined (POSIX_SIGNALS) */
 126
 127 #ifndef SIGMASKTYPE
 128 #define SIGMASKTYPE int
 129 #endif
 130
 131 #ifndef SIGEMPTYMASK
 132 #define SIGEMPTYMASK (0)
 133 #endif
 134
 135 #ifndef SIGFULLMASK
 136 #define SIGFULLMASK (0xffffffff)
 137 #endif
 138
 139 #ifndef sigmask
 140 #define sigmask(no) (1L << ((no) - 1))
 141 #endif
 142
 143 #ifndef sigunblock
 144 #define sigunblock(SIG) \
 145 { SIGMASKTYPE omask = sigblock (SIGFULLMASK); sigsetmask (omask & ~SIG); }
 146 #endif
 147
 148 #ifndef BSD4_1
 149 #define sigfree() sigsetmask (SIGEMPTYMASK)
 150 #endif /* not BSD4_1 */
 151
 152 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
 153 #undef SIGINFO
 154 #endif
 155 #if defined (SIGIO) && defined (BROKEN_SIGIO)
 156 # undef SIGIO
 157 # if defined (__Lynx__)
 158 # undef SIGPOLL /* Defined as SIGIO on LynxOS */
 159 # endif
 160 #endif
 161 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 162 #undef SIGPOLL
 163 #endif
 164 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 165 #undef SIGTSTP
 166 #endif
 167 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 168 #undef SIGURG
 169 #endif
 170 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 171 #undef SIGAIO
 172 #endif
 173 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 174 #undef SIGPTY
 175 #endif
 176
 177
 178 #if NSIG < NSIG_MINIMUM
 179 # ifdef NSIG
 180 #  undef NSIG
 181 # endif
 182 # define NSIG NSIG_MINIMUM
 183 #endif
 184
 185 #ifdef BSD4_1
 186 #define SIGIO SIGTINT
 187 /* sigfree is in sysdep.c */
 188 #endif /* BSD4_1 */
 189
 190 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 191    Must do that using the killpg call.  */
 192 #ifdef BSD_SYSTEM
 193 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 194 #else
 195 #ifdef WINDOWSNT
 196 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 197 #else
 198 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 199 #endif
 200 #endif
 201
 202 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 203    testing SIGCHLD.  */
 204 #ifndef VMS
 205 #ifdef SIGCLD
 206 #ifndef SIGCHLD
 207 #define SIGCHLD SIGCLD
 208 #endif /* SIGCHLD */
 209 #endif /* ! defined (SIGCLD) */
 210 #endif /* VMS */
 211
 212 #ifndef HAVE_STRSIGNAL
 213 /* strsignal is in sysdep.c */
 214 char *strsignal ();
 215 #endif
 216
 217 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 218 #define SIGNAL_THREAD_CHECK(signo)                                      \
 219   do {                                                                  \
 220     if (!pthread_equal (pthread_self (), main_thread))                  \
 221       {                                                                 \
 222         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 223            that is not true, but for other systems (FreeBSD at least)   \
 224            it is.  So direct the signal to the correct thread and block \
 225            it from this thread.  */                                     \
 226         sigset_t new_mask;                                              \
 227                                                                         \
 228         sigemptyset (&new_mask);                                        \
 229         sigaddset (&new_mask, signo);                                   \
 230         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 231         pthread_kill (main_thread, signo);                              \
 232         return;                                                         \
 233       }                                                                 \
 234    } while (0)
 235
 236 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 237 #define SIGNAL_THREAD_CHECK(signo)
 238 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 239 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 240    (do not change this comment) */