xref: /btstack/src/btstack_linked_queue.h (revision 2fca4dad957cd7b88f4657ed51e89c12615dda72)
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.
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20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
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37 
38 /**
39  * @title Linked Queue
40  *
41  */
42 
43 #ifndef BTSTACK_LINKED_QUEUE_H
44 #define BTSTACK_LINKED_QUEUE_H
45 
46 #include "btstack_bool.h"
47 #include "btstack_linked_list.h"
48 
49 #if defined __cplusplus
50 extern "C" {
51 #endif
52 
53 /* API_START */
54 
55 typedef struct {
56     btstack_linked_item_t * head;
57     btstack_linked_item_t * tail;
58 } btstack_linked_queue_t;
59 
60 /**
61  * @brief Tests if queue is empty
62  * @return true if emtpy
63  */
64 bool btstack_linked_queue_empty(btstack_linked_queue_t * queue);
65 
66 /**
67  * @brief Append item to queue
68  * @param queue
69  * @param item
70  */
71 void btstack_linked_queue_enqueue(btstack_linked_queue_t * queue, btstack_linked_item_t * item);
72 
73 /**
74  * @brief Pop next item from queue
75  * @param queue
76  * @return item or NULL if queue empty
77  */
78 btstack_linked_item_t * btstack_linked_queue_dequeue(btstack_linked_queue_t * queue);
79 
80 /**
81  * @brief Get first item from queue
82  * @param queue
83  * @return item or NULL if queue empty
84  */
85 btstack_linked_item_t * btstack_linked_queue_first(btstack_linked_queue_t * queue);
86 
87 /* API_END */
88 
89 #if defined __cplusplus
90 }
91 #endif
92 
93 #endif // BTSTACK_LINKED_QUEUE_H
94