C ++超过2个线程崩溃

Question

我是C ++的初学者，我遇到了问题。如果我做一个或两个线程，那么程序运行正常。如果我做了超过2个线程，那么当我按住“q”（GetAsyncKeyState（81））时它会崩溃。另外，有没有办法加快这个过程？提前谢谢。

#include <windows.h>
#include <iostream>
#include <stdio.h>
#include <string>
#include <thread>
#include <vector>

using namespace std;

/* Globals */
int ScreenX = 400;
int ScreenY = 400;
int CenterX = 686;
int CenterY = 410;
BYTE* ScreenData = 0;
HDC hScreen;
HBITMAP hBitmap;
HDC hdcMem;
HGDIOBJ hOld;
BITMAPINFOHEADER bmi;

void ScreenCap()
{
    hScreen = GetDC(NULL);

    hBitmap = CreateCompatibleBitmap(hScreen, ScreenX, ScreenY);

    hdcMem = CreateCompatibleDC (hScreen);
    hOld = SelectObject(hdcMem, hBitmap);
    BitBlt(hdcMem, 0, 0, ScreenX, ScreenY, hScreen, CenterX - 150, CenterY - 150, SRCCOPY);
    SelectObject(hdcMem, hOld);

    bmi = {0};
    bmi.biSize = sizeof(BITMAPINFOHEADER);
    bmi.biPlanes = 1;
    bmi.biBitCount = 32;
    bmi.biWidth = ScreenX;
    bmi.biHeight = -ScreenY;
    bmi.biCompression = BI_RGB;
    bmi.biSizeImage = 0;// 3 * ScreenX * ScreenY;

    if(ScreenData)
        free(ScreenData);
    ScreenData = (BYTE*)malloc(4 * ScreenX * ScreenY);

    GetDIBits(hdcMem, hBitmap, 0, ScreenY, ScreenData, (BITMAPINFO*)&bmi, DIB_RGB_COLORS);

    SelectObject(hdcMem, hBitmap);
    DeleteObject(hOld);

    ReleaseDC(GetDesktopWindow(),hScreen);
    DeleteDC(hdcMem);
}

inline int PosB(int x, int y)
{
    return ScreenData[4*((y*ScreenX)+x)];
}

inline int PosG(int x, int y)
{
    return ScreenData[4*((y*ScreenX)+x)+1];
}

inline int PosR(int x, int y)
{
    return ScreenData[4*((y*ScreenX)+x)+2];
}

bool ButtonPress(int Key)
{
    bool button_pressed = false;

    while(GetAsyncKeyState(Key))
        button_pressed = true;

    return button_pressed;
}

struct Foo {};

void ThreadT(const Foo& f)
{
    while (true)
    {
        Sleep(16);
        if (GetAsyncKeyState(81))
        {
            ScreenCap();
            int tobreak = 0;
            //POINT Highest;

            for (int x = 0; x < ScreenX; x++)
            {
                if (tobreak == 1)
                    break;
                for (int y = 0; y < ScreenY; y++)
                {
                    if (tobreak == 1)
                        break;

                    int Red = PosR(x, y);
                    int Green = PosG(x, y);
                    int Blue = PosB(x, y);

                    if (Blue < 100 && Red < 100 && Green > 200)
                    {
                        x = (x + (CenterX - 150));
                        y = (y + (CenterY - 150));

                        //cout << ">:D ";
                        /*POINT pos;
                        GetCursorPos(&pos);

                        int DX = x - CenterX;
                        int DY = y - CenterY;
                        //int DX = pos.x - x;
                        //int DY = pos.y - y;

                        //SetCursorPos(x + DX, y + DY);
                        SetCursorPos(pos.x + DX, pos.y + DY);*/
                        //SetCursorPos(x, y);

                        /*POINT newPos;
                        Sleep(1000);
                        GetCursorPos(&newPos);
                        cout << x << ", " << y << " / " << newPos.x << ", " << newPos.y << endl;*/

                        //cout << pos.x + DX << ", " << pos.y + DY << endl;
                        //cout << x << ", " << y << endl;
                        SetCursorPos(x, y);
                        tobreak = 1;
                    }
                }
            }
        }
    }
}

int main()
{
    vector<thread> threads;
    for (int i = 0; i < 1; i++)
    {
        threads.push_back(thread(ThreadT, Foo()));
    }

      // do some other stuff

      // loop again to join the threads
    for (auto& t : threads)
        t.join();

    system("PAUSE");
    return 0;
}