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 /* Don't #include <signal.h>.  That header should always be #included
  30    before "config.h", because some configuration files (like s/hpux.h)
  31    indicate that SIGIO doesn't work by #undef-ing SIGIO.  If this file
  32    #includes <signal.h>, then that will re-#define SIGIO and confuse
  33    things.  */
  34 /* XXX This is not correct anymore, there is a BROKEN_SIGIO macro. */
  35
  36 #define SIGMASKTYPE sigset_t
  37
  38 #define SIGEMPTYMASK (empty_mask)
  39 #define SIGFULLMASK (full_mask)
  40 extern sigset_t empty_mask, full_mask;
  41
  42 /* POSIX pretty much destroys any possibility of writing sigmask as a
  43    macro in standard C.  We always define our own version because the
  44    predefined macro in Glibc 2.1 is only provided for compatility for old
  45    programs that use int as signal mask type.  */
  46 #undef sigmask
  47 #ifdef __GNUC__
  48 #define sigmask(SIG)                            \
  49   ({                                            \
  50     sigset_t _mask;                             \
  51     sigemptyset (&_mask);                       \
  52     sigaddset (&_mask, SIG);                    \
  53     _mask;                                      \
  54   })
  55 #else /* ! defined (__GNUC__) */
  56 extern sigset_t sys_sigmask ();
  57 #define sigmask(SIG) (sys_sigmask (SIG))
  58 #endif /* ! defined (__GNUC__) */
  59
  60 #undef sigpause
  61 #define sigpause(MASK)    sigsuspend (&(MASK))
  62
  63 #define sigblock(SIG)    sys_sigblock (SIG)
  64 #define sigunblock(SIG)  sys_sigunblock (SIG)
  65 #ifndef sigsetmask
  66 #define sigsetmask(SIG)  sys_sigsetmask (SIG)
  67 #endif
  68 #undef signal
  69 #define signal(SIG,ACT)      sys_signal(SIG,ACT)
  70
  71 /* Whether this is what all systems want or not, this is what
  72    appears to be assumed in the source, for example data.c:arith_error.  */
  73 typedef RETSIGTYPE (*signal_handler_t) (int);
  74
  75 signal_handler_t sys_signal (int signal_number, signal_handler_t action);
  76 sigset_t sys_sigblock   (sigset_t new_mask);
  77 sigset_t sys_sigunblock (sigset_t new_mask);
  78 sigset_t sys_sigsetmask (sigset_t new_mask);
  79
  80 #define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)
  81
  82 #define sigfree() sigsetmask (SIGEMPTYMASK)
  83
  84 #if defined (SIGINFO) && defined (BROKEN_SIGINFO)
  85 #undef SIGINFO
  86 #endif
  87 #if defined (SIGIO) && defined (BROKEN_SIGIO)
  88 # undef SIGIO
  89 #endif
  90 #if defined (SIGPOLL) && defined (BROKEN_SIGPOLL)
  91 #undef SIGPOLL
  92 #endif
  93 #if defined (SIGTSTP) && defined (BROKEN_SIGTSTP)
  94 #undef SIGTSTP
  95 #endif
  96 #if defined (SIGURG) && defined (BROKEN_SIGURG)
  97 #undef SIGURG
  98 #endif
  99 #if defined (SIGAIO) && defined (BROKEN_SIGAIO)
 100 #undef SIGAIO
 101 #endif
 102 #if defined (SIGPTY) && defined (BROKEN_SIGPTY)
 103 #undef SIGPTY
 104 #endif
 105
 106
 107 #if NSIG < NSIG_MINIMUM
 108 # ifdef NSIG
 109 #  undef NSIG
 110 # endif
 111 # define NSIG NSIG_MINIMUM
 112 #endif
 113
 114 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
 115    Must do that using the killpg call.  */
 116 #ifdef BSD_SYSTEM
 117 #define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
 118 #else
 119 #ifdef WINDOWSNT
 120 #define EMACS_KILLPG(gid, signo) (kill (gid, signo))
 121 #else
 122 #define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
 123 #endif
 124 #endif
 125
 126 /* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
 127    testing SIGCHLD.  */
 128 #ifdef SIGCLD
 129 #ifndef SIGCHLD
 130 #define SIGCHLD SIGCLD
 131 #endif /* SIGCHLD */
 132 #endif /* ! defined (SIGCLD) */
 133
 134 #ifndef HAVE_STRSIGNAL
 135 /* strsignal is in sysdep.c */
 136 char *strsignal (int);
 137 #endif
 138
 139 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
 140 extern pthread_t main_thread;
 141 #define SIGNAL_THREAD_CHECK(signo)                                      \
 142   do {                                                                  \
 143     if (!pthread_equal (pthread_self (), main_thread))                  \
 144       {                                                                 \
 145         /* POSIX says any thread can receive the signal.  On GNU/Linux  \
 146            that is not true, but for other systems (FreeBSD at least)   \
 147            it is.  So direct the signal to the correct thread and block \
 148            it from this thread.  */                                     \
 149         sigset_t new_mask;                                              \
 150                                                                         \
 151         sigemptyset (&new_mask);                                        \
 152         sigaddset (&new_mask, signo);                                   \
 153         pthread_sigmask (SIG_BLOCK, &new_mask, 0);                      \
 154         pthread_kill (main_thread, signo);                              \
 155         return;                                                         \
 156       }                                                                 \
 157    } while (0)
 158
 159 #else /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 160 #define SIGNAL_THREAD_CHECK(signo)
 161 #endif /* not FORWARD_SIGNAL_TO_MAIN_THREAD */
 162 /* arch-tag: 4580e86a-340d-4574-9e11-a742b6e1a152
 163    (do not change this comment) */