src/syssignal.h

   1 /* syssignal.h - System-dependent definitions for signals.
   2    Copyright (C) 1993, 1999, 2001-2012  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 #ifdef HAVE_PTHREAD
  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 extern sigset_t empty_mask;
  39
  40 /* POSIX pretty much destroys any possibility of writing sigmask as a
  41    macro in standard C.  We always define our own version because the
  42    predefined macro in Glibc 2.1 is only provided for compatibility for old
  43    programs that use int as signal mask type.  */
  44 #undef sigmask
  45 #ifdef __GNUC__
  46 #define sigmask(SIG)                            \
  47   ({                                            \
  48     sigset_t _mask;                             \
  49     sigemptyset (&_mask);                       \
  50     sigaddset (&_mask, SIG);                    \
  51     _mask;                                      \
  52   })
  53 #else /* ! defined (__GNUC__) */
  54 extern sigset_t sys_sigmask ();
  55 #define sigmask(SIG) (sys_sigmask (SIG))
  56 #endif /* ! defined (__GNUC__) */
  57
  58 #undef sigpause
  59 #define sigpause(MASK)    sigsuspend (&(MASK))
  60
  61 #define sigblock(SIG)    sys_sigblock (SIG)
  62 #define sigunblock(SIG)  sys_sigunblock (SIG)
  63 #ifndef sigsetmask
  64 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  65 #endif
  66 #undef signal
  67 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  68
  69 /* Whether this is what all systems want or not, this is what
  70    appears to be assumed in the source, for example data.c:arith_error.  */
  71 typedef void (*signal_handler_t) (int);
  72
  73 signal_handler_t sys_signal (int signal_number, signal_handler_t action);
  74 sigset_t sys_sigblock   (sigset_t new_mask);
  75 sigset_t sys_sigunblock (sigset_t new_mask);
  76 sigset_t sys_sigsetmask (sigset_t new_mask);
  77 #if ! (defined TIOCNOTTY || defined USG5 || defined CYGWIN)
  78 void croak (char *) NO_RETURN;
  79 #endif
  80
  81 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  82
  83 #define sigfree() sigsetmask (SIGEMPTYMASK)
  84
  85 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
  86 #undef SIGINFO
  87 #endif
  88 #if defined (SIGIO) && defined (BROKEN_SIGIO)
  89 # undef SIGIO
  90 #endif
  91 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
  92 #undef SIGPOLL
  93 #endif
  94 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
  95 #undef SIGTSTP
  96 #endif
  97 #if defined (SIGURG) && defined (BROKEN_SIGURG)
  98 #undef SIGURG
  99 #endif
 100 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 101 #undef SIGAIO
 102 #endif
 103 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 104 #undef SIGPTY
 105 #endif
 106
 107
 108 #if NSIG < NSIG_MINIMUM
 109 # ifdef NSIG
 110 #  undef NSIG
 111 # endif
 112 # define NSIG NSIG_MINIMUM
 113 #endif
 114
 115 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 116    Must do that using the killpg call.  */
 117 #ifdef BSD_SYSTEM
 118 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 119 #else
 120 #ifdef WINDOWSNT
 121 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 122 #else
 123 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 124 #endif
 125 #endif
 126
 127 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 128    testing SIGCHLD.  */
 129 #ifdef SIGCLD
 130 #ifndef SIGCHLD
 131 #define SIGCHLD SIGCLD
 132 #endif /* SIGCHLD */
 133 #endif /* ! defined (SIGCLD) */
 134
 135 #ifndef HAVE_STRSIGNAL
 136 /* strsignal is in sysdep.c */
 137 char *strsignal (int);
 138 #endif
 139
 140 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 141 extern pthread_t main_thread;
 142 #define SIGNAL_THREAD_CHECK(signo)                                      \
 143   do {                                                                  \
 144     if (!pthread_equal (pthread_self (), main_thread))                  \
 145       {                                                                 \
 146         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 147            that is not true, but for other systems (FreeBSD at least)   \
 148            it is.  So direct the signal to the correct thread and block \
 149            it from this thread.  */                                     \
 150         sigset_t new_mask;                                              \
 151                                                                         \
 152         sigemptyset (&new_mask);                                        \
 153         sigaddset (&new_mask, signo);                                   \
 154         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 155         pthread_kill (main_thread, signo);                              \
 156         return;                                                         \
 157       }                                                                 \
 158    } while (0)
 159
 160 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 161 #define SIGNAL_THREAD_CHECK(signo)
 162 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */