ncursesw-morphos/ncurses/tty/lib_tstp.c
Thomas E. Dickey 41677b308e ncurses 5.7 - patch 20100515
+ add configure option --enable-pthreads-eintr to control whether the
  new EINTR feature is enabled.
+ modify logic in pthread configuration to allow EINTR to interrupt
  a read operation in wgetch() (Novell #540571, patch by Werner Fink).
+ drop mkdirs.sh, use "mkdir -p".
+ add configure option --disable-libtool-version, to use the
  "-version-number" feature which was added in libtool 1.5 (report by
  Peter Haering).  The default value for the option uses the newer
  feature, which makes libraries generated using libtool compatible
  with the standard builds of ncurses.
+ updated test/configure to match configure script macros.
+ fixes for configure script from lynx changes:
  + improve CF_FIND_LINKAGE logic for the case where a function is
    found in predefined libraries.
  + revert part of change to CF_HEADER (cf: 20100424)
2010-05-16 00:56:17 +00:00

409 lines
12 KiB
C

/****************************************************************************
* Copyright (c) 1998-2009,2010 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
* "Software"), to deal in the Software without restriction, including *
* without limitation the rights to use, copy, modify, merge, publish, *
* distribute, distribute with modifications, sublicense, and/or sell *
* copies of the Software, and to permit persons to whom the Software is *
* furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included *
* in all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
* IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
* THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
* *
* Except as contained in this notice, the name(s) of the above copyright *
* holders shall not be used in advertising or otherwise to promote the *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************/
/****************************************************************************
* Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
* and: Eric S. Raymond <esr@snark.thyrsus.com> *
* and: Thomas E. Dickey 1995-on *
****************************************************************************/
/*
** lib_tstp.c
**
** The routine _nc_signal_handler().
**
*/
#include <curses.priv.h>
#include <SigAction.h>
#if SVR4_ACTION && !defined(_POSIX_SOURCE)
#define _POSIX_SOURCE
#endif
MODULE_ID("$Id: lib_tstp.c,v 1.41 2010/05/15 21:31:12 tom Exp $")
#if defined(SIGTSTP) && (HAVE_SIGACTION || HAVE_SIGVEC)
#define USE_SIGTSTP 1
#else
#define USE_SIGTSTP 0
#endif
#ifdef TRACE
static const char *
signal_name(int sig)
{
switch (sig) {
#ifdef SIGALRM
case SIGALRM:
return "SIGALRM";
#endif
#ifdef SIGCONT
case SIGCONT:
return "SIGCONT";
#endif
case SIGINT:
return "SIGINT";
#ifdef SIGQUIT
case SIGQUIT:
return "SIGQUIT";
#endif
case SIGTERM:
return "SIGTERM";
#ifdef SIGTSTP
case SIGTSTP:
return "SIGTSTP";
#endif
#ifdef SIGTTOU
case SIGTTOU:
return "SIGTTOU";
#endif
#ifdef SIGWINCH
case SIGWINCH:
return "SIGWINCH";
#endif
default:
return "unknown signal";
}
}
#endif
/*
* Note: This code is fragile! Its problem is that different OSs
* handle restart of system calls interrupted by signals differently.
* The ncurses code needs signal-call restart to happen -- otherwise,
* interrupted wgetch() calls will return FAIL, probably making the
* application think the input stream has ended and it should
* terminate. In particular, you know you have this problem if, when
* you suspend an ncurses-using lynx with ^Z and resume, it dies
* immediately.
*
* Default behavior of POSIX sigaction(2) is not to restart
* interrupted system calls, but Linux's sigaction does it anyway (at
* least, on and after the 1.1.47 I (esr) use). Thus this code works
* OK under Linux. The 4.4BSD sigaction(2) supports a (non-portable)
* SA_RESTART flag that forces the right behavior. Thus, this code
* should work OK under BSD/OS, NetBSD, and FreeBSD (let us know if it
* does not).
*
* Stock System Vs (and anything else using a strict-POSIX
* sigaction(2) without SA_RESTART) may have a problem. Possible
* solutions:
*
* sigvec restarts by default (SV_INTERRUPT flag to not restart)
* signal restarts by default in SVr4 (assuming you link with -lucb)
* and BSD, but not SVr3.
* sigset restarts, but is only available under SVr4/Solaris.
*
* The signal(3) call is mandated by the ANSI standard, and its
* interaction with sigaction(2) is described in the POSIX standard
* (3.3.4.2, page 72,line 934). According to section 8.1, page 191,
* however, signal(3) itself is not required by POSIX.1. And POSIX is
* silent on whether it is required to restart signals.
*
* So. The present situation is, we use sigaction(2) with no
* guarantee of restart anywhere but on Linux and BSD. We could
* switch to signal(3) and collar Linux, BSD, and SVr4. Any way
* we slice it, System V UNIXes older than SVr4 will probably lose
* (this may include XENIX).
*
* This implementation will probably be changed to use signal(3) in
* the future. If nothing else, it's simpler...
*/
#if USE_SIGTSTP
static void
tstp(int dummy GCC_UNUSED)
{
SCREEN *sp = CURRENT_SCREEN;
sigset_t mask, omask;
sigaction_t act, oact;
#ifdef SIGTTOU
int sigttou_blocked;
#endif
T(("tstp() called"));
/*
* The user may have changed the prog_mode tty bits, so save them.
*
* But first try to detect whether we still are in the foreground
* process group - if not, an interactive shell may already have
* taken ownership of the tty and modified the settings when our
* parent was stopped before us, and we would likely pick up the
* settings already modified by the shell.
*/
if (sp != 0 && !sp->_endwin) /* don't do this if we're not in curses */
#if HAVE_TCGETPGRP
if (tcgetpgrp(STDIN_FILENO) == getpgrp())
#endif
NCURSES_SP_NAME(def_prog_mode) (NCURSES_SP_ARG);
/*
* Block window change and timer signals. The latter
* is because applications use timers to decide when
* to repaint the screen.
*/
(void) sigemptyset(&mask);
#ifdef SIGALRM
(void) sigaddset(&mask, SIGALRM);
#endif
#if USE_SIGWINCH
(void) sigaddset(&mask, SIGWINCH);
#endif
(void) sigprocmask(SIG_BLOCK, &mask, &omask);
#ifdef SIGTTOU
sigttou_blocked = sigismember(&omask, SIGTTOU);
if (!sigttou_blocked) {
(void) sigemptyset(&mask);
(void) sigaddset(&mask, SIGTTOU);
(void) sigprocmask(SIG_BLOCK, &mask, NULL);
}
#endif
/*
* End window mode, which also resets the terminal state to the
* original (pre-curses) modes.
*/
NCURSES_SP_NAME(endwin) (NCURSES_SP_ARG);
/* Unblock SIGTSTP. */
(void) sigemptyset(&mask);
(void) sigaddset(&mask, SIGTSTP);
#ifdef SIGTTOU
if (!sigttou_blocked) {
/* Unblock this too if it wasn't blocked on entry */
(void) sigaddset(&mask, SIGTTOU);
}
#endif
(void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
/* Now we want to resend SIGSTP to this process and suspend it */
act.sa_handler = SIG_DFL;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
#ifdef SA_RESTART
act.sa_flags |= SA_RESTART;
#endif /* SA_RESTART */
sigaction(SIGTSTP, &act, &oact);
kill(getpid(), SIGTSTP);
/* Process gets suspended...time passes...process resumes */
T(("SIGCONT received"));
sigaction(SIGTSTP, &oact, NULL);
NCURSES_SP_NAME(flushinp) (NCURSES_SP_ARG);
/*
* If the user modified the tty state while suspended, he wants
* those changes to stick. So save the new "default" terminal state.
*/
NCURSES_SP_NAME(def_shell_mode) (NCURSES_SP_ARG);
/*
* This relies on the fact that doupdate() will restore the
* program-mode tty state, and issue enter_ca_mode if need be.
*/
NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
/* Reset the signals. */
(void) sigprocmask(SIG_SETMASK, &omask, NULL);
}
#endif /* USE_SIGTSTP */
static void
cleanup(int sig)
{
SCREEN *sp = CURRENT_SCREEN;
/*
* Actually, doing any sort of I/O from within an signal handler is
* "unsafe". But we'll _try_ to clean up the screen and terminal
* settings on the way out.
*/
if (!_nc_globals.cleanup_nested++
&& (sig == SIGINT
#ifdef SIGQUIT
|| sig == SIGQUIT
#endif
)) {
#if HAVE_SIGACTION || HAVE_SIGVEC
sigaction_t act;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
if (sigaction(sig, &act, NULL) == 0)
#else
if (signal(sig, SIG_IGN) != SIG_ERR)
#endif
{
SCREEN *scan;
for (each_screen(scan)) {
if (scan->_ofp != 0
&& isatty(fileno(scan->_ofp))) {
scan->_cleanup = TRUE;
scan->_outch = NCURSES_SP_NAME(_nc_outch);
}
set_term(scan);
NCURSES_SP_NAME(endwin) (NCURSES_SP_ARG);
if (sp)
sp->_endwin = FALSE; /* in case we have an atexit! */
}
}
}
exit(EXIT_FAILURE);
}
#if USE_SIGWINCH
static void
sigwinch(int sig GCC_UNUSED)
{
_nc_globals.have_sigwinch = 1;
# if USE_PTHREADS_EINTR
if (_nc_globals.read_thread) {
if (!pthread_equal(pthread_self(), _nc_globals.read_thread))
pthread_kill(_nc_globals.read_thread, SIGWINCH);
_nc_globals.read_thread = 0;
}
# endif
}
#endif /* USE_SIGWINCH */
/*
* If the given signal is still in its default state, set it to the given
* handler.
*/
static int
CatchIfDefault(int sig, RETSIGTYPE (*handler) (int))
{
int result;
#if HAVE_SIGACTION || HAVE_SIGVEC
sigaction_t old_act;
sigaction_t new_act;
memset(&new_act, 0, sizeof(new_act));
sigemptyset(&new_act.sa_mask);
#ifdef SA_RESTART
#ifdef SIGWINCH
if (sig != SIGWINCH)
#endif
new_act.sa_flags |= SA_RESTART;
#endif /* SA_RESTART */
new_act.sa_handler = handler;
if (sigaction(sig, NULL, &old_act) == 0
&& (old_act.sa_handler == SIG_DFL
|| old_act.sa_handler == handler
#if USE_SIGWINCH
|| (sig == SIGWINCH && old_act.sa_handler == SIG_IGN)
#endif
)) {
(void) sigaction(sig, &new_act, NULL);
result = TRUE;
} else {
result = FALSE;
}
#else /* !HAVE_SIGACTION */
RETSIGTYPE (*ohandler) (int);
ohandler = signal(sig, SIG_IGN);
if (ohandler == SIG_DFL
|| ohandler == handler
#if USE_SIGWINCH
|| (sig == SIGWINCH && ohandler == SIG_IGN)
#endif
) {
signal(sig, handler);
result = TRUE;
} else {
signal(sig, ohandler);
result = FALSE;
}
#endif
T(("CatchIfDefault - will %scatch %s",
result ? "" : "not ", signal_name(sig)));
return result;
}
/*
* This is invoked once at the beginning (e.g., from 'initscr()'), to
* initialize the signal catchers, and thereafter when spawning a shell (and
* returning) to disable/enable the SIGTSTP (i.e., ^Z) catcher.
*
* If the application has already set one of the signals, we'll not modify it
* (during initialization).
*
* The XSI document implies that we shouldn't keep the SIGTSTP handler if
* the caller later changes its mind, but that doesn't seem correct.
*/
NCURSES_EXPORT(void)
_nc_signal_handler(bool enable)
{
T((T_CALLED("_nc_signal_handler(%d)"), enable));
#if USE_SIGTSTP /* Xenix 2.x doesn't have SIGTSTP, for example */
{
static bool ignore_tstp = FALSE;
if (!ignore_tstp) {
static sigaction_t new_sigaction, old_sigaction;
if (!enable) {
new_sigaction.sa_handler = SIG_IGN;
sigaction(SIGTSTP, &new_sigaction, &old_sigaction);
} else if (new_sigaction.sa_handler != SIG_DFL) {
sigaction(SIGTSTP, &old_sigaction, NULL);
} else if (sigaction(SIGTSTP, NULL, &old_sigaction) == 0
&& (old_sigaction.sa_handler == SIG_DFL)) {
sigemptyset(&new_sigaction.sa_mask);
#ifdef SA_RESTART
new_sigaction.sa_flags |= SA_RESTART;
#endif /* SA_RESTART */
new_sigaction.sa_handler = tstp;
(void) sigaction(SIGTSTP, &new_sigaction, NULL);
} else {
ignore_tstp = TRUE;
}
}
}
#endif /* !USE_SIGTSTP */
if (!_nc_globals.init_signals) {
if (enable) {
CatchIfDefault(SIGINT, cleanup);
CatchIfDefault(SIGTERM, cleanup);
#if USE_SIGWINCH
CatchIfDefault(SIGWINCH, sigwinch);
#endif
_nc_globals.init_signals = TRUE;
}
}
returnVoid;
}