/* ------
   hw3.c: Ski-lift simulation
   ------ */

#include <stdio.h>
#include <stdlib.h>
#include <ProSim4.h>


double ARRIVALRATE;	/* Avg # clients arriving per time unit */
double myP;		/* Inter chait time */
double myT;		/* Travel up-mountain time */


PCBType *Server;	/* The server thread */
PCBType *Generator;	/* The thread that create client threads */

			/* Variables to accumulate statistical data */
double    AccDelay;	/* Cumulative delay of all clients served */
long      NCust;	/* Number of clients served */
			/* Avg delay = AccDelay/NCust */


/* ---------------------------
   Error handling routine
   --------------------------- */
int OnAbort()
{ printf("Aborting the Simulation !!!!\n");
  Abort();
}


/* -------------------------------------------------------
   Client()
   ------------------------------------------------------- */
void ClientProc()
{
   Enqueue(TAIL, Server, NULL, NULL, NULL);

   Passivate(NULL, NULL);      /* Wait for chair */




   Hold(myT);			/* Travel up the mountain */

/*
   printf("Client...Delay = %lf\n", Now - CurrentPtr->ArrivalTime);
*/
   AccDelay += (Now - CurrentPtr->ArrivalTime);
   NCust++;

   Terminate();
}


/* -------------------------------------------------------
   Thread that create clients.... (generate arrivals)
   ------------------------------------------------------- */
void GeneratorProc()
{
   printf("Generator has started.\n");

   while(1)
    { Hold( RateExponential(ARRIVALRATE, 0) );
      Generate("Cli", ClientProc, 0);
    }
}



/* -------------------------------------------------------
   Server()
   ------------------------------------------------------- */
void ServerProc()
{
   PCBType *Client;

   while (1)
   {  
      /* -----------------------------
	 Wait for a chair to come by
         ----------------------------- */
      Hold(myP);

      /* ---------------------
	 First client
         --------------------- */
      if (MyQLength() > 0)
      {  
         Dequeue(HEAD, &Client, NULL, NULL, NULL);
         ReActivate(Client, DONE, NULL);
      }

      /* ---------------------
	 Second client 
         --------------------- */
      if (MyQLength() > 0)
      {  
         Dequeue(HEAD, &Client, NULL, NULL, NULL);
         ReActivate(Client, DONE, NULL);
      }

   }
}

int main(int argc, char **argv)
{
   double SimLength;

   ARRIVALRATE = atof(argv[1]);
   myT = atof(argv[2]);
   myP = atof(argv[3]);
   SimLength = atof(argv[4]);

   printf("%lf %lf %lf %lf\n",
	ARRIVALRATE, myT, myP, SimLength);

   AccDelay = 0.0;
   NCust = 0;

   printf("Init Prosim\n");
   InitProsim(1000, 1000, 1000);

   printf("Activate generator\n");
   Generator = Generate("Gen", GeneratorProc, 0);

   printf("Activate server\n");
   Server = Generate("Serv", ServerProc, 0);

   StartSimulate(SimLength);

   printf("Average Delay = %lf\n", AccDelay/NCust);

   printf("Done.\n");
   Abort();
}