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#ifndef QUEUE_H
#define QUEUE_H
#include <stdbool.h>
/** A FIFO queue */
typedef struct queue queue_t;
/**
* Creates a new heap-allocated FIFO queue. The queue is initially empty.
*
* @return a pointer to the new queue
*/
queue_t *queue_init(void);
/**
* Enqueues a value into a queue. There is no maximum capacity,
* so this should succeed unless the program runs out of memory.
* This function should be concurrency-safe:
* multiple threads may call queue_enqueue() or queue_dequeue() simultaneously.
*
* @param queue the queue to append to
* @param value the value to add to the back of the queue
*/
void queue_enqueue(queue_t *queue, void *value);
/**
* Dequeues a value from a queue.
* The value returned is the first enqueued value that was not yet dequeued.
* If the queue is empty, this thread should block until another thread enqueues a value.
* This function should be concurrency-safe:
* multiple threads may call queue_enqueue() or queue_dequeue() simultaneously.
*
* @param queue the queue to remove from
* @return the value at the front of the queue
*/
void *queue_dequeue(queue_t *queue);
/**
* Frees all resources associated with a heap-allocated queue.
* You may assume that the queue is already empty.
*
* @param queue a queue returned from queue_init()
*/
void queue_free(queue_t *queue);
#endif /* QUEUE_H */