NetBSD/usr.bin/vi/intr.c

180 lines
5.4 KiB
C

/*-
* Copyright (c) 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)intr.c 8.1 (Berkeley) 3/23/94";
#endif /* not lint */
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <bitstring.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include "compat.h"
#include <db.h>
#include <regex.h>
#include "vi.h"
/*
* There's a count of how deep the interrupt level in the SCR structure
* has gone. Each routine that wants to be interrupted increments this
* level, and decrements it when it tears the interrupts down. There are
* two simplifying assumptions:
*
* 1: All interruptible areas want the same handler (we don't have
* to save/restore the old handler).
* 2: This is the only way to turn on interrupts (we don't have to
* worry about them already being turned on if the interrupt
* level is 0).
*
* We do it this way because interrupts have to be very fast -- if the
* O_REMAPMAX option is turned off, we are setting interrupts per key
* stroke.
*
* If an interrupt arrives, the S_INTERRUPTED bit is set in any SCR that
* has the S_INTERRUPTIBLE bit set. In the future this may be a problem.
* The user should be able to move to another screen and keep typing while
* another screen runs. Currently, if the user does this and the user has
* more than one interruptible thing running, there will be no way to know
* which one to stop.
*/
static void intr_def __P((int));
/*
* intr_init --
* Set up a interrupts.
*/
int
intr_init(sp)
SCR *sp;
{
struct sigaction act;
struct termios nterm;
/* You can never interrupt sessions not using tty's. */
if (!F_ISSET(sp->gp, G_STDIN_TTY))
return (1);
/* If interrupts already set up, just increase the level. */
if (sp->intr_level++)
return (0);
/* Turn interrupts on in this screen. */
F_SET(sp, S_INTERRUPTIBLE);
/* Install a handler. */
act.sa_handler = intr_def;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
if (sigaction(SIGINT, &act, &sp->intr_act)) {
msgq(sp, M_SYSERR, "sigaction");
goto err1;
}
/*
* Turn on interrupts. ISIG turns on VINTR, VQUIT and VSUSP. We
* want VINTR to interrupt, so we install a handler. VQUIT is
* ignored by main() because nvi never wants to catch it. A handler
* for VSUSP should have been installed by the screen code.
*/
if (tcgetattr(STDIN_FILENO, &sp->intr_term)) {
msgq(sp, M_SYSERR, "tcgetattr");
goto err2;
}
nterm = sp->intr_term;
nterm.c_lflag |= ISIG;
if (tcsetattr(STDIN_FILENO, TCSANOW | TCSASOFT, &nterm)) {
msgq(sp, M_SYSERR, "tcsetattr");
/*
* If an error occurs, back out the changes and run
* without interrupts.
*/
err2: (void)sigaction(SIGINT, &sp->intr_act, NULL);
err1: sp->intr_level = 0;
F_CLR(sp, S_INTERRUPTIBLE);
return (1);
}
return (0);
}
/*
* intr_end --
* Tear down interrupts.
*/
void
intr_end(sp)
SCR *sp;
{
/* If not the bottom level of interrupts, just return. */
if (--sp->intr_level)
return;
/* Turn off interrupts. */
if (tcsetattr(STDIN_FILENO, TCSANOW | TCSASOFT, &sp->intr_term))
msgq(sp, M_SYSERR, "tcsetattr");
/* Reset the signal state. */
if (sigaction(SIGINT, &sp->intr_act, NULL))
msgq(sp, M_SYSERR, "sigaction");
/* Clear interrupt bits in this screen. */
F_CLR(sp, S_INTERRUPTED | S_INTERRUPTIBLE);
}
/*
* intr_def --
* Default interrupt handler.
*/
static void
intr_def(signo)
int signo;
{
SCR *sp;
for (sp = __global_list->dq.cqh_first;
sp != (void *)&__global_list->dq; sp = sp->q.cqe_next)
if (F_ISSET(sp, S_INTERRUPTIBLE))
F_SET(sp, S_INTERRUPTED);
}