| /* |
| Copyright (c) 2012-2014 Martin Sustrik All rights reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), |
| to deal in the Software without restriction, including without limitation |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| and/or sell copies of the Software, and to permit persons to whom |
| the Software is furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| IN THE SOFTWARE. |
| */ |
| |
| #ifndef NN_QUEUE_INCLUDED |
| #define NN_QUEUE_INCLUDED |
| |
| /* Undefined value for initialising a queue item which is not |
| part of a queue. */ |
| #define NN_QUEUE_NOTINQUEUE ((struct nn_queue_item*) -1) |
| |
| /* Use for initialising a queue item statically. */ |
| #define NN_QUEUE_ITEM_INITIALIZER {NN_LIST_NOTINQUEUE} |
| |
| struct nn_queue_item { |
| struct nn_queue_item *next; |
| }; |
| |
| struct nn_queue { |
| struct nn_queue_item *head; |
| struct nn_queue_item *tail; |
| }; |
| |
| /* Initialise the queue. */ |
| void nn_queue_init (struct nn_queue *self); |
| |
| /* Terminate the queue. Note that queue must be manually emptied before the |
| termination. */ |
| void nn_queue_term (struct nn_queue *self); |
| |
| /* Returns 1 if there are no items in the queue, 0 otherwise. */ |
| int nn_queue_empty (struct nn_queue *self); |
| |
| /* Inserts one element into the queue. */ |
| void nn_queue_push (struct nn_queue *self, struct nn_queue_item *item); |
| |
| /* Remove the item if it is present in the queue. */ |
| void nn_queue_remove (struct nn_queue *self, struct nn_queue_item *item); |
| |
| /* Retrieves one element from the queue. The element is removed |
| from the queue. Returns NULL if the queue is empty. */ |
| struct nn_queue_item *nn_queue_pop (struct nn_queue *self); |
| |
| /* Initialise a queue item. At this point it is not a part of any queue. */ |
| void nn_queue_item_init (struct nn_queue_item *self); |
| |
| /* Terminate a queue item. The item must not be in a queue prior to |
| this call. */ |
| void nn_queue_item_term (struct nn_queue_item *self); |
| |
| /* Returns 1 if item is a part of a queue. 0 otherwise. */ |
| int nn_queue_item_isinqueue (struct nn_queue_item *self); |
| |
| #endif |