c++ - How to remove memory leak in Qthreads? 12+Gb leak -

i'm trying speed (qt c++ opencv) program should count number of colors in photos future filtering. there no leak in single-threaded approach, slow.

with adding 8 threads i've speed process 5x times.

the problem starts when switch program multithreading.

there huge memory leak! http://snag.gy/chrrs.jpg

following advises (https://stackoverflow.com/a/12859444) prevented subclassing qthread , implementing run().

here loop counting each pixel in every new image shifted 1 pixel:

colorcountercontroller *cntrl[arrsize];  (int = 0; < box; i++)//x {     (int j = 0; j < box; ++j)//y     {         cv::mat res=process(image,i,j);           //using 1 core         //colors=colordetectcontroller::getinstance()->colorscount(res);          //using 8 cores         cntrl[cnt2%arrsize]= new colorcountercontroller(res,this);          ++cnt2;     }      ++cnt;     emit setstatusprogresssignal((int)(cnt/amnt*100)); }  delete[] *cntrl; 

comments:

when using 1 core (above code) have singleton run colorscount(res) function. in case of 8 cores use same function called colorcountercontroller.

class colorcountercontroller : public qobject{ q_object private: qthread thread; colorcounter *colorcntr; pixalate *pixelate; private slots: void freecolorcntr(){     delete colorcntr; } public: colorcountercontroller(const cv::mat &image,pixalate *pxobj) {     colorcntr= new colorcounter();     colorcntr->setimagethread(image);     colorcntr->movetothread(&thread);     connect(&thread, signal(started()), colorcntr, slot(colorscountthread()));     connect(colorcntr, signal(finished()), &thread, slot(quit()));     connect(colorcntr, signal(finished()), colorcntr, slot(deletelater()));         connect(colorcntr, signal(results(int)), pxobj, slot(results(int)));     thread.start(); }      ~colorcountercontroller() {     thread.quit();     thread.wait();      qdebug() << qstring("controller quit wait");     //delete colorcntr; //err } 

i suppose leak in colorcountercontroller constructor:

        colorcntr= new colorcounter(); 

but how avoid it? code causing error. in destructor:

//delete colorcntr; //err 

and in constructor:

//connect(&thread, signal(finished()), &thread, slot(deletelater())); 

please help!

p.s.

i changed this

delete[] *cntrl; 

to this

    (int = 0; < arrsize; i++){     if (cntrl[i])         delete cntrl[i];     } 

and null pointers @ beginning before cntrl[cnt2%arrsize]

nothing changed

p.p.s. in case want contribute question: https://github.com/ivanesses/curiosity

2 problems cause leakage:

1. pointers new colorcountercontroller objects lost forever (and memory leaked) body of "for" loop run n times (n=box*box) creating n colorcountercontroller objects pointers 8 of them fit array later use delete objects.

2. cntrl array of pointers. need iterate through , call delete (plain delete, not delete[]) on each of it's elements.

3. as found op: must use imagethread.release(); instead of imagethread.deallocate()