undefined reference to vtable (class) - c++

Question

I am getting this error:
Linking CXX executable muse3.exe
driver/libmuse_driver.a(qttimer.obj):qttimer.cpp:(.rdata$.refptr._ZTVN8MusECore10InnerTimerE[.refptr._ZTVN8MusECore10InnerTimerE]+0x0): undefined reference to `vtable for MusECore::InnerTimer'
collect2.exe: error: ld returned 1 exit status
mingw32-make[2]: *** [muse\CMakeFiles\muse.dir\build.make:212: muse/muse3.exe] Error 1
mingw32-make[1]: *** [CMakeFiles/Makefile2:600: muse/CMakeFiles/muse.dir/all] Error 2
mingw32-make: *** [Makefile:151: all] Error 2
I understand that the message is a little unclear and the issue is probably with some method.
Here is my .h file:
#ifndef __QTTIMER_H__
#define __QTTIMER_H__
#include <fcntl.h>
#include <QThread>
#include <QBasicTimer>
#include <QTimerEvent>
#include "timerdev.h"
namespace MusECore {
//---------------------------------------------------------
// QtTimer
//---------------------------------------------------------
class InnerTimer : public QObject {
Q_OBJECT
int writePipe;
long int tickCount;
QBasicTimer timer;
public:
void setupTimer(int fd, int timeoutms);
~InnerTimer();
long int getTick();
bool isRunning() { return timer.isActive(); }
protected:
void timerEvent(QTimerEvent *event);
};
class QtTimer : public Timer, public QThread {
int writePipe;
int readPipe;
bool keepRunning;
InnerTimer *innerTimer;
int timeoutms;
public:
QtTimer();
virtual ~QtTimer();
virtual signed int initTimer(unsigned long init);
virtual long unsigned int setTimerResolution(unsigned long resolution);
virtual long unsigned int getTimerResolution();
virtual long unsigned int setTimerFreq(unsigned long freq);
virtual long unsigned int getTimerFreq();
virtual bool startTimer();
virtual bool stopTimer();
virtual long unsigned int getTimerTicks(bool printTicks=false);
void setFindBestTimer(bool ) { }
private:
virtual void run();
};
} // namespace MusECore
#endif //__QTTIMER_H__
And here is the .cpp file:
#include <cstdio>
#include <unistd.h>
#include <fcntl.h>
#include "qttimer.h"
#ifndef TIMER_DEBUG
#define TIMER_DEBUG 1
#endif
#ifdef _WIN32
#define pipe(fds) _pipe(fds, 4096, _O_BINARY)
#endif
namespace MusECore {
QtTimer::QtTimer()
{
if(TIMER_DEBUG)
fprintf(stderr,"QtTimer::QtTimer(this=%p) called\n",this);
innerTimer = NULL;
timeoutms = 10;
readPipe=-1;
writePipe=-1;
}
QtTimer::~QtTimer()
{
if(TIMER_DEBUG)
fprintf(stderr,"QtTimer::~QtTimer(this=%p) called\n",this);
exit(); // thread exit
}
signed int QtTimer::initTimer(unsigned long)
{
if(TIMER_DEBUG)
printf("QtTimer::initTimer(this=%p)\n",this);
int filedes[2]; // 0 - reading 1 - writing
if (pipe(filedes) == -1) {
perror("QtTimer - creating pipe failed");
exit(-1);
}
#ifndef _WIN32
int rv = fcntl(filedes[1], F_SETFL, O_NONBLOCK);
if (rv == -1)
perror("set pipe O_NONBLOCK");
#endif
if (pipe(filedes) == -1) {
perror("QtTimer - creating pipe1");
exit(-1);
}
writePipe = filedes[1];
readPipe = filedes[0];
return filedes[0];
}
long unsigned int QtTimer::setTimerResolution(unsigned long)
{
return 0;
}
long unsigned int QtTimer::setTimerFreq(unsigned long freq)
{
if (freq > 1000)
freq = 1000;
if (freq < 100)
freq = 100;
timeoutms = 1000/freq;
return 1000/timeoutms;
}
long unsigned int QtTimer::getTimerResolution()
{
return 20;
}
long unsigned int QtTimer::getTimerFreq()
{
return 1000/timeoutms;
}
bool QtTimer::startTimer()
{
QThread::start();
return true;
}
bool QtTimer::stopTimer()
{
QThread::quit();
return true;
}
unsigned long int QtTimer::getTimerTicks(bool /*printTicks*/)
{
if(TIMER_DEBUG)
printf("getTimerTicks()\n");
unsigned long int nn;
if (readPipe==-1) {
fprintf(stderr,"QtTimer::getTimerTicks(): no pipe open to read!\n");
return 0;
}
if (read(readPipe, &nn, sizeof(char)) != sizeof(char)) {
fprintf(stderr,"QtTimer::getTimerTicks(): error reading pipe\n");
return 0;
}
//return nn;
return innerTimer != 0 ? innerTimer->getTick() : 0;
}
void QtTimer::run()
{
//bool keepRunning = true;
innerTimer = new InnerTimer();
innerTimer->setupTimer(writePipe, timeoutms); // make sure it is running in the right thread
exec();
}
void InnerTimer::setupTimer(int fd, int timeoutms)
{
tickCount=0;
writePipe = fd;
timer.start(timeoutms, this);
printf("InnerTimer::setupTimer() started\n");
}
InnerTimer::~InnerTimer()
{
timer.stop();
}
void InnerTimer::timerEvent(QTimerEvent *event)
{
//if (tickCount%1000)
//printf("InnerTimer::timerEvent %ld ++++++++++++++++++++++\n",tickCount);
if (event->timerId() == timer.timerId()) {
tickCount++;
write(writePipe,"t",1);
}
}
long int InnerTimer::getTick()
{
return tickCount;
}
} // namespace MusECore
I have read other posts on this error, and they mostly point to some virtual methods that were not defined. But, to me, it seems that everything is defined properly and I also have the destructor defined.
Can anybody point me out to what is wrong?