/* * Copyright (c) 1988 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted provided * that: (1) source distributions retain this entire copyright notice and * comment, and (2) distributions including binaries display the following * acknowledgement: ``This product includes software developed by the * University of California, Berkeley and its contributors'' in the * documentation or other materials provided with the distribution and in * all advertising materials mentioning features or use of this software. * 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * @(#)ring.h 1.10 (Berkeley) 6/28/90 */ /* * This defines a structure for a ring buffer. * * The circular buffer has two parts: *((( * full: [consume, supply) * empty: [supply, consume) *]]] * */ typedef struct { 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 */ #if defined(LINT_ARGS) /* Initialization routine */ extern int ring_init(Ring *ring, char *buffer, int count); /* Data movement routines */ extern void ring_supply_data(Ring *ring, char *buffer, int count); #ifdef notdef extern void ring_consume_data(Ring *ring, char *buffer, int count); #endif /* Buffer state transition routines */ extern void ring_supplied(Ring *ring, int count), ring_consumed(Ring *ring, int count); /* Buffer state query routines */ extern int ring_empty_count(Ring *ring), ring_empty_consecutive(Ring *ring), ring_full_count(Ring *ring), ring_full_consecutive(Ring *ring); #else /* LINT_ARGS */ extern int ring_init(); extern void ring_supply_data(); #ifdef notdef extern void ring_consume_data(); #endif extern void ring_supplied(), ring_consumed(); extern void ring_clear_mark(), ring_mark(); extern int ring_empty_count(), ring_empty_consecutive(), ring_full_count(), ring_full_consecutive(); #endif /* defined(LINT_ARGS) */