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
  43 #define SIGMASKTYPE sigset_t
  44
  45 #define SIGEMPTYMASK (empty_mask)
  46 #define SIGFULLMASK (full_mask)
  47 extern sigset_t empty_mask, full_mask;
  48
  49 /* POSIX pretty much destroys any possibility of writing sigmask as a
  50    macro in standard C.  We always define our own version because the
  51    predefined macro in Glibc 2.1 is only provided for compatility for old
  52    programs that use int as signal mask type.  */
  53 #undef sigmask
  54 #ifdef __GNUC__
  55 #define sigmask(SIG)                            \
  56   ({                                            \
  57     sigset_t _mask;                             \
  58     sigemptyset (&_mask);                       \
  59     sigaddset (&_mask, SIG);                    \
  60     _mask;                                      \
  61   })
  62 #else /* ! defined (__GNUC__) */
  63 extern sigset_t sys_sigmask ();
  64 #define sigmask(SIG) (sys_sigmask (SIG))
  65 #endif /* ! defined (__GNUC__) */
  66
  67 #undef sigpause
  68 #define sigpause(MASK)    sigsuspend (&(MASK))
  69
  70 #define sigblock(SIG)    sys_sigblock (SIG)
  71 #define sigunblock(SIG)  sys_sigunblock (SIG)
  72 #ifndef sigsetmask
  73 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  74 #endif
  75 #define sighold(SIG)     ONLY_USED_IN_BSD_4_1
  76 #define sigrelse(SIG)    ONLY_USED_IN_BSD_4_1
  77 #undef signal
  78 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  79
  80 /* Whether this is what all systems want or not, this is what
  81    appears to be assumed in the source, for example data.c:arith_error.  */
  82 typedef RETSIGTYPE (*signal_handler_t) (/*int*/);
  83
  84 signal_handler_t sys_signal P_ ((int signal_number, signal_handler_t action));
  85 sigset_t sys_sigblock   P_ ((sigset_t new_mask));
  86 sigset_t sys_sigunblock P_ ((sigset_t new_mask));
  87 sigset_t sys_sigsetmask P_ ((sigset_t new_mask));
  88
  89 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  90
  91 #else /* ! defined (POSIX_SIGNALS) */
  92 #ifdef USG5_4
  93
  94 extern SIGMASKTYPE sigprocmask_set;
  95
  96 #ifndef sigblock
  97 #define sigblock(sig)                                   \
  98      (sigprocmask_set = SIGEMPTYMASK | (sig),           \
  99       sigprocmask (SIG_BLOCK, &sigprocmask_set, NULL))
 100 #endif
 101
 102 #ifndef sigunblock
 103 #define sigunblock(sig)                                         \
 104      (sigprocmask_set = SIGFULLMASK & ~(sig),                   \
 105       sigprocmask (SIG_SETMASK, &sigprocmask_set, NULL))
 106 #endif
 107
 108 #else
 109 #ifdef USG
 110
 111 #ifndef sigunblock
 112 #define sigunblock(sig)
 113 #endif
 114
 115 #else
 116
 117 #ifndef sigunblock
 118 #define sigunblock(SIG) \
 119 { SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }
 120 #endif
 121
 122 #endif /* ! defined (USG) */
 123 #endif /* ! defined (USG5_4) */
 124 #endif /* ! defined (POSIX_SIGNALS) */
 125
 126 #ifndef SIGMASKTYPE
 127 #define SIGMASKTYPE int
 128 #endif
 129
 130 #ifndef SIGEMPTYMASK
 131 #define SIGEMPTYMASK (0)
 132 #endif
 133
 134 #ifndef SIGFULLMASK
 135 #define SIGFULLMASK (0xffffffff)
 136 #endif
 137
 138 #ifndef sigmask
 139 #define sigmask(no) (1L << ((no) - 1))
 140 #endif
 141
 142 #ifndef sigunblock
 143 #define sigunblock(SIG) \
 144 { SIGMASKTYPE omask = sigblock (SIGFULLMASK); sigsetmask (omask & ~SIG); }
 145 #endif
 146
 147 #ifndef BSD4_1
 148 #define sigfree() sigsetmask (SIGEMPTYMASK)
 149 #endif /* not BSD4_1 */
 150
 151 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
 152 #undef SIGINFO
 153 #endif
 154 #if defined (SIGIO) && defined (BROKEN_SIGIO)
 155 # undef SIGIO
 156 # if defined (__Lynx__)
 157 # undef SIGPOLL /* Defined as SIGIO on LynxOS */
 158 # endif
 159 #endif
 160 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 161 #undef SIGPOLL
 162 #endif
 163 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 164 #undef SIGTSTP
 165 #endif
 166 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 167 #undef SIGURG
 168 #endif
 169 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 170 #undef SIGAIO
 171 #endif
 172 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 173 #undef SIGPTY
 174 #endif
 175
 176
 177 #if NSIG < NSIG_MINIMUM
 178 # ifdef NSIG
 179 #  undef NSIG
 180 # endif
 181 # define NSIG NSIG_MINIMUM
 182 #endif
 183
 184 #ifdef BSD4_1
 185 #define SIGIO SIGTINT
 186 /* sigfree is in sysdep.c */
 187 #endif /* BSD4_1 */
 188
 189 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 190    Must do that using the killpg call.  */
 191 #ifdef BSD_SYSTEM
 192 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 193 #else
 194 #ifdef WINDOWSNT
 195 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 196 #else
 197 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 198 #endif
 199 #endif
 200
 201 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 202    testing SIGCHLD.  */
 203 #ifndef VMS
 204 #ifdef SIGCLD
 205 #ifndef SIGCHLD
 206 #define SIGCHLD SIGCLD
 207 #endif /* SIGCHLD */
 208 #endif /* ! defined (SIGCLD) */
 209 #endif /* VMS */
 210
 211 #ifndef HAVE_STRSIGNAL
 212 /* strsignal is in sysdep.c */
 213 char *strsignal ();
 214 #endif
 215
 216 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 217 #define SIGNAL_THREAD_CHECK(signo)                                      \
 218   do {                                                                  \
 219     if (!pthread_equal (pthread_self (), main_thread))                  \
 220       {                                                                 \
 221         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 222            that is not true, but for other systems (FreeBSD at least)   \
 223            it is.  So direct the signal to the correct thread and block \
 224            it from this thread.  */                                     \
 225         sigset_t new_mask;                                              \
 226                                                                         \
 227         sigemptyset (&new_mask);                                        \
 228         sigaddset (&new_mask, signo);                                   \
 229         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 230         pthread_kill (main_thread, signo);                              \
 231         return;                                                         \
 232       }                                                                 \
 233    } while (0)
 234
 235 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 236 #define SIGNAL_THREAD_CHECK(signo)
 237 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 238 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 239    (do not change this comment) */