xref: /btstack/src/btstack_linked_queue.h (revision cd5f23a3250874824c01a2b3326a9522fea3f99f)
1 /*
2  * Copyright (C) 2019 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
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7  *
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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.
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15  *    from this software without specific prior written permission.
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19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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36  */
37 
38 /*
39  *  btstack_linked_queue.h
40  */
41 
42 #ifndef BTSTACK_LINKED_QUEUE_H
43 #define BTSTACK_LINKED_QUEUE_H
44 
45 #include "btstack_bool.h"
46 #include "btstack_linked_list.h"
47 
48 #if defined __cplusplus
49 extern "C" {
50 #endif
51 
52 /* API_START */
53 
54 typedef struct {
55     btstack_linked_item_t * head;
56     btstack_linked_item_t * tail;
57 } btstack_linked_queue_t;
58 
59 /**
60  * @brief Tests if queue is empty
61  * @return true if emtpy
62  */
63 bool btstack_linked_queue_empty(btstack_linked_queue_t * queue);
64 
65 /**
66  * @brief Append item to queue
67  * @param queue
68  * @param item
69  */
70 void btstack_linked_queue_enqueue(btstack_linked_queue_t * queue, btstack_linked_item_t * item);
71 
72 /**
73  * @brief Pop next item from queue
74  * @param queue
75  * @return item or NULL if queue empty
76  */
77 btstack_linked_item_t * btstack_linked_queue_dequeue(btstack_linked_queue_t * queue);
78 
79 /**
80  * @brief Get first item from queue
81  * @param queue
82  * @return item or NULL if queue empty
83  */
84 btstack_linked_item_t * btstack_linked_queue_first(btstack_linked_queue_t * queue);
85 
86 /* API_END */
87 
88 #if defined __cplusplus
89 }
90 #endif
91 
92 #endif // BTSTACK_LINKED_QUEUE_H
93