typedef struct __fifo_elem_t {
    struct __fifo_t* prev;
    struct __fifo_t* next;
} fifo_elem_t;

typedef struct __fifo_t {
    fifo_elem_t* head;
    fifo_elem_t* tail;
} fifo_t;

/*
 *
 */
fifo_t*      fifo_create( void );

/*
 *
 */
int          fifo_push( fifo_t* fifo, fifo_elem_t* elem );

/*
 *
 */
fifo_elem_t* fifo_pop( fifo_t* fifo );

/*
 *
 */
int          fifo_destroy( fifo_t** fifo );