sys/sys/buf_ring.h

76 buf_ring_enqueue(struct buf_ring *br, void *buf)
83 	for (i = br->br_cons_head; i != br->br_prod_head;
84 	     i = ((i + 1) & br->br_cons_mask))
85 		if(br->br_ring[i] == buf)
87 			    buf, i, br->br_prod_tail, br->br_cons_tail);
91 		prod_head = br->br_prod_head;
92 		cons_tail = br->br_cons_tail;
94 		prod_next = (prod_head + 1) & br->br_prod_mask;
97 			br->br_drops++;
102 		success = atomic_cmpset_int(&br->br_prod_head, prod_head,
106 	if (br->br_ring[prod_head] != NULL)
109 	br->br_ring[prod_head] = buf;
117 	while (br->br_prod_tail != prod_head)
119 	br->br_prod_bufs++;
120 	br->br_prod_tail = prod_next;
130 buf_ring_dequeue_mc(struct buf_ring *br)
139 		cons_head = br->br_cons_head;
140 		prod_tail = br->br_prod_tail;
142 		cons_next = (cons_head + 1) & br->br_cons_mask;
149 		success = atomic_cmpset_int(&br->br_cons_head, cons_head,
153 	buf = br->br_ring[cons_head];
155 	br->br_ring[cons_head] = NULL;
164 	while (br->br_cons_tail != cons_head)
167 	br->br_cons_tail = cons_next;
179 buf_ring_dequeue_sc(struct buf_ring *br)
185 	cons_head = br->br_cons_head;
186 	prod_tail = br->br_prod_tail;
188 	cons_next = (cons_head + 1) & br->br_cons_mask;
189 	cons_next_next = (cons_head + 2) & br->br_cons_mask;
196 		prefetch(br->br_ring[cons_next]);
198 			prefetch(br->br_ring[cons_next_next]);
201 	br->br_cons_head = cons_next;
202 	buf = br->br_ring[cons_head];
205 	br->br_ring[cons_head] = NULL;
206 	if (!mtx_owned(br->br_lock))
208 	if (br->br_cons_tail != cons_head)
210 		    br->br_cons_tail, cons_head);
212 	br->br_cons_tail = cons_next;
222 buf_ring_advance_sc(struct buf_ring *br)
227 	cons_head = br->br_cons_head;
228 	prod_tail = br->br_prod_tail;
230 	cons_next = (cons_head + 1) & br->br_cons_mask;
233 	br->br_cons_head = cons_next;
235 	br->br_ring[cons_head] = NULL;
237 	br->br_cons_tail = cons_next;
257 buf_ring_putback_sc(struct buf_ring *br, void *new)
259 	KASSERT(br->br_cons_head != br->br_prod_tail,
261 	br->br_ring[br->br_cons_head] = new;
270 buf_ring_peek(struct buf_ring *br)
274 	if ((br->br_lock != NULL) && !mtx_owned(br->br_lock))
283 	if (br->br_cons_head == br->br_prod_tail)
286 	return (br->br_ring[br->br_cons_head]);
290 buf_ring_full(struct buf_ring *br)
293 	return (((br->br_prod_head + 1) & br->br_prod_mask) == br->br_cons_tail);
297 buf_ring_empty(struct buf_ring *br)
300 	return (br->br_cons_head == br->br_prod_tail);
304 buf_ring_count(struct buf_ring *br)
307 	return ((br->br_prod_size + br->br_prod_tail - br->br_cons_tail)
308 	    & br->br_prod_mask);
313 void buf_ring_free(struct buf_ring *br, struct malloc_type *type);