/* dequeue.h
 *	a generalized doubly linked circular list structure
 */

/* macro to return last and first dequeue element
(nb: lastnode is least recently used file descriptor in mfile application)
*/ 
#define lastNode	(qNode->pNode)
#define firstNode	(qNode->nNode)

/* generalized dequeue structure prefix - overlayed on user defined struct */
typedef struct q
	{
	struct q
		*pNode,	/* ptr to prev  node */
		*nNode;	/* ptr to next node */
	int	nodeNum;	/* node number - redundancy/optional */

	/* rest of user defined structure resides here */

	}
	QUEUE;

/* storage for dequeue package */
extern QUEUE	Nodeq;	/* semaphore element - signals start & end of dequeue */
extern QUEUE	*qNode;	/* pointer to element */

/* end of dequeue.h */