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, 2009, 2010  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_NS)
  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 #define sigfree() sigsetmask (SIGEMPTYMASK)
 147
 148 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
 149 #undef SIGINFO
 150 #endif
 151 #if defined (SIGIO) && defined (BROKEN_SIGIO)
 152 # undef SIGIO
 153 # if defined (__Lynx__)
 154 # undef SIGPOLL /* Defined as SIGIO on LynxOS */
 155 # endif
 156 #endif
 157 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 158 #undef SIGPOLL
 159 #endif
 160 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 161 #undef SIGTSTP
 162 #endif
 163 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 164 #undef SIGURG
 165 #endif
 166 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 167 #undef SIGAIO
 168 #endif
 169 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 170 #undef SIGPTY
 171 #endif
 172
 173
 174 #if NSIG < NSIG_MINIMUM
 175 # ifdef NSIG
 176 #  undef NSIG
 177 # endif
 178 # define NSIG NSIG_MINIMUM
 179 #endif
 180
 181 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 182    Must do that using the killpg call.  */
 183 #ifdef BSD_SYSTEM
 184 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 185 #else
 186 #ifdef WINDOWSNT
 187 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 188 #else
 189 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 190 #endif
 191 #endif
 192
 193 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 194    testing SIGCHLD.  */
 195 #ifdef SIGCLD
 196 #ifndef SIGCHLD
 197 #define SIGCHLD SIGCLD
 198 #endif /* SIGCHLD */
 199 #endif /* ! defined (SIGCLD) */
 200
 201 #ifndef HAVE_STRSIGNAL
 202 /* strsignal is in sysdep.c */
 203 char *strsignal ();
 204 #endif
 205
 206 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 207 #define SIGNAL_THREAD_CHECK(signo)                                      \
 208   do {                                                                  \
 209     if (!pthread_equal (pthread_self (), main_thread))                  \
 210       {                                                                 \
 211         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 212            that is not true, but for other systems (FreeBSD at least)   \
 213            it is.  So direct the signal to the correct thread and block \
 214            it from this thread.  */                                     \
 215         sigset_t new_mask;                                              \
 216                                                                         \
 217         sigemptyset (&new_mask);                                        \
 218         sigaddset (&new_mask, signo);                                   \
 219         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 220         pthread_kill (main_thread, signo);                              \
 221         return;                                                         \
 222       }                                                                 \
 223    } while (0)
 224
 225 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 226 #define SIGNAL_THREAD_CHECK(signo)
 227 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 228 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 229    (do not change this comment) */