1 /* 2 * Copyright (C) 2013-2014 Vincenzo Maffione 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * $FreeBSD$ 29 */ 30 31 32 #ifndef __NETMAP_MBQ_H__ 33 #define __NETMAP_MBQ_H__ 34 35 /* 36 * These function implement an mbuf tailq with an optional lock. 37 * The base functions act ONLY ON THE QUEUE, whereas the "safe" 38 * variants (mbq_safe_*) also handle the lock. 39 */ 40 41 /* XXX probably rely on a previous definition of SPINLOCK_T */ 42 #ifdef linux 43 #define SPINLOCK_T safe_spinlock_t 44 #elif defined (_WIN32) 45 #define SPINLOCK_T win_spinlock_t 46 #else 47 #define SPINLOCK_T struct mtx 48 #endif 49 50 /* A FIFO queue of mbufs with an optional lock. */ 51 struct mbq { 52 struct mbuf *head; 53 struct mbuf *tail; 54 int count; 55 SPINLOCK_T lock; 56 }; 57 58 /* We should clarify whether init can be used while 59 * holding a lock, and whether mbq_safe_destroy() is a NOP. 60 */ 61 void mbq_init(struct mbq *q); 62 void mbq_fini(struct mbq *q); 63 void mbq_enqueue(struct mbq *q, struct mbuf *m); 64 struct mbuf *mbq_dequeue(struct mbq *q); 65 void mbq_purge(struct mbq *q); 66 67 static inline struct mbuf * 68 mbq_peek(struct mbq *q) 69 { 70 return q->head ? q->head : NULL; 71 } 72 73 static inline void 74 mbq_lock(struct mbq *q) 75 { 76 mtx_lock_spin(&q->lock); 77 } 78 79 static inline void 80 mbq_unlock(struct mbq *q) 81 { 82 mtx_unlock_spin(&q->lock); 83 } 84 85 86 void mbq_safe_init(struct mbq *q); 87 void mbq_safe_fini(struct mbq *q); 88 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m); 89 struct mbuf *mbq_safe_dequeue(struct mbq *q); 90 void mbq_safe_purge(struct mbq *q); 91 92 static inline unsigned int mbq_len(struct mbq *q) 93 { 94 return q->count; 95 } 96 97 #endif /* __NETMAP_MBQ_H_ */ 98