c言語が難しい-キューの実現

#define NULL 0
#define FALUSE -1

struct queue_def
{
  unsigned char *head;
  unsigned char *tail;
  unsigned char *buffer;
  unsigned char block_size;
  unsigned char block_deep;
};

/*
 * @bief  :
 * @input : struct queue_def *queue : input queue
 *          unsigned int buffer_deep : queue deep
 *          unsigned char block_size : operator buffer unit
 * @output: FALSE :queue is fully
 *          NULL  :pop sucess
 * @data  : 2018.12.19
 * @author: martin
 */
void queue_init(struct queue_def *queue,
                unsigned int buffer_deep,
                unsigned int block_size)
{
  queue->block_size = block_size;
  queue->buffer = (unsigned char*)malloc(buffer_deep*block_size);
  queue->head = queue->buffer;
  queue->tail = queue->tail;
  queue->block_deep = block_deep;
}

/*
 * @bief  :
 * @input : struct queue_def *queue : input queue
 *          unsigned char *dest : operator array
 *          unsigned char buffer_size : operator array lenght
 * @output: FALSE :queue is empty
 *          NULL  :pop sucess
 * @data  : 2018.12.19
 * @author: martin
 */
int queue_push(struct queue_def *queue,unsigned char *dest,unsigned char buffer_size)
{
  if((queue->block_size == (&queue->tail-&queue->head))
     || (&queue->tail == (&queue->buffer+queue->block_deep*queue->block_size))
     || (buffer_size > queue->block_size)){
    return FALSE;
  }else{
    /* critical segment */
    queue->tial += queue->block_size;
    if (&queue->tail == (&queue->buffer+queue->block_deep*queue->block_siz))
        queue->tail = queue->buffer;
    /* critical segment  */
    memset(queue->tail,0,queue->buffer_size);
    memcpy(queue->tail,dest,buffer_size);
  }
  return NULL;
}

/*
 * @bief  :
 * @input : struct queue_def *queue : input queue
 * @output: FALSE :queue is empty
 *          NULL  :pop sucess
 * @data  : 2018.12.19
 * @author: martin
 */
int queue_pop(struct queue_def *queue,unsigned char *source,unsigned char buffer_size)
{
  if(&queue->tail == &queue->head)
    return FALSE;
  }else{
    memcpy(source,queue->head,buffer_size);
    /* critical segment */
    queue->head += queue->block_size;
    if (&queue->head == (&queue->buffer+queue->block_deep*queue->block_siz))
        queue->head = queue->buffer;
    /* critical segment  */

  }
  return NULL;
}