多线程c++队列的使用

我有一个队列的全局变量，然后一个线程不断的获取数据，向这个队列里面压入，然后另一个线程每次读取队列的第一个元素，然后删掉。

#include<iostream>#include<queue>#include<windows.h>#include<stdlib.h>#include<process.h>#include<opencv2/core/core.hpp>#include<opencv2/imgproc/imgproc.hpp>#include<opencv2/highgui/highgui.hpp>using namespace std;using namespace cv;CRITICAL_SECTION g_cs;VideoCapture cap;std::queue<Mat> myQ;unsigned int __stdcall producer(PVOID para){int i = 0;Mat frame;while (1){cap >> frame;EnterCriticalSection(&g_cs);myQ.push(frame.clone());LeaveCriticalSection(&g_cs);//i++;Sleep(2);}}unsigned int __stdcall consumer(PVOID para){int i = 0;Mat frame;while (1){while (myQ.empty())Sleep(2);EnterCriticalSection(&g_cs);//cout << myQ.front()<<"  ";frame = myQ.front();myQ.pop();LeaveCriticalSection(&g_cs);Sleep(2);imshow("frame", frame);waitKey(1);i++;if (i >= 1000){i = 0;EnterCriticalSection(&g_cs);//一次性清空队列里的所有数据while (myQ.size())myQ.pop();LeaveCriticalSection(&g_cs);Sleep(2);}}}int main(){
cap.open(0);//初始化关键段InitializeCriticalSection(&g_cs);HANDLE tid1, tid2;tid1 = (HANDLE)_beginthreadex(NULL, 0, producer, NULL, 0, NULL);tid2 = (HANDLE)_beginthreadex(NULL, 0, consumer, NULL, 0, NULL);/*等待两个线程结束,这是必须要有的，否则主程序线程和其它子线程是同时执行的，主线程开完子线程之后，直接return 0，退出了，子线程也就退出了*///linux中也有类似的，pthread_joinWaitForSingleObject(tid1, INFINITE);WaitForSingleObject(tid2, INFINITE);CloseHandle(tid1);CloseHandle(tid2);DeleteCriticalSection(&g_cs);system("pause");return 0;}