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2 .\" Written by: Kip Macy <kmacy@FreeBSD.org>
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28 .Dd September 27, 2012
35 .Nm buf_ring_enqueue ,
36 .Nm buf_ring_dequeue_mc ,
37 .Nm buf_ring_dequeue_sc ,
42 .Nd multi-producer, {single, multi}-consumer lock-less ring buffer
47 .Fn buf_ring_alloc "int count" "struct malloc_type *type" "int flags" "struct mtx *sc_lock"
49 .Fn buf_ring_free "struct buf_ring *br" "struct malloc_type *type"
51 .Fn buf_ring_enqueue "struct buf_ring *br" "void *buf"
53 .Fn buf_ring_dequeue_mc "struct buf_ring *br"
55 .Fn buf_ring_dequeue_sc "struct buf_ring *br"
57 .Fn buf_ring_count "struct buf_ring *br"
59 .Fn buf_ring_empty "struct buf_ring *br"
61 .Fn buf_ring_full "struct buf_ring *br"
63 .Fn buf_ring_peek "struct buf_ring *br"
67 functions provide a lock-less multi-producer and lock-less multi-consumer as
68 well as single-consumer ring buffer.
72 function is used to allocate a buf_ring ring buffer with
74 slots using malloc_type
78 The single consumer interface is protected by
83 function is used to free a buf_ring.
84 The user is responsible for freeing any enqueued items.
88 function is used to enqueue a buffer to a buf_ring.
91 .Fn buf_ring_dequeue_mc
92 function is a multi-consumer safe way of dequeueing elements from a buf_ring.
95 .Fn buf_ring_dequeue_sc
96 function is a single-consumer interface to dequeue elements - requiring
97 the user to serialize accesses with a lock.
101 function returns the number of elements in a buf_ring.
107 if the buf_ring is empty,
115 if no more items can be enqueued,
121 function returns a pointer to the last element in the buf_ring if the
122 buf_ring is not empty,
130 if there are no available slots in the buf_ring.
132 These functions were introduced in