I have a Visual Studio C++ 2013 MFC application that writes/reads data from a serial rotary encoder, and sends the read data to a stepper motor. The reading is in a while (flagTrue) {}. The while loop is spooled in a separate thread.
It does the job, but when I try to exit the application graciously,I keep getting this:
'System.ObjectDisposedException' mscorlib.dll
I tried setting timers for 1-2 seconds to let the serial listening finish, but it seems like the listening keeps going even when I seemingly have exited the thread. Here are snippets of the code:
//this is inside of the main window CDlg class
pSerialThread = (CSerialThread*)AfxBeginThread(RUNTIME_CLASS(CSerialThread));
//this is inside the CSerialThread::InitInstance() function
init_serial_port();
//this is the serial listening while loop
void init_serial_port() {
SerialPort^ serialPort = gcnew SerialPort();
while (bSerialListen) {
//do read/write using the serialPort object
}
serialPort->Close();
}
///this is in the OnOK() function
bSerialListen = false;
pSerialThread->ExitInstance();
An incomplete workaround, inspired Hans's answer below, was to have the thread reset a flag after port closes:
SerialPort^ serialPort = gcnew SerialPort();
serialIsOpen = true;
while (bSerialListen) {
//do read/write using the serialPort object
}
serialPort->Close();
serialIsOpen = false;
}
Then inside OnOK() (which does result in a clean exit):
bSerialListen=false;
//do other stuff which normally takes longer than the port closing.
if (serialIsOpen) {
//ask user to press Exit again;
return;
}
OnOK();
}
However, the user always has to press Exit twice, because the following never works
while (serialIsOpen) {
Sleep(100);
//safety counter, do not proceed to OnOK();
}
OnOK();
while expires before the port resets the flag, even if one waits for 10 seconds -- much longer than the user pressing the button twice:
