freebsd-nq/sys/sys/msgbuf.h

80 lines
3.3 KiB
C

/*
* Copyright (c) 1981, 1984, 1993
* 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.
*
* @(#)msgbuf.h 8.1 (Berkeley) 6/2/93
* $FreeBSD$
*/
#ifndef _SYS_MSGBUF_H_
#define _SYS_MSGBUF_H_
struct msgbuf {
char *msg_ptr; /* pointer to buffer */
#define MSG_MAGIC 0x063062
u_int msg_magic;
u_int msg_size; /* size of buffer area */
u_int msg_wseq; /* write sequence number */
u_int msg_rseq; /* read sequence number */
u_int msg_cksum; /* checksum of contents */
u_int msg_seqmod; /* range for sequence numbers */
};
/* Normalise a sequence number or a difference between sequence numbers. */
#define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \
(mbp)->msg_seqmod)
#define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size)
/* Subtract sequence numbers. Note that only positive values result. */
#define MSGBUF_SEQSUB(mbp, seq1, seq2) (MSGBUF_SEQNORM((mbp), (seq1) - (seq2)))
#ifdef _KERNEL
extern int msgbuftrigger;
extern struct msgbuf *msgbufp;
void msgbufinit(void *ptr, int size);
void msgbuf_addchar(struct msgbuf *mbp, int c);
void msgbuf_clear(struct msgbuf *mbp);
void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst);
int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen);
int msgbuf_getchar(struct msgbuf *mbp);
int msgbuf_getcount(struct msgbuf *mbp);
void msgbuf_init(struct msgbuf *mbp, void *ptr, int size);
int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen,
u_int *seqp);
void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size);
#ifndef MSGBUF_SIZE
#define MSGBUF_SIZE 32768
#endif
#endif /* KERNEL */
#endif /* !_SYS_MSGBUF_H_ */