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 of the License, or
  10 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 extern void init_signals P_ ((void));
  21
  22 #if defined (HAVE_GTK_AND_PTHREAD) || (defined (HAVE_CARBON) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1020)
  23 #include <pthread.h>
  24 /* If defined, asynchronous signals delivered to a non-main thread are
  25    forwarded to the main thread.  */
  26 #define FORWARD_SIGNAL_TO_MAIN_THREAD
  27 #endif
  28
  29 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
  30 extern pthread_t main_thread;
  31 #endif
  32
  33 #ifdef POSIX_SIGNALS
  34
  35 /* Don't #include <signal.h>.  That header should always be #included
  36    before "config.h", because some configuration files (like s/hpux.h)
  37    indicate that SIGIO doesn't work by #undef-ing SIGIO.  If this file
  38    #includes <signal.h>, then that will re-#define SIGIO and confuse
  39    things.  */
  40 /* XXX This is not correct anymore, there is a BROKEN_SIGIO macro. */
  41
  42 #define SIGMASKTYPE sigset_t
  43
  44 #define SIGEMPTYMASK (empty_mask)
  45 #define SIGFULLMASK (full_mask)
  46 extern sigset_t empty_mask, full_mask;
  47
  48 /* POSIX pretty much destroys any possibility of writing sigmask as a
  49    macro in standard C.  We always define our own version because the
  50    predefined macro in Glibc 2.1 is only provided for compatility for old
  51    programs that use int as signal mask type.  */
  52 #undef sigmask
  53 #ifdef __GNUC__
  54 #define sigmask(SIG)                            \
  55   ({                                            \
  56     sigset_t _mask;                             \
  57     sigemptyset (&_mask);                       \
  58     sigaddset (&_mask, SIG);                    \
  59     _mask;                                      \
  60   })
  61 #else /* ! defined (__GNUC__) */
  62 extern sigset_t sys_sigmask ();
  63 #define sigmask(SIG) (sys_sigmask (SIG))
  64 #endif /* ! defined (__GNUC__) */
  65
  66 #undef sigpause
  67 #define sigpause(MASK)    sigsuspend (&(MASK))
  68
  69 #define sigblock(SIG)    sys_sigblock (SIG)
  70 #define sigunblock(SIG)  sys_sigunblock (SIG)
  71 #ifndef sigsetmask
  72 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  73 #endif
  74 #define sighold(SIG)     ONLY_USED_IN_BSD_4_1
  75 #define sigrelse(SIG)    ONLY_USED_IN_BSD_4_1
  76 #undef signal
  77 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  78
  79 /* Whether this is what all systems want or not, this is what
  80    appears to be assumed in the source, for example data.c:arith_error.  */
  81 typedef RETSIGTYPE (*signal_handler_t) (/*int*/);
  82
  83 signal_handler_t sys_signal P_ ((int signal_number, signal_handler_t action));
  84 sigset_t sys_sigblock   P_ ((sigset_t new_mask));
  85 sigset_t sys_sigunblock P_ ((sigset_t new_mask));
  86 sigset_t sys_sigsetmask P_ ((sigset_t new_mask));
  87
  88 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  89
  90 #else /* ! defined (POSIX_SIGNALS) */
  91 #ifdef USG5_4
  92
  93 extern SIGMASKTYPE sigprocmask_set;
  94
  95 #ifndef sigblock
  96 #define sigblock(sig)                                   \
  97      (sigprocmask_set = SIGEMPTYMASK | (sig),           \
  98       sigprocmask (SIG_BLOCK, &sigprocmask_set, NULL))
  99 #endif
 100
 101 #ifndef sigunblock
 102 #define sigunblock(sig)                                         \
 103      (sigprocmask_set = SIGFULLMASK & ~(sig),                   \
 104       sigprocmask (SIG_SETMASK, &sigprocmask_set, NULL))
 105 #endif
 106
 107 #else
 108 #ifdef USG
 109
 110 #ifndef sigunblock
 111 #define sigunblock(sig)
 112 #endif
 113
 114 #else
 115
 116 #ifndef sigunblock
 117 #define sigunblock(SIG) \
 118 { SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }
 119 #endif
 120
 121 #endif /* ! defined (USG) */
 122 #endif /* ! defined (USG5_4) */
 123 #endif /* ! defined (POSIX_SIGNALS) */
 124
 125 #ifndef SIGMASKTYPE
 126 #define SIGMASKTYPE int
 127 #endif
 128
 129 #ifndef SIGEMPTYMASK
 130 #define SIGEMPTYMASK (0)
 131 #endif
 132
 133 #ifndef SIGFULLMASK
 134 #define SIGFULLMASK (0xffffffff)
 135 #endif
 136
 137 #ifndef sigmask
 138 #define sigmask(no) (1L << ((no) - 1))
 139 #endif
 140
 141 #ifndef sigunblock
 142 #define sigunblock(SIG) \
 143 { SIGMASKTYPE omask = sigblock (SIGFULLMASK); sigsetmask (omask & ~SIG); }
 144 #endif
 145
 146 #ifndef BSD4_1
 147 #define sigfree() sigsetmask (SIGEMPTYMASK)
 148 #endif /* not BSD4_1 */
 149
 150 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
 151 #undef SIGINFO
 152 #endif
 153 #if defined (SIGIO) && defined (BROKEN_SIGIO)
 154 # undef SIGIO
 155 # if defined (__Lynx__)
 156 # undef SIGPOLL /* Defined as SIGIO on LynxOS */
 157 # endif
 158 #endif
 159 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 160 #undef SIGPOLL
 161 #endif
 162 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 163 #undef SIGTSTP
 164 #endif
 165 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 166 #undef SIGURG
 167 #endif
 168 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 169 #undef SIGAIO
 170 #endif
 171 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 172 #undef SIGPTY
 173 #endif
 174
 175
 176 #if NSIG < NSIG_MINIMUM
 177 # ifdef NSIG
 178 #  undef NSIG
 179 # endif
 180 # define NSIG NSIG_MINIMUM
 181 #endif
 182
 183 #ifdef BSD4_1
 184 #define SIGIO SIGTINT
 185 /* sigfree is in sysdep.c */
 186 #endif /* BSD4_1 */
 187
 188 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 189    Must do that using the killpg call.  */
 190 #ifdef BSD_SYSTEM
 191 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 192 #else
 193 #ifdef WINDOWSNT
 194 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 195 #else
 196 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 197 #endif
 198 #endif
 199
 200 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 201    testing SIGCHLD.  */
 202 #ifndef VMS
 203 #ifdef SIGCLD
 204 #ifndef SIGCHLD
 205 #define SIGCHLD SIGCLD
 206 #endif /* SIGCHLD */
 207 #endif /* ! defined (SIGCLD) */
 208 #endif /* VMS */
 209
 210 #ifndef HAVE_STRSIGNAL
 211 /* strsignal is in sysdep.c */
 212 char *strsignal ();
 213 #endif
 214
 215 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 216 #define SIGNAL_THREAD_CHECK(signo)                                      \
 217   do {                                                                  \
 218     if (!pthread_equal (pthread_self (), main_thread))                  \
 219       {                                                                 \
 220         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 221            that is not true, but for other systems (FreeBSD at least)   \
 222            it is.  So direct the signal to the correct thread and block \
 223            it from this thread.  */                                     \
 224         sigset_t new_mask;                                              \
 225                                                                         \
 226         sigemptyset (&new_mask);                                        \
 227         sigaddset (&new_mask, signo);                                   \
 228         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 229         pthread_kill (main_thread, signo);                              \
 230         return;                                                         \
 231       }                                                                 \
 232    } while (0)
 233
 234 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 235 #define SIGNAL_THREAD_CHECK(signo)
 236 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 237 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 238    (do not change this comment) */