| 1 | /* Copyright (c) 2007-2009, Stanford University |
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| 2 | * All rights reserved. |
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| 3 | * |
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| 4 | * Redistribution and use in source and binary forms, with or without |
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| 5 | * modification, are permitted provided that the following conditions are met: |
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| 6 | * * Redistributions of source code must retain the above copyright |
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| 7 | * notice, this list of conditions and the following disclaimer. |
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| 8 | * * Redistributions in binary form must reproduce the above copyright |
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| 9 | * notice, this list of conditions and the following disclaimer in the |
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| 10 | * documentation and/or other materials provided with the distribution. |
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| 11 | * * Neither the name of Stanford University nor the names of its |
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| 12 | * contributors may be used to endorse or promote products derived from |
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| 13 | * this software without specific prior written permission. |
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| 14 | * |
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| 15 | * THIS SOFTWARE IS PROVIDED BY STANFORD UNIVERSITY ``AS IS'' AND ANY |
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| 16 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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| 17 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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| 18 | * DISCLAIMED. IN NO EVENT SHALL STANFORD UNIVERSITY BE LIABLE FOR ANY |
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| 19 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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| 20 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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| 21 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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| 22 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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| 24 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 25 | */ |
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| 26 | |
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| 27 | #ifndef QUEUE_H_ |
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| 28 | #define QUEUE_H_ |
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| 29 | |
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| 30 | #include "list.h" |
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| 31 | |
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| 32 | typedef list queue_t; |
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| 33 | typedef list_ent queue_elem_t; |
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| 34 | |
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| 35 | #define queue_entry(QUEUE_ELEM, STRUCT, MEMBER) \ |
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| 36 | list_entry(QUEUE_ELEM, STRUCT, MEMBER) |
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| 37 | |
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| 38 | /** |
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| 39 | * Initialize queue for use |
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| 40 | */ |
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| 41 | static inline void queue_init (queue_t *q) |
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| 42 | { |
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| 43 | assert (q != NULL); |
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| 44 | list_init(q); |
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| 45 | } |
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| 46 | |
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| 47 | /** |
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| 48 | * Add element to end of queue |
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| 49 | */ |
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| 50 | static inline void queue_push_back (queue_t *q, queue_elem_t *qe) |
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| 51 | { |
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| 52 | assert (q != NULL); |
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| 53 | assert (qe != NULL); |
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| 54 | |
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| 55 | list_add_tail(q, qe); |
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| 56 | } |
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| 57 | |
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| 58 | /** |
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| 59 | * Remove element at end of queue |
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| 60 | * @return 0 on empty, 1 if found |
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| 61 | */ |
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| 62 | static inline int queue_pop_back (queue_t *q, queue_elem_t **qe) |
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| 63 | { |
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| 64 | queue_elem_t *tail; |
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| 65 | |
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| 66 | assert (q != NULL); |
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| 67 | assert (qe != NULL); |
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| 68 | |
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| 69 | tail = list_remove_tail(q); |
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| 70 | if (tail == NULL) |
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| 71 | return 0; |
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| 72 | |
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| 73 | *qe = tail; |
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| 74 | |
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| 75 | return 1; |
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| 76 | } |
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| 77 | |
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| 78 | /** |
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| 79 | * Put element at front of queue |
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| 80 | */ |
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| 81 | static inline void queue_push_front (queue_t *q, queue_elem_t *qe) |
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| 82 | { |
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| 83 | assert (q != NULL); |
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| 84 | assert (qe != NULL); |
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| 85 | |
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| 86 | list_add_head(q, qe); |
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| 87 | } |
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| 88 | |
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| 89 | /** |
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| 90 | * Remove element from front of queue |
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| 91 | * @return 0 if queue was empty, 1 if successful |
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| 92 | */ |
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| 93 | static inline int queue_pop_front (queue_t *q, queue_elem_t **qe) |
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| 94 | { |
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| 95 | queue_elem_t *head; |
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| 96 | |
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| 97 | assert (q != NULL); |
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| 98 | assert (qe != NULL); |
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| 99 | |
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| 100 | head = list_remove_head(q); |
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| 101 | if (head == NULL) |
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| 102 | return 0; |
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| 103 | |
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| 104 | *qe = head; |
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| 105 | |
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| 106 | return 1; |
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| 107 | } |
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| 108 | |
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| 109 | #endif /* QUEUE_H_ */ |
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