Parallel merge sort useing _beginthreadex windows API in C++ - c++

Question

I'm trying to implement merge sort using win32 _beginthreadex multiple threads in c++. basically it uses _beginthreadex instead of function call to make recursion in each thread. so it will has as many threads as possible. the while loop after the two _beginthreadex call is to check if the children threads finish there job. But when the program access the array a and b, it gives an error that unable to read the memory, I can't find what the problem is. It seems that in the sorting section in children threads the program try to access invalid memory address that info->b goes to the address 0xcccccccc {???}
Thank you
#include "stdafx.h"
#include <windows.h>
#include <iostream>
#include <process.h>
#include <stdlib.h>
#include <time.h>
#include <string>
#include <sstream>
#include <array>
#include <stdio.h>
using namespace std;
struct ThreadInfo
{
int* a;
int* b;
int low;
int high;
bool run;
};
unsigned __stdcall mergesort(void* x) {
ThreadInfo* info = (ThreadInfo*)x;
if ((info->low) < (info->high))
{
int pivot = ((info->low)+(info->high))/2;
ThreadInfo lowInfo;
ThreadInfo highInfo;
lowInfo.a=info->a;
lowInfo.low=info->low;
lowInfo.high=pivot;
lowInfo.run=true;
highInfo.b=info->b;
highInfo.low=pivot+1;
highInfo.high=info->high;
highInfo.run=true;
//HANDLE myhandlerUp, myhandlerDown;
//creat sub-thread
_beginthreadex(NULL, 0, mergesort, &lowInfo, 0, 0);
//WaitForSingleObject(myhandlerUp,INFINITE);
_beginthreadex(NULL, 0, mergesort, &highInfo, 0, 0);
//WaitForSingleObject(myhandlerDown,INFINITE);
//check if any child threads are working
bool anyRun = true;
while (anyRun)
{
anyRun = false;
anyRun = lowInfo.run || highInfo.run;
}
//doing merge sort
int h,i,j,k,low, high;
low = info->low;
high = info->high;
h=low;
i=low;
j=pivot+1;
while((h<=pivot)&&(j<=high))
{
if(info->a[h]<=info->a[j])
{
info->b[i]=info->a[h];
h++;
}
else
{
info->b[i]=info->a[j];
j++;
}
i++;
}
if(h>pivot)
{
for(k=j; k<=high; k++)
{
info->b[i]=info->a[k];
i++;
}
}
else
{
for(k=h; k<=pivot; k++)
{
info->b[i]=info->a[k];
i++;
}
}
for(k=low; k<=high; k++) info->a[k]=info->b[k];
}
info->run = false;
return 0;
}
void main()
{
ThreadInfo info;
int inputArr[12] = {12,10,43,23,-78,45,123,56,98,41,90,24};
int copiedArr[12]={0,0,0,0,0,0,0,0,0,0,0,0};
info.a=inputArr;
info.b=copiedArr;
for(int i=0; i<12; i++)
cout<<info.a[i]<<" ";
cout<<endl;
info.low=0;
info.high=(11);
info.run=true;
_beginthreadex(NULL, 0, mergesort, &info, 0, 0);
bool finish = info.run;
while(finish){
cout<<"Running...."<<endl;
Sleep(1000);
}
cout<<"After run the result is "<<endl;
for(int i=0; i<12; i++)
cout<<inputArr[i]<<" ";
cout<<endl;
getchar();
}