9  * FIFO-style "memory queue" permitting enqueue at tail and dequeue from head.
14  * is given by head == tail.
29  *   where H is the pointer to Head link-element (oldest element).
47  * @param head[out] Head of queue. Will be updated
51 memq_link_t *memq_init(memq_link_t *link, memq_link_t **head, memq_link_t **tail)  in memq_init()  argument
53 	/* Head and tail pointer to the initial link - forms an empty queue */  in memq_init()
54 	*head = *tail = link;  in memq_init()
62  * @param head[in,out] Head of queue. Will be updated
64  * @return          Head of queue before invalidation; NULL if queue was empty
66 memq_link_t *memq_deinit(memq_link_t **head, memq_link_t **tail)  in memq_deinit()  argument
70 	/* If head and tail are not equal, then queue is not empty */  in memq_deinit()
71 	if (*head != *tail) {  in memq_deinit()
75 	old_head = *head;  in memq_deinit()
76 	*head = *tail = NULL;  in memq_deinit()
110  * @brief Non-destructive peek of head of queue.
112  * @param head[in] Pointer to head link-element of queue
114  * @param mem[out] The memory pointed to by head-element
115  * @return         head or NULL if queue is empty
117 memq_link_t *memq_peek(memq_link_t *head, memq_link_t *tail, void **mem)  in memq_peek()  argument
119 	/* If head and tail are equal, then queue empty */  in memq_peek()
120 	if (head == tail) {  in memq_peek()
124 	/* Extract the head link-element's memory */  in memq_peek()
126 		*mem = head->mem;  in memq_peek()
129 	return head; /* queue was not empty */  in memq_peek()
135  * @param head[in] Pointer to head link-element of queue
138  * @param mem[out] The memory pointed to by head-element
139  * @return         head or NULL if queue is empty
141 memq_link_t *memq_peek_n(memq_link_t *head, memq_link_t *tail, uint8_t n,  in memq_peek_n()  argument
146 		/* Use memq peek to get the current head and its mem */  in memq_peek_n()
147 		head = memq_peek(head, tail, mem);  in memq_peek_n()
148 		if (head == NULL) {  in memq_peek_n()
153 		head = head->next;  in memq_peek_n()
156 	return head; /*  queue was not empty */  in memq_peek_n()
160  * @brief Remove and returns the head of queue.
161  * @details Dequeue is destructive so head will change to new head
164  * @param head[in,out] Pointer to head link-element of queue. Will be updated
165  * @param mem[out]     The memory pointed to by head-element
166  * @return             head or NULL if queue is empty
168 memq_link_t *memq_dequeue(memq_link_t *tail, memq_link_t **head, void **mem)  in memq_dequeue()  argument
172 	/* Use memq peek to get the old head and its mem */  in memq_dequeue()
173 	old_head = memq_peek(*head, tail, mem);  in memq_dequeue()
178 	/* Update the head-pointer to point to the new head element */  in memq_dequeue()
179 	*head = old_head->next;  in memq_dequeue()