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
  92 #ifndef sigunblock
  93 #define sigunblock(SIG) \
  94 { SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }
  95 #endif
  96
  97 #endif /* ! defined (POSIX_SIGNALS) */
  98
  99 #ifndef SIGMASKTYPE
 100 #define SIGMASKTYPE int
 101 #endif
 102
 103 #ifndef SIGEMPTYMASK
 104 #define SIGEMPTYMASK (0)
 105 #endif
 106
 107 #ifndef SIGFULLMASK
 108 #define SIGFULLMASK (0xffffffff)
 109 #endif
 110
 111 #ifndef sigmask
 112 #define sigmask(no) (1L << ((no) - 1))
 113 #endif
 114
 115 #ifndef sigunblock
 116 #define sigunblock(SIG) \
 117 { SIGMASKTYPE omask = sigblock (SIGFULLMASK); sigsetmask (omask & ~SIG); }
 118 #endif
 119
 120 #define sigfree() sigsetmask (SIGEMPTYMASK)
 121
 122 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
 123 #undef SIGINFO
 124 #endif
 125 #if defined (SIGIO) && defined (BROKEN_SIGIO)
 126 # undef SIGIO
 127 # if defined (__Lynx__)
 128 # undef SIGPOLL /* Defined as SIGIO on LynxOS */
 129 # endif
 130 #endif
 131 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
 132 #undef SIGPOLL
 133 #endif
 134 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
 135 #undef SIGTSTP
 136 #endif
 137 #if defined (SIGURG) && defined (BROKEN_SIGURG)
 138 #undef SIGURG
 139 #endif
 140 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 141 #undef SIGAIO
 142 #endif
 143 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 144 #undef SIGPTY
 145 #endif
 146
 147
 148 #if NSIG < NSIG_MINIMUM
 149 # ifdef NSIG
 150 #  undef NSIG
 151 # endif
 152 # define NSIG NSIG_MINIMUM
 153 #endif
 154
 155 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 156    Must do that using the killpg call.  */
 157 #ifdef BSD_SYSTEM
 158 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 159 #else
 160 #ifdef WINDOWSNT
 161 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 162 #else
 163 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 164 #endif
 165 #endif
 166
 167 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 168    testing SIGCHLD.  */
 169 #ifdef SIGCLD
 170 #ifndef SIGCHLD
 171 #define SIGCHLD SIGCLD
 172 #endif /* SIGCHLD */
 173 #endif /* ! defined (SIGCLD) */
 174
 175 #ifndef HAVE_STRSIGNAL
 176 /* strsignal is in sysdep.c */
 177 char *strsignal ();
 178 #endif
 179
 180 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 181 #define SIGNAL_THREAD_CHECK(signo)                                      \
 182   do {                                                                  \
 183     if (!pthread_equal (pthread_self (), main_thread))                  \
 184       {                                                                 \
 185         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 186            that is not true, but for other systems (FreeBSD at least)   \
 187            it is.  So direct the signal to the correct thread and block \
 188            it from this thread.  */                                     \
 189         sigset_t new_mask;                                              \
 190                                                                         \
 191         sigemptyset (&new_mask);                                        \
 192         sigaddset (&new_mask, signo);                                   \
 193         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 194         pthread_kill (main_thread, signo);                              \
 195         return;                                                         \
 196       }                                                                 \
 197    } while (0)
 198
 199 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 200 #define SIGNAL_THREAD_CHECK(signo)
 201 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 202 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 203    (do not change this comment) */