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