#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>

#define dprintf(format,  args...) fprintf(stderr, format, ##args)

#define MAX_WIN_SIZE 32
#define MAX_APP_SIZE 1024

typedef struct rps_hdr_type
{
   unsigned int   sig;       /* tv_usec at creation time    */
   unsigned short magic;     /* 0x1a2b in net byte order    */
   unsigned short len;       /* payload length excludes hdr */
   unsigned char  seq;       /* seq # of this packet        */
   unsigned char  ack;       /* seq # of next rcv packet    */
   unsigned char  win;       /* # of free receive buffers   */
   unsigned char  flags;     /* See bit defs above.         */
}  rps_hdr_t;

/* This structure defines an element of the send or receive */
/* ring buffer.                                             */

typedef struct rps_buf_type
{
   double     ts;             /* Transmit time stamp        */
   rps_hdr_t  hdr;            /* rps hdr                    */
   unsigned   char data[MAX_APP_SIZE];   /* the app data    */
}  rps_buf_t;

/* This structure defines a ring buffer.  Each rps          */
/* has both a sender ring and a receiver ring.              */

typedef struct ring_type
{
   int shutdown;              /* 1 -> connection shutdown   */

   int nextin;                /* next producer slot         */
   int nextout;               /* next consumer item         */

   int slots;                 /* # of free slots            */
   int items;                 /* # of free items            */

   pthread_cond_t  slot_cv;   /* synchronization structs    */
   pthread_mutex_t slot_mtx;

   pthread_cond_t  item_cv;
   pthread_mutex_t item_mtx;

   rps_buf_t bufs[MAX_WIN_SIZE];  /* ring buffers           */
} ring_t;