[QtSerialPort] Simple example crashes

M4chin3

Hi,

i'm trying to use the QtSerialPort Libary (http://qt-project.org/wiki/QtSerialPort). The install process worked fine (with Perl installed) and the library files were copied into my Qt installation. (C:\Tools\Qt\Qt5.0.2\5.0.2\mingw47_32 and some other folders).
The problem is, as soon as i start the simple example of the project wiki (debug or release mode) it crashes with this error:

Problemsignatur:
Problemereignisname: APPCRASH
Anwendungsname: Test.exe
Anwendungsversion: 0.0.0.0
Anwendungszeitstempel: 51a3623c
Fehlermodulname: Qt5Cored.dll
Fehlermodulversion: 5.0.2.0
Fehlermodulzeitstempel: 516367ae
Ausnahmecode: c0000005
Ausnahmeoffset: 00021f3b
Betriebsystemversion: 6.1.7601.2.1.0.256.48
Gebietsschema-ID: 1031
Zusatzinformation 1: 0a9e
Zusatzinformation 2: 0a9e372d3b4ad19135b953a78882e789
Zusatzinformation 3: 0a9e
Zusatzinformation 4: 0a9e372d3b4ad19135b953a78882e789

.cpp file:
@
#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>

#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>
 
QT_USE_NAMESPACE
 
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
 
qDebug() << "Begin";
 
// Example use QSerialPortInfo
foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts()) {
qDebug() << "Name : " << info.portName();
qDebug() << "Description : " << info.description();
qDebug() << "Manufacturer: " << info.manufacturer();
 
// Example use QSerialPort
QSerialPort serial;
serial.setPort(info);
if (serial.open(QIODevice::ReadWrite))
serial.close();
}
 
qDebug() << "End";
return a.exec&#40;&#41;;
}

@

.pro file:
@
#-------------------------------------------------
#
# Project created by QtCreator 2013-05-10T15:50:24
#
#-------------------------------------------------

QT += core
 
QT -= gui
 
QT += serialport
 
TARGET = Test
CONFIG += console
CONFIG -= app_bundle
 
TEMPLATE = app
 
 
SOURCES += main.cpp

@

My setup is:
Windows 7 Prof. 64 bit
Qt 5.0.2 32 bit
QtSerialPort Stable (f301591)

I already tracked the error with debug mode and there i get a "SIGSEGV" "Segmentation fault" error within the file: "qserialportinfo_win.cpp" in line 132 (QByteArray data(datasize, 0)) while creating a QByteArray for the COM device name (datasize = 10 btw). But i think this can't be the error source, creating a QByteArray within my main.c works perfectly.

Any further ideas how i can fix this?

kuzulis

Hi M4chin3.

Here at a forum already there was the same problem, but I can't find a this thread. It is strange. Solutions of this problem, certainly still aren't present because the reason is unclear.

Whether your OS has serial ports? Give please a screenshot from Device Manager (with numbers and names of ports).
Can you reproduce a problem without this code?

@// Example use QSerialPort
QSerialPort serial;
serial.setPort(info);
if (serial.open(QIODevice::ReadWrite))
serial.close();
}@

Can you reproduce a problem with Release branch?

https://qt.gitorious.org/qt/qtserialport/commits/release

M4chin3

Hi,

right now i'm at home. I'll test your recommendations tomorrow.
Just for the information: I've set up a virtual machine here at home with Qt and QtSerialPort and it works. Same installation process, so this should be fine.

I will answer to your questions tomorrow.

Thanks in advance!

kuzulis

For me, this problem doesn't repeat, I can't reproduce it. Probably, you incorrectly compiled library.

quickybr

I got the same error. I followed this tutorial:
http://gracianotorrao.com/2013/05/07/how-to-build-the-qserialport-module-using-qt5-windows-7/

kuzulis

Please try build and install through QtCreator.

mranger90

I just built this with the latest-greatest 5.1 RC1 candidate on Ubuntu 12.04 64 bit. It ran with no problems.

kuzulis

@mranger90,

because this "bug" only for Windows!

quickybr

I got the problem!
On my linux environment (arch Linux x86_64) it works perfectly (I compiled using qt creator).

On my windows 7 I was having some troubles to make it works. I was getting the same dll issues that you're having and I solved, that's what I did:

I reinstalled QT with all the addons (full-installation).
Removed the Perl that I was using (strawberry Perl)
Installed Active Perl (the last version)
Compiled the qtserialport module following this tutorial:
http://gracianotorrao.com/2013/05/07/how-to-build-the-qserialport-module-using-qt5-windows-7/

The only exception was that I got the source by cloning the git repository.

By now it compiles!
Probably it will work to you too.
Good luck ^^

M4chin3

kuzulis:

Hi,

I'm trying to use USB-to-Comport devices with a FTDI IC (FT232R). Here's a picture of my device mger:

"Device manager screen (imgshack)":http://imageshack.us/a/img29/4827/mzma.png

I can reproduce the same error without the lines of code you mentioned. I forgot about this: The error occurs in the head of the foreach loop within the static method "availablePorts()" of class QSerialPortInfo.
I can reproduce the same error with the release branch version of QtSerialPort.

[quote author="kuzulis" date="1371481349"]Hi M4chin3.

Here at a forum already there was the same problem, but I can't find a this thread. It is strange. Solutions of this problem, certainly still aren't present because the reason is unclear.

Whether your OS has serial ports? Give please a screenshot from Device Manager (with numbers and names of ports).
Can you reproduce a problem without this code?

@// Example use QSerialPort
QSerialPort serial;
serial.setPort(info);
if (serial.open(QIODevice::ReadWrite))
serial.close();
}@

Can you reproduce a problem with Release branch?

https://qt.gitorious.org/qt/qtserialport/commits/release[/quote]

M4chin3

quickybr:

I also got strawberry perl, so i tried your way with Active Perl on the WinXp machine.
-> The QtSerialPort lib was compiled fine (same like with strawberry perl). I also could use it in Qt Creator but it didn't find any of my serial ports. I will check about this in detail tomorrow.

Why WinXP machine and not the Win7 one iam actually working with?
-> i dont have admin on the win7 machine. I have to wait for the IT guys untill tomorrow.
:-/

kuzulis

bq. Removed the Perl that I was using (strawberry Perl)
Installed Active Perl (the last version)

Hmm.. It is interesting, thx! May it is a cause of problem? Because I'm using Active perl and don't have a problem.

Can anyone try to check with this difference of Perl?

M4chin3

IT department has to check the licences before installtion, so it might take a while. But i'll try as soon as possible.

quickybr

Yesterday I didn't have tried to communicate. But I tested now and I confirm, it's working properly

M4chin3

Hi everybody,

finally i got ActivePerl installed on the Win7 machine. Sadly it didn't change anything for me :-(. I compiled and installed QtSerialPort both ways: via console and via QtCreator and tested it.

The programm still crashes in the same behaviour as described before.

This is the crash track in detail:
main (QSerialPortInfo::availablePorts()) -> qserialportinfo_win.cpp;line 166 (QString s = devicePortName(deviceInfoSet, &deviceInfoData);) -> qserialportinfo_win.cpp;line 132 (QByteArray data(dataSize, 0);)

The construction of the QByteArray fails somehow and this creates the Qt5Core.dll error. The question is why?

M4chin3

Hi,

okay i' one step further:

WinXP 32bit:
Status:
Couldn't find any serial ports but did not crash like Win7 Pro 64bit. QtSerialPort compiled with Strawberry Perl or ActivePerl didn't matter.

Problem:
Administrator priviliges are needed otherwise "::SetupDiEnumDeviceInfo(deviceInfoSet, index++, &deviceInfoData)" returns true but the &deviceInfoData is emtpy respectivly the device name is empty (QString s = devicePortName(deviceInfoSet, &deviceInfoData))

I'll try to get administrator priviliges tomorrow to try this on Windows7. At least i know how the serial ports are searched on windows systems.

Will this be changed? Otherwise users of my programm will also need administrator priviliges right? Wouldn't be that good.

kuzulis

@M4chin3,

bq. The question is why?

I don't know. For a solution I need to reproduce at itself crash - but I can't.

bq. Otherwise users of my programm will also need administrator priviliges right?

No. Privileges of the administrator aren't required. Most likely you have any other restrictions on your user account.

M4chin3

Hello everyone,

in the last weeks i had no time for further investigation about the error. Today i opened the example project again, ran it and it works! I Didn't change anything in the code and my priviliges on this machine are the same than i posted the last time.

I assume that in the time i didn't touch the project the IT department did a windows update via their updatemanagement that fixed my problem. I'll contact them for a list of updates they did in this time. I hope i get a list from them. Maybe i find a patch that could be related to my error.

I don't have any other explanation for this.

artem_pisarenko

Similar issue.

Using QtSerialPort built from current 'stable' branch (50ab4d) causes simple example (from wiki) to crash in first QSerialPort::open() with segmentation fault (application terminates with exit code 255). Using QtSerialPort built from current 'release' branch (84df6e) works ok.

My setup is:
Win7 Pro x64
Qt 4.8.4

artem_pisarenko

Bisecting between revisions I got following results:

da0c6b works ok
43f7c6 seems works ok but adds messages to debug output: "virtual void QSerialPort::close(): device not open"
50ab4d causes crash (as described in previous post)

(Tests was performed by reusing full rebuild cycle: <module build dir> mingw32-make clean, <module build dir> mingw32-make uninstall, clean <module build dir>, clean <app project>, run qmake on <app project>, ...)