usr/src/sys/luna68k/stand/rcvbuf.h

/*
 * Copyright (c) 1992 OMRON Corporation.
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * OMRON Corporation.
 *
 * 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.
 *
 *      @(#)rcvbuf.h    8.1 (Berkeley) 6/10/93
 */

/*
 * rcvbuf.h -- receive buffer control structure definition
 *      by A.Fujita, Dec-12-1992
 */

#define RBUF_SIZE       128

struct rcvbuf {
        u_char  *rb_push;
        u_char  *rb_pop;
        u_char   rb_buf[RBUF_SIZE+4];
};

#define RBUF_INIT(n)    rcvbuf[n].rb_pop = rcvbuf[n].rb_push = &rcvbuf[n].rb_buf[RBUF_SIZE]

#define PUSH_RBUF(n, c) *(--rcvbuf[n].rb_push) = c ; \
                        if (rcvbuf[n].rb_push == rcvbuf[n].rb_buf) \
                                rcvbuf[n].rb_push = &rcvbuf[n].rb_buf[RBUF_SIZE]

#define POP_RBUF(n, c)  c= *(--rcvbuf[n].rb_pop); \
                        if (rcvbuf[n].rb_pop == rcvbuf[n].rb_buf) \
                                rcvbuf[n].rb_pop = &rcvbuf[n].rb_buf[RBUF_SIZE]

#define RBUF_EMPTY(n)   (rcvbuf[n].rb_push == rcvbuf[n].rb_pop ? 1: 0)