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Diffstat (limited to 'usr.bin/vi/intr.c')
| -rw-r--r-- | usr.bin/vi/intr.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/usr.bin/vi/intr.c b/usr.bin/vi/intr.c new file mode 100644 index 000000000000..512e3ae025c8 --- /dev/null +++ b/usr.bin/vi/intr.c @@ -0,0 +1,178 @@ +/*- + * 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 <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 <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); +} |