src/syssignal.h

   1 /* syssignal.h - System-dependent definitions for signals.
   2    Copyright (C) 1993, 1999, 2001-2011  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, either version 3 of the License, or
   9 (at your option) any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 extern void init_signals (void);
  20
  21 #if defined (HAVE_GTK_AND_PTHREAD) || defined (HAVE_NS)
  22 #include <pthread.h>
  23 /* If defined, asynchronous signals delivered to a non-main thread are
  24    forwarded to the main thread.  */
  25 #define FORWARD_SIGNAL_TO_MAIN_THREAD
  26 #endif
  27
  28 /* Don't #include <signal.h>.  That header should always be #included
  29    before "config.h", because some configuration files (like s/hpux.h)
  30    indicate that SIGIO doesn't work by #undef-ing SIGIO.  If this file
  31    #includes <signal.h>, then that will re-#define SIGIO and confuse
  32    things.  */
  33 /* XXX This is not correct anymore, there is a BROKEN_SIGIO macro. */
  34
  35 #define SIGMASKTYPE sigset_t
  36
  37 #define SIGEMPTYMASK (empty_mask)
  38 #define SIGFULLMASK (full_mask)
  39 extern sigset_t empty_mask, full_mask;
  40
  41 /* POSIX pretty much destroys any possibility of writing sigmask as a
  42    macro in standard C.  We always define our own version because the
  43    predefined macro in Glibc 2.1 is only provided for compatility for old
  44    programs that use int as signal mask type.  */
  45 #undef sigmask
  46 #ifdef __GNUC__
  47 #define sigmask(SIG)                            \
  48   ({                                            \
  49     sigset_t _mask;                             \
  50     sigemptyset (&_mask);                       \
  51     sigaddset (&_mask, SIG);                    \
  52     _mask;                                      \
  53   })
  54 #else /* ! defined (__GNUC__) */
  55 extern sigset_t sys_sigmask ();
  56 #define sigmask(SIG) (sys_sigmask (SIG))
  57 #endif /* ! defined (__GNUC__) */
  58
  59 #undef sigpause
  60 #define sigpause(MASK)    sigsuspend (&(MASK))
  61
  62 #define sigblock(SIG)    sys_sigblock (SIG)
  63 #define sigunblock(SIG)  sys_sigunblock (SIG)
  64 #ifndef sigsetmask
  65 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  66 #endif
  67 #undef signal
  68 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  69
  70 /* Whether this is what all systems want or not, this is what
  71    appears to be assumed in the source, for example data.c:arith_error.  */
  72 typedef RETSIGTYPE (*signal_handler_t) (int);
  73
  74 signal_handler_t sys_signal (int signal_number, signal_handler_t action);
  75 sigset_t sys_sigblock   (sigset_t new_mask);
  76 sigset_t sys_sigunblock (sigset_t new_mask);
  77 sigset_t sys_sigsetmask (sigset_t new_mask);
  78
  79 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  80
  81 #define sigfree() sigsetmask (SIGEMPTYMASK)
  82
  83 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
  84 #undef SIGINFO
  85 #endif
  86 #if defined (SIGIO) && defined (BROKEN_SIGIO)
  87 # undef SIGIO
  88 #endif
  89 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
  90 #undef SIGPOLL
  91 #endif
  92 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
  93 #undef SIGTSTP
  94 #endif
  95 #if defined (SIGURG) && defined (BROKEN_SIGURG)
  96 #undef SIGURG
  97 #endif
  98 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
  99 #undef SIGAIO
 100 #endif
 101 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 102 #undef SIGPTY
 103 #endif
 104
 105
 106 #if NSIG < NSIG_MINIMUM
 107 # ifdef NSIG
 108 #  undef NSIG
 109 # endif
 110 # define NSIG NSIG_MINIMUM
 111 #endif
 112
 113 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 114    Must do that using the killpg call.  */
 115 #ifdef BSD_SYSTEM
 116 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 117 #else
 118 #ifdef WINDOWSNT
 119 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 120 #else
 121 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 122 #endif
 123 #endif
 124
 125 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 126    testing SIGCHLD.  */
 127 #ifdef SIGCLD
 128 #ifndef SIGCHLD
 129 #define SIGCHLD SIGCLD
 130 #endif /* SIGCHLD */
 131 #endif /* ! defined (SIGCLD) */
 132
 133 #ifndef HAVE_STRSIGNAL
 134 /* strsignal is in sysdep.c */
 135 char *strsignal (int);
 136 #endif
 137
 138 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 139 extern pthread_t main_thread;
 140 #define SIGNAL_THREAD_CHECK(signo)                                      \
 141   do {                                                                  \
 142     if (!pthread_equal (pthread_self (), main_thread))                  \
 143       {                                                                 \
 144         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 145            that is not true, but for other systems (FreeBSD at least)   \
 146            it is.  So direct the signal to the correct thread and block \
 147            it from this thread.  */                                     \
 148         sigset_t new_mask;                                              \
 149                                                                         \
 150         sigemptyset (&new_mask);                                        \
 151         sigaddset (&new_mask, signo);                                   \
 152         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 153         pthread_kill (main_thread, signo);                              \
 154         return;                                                         \
 155       }                                                                 \
 156    } while (0)
 157
 158 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 159 #define SIGNAL_THREAD_CHECK(signo)
 160 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */