+
−/* syssignal.h - System-dependent definitions for signals.
+
−   Copyright (C) 1992, 1993 Free Software Foundation, Inc.
+
−   Copyright (C) 1996 Ben Wing.
+
−   
+
−This file is part of XEmacs.
+
−
+
−XEmacs is free software; you can redistribute it and/or modify it
+
−under the terms of the GNU General Public License as published by the
+
−Free Software Foundation; either version 2, or (at your option) any
+
−later version.
+
−
+
−XEmacs is distributed in the hope that it will be useful, but WITHOUT
+
−ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+
−FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+
−for more details.
+
−
+
−You should have received a copy of the GNU General Public License
+
−along with XEmacs; see the file COPYING.  If not, write to
+
−the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+
−Boston, MA 02111-1307, USA.  */
+
−
+
−/* Synched up with: FSF 19.30. */
+
−
+
−#ifndef INCLUDED_syssignal_h_
+
−#define INCLUDED_syssignal_h_
+
−
+
−/* In the old world, one could not #include <signal.h> here.  The party line
+
−   was that that header should always be #included before <config.h>, because
+
−   some configuration files (like s/hpux.h) indicate that SIGIO doesn't work
+
−   by #undef-ing SIGIO, and if this file #includes <signal.h>, then that will
+
−   re-#define SIGIO and confuse things.
+
−
+
−   This was, however, a completely fucked up state of affairs, because on some
+
−   systems it's necessary for the s/m files to #define things in order to get
+
−   <signal.h> to provide the right typedefs, etc.  And it's generally a broken
+
−   concept for <config.h> to not be the very very first file included.
+
−
+
−   So instead of #undef'ing SIGIO in the various s/m files, I've changed them
+
−   to define BROKEN_SIGIO instead, then we (syssignal.h) do an #undef SIGIO
+
−   at the end, after including signal.h.  Therefore, it's important that
+
−   <signal.h> not be included after "syssignal.h", but that's the normal state:
+
−   nothing should be directly including <signal.h> these days.
+
−							-- jwz, 29-nov-93
+
− */
+
−
+
−#include <signal.h>
+
−#include <errno.h>
+
−
+
−/* SIGPOLL is the SVR4 signal.  Those systems generally define
+
−   SIGIO as an alias for SIGPOLL, but just in case ... */
+
−
+
−#if defined (BROKEN_SIGIO)
+
−#  if defined (SIGIO) && defined (SIGPOLL)
+
−#    if SIGIO == SIGPOLL
+
−#      undef SIGIO
+
−#      undef SIGPOLL
+
−#    else
+
−#      undef SIGIO
+
−#    endif
+
−#  endif
+
−#else /* Not BROKEN_SIGIO */
+
−#  if !defined (SIGIO) && defined (SIGPOLL)
+
−#    define SIGIO SIGPOLL
+
−#  endif
+
−#endif
+
−
+
−/* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
+
−   testing SIGCHLD.  */
+
−#if defined (SIGCLD) && !defined (SIGCHLD)
+
−# define SIGCHLD SIGCLD
+
−#endif /* SIGCHLD */
+
−
+
−#ifdef BROKEN_SIGCHLD
+
−#undef SIGCHLD
+
−#endif
+
−
+
−#ifdef SIGCHLD
+
−#define EMACS_BLOCK_SIGCHLD EMACS_BLOCK_SIGNAL (SIGCHLD)
+
−#define EMACS_UNBLOCK_SIGCHLD EMACS_UNBLOCK_SIGNAL (SIGCHLD)
+
−#else
+
−#define EMACS_BLOCK_SIGCHLD
+
−#define EMACS_UNBLOCK_SIGCHLD
+
−#endif
+
−
+
−/* According to W.R. Stevens __Advanced Programming in the Unix
+
−   Environment__, there are four different paradigms for handling
+
−   signals.  We use autoconf to tell us which one applies.
+
−
+
−   Note that on some systems, more than one paradigm is implemented
+
−   (typically, the POSIX sigaction/sigprocmask and either the older
+
−   SYSV or BSD way).  In such a case, we prefer the POSIX way.
+
−
+
−   We used to say this:
+
−
+
−   [[ NOTE: We use EMACS_* macros for most signal operations, but
+
−   just signal() for the standard signal-setting operation.
+
−   Perhaps we should change this to EMACS_SIGNAL(), but that runs
+
−   the risk of someone forgetting this convention and calling
+
−   signal() directly. ]]
+
−
+
−   But current policy is to avoid playing with macros as much as
+
−   possible, since in the long run it really just ends up creating
+
−   unmaintainable code -- someone newly reading the code is never
+
−   going to realize exactly which calls are redirected, and on
+
−   which systems, and where the redirection occurs.
+
−
+
−   Possibly we should use the new "qxe" convention.
+
−*/
+
−
+
−#ifndef NeXT
+
−typedef RETSIGTYPE (XCDECL * signal_handler_t) (int);
+
−#endif
+
−
+
−#if defined (HAVE_SIGPROCMASK)
+
−
+
−/* The POSIX way (sigaction, sigprocmask, sigpending, sigsuspend) */
+
−
+
−signal_handler_t qxe_reliable_signal (int signal_number,
+
−				      signal_handler_t action);
+
−
+
−#define EMACS_SIGNAL qxe_reliable_signal
+
−
+
−#define EMACS_BLOCK_SIGNAL(sig) do		\
+
−{						\
+
−  sigset_t ES_mask;				\
+
−  sigemptyset (&ES_mask);			\
+
−  sigaddset (&ES_mask, sig);			\
+
−  sigprocmask (SIG_BLOCK, &ES_mask, NULL);	\
+
−} while (0)
+
−#define EMACS_UNBLOCK_SIGNAL(sig) do		\
+
−{						\
+
−  sigset_t ES_mask;				\
+
−  sigemptyset (&ES_mask);			\
+
−  sigaddset (&ES_mask, sig);			\
+
−  sigprocmask (SIG_UNBLOCK, &ES_mask, NULL);	\
+
−} while (0)
+
−#define EMACS_UNBLOCK_ALL_SIGNALS() do		\
+
−{						\
+
−  sigset_t ES_mask;				\
+
−  sigemptyset (&ES_mask);			\
+
−  sigprocmask (SIG_SETMASK, &ES_mask, NULL);	\
+
−} while (0)
+
−#define EMACS_WAIT_FOR_SIGNAL(sig) do		\
+
−{						\
+
−  sigset_t ES_mask;				\
+
−  sigprocmask (0, NULL, &ES_mask);		\
+
−  sigdelset (&ES_mask, sig);			\
+
−  sigsuspend (&ES_mask);			\
+
−} while (0)
+
−#define EMACS_REESTABLISH_SIGNAL(sig, handler)
+
−#define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl)
+
−
+
−#elif defined (HAVE_SIGBLOCK)
+
−
+
−/* The older BSD way (signal/sigvec, sigblock, sigsetmask, sigpause) */
+
−
+
−/* It's OK to use signal() here directly.  No unreliable signal
+
−   problems.  However, we use sigvec() because it allows us to
+
−   request interruptible I/O. */
+
−
+
−#define EMACS_SIGNAL qxe_reliable_signal
+
−
+
−/* Is it necessary to define sigmask like this? */
+
−#ifndef sigmask
+
−# define sigmask(no) (1L << ((no) - 1))
+
−#endif
+
−
+
−#define EMACS_BLOCK_SIGNAL(sig) sigblock (sigmask (sig))
+
−#define EMACS_UNBLOCK_SIGNAL(sig) sigsetmask (sigblock (0) & ~sigmask (sig))
+
−#define EMACS_UNBLOCK_ALL_SIGNALS() sigsetmask (0)
+
−#define EMACS_WAIT_FOR_SIGNAL(sig) do		\
+
−{						\
+
−  int ES_mask = sigblock (0);			\
+
−  sigpause (ES_mask & ~sigmask (sig));		\
+
−} while (0)
+
−#define EMACS_REESTABLISH_SIGNAL(sig, handler)
+
−#define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl)
+
−
+
−#elif defined (HAVE_SIGHOLD)
+
−
+
−/* The older SYSV way (signal/sigset, sighold, sigrelse, sigignore,
+
−   sigpause) */
+
−
+
−#define EMACS_SIGNAL sigset
+
−#define EMACS_BLOCK_SIGNAL(sig) sighold (sig)
+
−#define EMACS_UNBLOCK_SIGNAL(sig) sigrelse (sig)
+
−/* #### There's not really any simple way to implement this.
+
−   Since EMACS_UNBLOCK_ALL_SIGNALS() is only called once (at startup),
+
−   it's probably OK to just ignore it. */
+
−#define EMACS_UNBLOCK_ALL_SIGNALS() 0
+
−#define EMACS_WAIT_FOR_SIGNAL(sig) sigpause (sig)
+
−#define EMACS_REESTABLISH_SIGNAL(sig, handler)
+
−#define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl)
+
−
+
−#elif defined (WIN32_NATIVE)
+
−
+
−/* MS Windows signal emulation (in turns emulates the sigset/sighold
+
−   paradigm) */
+
−
+
−#define EMACS_SIGNAL mswindows_sigset
+
−#define EMACS_BLOCK_SIGNAL(sig) mswindows_sighold (sig)
+
−#define EMACS_UNBLOCK_SIGNAL(sig) mswindows_sigrelse (sig)
+
−/* #### There's not really any simple way to implement this.
+
−   Since EMACS_UNBLOCK_ALL_SIGNALS() is only called once (at startup),
+
−   it's probably OK to just ignore it. */
+
−#define EMACS_UNBLOCK_ALL_SIGNALS() 0
+
−#define EMACS_WAIT_FOR_SIGNAL(sig) mswindows_sigpause (sig)
+
−#define EMACS_REESTABLISH_SIGNAL(sig, handler)
+
−#define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl)
+
−
+
−/* Defines that we need that aren't in the standard signal.h  */
+
−#define SIGHUP  1               /* Hang up */
+
−#define SIGQUIT 3               /* Quit process */
+
−#define SIGKILL 9               /* Die, die die */
+
−#define SIGALRM 14              /* Alarm */
+
−#define SIGPROF 29		/* Profiling timer exp */
+
−
+
−#else
+
−
+
−/* The oldest SYSV way (signal only; unreliable signals) */
+
−
+
−/* Old USG systems don't really have signal blocking.
+
−   We indicate this by not defining EMACS_BLOCK_SIGNAL or
+
−   EMACS_WAIT_FOR_SIGNAL. */
+
−#define EMACS_SIGNAL signal
+
−#define EMACS_UNBLOCK_SIGNAL(sig) 0
+
−#define EMACS_UNBLOCK_ALL_SIGNALS() 0
+
−#define EMACS_REESTABLISH_SIGNAL(sig, handler) do	\
+
−{							\
+
−  int old_errno = errno;				\
+
−  signal (sig, handler);				\
+
−  errno = old_errno;					\
+
−} while (0)
+
−#define SIG_ARG_MAYBE_UNUSED(decl) decl
+
−
+
−/* Under SYSV, setting a signal handler for SIGCLD causes
+
−   SIGCLD to immediately be sent if there any unwaited processes
+
−   out there.  This means that the SIGCLD handler *must* call
+
−   wait() to reap the status of all processes -- it cannot
+
−   simply set a flag and then reestablish the handler, because
+
−   it will get called again, infinitely.  We only need to
+
−   worry about this on systems where signals need to be
+
−   reestablished (SYSV Release 2 and earlier). */
+
−#define OBNOXIOUS_SYSV_SIGCLD_BEHAVIOR
+
−
+
−#endif /* different signalling methods */
+
−
+
−/* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
+
−   Must do that using the killpg call.  */
+
−#ifdef HAVE_KILLPG
+
−#define EMACS_KILLPG(pid, signo) killpg (pid, signo)
+
−#elif defined (WIN32_NATIVE)
+
−#define EMACS_KILLPG(pid, signo) should never be called
+
−#else
+
−#define EMACS_KILLPG(pid, signo) kill (-(pid), signo)
+
−#endif
+
−
+
−#ifndef NSIG
+
−# ifdef USG5_4
+
−/* Some SVr4s don't define NSIG in sys/signal.h for ANSI environments;
+
− * instead, there's a system variable _sys_nsig.  Unfortunately, we need the
+
− * constant to dimension an array.  So wire in the appropriate value here.
+
− */
+
−#  define NSIG 32
+
−# else
+
−#  define NSIG (SIGUSR2+1) /* guess how many elements are in sys_siglist... */
+
−# endif
+
−#endif
+
−
+
−/* HAVE_DECL_SYS_SIGLIST is determined by configure.  On Linux, it seems,
+
−   configure incorrectly fails to find it, so s/linux.h defines
+
−   HAVE_SYS_SIGLIST. */
+
−#if (!defined(HAVE_DECL_SYS_SIGLIST) || !HAVE_DECL_SYS_SIGLIST ) && !defined (HAVE_SYS_SIGLIST)
+
−extern const char *sys_siglist[];
+
−#endif
+
−
+
−#ifdef SIGDANGER
+
−SIGTYPE memory_warning_signal (int sig);
+
−#endif
+
−
+
−#if defined (WIN32_NATIVE) || defined (CYGWIN_BROKEN_SIGNALS)
+
−typedef void (__cdecl *mswindows_sighandler) (int);
+
−
+
−/* Prototypes for signal functions, see win32.c */
+
−int mswindows_sighold (int nsig);
+
−int mswindows_sigrelse (int nsig);
+
−int mswindows_sigpause (int nsig);
+
−int mswindows_raise (int nsig);
+
−mswindows_sighandler mswindows_sigset (int sig, mswindows_sighandler handler);
+
−
+
−#endif /* defined (WIN32_NATIVE) || defined (CYGWIN_BROKEN_SIGNALS) */
+
−
+
−signal_handler_t set_timeout_signal (int signal_number,
+
−				     signal_handler_t action);
+
−
+
−
+
−#endif /* INCLUDED_syssignal_h_ */