tail head cat sleep
QR code linking to this page

Manual Pages  — BUF_RING

NAME

buf_ring, buf_ring_alloc, buf_ring_free, buf_ring_enqueue, buf_ring_dequeue_mc, buf_ring_dequeue_sc, buf_ring_count, buf_ring_empty, buf_ring_full, buf_ring_peek – multi-producer, {single, multi}-consumer lock-less ring buffer

CONTENTS

SYNOPSIS

#include <sys/param.h>
#include <sys/buf_ring.h>

struct buf_ring *
buf_ring_alloc(int count, struct malloc_type *type, int flags, struct mtx *sc_lock);

void
buf_ring_free(struct buf_ring *br, struct malloc_type *type);

int
buf_ring_enqueue(struct buf_ring *br, void *buf);

void *
buf_ring_dequeue_mc(struct buf_ring *br);

void *
buf_ring_dequeue_sc(struct buf_ring *br);

int
buf_ring_count(struct buf_ring *br);

int
buf_ring_empty(struct buf_ring *br);

int
buf_ring_full(struct buf_ring *br);

void *
buf_ring_peek(struct buf_ring *br);

DESCRIPTION

The buf_ring functions provide a lock-less multi-producer and lock-less multi-consumer as well as single-consumer ring buffer.

The buf_ring_alloc() function is used to allocate a buf_ring ring buffer with count slots using malloc_type type and memory flags flags. The single consumer interface is protected by sc_lock.

The buf_ring_free() function is used to free a buf_ring. The user is responsible for freeing any enqueued items.

The buf_ring_enqueue() function is used to enqueue a buffer to a buf_ring.

The buf_ring_dequeue_mc() function is a multi-consumer safe way of dequeueing elements from a buf_ring.

The buf_ring_dequeue_sc() function is a single-consumer interface to dequeue elements - requiring the user to serialize accesses with a lock.

The buf_ring_count() function returns the number of elements in a buf_ring.

The buf_ring_empty() function returns TRUE if the buf_ring is empty, FALSE otherwise.

The buf_ring_full() function returns TRUE if no more items can be enqueued, FALSE otherwise.

The buf_ring_peek() function returns a pointer to the last element in the buf_ring if the buf_ring is not empty, NULL otherwise.

RETURN VALUES

The buf_ring_enqueue() function return ENOBUFS if there are no available slots in the buf_ring.

HISTORY

These functions were introduced in FreeBSD 8.0 .

BUF_RING (9) September 27, 2012

tail head cat sleep
QR code linking to this page


Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

Unix is a junk OS designed by a committee of PhDs.
— Dave Cutler