2 * Copyright (c) 1981, 1984, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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9 * notice, this list of conditions and the following disclaimer.
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11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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29 * @(#)msgbuf.h 8.1 (Berkeley) 6/2/93
33 #ifndef _SYS_MSGBUF_H_
34 #define _SYS_MSGBUF_H_
37 char *msg_ptr; /* pointer to buffer */
38 #define MSG_MAGIC 0x063062
40 u_int msg_size; /* size of buffer area */
41 u_int msg_wseq; /* write sequence number */
42 u_int msg_rseq; /* read sequence number */
43 u_int msg_cksum; /* checksum of contents */
44 u_int msg_seqmod; /* range for sequence numbers */
47 /* Normalise a sequence number or a difference between sequence numbers. */
48 #define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \
50 #define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size)
51 /* Subtract sequence numbers. Note that only positive values result. */
52 #define MSGBUF_SEQSUB(mbp, seq1, seq2) (MSGBUF_SEQNORM((mbp), (seq1) - (seq2)))
55 extern int msgbufsize;
56 extern int msgbuftrigger;
57 extern struct msgbuf *msgbufp;
58 extern struct mtx msgbuf_lock;
60 void msgbufinit(void *ptr, int size);
61 void msgbuf_addchar(struct msgbuf *mbp, int c);
62 void msgbuf_clear(struct msgbuf *mbp);
63 void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst);
64 int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen);
65 int msgbuf_getchar(struct msgbuf *mbp);
66 int msgbuf_getcount(struct msgbuf *mbp);
67 void msgbuf_init(struct msgbuf *mbp, void *ptr, int size);
68 int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen,
70 void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size);
73 #define MSGBUF_SIZE (32768 * 2)
77 #endif /* !_SYS_MSGBUF_H_ */