#include "vpi_user.h"

#define NULL 0L

typedef struct myStruct *myStruct_p;
typedef struct myStruct {
  PLI_INT32 d1;
  PLI_INT32 d2;
  myStruct_p next;
} myStruct_s;

static myStruct_p firstWrk = NULL;

PLI_INT32 consumer_restart(p_cb_data data)
{
  struct myStruct *wrk; /* myStruct is defined in vpi_put_data() example */
  PLI_INT32 status;
  PLI_INT32 cnt, size;
  PLI_INT32 id = (PLI_INT32)data->user_data;

  /* Get the number of structures. */
  status = vpi_get_data(id,(PLI_BYTE8 *)&cnt,sizeof(PLI_INT32));
  assert(status > 0); /* Check returned status. */

  /* allocate memory for the structures */
  size = cnt * sizeof(struct myStruct);
  firstWrk = (myStruct_p)malloc(size);

  /* retrieve the data structures */
  if (cnt != vpi_get_data(id, (PLI_BYTE8 *)firstWrk,cnt))
    return(1); /* error. */

  firstWrk = wrk;
  /* Fix the next pointers in the link list. */
  for (wrk = firstWrk; cnt > 0; cnt--)
    {
      wrk->next = wrk + 1;
      wrk = wrk->next;
    }
  wrk->next = NULL;
  return(0); /* SUCCESS. */
}

PLI_INT32 consumer_save(p_cb_data data)
{
  myStruct_p wrk;
  s_cb_data cbData;
  vpiHandle cbHdl;
  PLI_INT32 id = 0;
  PLI_INT32 cnt = 0;

  /* Get the number of structures */
  wrk = firstWrk;
  while (wrk)
    {
      cnt++;
      wrk = wrk->next;
    }

  /* now save the data */
  wrk = firstWrk;
  id = vpi_get(vpiSaveRestartID, NULL);

  /* save the number of data structures */
  vpi_put_data(id,(PLI_BYTE8 *)cnt,sizeof(PLI_INT32));

  /* Save the different data structures.  Please note that
   * a pointer is being saved.  While this is allowed, an
   * application must change it to something useful on a
   * restart.
   */
  while (wrk)
    {
      vpi_put_data(id,(PLI_BYTE8 *)wrk,sizeof(myStruct_s));
      wrk = wrk->next;
    }
  /* register a call for restart */
  /* We need the "id" so that the saved data can be
   * retrieved.  Using the user_data field of the
   * callback structure is the easiest way to pass this
   * information to retrieval operation.
   */
  cbData.user_data = (PLI_BYTE8 *)id;
  cbData.reason = cbStartOfRestart;

  /* Please see 27.8 vpi_get_data() for a description of
   * how the callback routine can be used to retrieve the
   * data.
   */
  cbData.cb_rtn = consumer_restart;

  cbData.value = NULL;
  cbData.time = NULL;
  cbHdl = vpi_register_cb(&cbData);
  vpi_free_object(cbHdl);
  return(0);
}