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octa21fs.zip
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octave
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octave-2.1.23
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src
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sighandlers.cc
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2000-01-15
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/*
Copyright (C) 1996, 1997 John W. Eaton
This file is part of Octave.
Octave 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.
Octave 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 Octave; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* Modified by Klaus Gebhardt, 1995 - 1996 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <cstdlib>
#include <csignal>
#include <new>
#include <iostream.h>
#ifdef HAVE_UNISTD_H
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <unistd.h>
#endif
#include "cmd-edit.h"
#ifdef __EMX__
#include <float.h>
#include <sys/uflags.h>
#endif
#include "error.h"
#include "load-save.h"
#include "pager.h"
#include "sighandlers.h"
#include "syswait.h"
#include "toplev.h"
#include "utils.h"
// Nonzero means we have already printed a message for this series of
// SIGPIPES. We assume that the writer will eventually give up.
int pipe_handler_error_count = 0;
// TRUE means we can be interrupted.
bool can_interrupt = false;
// Allow us to save the signal mask and then restore it to the most
// recently saved value. This is necessary when using the POSIX
// signal handling interface on some systems calling longjmp out of
// the signal handler to get to the top level on an interrupt doesn't
// restore the original signal mask. Alternatively, we could use
// sigsetjmp/siglongjmp, but saving and restoring the signal mask
// ourselves works ok and seems simpler just now.
#if defined (HAVE_POSIX_SIGNALS)
static sigset_t octave_signal_mask;
#endif
#if RETSIGTYPE == void
#define SIGHANDLER_RETURN(status) return
#else
#define SIGHANDLER_RETURN(status) return status
#endif
#if defined (MUST_REINSTALL_SIGHANDLERS)
#define MAYBE_REINSTALL_SIGHANDLER(sig, handler) \
octave_set_signal_handler (sig, handler)
#define REINSTALL_USES_SIG 1
#else
#define MAYBE_REINSTALL_SIGHANDLER(sig, handler) \
do { } while (0)
#endif
#if defined (__EMX__)
#define MAYBE_ACK_SIGNAL(sig) \
signal (sig, SIG_ACK)
#define ACK_USES_SIG 1
#else
#define MAYBE_ACK_SIGNAL(sig) \
do { } while (0)
#endif
#if defined (SIGABRT)
#define OCTAVE_MEMORY_EXHAUSTED_ERROR SIGABRT
#else
#define OCTAVE_MEMORY_EXHAUSTED_ERROR (-1)
#endif
void
octave_save_signal_mask (void)
{
#if defined (HAVE_POSIX_SIGNALS)
sigprocmask (0, 0, &octave_signal_mask);
#endif
}
void
octave_restore_signal_mask (void)
{
#if defined (HAVE_POSIX_SIGNALS)
sigprocmask (SIG_SETMASK, &octave_signal_mask, 0);
#endif
}
static void
my_friendly_exit (const char *sig_name, int sig_number)
{
static bool been_there_done_that = false;
if (been_there_done_that)
{
#if defined (SIGABRT)
octave_set_signal_handler (SIGABRT, SIG_DFL);
#endif
cerr << "error: attempted clean up apparently failed -- aborting...\n";
abort ();
}
else
{
been_there_done_that = true;
cerr << "\n\nerror: " << sig_name << " -- stopping myself...\n";
save_user_variables ();
if (sig_number < 0)
exit (1);
else
{
octave_set_signal_handler (sig_number, SIG_DFL);
kill (getpid (), sig_number);
}
}
}
// I know, not really a signal handler.
static void
octave_new_handler (void)
{
cerr << "error: memory exhausted -- trying to return to prompt\n";
if (can_interrupt)
{
#ifdef __EMX__
_uflags (_UF_SBRK_MODEL, _UF_SBRK_ARBITRARY);
#endif
jump_to_top_level ();
panic_impossible ();
}
else
my_friendly_exit ("operator new", OCTAVE_MEMORY_EXHAUSTED_ERROR);
}
sig_handler *
octave_set_signal_handler (int sig, sig_handler *handler)
{
#if defined (HAVE_POSIX_SIGNALS)
struct sigaction act, oact;
act.sa_handler = handler;
act.sa_flags = 0;
sigemptyset (&act.sa_mask);
sigemptyset (&oact.sa_mask);
sigaction (sig, &act, &oact);
return oact.sa_handler;
#elif defined (__EMX__)
sig_handler *signal_handler = signal (sig, handler);
MAYBE_ACK_SIGNAL(sig);
return signal_handler;
#else
return signal (sig, handler);
#endif
}
static RETSIGTYPE
generic_sig_handler (int sig)
{
my_friendly_exit (sys_siglist[sig], sig);
SIGHANDLER_RETURN (0);
}
// Handle SIGCHLD.
static RETSIGTYPE
sigchld_handler (int sig)
{
volatile octave_interrupt_handler saved_interrupt_handler
= octave_ignore_interrupts ();
// I wonder if this is really right, or if SIGCHLD should just be
// blocked on OS/2 systems the same as for systems with POSIX signal
// functions.
#if defined (__EMX__)
volatile sig_handler *saved_sigchld_handler
= octave_set_signal_handler (SIGCHLD, SIG_IGN);
#else
sigset_t set, oset;
BLOCK_CHILD (set, oset);
#endif
int i = 0;
int n = octave_child_list::length ();
for (i = 0; i < n; i++)
{
octave_child& elt = octave_child_list::elem (i);
pid_t pid = elt.pid;
if (pid > 0)
{
int status;
if (waitpid (pid, &status, WNOHANG) > 0)
{
elt.pid = -1;
octave_child::dead_child_handler f = elt.handler;
if (f) f (pid, status);
else
{
string file = elt.filename;
unlink (file.c_str ());
}
break;
}
}
}
if (i == n) waitpid (-1, NULL, WNOHANG);
octave_set_interrupt_handler (saved_interrupt_handler);
#ifndef __EMX__
UNBLOCK_CHILD (oset);
#else
octave_set_signal_handler (SIGCHLD, saved_sigchld_handler);
#endif
MAYBE_ACK_SIGNAL (SIGCHLD);
MAYBE_REINSTALL_SIGHANDLER (SIGCHLD, sigchld_handler);
SIGHANDLER_RETURN (0);
}
#if defined (__alpha__)
static RETSIGTYPE
sigfpe_handler (int sig)
{
MAYBE_ACK_SIGNAL (SIGFPE);
MAYBE_REINSTALL_SIGHANDLER (SIGFPE, sigfpe_handler);
cerr << "error: floating point exception -- trying to return to prompt\n";
if (can_interrupt)
{
#if defined (__EMX__)
_control87 (EM_INVALID | EM_DENORMAL | EM_ZERODIVIDE | EM_OVERFLOW |
EM_UNDERFLOW | EM_INEXACT, MCW_EM);
#endif
jump_to_top_level ();
panic_impossible ();
}
SIGHANDLER_RETURN (0);
}
#endif
#if 0
#if defined (SIGWINCH)
static RETSIGTYPE
sigwinch_handler (int /* sig */)
{
MAYBE_ACK_SIGNAL (SIGWINCH);
MAYBE_REINSTALL_SIGHANDLER (SIGWINCH, sigwinch_handler);
command_editor::resize_terminal ();
SIGHANDLER_RETURN (0);
}
#endif
#endif
// Handle SIGINT by restarting the parser (see octave.cc).
//
// This also has to work for SIGBREAK (on systems that have it), so we
// use the value of sig, instead of just assuming that it is called
// for SIGINT only.
static RETSIGTYPE
#if defined (ACK_USES_SIG) || defined (REINSTALL_USES_SIG)
sigint_handler (int sig)
#else
sigint_handler (int)
#endif
{
MAYBE_ACK_SIGNAL (sig);
MAYBE_REINSTALL_SIGHANDLER (sig, sigint_handler);
if (can_interrupt)
{
jump_to_top_level ();
panic_impossible ();
}
SIGHANDLER_RETURN (0);
}
static RETSIGTYPE
sigpipe_handler (int sig)
{
MAYBE_ACK_SIGNAL (SIGPIPE);
MAYBE_REINSTALL_SIGHANDLER (SIGPIPE, sigpipe_handler);
if (pipe_handler_error_count++ == 0)
cerr << "warning: broken pipe\n";
// Don't loop forever on account of this.
if (pipe_handler_error_count > 100)
jump_to_top_level ();
SIGHANDLER_RETURN (0);
}
octave_interrupt_handler
octave_catch_interrupts (void)
{
octave_interrupt_handler retval;
#ifdef SIGINT
octave_set_signal_handler (SIGINT, sigint_handler);
retval.int_handler = sigint_handler;
MAYBE_ACK_SIGNAL (SIGINT);
#endif
#ifdef SIGBREAK
octave_set_signal_handler (SIGBREAK, sigint_handler);
retval.brk_handler = sigint_handler;
MAYBE_ACK_SIGNAL (SIGBREAK);
#endif
return retval;
}
octave_interrupt_handler
octave_ignore_interrupts (void)
{
octave_interrupt_handler retval;
#ifdef SIGINT
retval.int_handler = octave_set_signal_handler (SIGINT, SIG_IGN);
#endif
#ifdef SIGBREAK
retval.brk_handler = octave_set_signal_handler (SIGBREAK, SIG_IGN);
#endif
return retval;
}
octave_interrupt_handler
octave_set_interrupt_handler (RETSIGTYPE (*f)(int))
{
octave_interrupt_handler retval;
if (f)
{
#ifdef SIGINT
retval.int_handler = octave_set_signal_handler (SIGINT, f);
MAYBE_ACK_SIGNAL (SIGINT);
#endif
#ifdef SIGBREAK
retval.brk_handler = octave_set_signal_handler (SIGBREAK, f);
MAYBE_ACK_SIGNAL (SIGBREAK);
#endif
}
return retval;
}
octave_interrupt_handler
octave_set_interrupt_handler (const volatile octave_interrupt_handler& h)
{
octave_interrupt_handler retval;
#ifdef SIGINT
retval.int_handler = octave_set_signal_handler (SIGINT, h.int_handler);
MAYBE_ACK_SIGNAL (SIGINT);
#endif
#ifdef SIGBREAK
retval.brk_handler = octave_set_signal_handler (SIGBREAK, h.brk_handler);
MAYBE_ACK_SIGNAL (SIGBREAK);
#endif
return retval;
}
// Install all the handlers for the signals we might care about.
void
install_signal_handlers (void)
{
set_new_handler (octave_new_handler);
octave_catch_interrupts ();
#ifdef SIGABRT
octave_set_signal_handler (SIGABRT, generic_sig_handler);
#endif
#ifdef SIGALRM
octave_set_signal_handler (SIGALRM, generic_sig_handler);
#endif
#ifdef SIGBUS
octave_set_signal_handler (SIGBUS, generic_sig_handler);
#endif
#ifdef SIGCHLD
octave_set_signal_handler (SIGCHLD, sigchld_handler);
#endif
// SIGCLD
// SIGCONT
#ifdef SIGEMT
octave_set_signal_handler (SIGEMT, generic_sig_handler);
#endif
#ifdef SIGFPE
#if defined (__alpha__)
octave_set_signal_handler (SIGFPE, sigfpe_handler);
#else
octave_set_signal_handler (SIGFPE, generic_sig_handler);
#endif
#endif
#ifdef SIGHUP
octave_set_signal_handler (SIGHUP, generic_sig_handler);
#endif
#ifdef SIGILL
octave_set_signal_handler (SIGILL, generic_sig_handler);
#endif
// SIGINFO
// SIGINT
#ifdef SIGIOT
octave_set_signal_handler (SIGIOT, generic_sig_handler);
#endif
#ifdef SIGLOST
octave_set_signal_handler (SIGLOST, generic_sig_handler);
#endif
#ifdef SIGPIPE
octave_set_signal_handler (SIGPIPE, sigpipe_handler);
#endif
#ifdef SIGPOLL
octave_set_signal_handler (SIGPOLL, SIG_IGN);
#endif
#ifdef SIGPROF
octave_set_signal_handler (SIGPROF, generic_sig_handler);
#endif
// SIGPWR
#ifdef SIGQUIT
octave_set_signal_handler (SIGQUIT, generic_sig_handler);
#endif
#ifdef SIGSEGV
octave_set_signal_handler (SIGSEGV, generic_sig_handler);
#endif
// SIGSTOP
#ifdef SIGSYS
octave_set_signal_handler (SIGSYS, generic_sig_handler);
#endif
#ifdef SIGTERM
#ifdef __EMX__
signal (SIGTERM, SIG_DFL);
#else
octave_set_signal_handler (SIGTERM, generic_sig_handler);
#endif
#endif
#ifdef SIGTRAP
octave_set_signal_handler (SIGTRAP, generic_sig_handler);
#endif
// SIGTSTP
// SIGTTIN
// SIGTTOU
// SIGURG
#ifdef SIGUSR1
octave_set_signal_handler (SIGUSR1, generic_sig_handler);
#endif
#ifdef SIGUSR2
octave_set_signal_handler (SIGUSR2, generic_sig_handler);
#endif
#ifdef SIGVTALRM
octave_set_signal_handler (SIGVTALRM, generic_sig_handler);
#endif
#ifdef SIGIO
octave_set_signal_handler (SIGIO, SIG_IGN);
#endif
#if 0
#ifdef SIGWINCH
octave_set_signal_handler (SIGWINCH, sigwinch_handler);
#endif
#endif
#ifdef SIGXCPU
octave_set_signal_handler (SIGXCPU, generic_sig_handler);
#endif
#ifdef SIGXFSZ
octave_set_signal_handler (SIGXFSZ, generic_sig_handler);
#endif
}
#ifndef HAVE_SYS_SIGLIST
char *sys_siglist[NSIG + 1] =
{
#ifdef AIX
/* AIX has changed the signals a bit */
"bogus signal", /* 0 */
"hangup", /* 1 SIGHUP */
"interrupt", /* 2 SIGINT */
"quit", /* 3 SIGQUIT */
"illegal instruction", /* 4 SIGILL */
"trace trap", /* 5 SIGTRAP */
"IOT instruction", /* 6 SIGIOT */
"crash likely", /* 7 SIGDANGER */
"floating point exception", /* 8 SIGFPE */
"kill", /* 9 SIGKILL */
"bus error", /* 10 SIGBUS */
"segmentation violation", /* 11 SIGSEGV */
"bad argument to system call", /* 12 SIGSYS */
"write on a pipe with no one to read it", /* 13 SIGPIPE */
"alarm clock", /* 14 SIGALRM */
"software termination signum", /* 15 SIGTERM */
"user defined signal 1", /* 16 SIGUSR1 */
"user defined signal 2", /* 17 SIGUSR2 */
"death of a child", /* 18 SIGCLD */
"power-fail restart", /* 19 SIGPWR */
"bogus signal", /* 20 */
"bogus signal", /* 21 */
"bogus signal", /* 22 */
"bogus signal", /* 23 */
"bogus signal", /* 24 */
"LAN I/O interrupt", /* 25 SIGAIO */
"PTY I/O interrupt", /* 26 SIGPTY */
"I/O intervention required", /* 27 SIGIOINT */
"HFT grant", /* 28 SIGGRANT */
"HFT retract", /* 29 SIGRETRACT */
"HFT sound done", /* 30 SIGSOUND */
"HFT input ready", /* 31 SIGMSG */
#else /* not AIX */
#ifdef __EMX__
"bogus signal #0", /* 0 */
"hangup", /* 1 SIGHUP */
"interrupt (Ctrl-C)", /* 2 SIGINT (Ctrl-C) */
"quit", /* 3 SIGQUIT */
"illegal instruction", /* 4 SIGILL */
"single step", /* 5 SIGTRAP */
"abort", /* 6 SIGABRT */
"EMT instruction", /* 7 SIGEMT */
"floating point exception", /* 8 SIGFPE */
"kill", /* 9 SIGKILL */
"bus error", /* 10 SIGBUS */
"segmentation violation", /* 11 SIGSEGV */
"bad argument to system call", /* 12 SIGSYS */
"broken pipe", /* 13 SIGPIPE */
"alarm clock", /* 14 SIGALRM */
"software termination signum", /* 15 SIGTERM */
"user defined signal 1", /* 16 SIGUSR1 */
"user defined signal 2", /* 17 SIGUSR2 */
"death of a child", /* 18 SIGCHLD */
"bogus signal #20", /* 19 */
"bogus signal #21", /* 20 */
"break (Ctrl-Break)", /* 21 SIGBREAK */
#else /* not __EMX__ */
"bogus signal", /* 0 */
"hangup", /* 1 SIGHUP */
"interrupt", /* 2 SIGINT */
"quit", /* 3 SIGQUIT */
"illegal instruction", /* 4 SIGILL */
"trace trap", /* 5 SIGTRAP */
"IOT instruction", /* 6 SIGIOT */
"EMT instruction", /* 7 SIGEMT */
"floating point exception", /* 8 SIGFPE */
"kill", /* 9 SIGKILL */
"bus error", /* 10 SIGBUS */
"segmentation violation", /* 11 SIGSEGV */
"bad argument to system call", /* 12 SIGSYS */
"write on a pipe with no one to read it", /* 13 SIGPIPE */
"alarm clock", /* 14 SIGALRM */
"software termination signum", /* 15 SIGTERM */
"user defined signal 1", /* 16 SIGUSR1 */
"user defined signal 2", /* 17 SIGUSR2 */
"death of a child", /* 18 SIGCLD */
"power-fail restart", /* 19 SIGPWR */
#ifdef sun
"window size change", /* 20 SIGWINCH */
"urgent socket condition", /* 21 SIGURG */
"pollable event occured", /* 22 SIGPOLL */
"stop (cannot be caught or ignored)", /* 23 SIGSTOP */
"user stop requested from tty", /* 24 SIGTSTP */
"stopped process has been continued", /* 25 SIGCONT */
"background tty read attempted", /* 26 SIGTTIN */
"background tty write attempted", /* 27 SIGTTOU */
"virtual timer expired", /* 28 SIGVTALRM */
"profiling timer expired", /* 29 SIGPROF */
"exceeded cpu limit", /* 30 SIGXCPU */
"exceeded file size limit", /* 31 SIGXFSZ */
"process's lwps are blocked", /* 32 SIGWAITING */
"special signal used by thread library", /* 33 SIGLWP */
#ifdef SIGFREEZE
"Special Signal Used By CPR", /* 34 SIGFREEZE */
#endif
#ifdef SIGTHAW
"Special Signal Used By CPR", /* 35 SIGTHAW */
#endif
#endif /* sun */
#endif /* __EMX__ */
#endif /* AIX */
0
};
#endif
octave_child_list *octave_child_list::instance = 0;
bool
octave_child_list::instance_ok (void)
{
bool retval = true;
if (! instance)
instance = new octave_child_list ();
if (! instance)
{
::error ("unable to create child list object!");
retval = false;
}
return retval;
}
void
octave_child_list::insert (pid_t pid, octave_child::dead_child_handler f,
string name)
{
if (instance_ok ())
instance->do_insert (pid, f, name);
}
void
octave_child_list::remove (pid_t pid)
{
if (instance_ok ())
instance->do_remove (pid);
}
int
octave_child_list::length (void)
{
return (instance_ok ()) ? instance->do_length () : 0;
}
octave_child&
octave_child_list::elem (int i)
{
static octave_child foo;
return (instance_ok ()) ? instance->do_elem (i) : foo;
}
void
octave_child_list::do_insert (pid_t pid, octave_child::dead_child_handler f,
string name)
{
// Insert item in first open slot, increasing size of list if
// necessary.
bool enlarge = true;
for (int i = 0; i < curr_len; i++)
{
octave_child& tmp = list (i);
if (tmp.pid < 0)
{
list (i) = octave_child (pid, f, name);
enlarge = false;
break;
}
}
if (enlarge)
{
int total_len = list.length ();
if (curr_len == total_len)
{
if (total_len == 0)
list.resize (16);
else
list.resize (total_len * 2);
}
list (curr_len) = octave_child (pid, f, name);
curr_len++;
}
}
void
octave_child_list::do_remove (pid_t pid)
{
// Mark the record for PID invalid.
for (int i = 0; i < curr_len; i++)
{
octave_child& tmp = list (i);
if (tmp.pid == pid)
{
tmp.pid = -1;
octave_child::dead_child_handler f = tmp.handler;
if (f)
{
int status;
if (waitpid (pid, &status, WNOHANG) <= 0) status = 127;
f (pid, status);
}
else
{
string file = tmp.filename;
unlink (file.c_str ());
}
break;
}
}
}
int
octave_child_list::do_length (void) const
{
return curr_len;
}
octave_child&
octave_child_list::do_elem (int i)
{
static octave_child foo;
int n = do_length ();
if (i >= 0 && i < n)
return list (i);
else
return foo;
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/