/****************************************************************************
- * Copyright (c) 1998,1999,2000 Free Software Foundation, Inc. *
+ * Copyright (c) 1998-2013,2014 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 *
/****************************************************************************
* Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995 *
* and: Eric S. Raymond <esr@snark.thyrsus.com> *
+ * and: Thomas E. Dickey 1995-on *
****************************************************************************/
/*
** The routine _nc_signal_handler().
**
*/
-
#include <curses.priv.h>
-#include <signal.h>
#include <SigAction.h>
-#if SVR4_ACTION && !defined(_POSIX_SOURCE)
-#define _POSIX_SOURCE
-#endif
-
-MODULE_ID("$Id: lib_tstp.c,v 1.22 2000/09/02 18:33:17 tom Exp $")
+MODULE_ID("$Id: lib_tstp.c,v 1.48 2014/04/26 18:47:35 juergen Exp $")
#if defined(SIGTSTP) && (HAVE_SIGACTION || HAVE_SIGVEC)
#define USE_SIGTSTP 1
#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.
#if USE_SIGTSTP
static void
-tstp(int dummy GCC_UNUSED)
+handle_SIGTSTP(int dummy GCC_UNUSED)
{
+ SCREEN *sp = CURRENT_SCREEN;
sigset_t mask, omask;
sigaction_t act, oact;
int sigttou_blocked;
#endif
- T(("tstp() called"));
+ _nc_globals.have_sigtstp = 1;
+ T(("handle_SIGTSTP() called"));
/*
* The user may have changed the prog_mode tty bits, so save them.
* 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 (sp != 0 && !sp->_endwin) /* don't do this if we're not in curses */
#if HAVE_TCGETPGRP
if (tcgetpgrp(STDIN_FILENO) == getpgrp())
#endif
- def_prog_mode();
+ NCURSES_SP_NAME(def_prog_mode) (NCURSES_SP_ARG);
/*
* Block window change and timer signals. The latter
* to repaint the screen.
*/
(void) sigemptyset(&mask);
+#ifdef SIGALRM
(void) sigaddset(&mask, SIGALRM);
+#endif
#if USE_SIGWINCH
(void) sigaddset(&mask, SIGWINCH);
#endif
* End window mode, which also resets the terminal state to the
* original (pre-curses) modes.
*/
- endwin();
+ NCURSES_SP_NAME(endwin) (NCURSES_SP_ARG);
/* Unblock SIGTSTP. */
(void) sigemptyset(&mask);
T(("SIGCONT received"));
sigaction(SIGTSTP, &oact, NULL);
- flushinp();
+ 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.
*/
- def_shell_mode();
+ 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.
*/
- doupdate();
+ NCURSES_SP_NAME(doupdate) (NCURSES_SP_ARG);
/* Reset the signals. */
(void) sigprocmask(SIG_SETMASK, &omask, NULL);
#endif /* USE_SIGTSTP */
static void
-cleanup(int sig)
+handle_SIGINT(int sig)
{
- static int nested;
+ 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.
+ * Much of this is unsafe from a signal handler. But we'll _try_ to clean
+ * up the screen and terminal settings on the way out.
+ *
+ * There are at least the following problems:
+ * 1) Walking the SCREEN list is unsafe, since all list management
+ * is done without any signal blocking.
+ * 2) On systems which have REENTRANT turned on, set_term() uses
+ * _nc_lock_global() which could deadlock or misbehave in other ways.
+ * 3) endwin() calls all sorts of stuff, many of which use stdio or
+ * other library functions which are clearly unsafe.
*/
- if (!nested++
- && (sig == SIGINT
- || sig == SIGQUIT)) {
+ if (!_nc_globals.cleanup_nested++
+ && (sig == SIGINT || sig == SIGTERM)) {
#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, (sigaction_t *) 0) == 0)
+ if (sigaction(sig, &act, NULL) == 0)
#else
if (signal(sig, SIG_IGN) != SIG_ERR)
#endif
{
- SCREEN *scan = _nc_screen_chain;
- while (scan) {
- if (SP != 0
- && SP->_ofp != 0
- && isatty(fileno(SP->_ofp))) {
- SP->_cleanup = TRUE;
- SP->_outch = _nc_outch;
+ SCREEN *scan;
+ for (each_screen(scan)) {
+ if (scan->_ofp != 0
+ && NC_ISATTY(fileno(scan->_ofp))) {
+ scan->_outch = NCURSES_SP_NAME(_nc_outch);
}
set_term(scan);
- endwin();
- if (SP)
- SP->_endwin = FALSE; /* in case we have an atexit! */
- scan = scan->_next_screen;
+ NCURSES_SP_NAME(endwin) (NCURSES_SP_ARG);
+ if (sp)
+ sp->_endwin = FALSE; /* in case of reuse */
}
}
}
- exit(EXIT_FAILURE);
+ _exit(EXIT_FAILURE);
}
#if USE_SIGWINCH
static void
-sigwinch(int sig GCC_UNUSED)
+handle_SIGWINCH(int sig GCC_UNUSED)
{
- SCREEN *scan = _nc_screen_chain;
- while (scan) {
- scan->_sig_winch = TRUE;
- scan = scan->_next_screen;
+ _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.
*/
-#if HAVE_SIGACTION || HAVE_SIGVEC
static int
-CatchIfDefault(int sig, sigaction_t * act)
+CatchIfDefault(int sig, void (*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, (sigaction_t *) 0, &old_act) == 0
+ 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, act, (sigaction_t *) 0);
- return TRUE;
+ (void) sigaction(sig, &new_act, NULL);
+ result = TRUE;
+ } else {
+ result = FALSE;
}
- return FALSE;
-}
-#else
-static int
-CatchIfDefault(int sig, RETSIGTYPE(*handler) (int))
-{
+#else /* !HAVE_SIGACTION */
void (*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);
- return TRUE;
+ result = TRUE;
} else {
signal(sig, ohandler);
- return FALSE;
+ 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
* 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.
*/
-void
-_nc_signal_handler(bool enable)
+NCURSES_EXPORT(void)
+_nc_signal_handler(int enable)
{
+ T((T_CALLED("_nc_signal_handler(%d)"), enable));
#if USE_SIGTSTP /* Xenix 2.x doesn't have SIGTSTP, for example */
- static sigaction_t act, oact;
- static int ignore;
-
- if (!ignore) {
- if (!enable) {
- act.sa_handler = SIG_IGN;
- sigaction(SIGTSTP, &act, &oact);
- } else if (act.sa_handler) {
- sigaction(SIGTSTP, &oact, NULL);
- } else { /*initialize */
- sigemptyset(&act.sa_mask);
- act.sa_flags = 0;
-#if USE_SIGWINCH
- act.sa_handler = sigwinch;
- CatchIfDefault(SIGWINCH, &act);
-#endif
-
+ {
+ 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
- act.sa_flags |= SA_RESTART;
+ new_sigaction.sa_flags |= SA_RESTART;
#endif /* SA_RESTART */
- act.sa_handler = cleanup;
- CatchIfDefault(SIGINT, &act);
- CatchIfDefault(SIGTERM, &act);
-
- act.sa_handler = tstp;
- if (!CatchIfDefault(SIGTSTP, &act))
- ignore = TRUE;
+ new_sigaction.sa_handler = handle_SIGTSTP;
+ (void) sigaction(SIGTSTP, &new_sigaction, NULL);
+ } else {
+ ignore_tstp = TRUE;
+ }
}
}
-#else /* !USE_SIGTSTP */
- if (enable) {
-#if HAVE_SIGACTION || HAVE_SIGVEC
- static sigaction_t act;
- sigemptyset(&act.sa_mask);
-#if USE_SIGWINCH
- act.sa_handler = sigwinch;
- CatchIfDefault(SIGWINCH, &act);
-#endif
-#ifdef SA_RESTART
- act.sa_flags |= SA_RESTART;
-#endif /* SA_RESTART */
- act.sa_handler = cleanup;
- CatchIfDefault(SIGINT, &act);
- CatchIfDefault(SIGTERM, &act);
-
-#else /* !(HAVE_SIGACTION || HAVE_SIGVEC) */
+#endif /* !USE_SIGTSTP */
- CatchIfDefault(SIGINT, cleanup);
- CatchIfDefault(SIGTERM, cleanup);
+ if (!_nc_globals.init_signals) {
+ if (enable) {
+ CatchIfDefault(SIGINT, handle_SIGINT);
+ CatchIfDefault(SIGTERM, handle_SIGINT);
#if USE_SIGWINCH
- CatchIfDefault(SIGWINCH, sigwinch);
+ CatchIfDefault(SIGWINCH, handle_SIGWINCH);
#endif
-#endif /* !(HAVE_SIGACTION || HAVE_SIGVEC) */
+ _nc_globals.init_signals = TRUE;
+ }
}
-#endif /* !USE_SIGTSTP */
+ returnVoid;
}