mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-22 11:17:19 +00:00
97 lines
3.2 KiB
C
97 lines
3.2 KiB
C
/*
|
|
* Copyright (c) 1988, 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.
|
|
*
|
|
* @(#)ring.h 8.1 (Berkeley) 6/6/93
|
|
*/
|
|
|
|
#if defined(P)
|
|
# undef P
|
|
#endif
|
|
|
|
#if defined(__STDC__) || defined(LINT_ARGS)
|
|
# define P(x) x
|
|
#else
|
|
# define P(x) ()
|
|
#endif
|
|
|
|
/*
|
|
* This defines a structure for a ring buffer.
|
|
*
|
|
* The circular buffer has two parts:
|
|
*(((
|
|
* full: [consume, supply)
|
|
* empty: [supply, consume)
|
|
*]]]
|
|
*
|
|
*/
|
|
typedef struct {
|
|
unsigned char *consume, /* where data comes out of */
|
|
*supply, /* where data comes in to */
|
|
*bottom, /* lowest address in buffer */
|
|
*top, /* highest address+1 in buffer */
|
|
*mark; /* marker (user defined) */
|
|
int size; /* size in bytes of buffer */
|
|
u_long consumetime, /* help us keep straight full, empty, etc. */
|
|
supplytime;
|
|
} Ring;
|
|
|
|
/* Here are some functions and macros to deal with the ring buffer */
|
|
|
|
/* Initialization routine */
|
|
extern int
|
|
ring_init P((Ring *ring, unsigned char *buffer, int count));
|
|
|
|
/* Data movement routines */
|
|
extern void
|
|
ring_supply_data P((Ring *ring, unsigned char *buffer, int count));
|
|
#ifdef notdef
|
|
extern void
|
|
ring_consume_data P((Ring *ring, unsigned char *buffer, int count));
|
|
#endif
|
|
|
|
/* Buffer state transition routines */
|
|
extern void
|
|
ring_supplied P((Ring *ring, int count)),
|
|
ring_consumed P((Ring *ring, int count));
|
|
|
|
/* Buffer state query routines */
|
|
extern int
|
|
ring_empty_count P((Ring *ring)),
|
|
ring_empty_consecutive P((Ring *ring)),
|
|
ring_full_count P((Ring *ring)),
|
|
ring_full_consecutive P((Ring *ring));
|
|
|
|
|
|
extern void
|
|
ring_clear_mark(),
|
|
ring_mark();
|