"QObject::~QObject: Timers cannot be stopped from another thread" in C++ - c++

Question

I got the problem about timers which is
QObject::~QObject: Timers cannot be stopped from another thread
Below is the log data from my terminal.
$ ./boost_tutorials
init done
All done. Exit safely!
QObject::~QObject: Timers cannot be stopped from another thread
Here is my C++ code with thread from boost. I build it via CMakeLists.
#include <boost/thread.hpp>
#include <boost/chrono.hpp>
#include <iostream>
#include <opencv2/opencv.hpp>
class Robot {
public:
Robot() {
cap.open(-1);
SYSTEM_QUIT = false;
if (!cap.isOpened()) {
cout << "Error opening the video" << endl;
SYSTEM_QUIT = true;
}
}
~Robot() {
destroyAllWindows();
cout << "All done. Exit safely!" << endl;
}
void run() {
boost::thread* t1 = new boost::thread(boost::bind(&Robot::imageProcCallback, this));
boost::thread* t2 = new boost::thread(boost::bind(&Robot::simpleCallback, this));
t1->join();
t2->join();
}
void imageProcCallback() {
Mat frame;
int cc = 0;
while(!SYSTEM_QUIT) {
cap >> frame;
if (!msgs.empty()) {
Point pt(rand()%frame.cols, rand()%frame.rows);
putText(frame, msgs.back(), pt, cv::FONT_HERSHEY_COMPLEX, 2, Scalar(0, 255, 0));
}
imshow(filename, frame);
if (waitKey(5) == 27)
SYSTEM_QUIT = true;
}
frame.release();
}
void simpleCallback() {
while(!SYSTEM_QUIT) {
int count = rand() % 100;
std::string str = std::to_string(count);
msgs.push_back(str);
}
}
private:
string filename;
VideoCapture cap;
bool SYSTEM_QUIT;
std::vector<std::string> msgs;
};
void main() {
Robot robot;
robot.run();
}