2 * Copyright (c) 1988, 1993
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15 * This product includes software developed by the University of
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33 * @(#)ring.h 8.1 (Berkeley) 6/6/93
40 #if defined(__STDC__) || defined(LINT_ARGS)
47 * This defines a structure for a ring buffer.
49 * The circular buffer has two parts:
51 * full: [consume, supply)
52 * empty: [supply, consume)
57 unsigned char *consume, /* where data comes out of */
58 *supply, /* where data comes in to */
59 *bottom, /* lowest address in buffer */
60 *top, /* highest address+1 in buffer */
61 *mark; /* marker (user defined) */
62 int size; /* size in bytes of buffer */
63 u_long consumetime, /* help us keep straight full, empty, etc. */
67 /* Here are some functions and macros to deal with the ring buffer */
69 /* Initialization routine */
71 ring_init P((Ring *ring, unsigned char *buffer, int count));
73 /* Data movement routines */
75 ring_supply_data P((Ring *ring, unsigned char *buffer, int count));
78 ring_consume_data P((Ring *ring, unsigned char *buffer, int count));
81 /* Buffer state transition routines */
83 ring_supplied P((Ring *ring, int count)),
84 ring_consumed P((Ring *ring, int count));
86 /* Buffer state query routines */
88 ring_empty_count P((Ring *ring)),
89 ring_empty_consecutive P((Ring *ring)),
90 ring_full_count P((Ring *ring)),
91 ring_full_consecutive P((Ring *ring));