Manage shared variable in multithreading application

 /* Circular Queues */

#include <iostream>
using namespace std;
#include<windows.h>

const int chunk = 512;		//buffer read data 
const int MAX = 2*chunk ;	//queue size
unsigned int Size ;
FILE *fpOut;
FILE *fp=fopen("Test_1K.txt","rb");

//class queue 
class cqueue
{
	public :
		static int front,rear;
		static char *a;
	   cqueue()
	   {
		 front=rear=-1;
		 a=new char[MAX];
	   }
	   ~cqueue()
	   {
		delete[] a;
	   }
};

int cqueue::front;
int cqueue::rear;
char* cqueue::a;

DWORD WINAPI Thread1(LPVOID param)
{	
	int i;

	fseek(fp,0,SEEK_END);
	Size=ftell(fp);				//Read file size
	cout<<"\nsize is"<<Size;
	rewind(fp);

 	for(i=0;i<Size;i+=chunk)	//read data in chunk as buffer half size 
	{
		while((cqueue::rear==MAX-1)); //wait until buffer is full?
			if((cqueue::rear>MAX-1))		
			  cqueue::rear=0;		
		   else{
			   fread(cqueue::a,1,chunk,fp);	//read data from in buffer
 			    cqueue::rear+=chunk;		//increment rear pointer of queue to indicate buffer is filled up with data
				 if((cqueue::front==-1))	
					cqueue::front=0;		//update front pointer value to read data from buffer in Thread2
		   } 
	}
	fclose(fp);
	cout<<"\nQueue write completed\n";
    return 0;
}
DWORD WINAPI Thread2(LPVOID param)
{
	for(int j=0;j<Size;j+=chunk)
	{
		while((cqueue::front==-1)); //wait until buffer is empty
		cqueue::front+=chunk;		//update front pointer after read data from queue
		fwrite(cqueue::a,1,chunk,fpOut);	//write data file
		
	   if((cqueue::front==MAX-1))
		  cqueue::front=0;		//update queue front pointer when it reads upto queue Max size
	}
	fclose(fpOut);
	cout<<"\nQueue read completed\n";
	return 0;
}


void startThreads()
{
    DWORD  threadIDs[2];
	HANDLE threads[2];	
	fpOut=fopen("V-1.7OutFile.txt","wb");
    threads[0] = CreateThread(NULL,0,Thread1,NULL,0,&threadIDs[0]);
    threads[1] = CreateThread(NULL,0,Thread2,NULL,0,&threadIDs[1]);	
	
    if(threads[0] && threads[1])
    {
        printf("Threads Created.(IDs %d and %d)",threadIDs[0],threadIDs[1]);
    }
}

void main()
{
	 cqueue c1;
	 startThreads();
	 system("pause");
}