/*      @(#)wwflush.c   8.1 (Berkeley) 6/6/93   */
/*      $NetBSD: wwflush.c,v 1.10 2006/12/18 20:04:55 christos Exp $    */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Edward Wang at The University of California, Berkeley.
 *
 * 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. 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.
 */

#include <signal.h>
#include <string.h>
#include <unistd.h>
#include "ww.h"
#include "tt.h"
#include "xx.h"

void
wwflush(void)
{
        int row, col;

        if ((row = wwcursorrow) < 0)
                row = 0;
        else if (row >= wwnrow)
                row = wwnrow - 1;
        if ((col = wwcursorcol) < 0)
                col = 0;
        else if (col >= wwncol)
                col = wwncol - 1;
        xxmove(row, col);
        if (wwdocheckpoint) {
                xxflush(0);
                wwcheckpoint();
        } else
                xxflush(1);
}

void
wwcheckpoint(void)
{
        sigset_t nsigset, osigset;

        sigemptyset(&nsigset);
        sigaddset(&nsigset, SIGALRM);
        sigprocmask(SIG_BLOCK, &nsigset, &osigset);

        tt.tt_ack = 0;
        do {
                (*tt.tt_checkpoint)();
#ifndef OLD_TTY
                (void) tcdrain(1);
#endif
                (void) alarm(3);
                for (wwdocheckpoint = 0; !wwdocheckpoint && tt.tt_ack == 0;)
                        sigsuspend(&osigset);
        } while (tt.tt_ack == 0);
        (void) alarm(0);
        wwdocheckpoint = 0;
        if (tt.tt_ack < 0) {
                wwcopyscreen(wwcs, wwos);
                (void) alarm(1);
                wwreset();
                wwupdate();
                wwflush();
        } else {
                wwcopyscreen(wwos, wwcs);
                (void) alarm(3);
        }

        sigprocmask(SIG_SETMASK, &osigset, (sigset_t *)0);
}

void
wwcopyscreen(union ww_char **s1, union ww_char **s2)
{
        int i;
        int s = wwncol * sizeof **s1;

        for (i = wwnrow; --i >= 0;)
                memmove((char *) *s2++, (char *) *s1++, s);
}

void
wwalarm(int dummy __unused)
{
        wwdocheckpoint = 1;
}