1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)ring.h 1.9 (Berkeley) 06/01/90 8 */ 9 10 /* 11 * This defines a structure for a ring buffer. 12 * 13 * The circular buffer has two parts: 14 *((( 15 * full: [consume, supply) 16 * empty: [supply, consume) 17 *]]] 18 * 19 */ 20 typedef struct { 21 char *consume, /* where data comes out of */ 22 *supply, /* where data comes in to */ 23 *bottom, /* lowest address in buffer */ 24 *top, /* highest address+1 in buffer */ 25 *mark; /* marker (user defined) */ 26 int size; /* size in bytes of buffer */ 27 u_long consumetime, /* help us keep straight full, empty, etc. */ 28 supplytime; 29 } Ring; 30 31 /* Here are some functions and macros to deal with the ring buffer */ 32 33 34 #if defined(LINT_ARGS) 35 36 /* Initialization routine */ 37 extern int 38 ring_init(Ring *ring, char *buffer, int count); 39 40 /* Data movement routines */ 41 extern void 42 ring_supply_data(Ring *ring, char *buffer, int count), 43 ring_consume_data(Ring *ring, char *buffer, int count); 44 45 /* Buffer state transition routines */ 46 extern void 47 ring_supplied(Ring *ring, int count), 48 ring_consumed(Ring *ring, int count); 49 50 /* Buffer state query routines */ 51 extern int 52 ring_empty_count(Ring *ring), 53 ring_empty_consecutive(Ring *ring), 54 ring_full_count(Ring *ring), 55 ring_full_consecutive(Ring *ring); 56 57 #else /* LINT_ARGS */ 58 extern int 59 ring_init(); 60 61 extern void 62 ring_supply_data(), 63 ring_consume_data(); 64 65 extern void 66 ring_supplied(), 67 ring_consumed(); 68 69 extern void 70 ring_clear_mark(), 71 ring_mark(); 72 73 extern int 74 ring_empty_count(), 75 ring_empty_consecutive(), 76 ring_full_count(), 77 ring_full_consecutive(); 78 #endif /* defined(LINT_ARGS) */ 79