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 (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 (int signal_number, signal_handler_t action);
  82 sigset_t sys_sigblock   (sigset_t new_mask);
  83 sigset_t sys_sigunblock (sigset_t new_mask);
  84 sigset_t sys_sigsetmask (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 #endif
 117 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 118 #undef SIGPOLL
 119 #endif
 120 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 121 #undef SIGTSTP
 122 #endif
 123 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 124 #undef SIGURG
 125 #endif
 126 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 127 #undef SIGAIO
 128 #endif
 129 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 130 #undef SIGPTY
 131 #endif
 132
 133
 134 #if NSIG < NSIG_MINIMUM
 135 # ifdef NSIG
 136 #  undef NSIG
 137 # endif
 138 # define NSIG NSIG_MINIMUM
 139 #endif
 140
 141 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 142    Must do that using the killpg call.  */
 143 #ifdef BSD_SYSTEM
 144 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 145 #else
 146 #ifdef WINDOWSNT
 147 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 148 #else
 149 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 150 #endif
 151 #endif
 152
 153 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 154    testing SIGCHLD.  */
 155 #ifdef SIGCLD
 156 #ifndef SIGCHLD
 157 #define SIGCHLD SIGCLD
 158 #endif /* SIGCHLD */
 159 #endif /* ! defined (SIGCLD) */
 160
 161 #ifndef HAVE_STRSIGNAL
 162 /* strsignal is in sysdep.c */
 163 char *strsignal (int);
 164 #endif
 165
 166 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 167 #define SIGNAL_THREAD_CHECK(signo)                                      \
 168   do {                                                                  \
 169     if (!pthread_equal (pthread_self (), main_thread))                  \
 170       {                                                                 \
 171         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 172            that is not true, but for other systems (FreeBSD at least)   \
 173            it is.  So direct the signal to the correct thread and block \
 174            it from this thread.  */                                     \
 175         sigset_t new_mask;                                              \
 176                                                                         \
 177         sigemptyset (&new_mask);                                        \
 178         sigaddset (&new_mask, signo);                                   \
 179         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 180         pthread_kill (main_thread, signo);                              \
 181         return;                                                         \
 182       }                                                                 \
 183    } while (0)
 184
 185 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 186 #define SIGNAL_THREAD_CHECK(signo)
 187 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 188 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 189    (do not change this comment) */