[Interest] Crash in QSerialPort when closing?

[Murphy, Sean]

I'm getting a weird issue where I can repeatedly cause a crash to happen in QSerialPort if I attempt to close the serial port when I'm in a slot connected to the readyRead() signal, and I'm just wondering if I'm doing something weird.

I've got a class that inherits from QSerialPort.  I instantiate this object in the UI thread but immediately move it to a separate thread.  This object has a slot, disconnectFromDevice(), that sends a reset command to the serial device.

So the way I intended the software to work is the user clicks the disconnect button in the UI thread, which sends a signal to the serial port object.  That object sends the reset command to the serial device and the serial device responds with an acknowledge response.  The acknowledge response triggers the QSerialPort::readyRead() signal, which triggers my readyRead() slot.  I parse the acknowledge, then emit a signal back to the UI thread letting the UI know that the disconnect was successful, and then call QSerialPort::close() in the serial port object (still inside of my readyRead() slot).

When I execute setup in a debug build, at this point the application crashes with a SIGSEV.  For some reason it kicks me into the disassembler instead of breaking in my code.  If I comment out the close() call, the segfault doesn't happen.

Below is what's shown in the call stack, but since none of my code is shown in the call stack, I don't know if I'm crashing on the close() call itself, or if I crash sometime later because I'm doing something when the port isn't open.  If I set a breakpoint anywhere in my readyRead() slot the crash DOESN'T occur.  I only know that removing the close() call removes the crash.

Any ideas?  Specifically, why am I not seeing any of my calls in the call stack?
Sean

0              ReadOverlappedCompletionNotifier::processCompletionRoutine            qserialport_win.cpp       188         0x6704e8ed
1              AbstractOverlappedEventNotifier::event             qserialport_win.cpp       119         0x6704e6d2
2              QApplicationPrivate::notify_helper         qapplication.cpp               3467       0xa9ede0f
3              QApplication::notify       qapplication.cpp               2888       0xa9eb72b
4              QCoreApplication::notifyInternal              qcoreapplication.cpp      878         0x6b91b572
5              QCoreApplication::sendEvent    qcoreapplication.h          232         0x6b9bee2b
6              QEventDispatcherWin32Private::activateEventNotifier  qeventdispatcher_win.cpp         335         0x6b9646e8
7              QEventDispatcherWin32::processEvents               qeventdispatcher_win.cpp         759         0x6b965de7
8              QEventLoop::processEvents       qeventloop.cpp                136         0x6b919650
9              QEventLoop::exec           qeventloop.cpp                212         0x6b9198eb
10           QThread::exec  qthread.cpp       509         0x6b794f85
11           QThread::run     qthread.cpp       576         0x6b7950ed
12           QThreadPrivate::start    qthread_win.cpp             347         0x6b797ac2
13           msvcrt!_itow_s                C:\windows\syswow64\msvcrt.dll                           0x775d1287
14           msvcrt!_endthreadex   C:\windows\syswow64\msvcrt.dll                           0x775d1328
15           KERNEL32!BaseCleanupAppcompatCacheSupport            C:\windows\syswow64\kernel32.dll                       0x7594338a
16           ??                                           0x16d0ffd4
17           ntdll!RtlpNtSetValueKey              C:\windows\system32\ntdll.dll                 0x77c19f72
18           ??                                           0x166b7660
19           ntdll!RtlpNtSetValueKey              C:\windows\system32\ntdll.dll                 0x77c19f45
20           msvcrt!_endthreadex   C:\windows\syswow64\msvcrt.dll                           0x775d12e5
21           ??


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