// here is a list of common including files
#include <iostream.h>
#include <stdlib.h>
#include <new.h>
#include <sys/types.h>

// type definition
enum boolean {FALSE, TRUE};
enum eventType {ARRIVE, COMP, NONE};  // event type

class jobType
// definition for job class
{
 public:
   double arrivalTime;
   double cpuReq;
   int id;
   jobType * next;            // this is used in job queue
   jobType();                 // constructors
   jobType(double,double);            
   void set(double, double);
};

class eventClass
// definition for event
{
public:
    eventType eventtype;      // event type
    double    eventtime;      // event time
    jobType   job;            // job associated with this event
    eventClass *prev, *next;  // event queue now is a doubly linked
			      // list
    eventClass();             // the constructor
    void create(double,eventType,jobType); 
                              // initialize a event
};

class eventQClass
// definition for event queue
{
private:
   eventClass *head, *tail;
public:
   int count;               // event count
   eventQClass();           // constructor
   boolean Empty();
   void Enqueue(eventClass); 
   eventClass Front();
   void Dequeue();
   int Length();
};


class jobQClass
// queue that holds the waiting jobs
{
private:
   jobType *head, *tail;
 public:
   jobQClass();
   boolean Empty();
   void Enqueue(jobType);
   jobType Front();
   void Dequeue();
};

class Server
// server
{
private:
    boolean busy;            // server status
    int numOfFinished;       // how many jobs finished

    double waitTime;         // this section of variables are for
    double meanWait;         // statistics only
    double tempWait;
    int meanCollected;
    double groupMean[300];   // at most 300 group means collected
    double variance;
    double confInterval;
public:
    jobQClass jobQ;
    Server();                // constructor
    void setBusy();          // set the state of server to be busy
    void setFree();          // set the state of server to be free
    boolean isBusy();        // test if the server is busy
    void increment();        // increment the number of arrivals
    void collectStats(double,double);
                             // collecting statistics
    void printStats();
    int BATCHSIZE;           // group size, used for statistics collection
    int arrivals;            // number of arrivals at the server

    // some friend functions
friend    double getNAvg(int,double*); // calculate average
friend    double getVar(int,double,double*);  
                                       // calculate variance
friend    double getConf(int,double);  // calcualte confidence interval at
                                       // 95% confidence level
};

// external functions
// these are the functions in rand.cc and statis.cc , residing at ~meng/lib/C
extern int    stream(int);    
extern double expntl(double);          // in rand.o
extern double getNAvg(int,double*);    // in statis.o
extern double getVar(int,double,double*);
extern double getConf(int,double);