Segmentation Fault (Core dumped) Wt With Qt helloqt - c++

Question

I Wrote before but the details was not explained.
I explain step by step what I do;
Witty installation Guide Ubuntu
I did in order what ever said in this page.
sudo apt-get install gcc g++ libboost-all-dev cmake make
sudo apt-get install libssl-dev libfcgi-dev
sudo apt-get install libpq-dev libmysqlclient-dev firebird-dev
sudo apt-get install libpng12-dev libgraphicsmagick1-dev libhpdf-dev libpng12-dev libpango1.0-dev mesa-common-dev
sudo apt-get install asciidoc libqt4-dev
sudo apt-get install doxygen graphviz
wget -c http://kent.dl.sourceforge.net/sourceforge/witty/wt-3.3.4.tar.gz
tar xvxf wt-3.3.4.tar.gz
cd wt-3.3.4
mkdir build
cd build
cmake ..
make
make -C examples
and Test helloqt.wt test
./helloqt.wt --http-port 10000 --http-addr 0.0.0.0 --docroot .
Every things work fine
and then I changed someline for Qt events loop working
// Needed when using WQApplication with Qt eventloop = true
#include <QApplication>
Dictionary::Dictionary(const WEnvironment& env)
: WQApplication(env , true )
{
/*
* Note: do not create any Qt objects from here. Initialize your
* application from within the virtual create() method.
*/
}
.
.
.
int main(int argc, char **argv)
{
// Needed for Qt's eventloop threads to work
QApplication app(argc, argv);
return WRun(argc, argv, &createApplication);
}
still result is fine everything OK. eventloops( signal/slot working )
and I clean everything with
make clean
add line to cmakefiles.txt QtNetwork
.
.
.
IF(ENABLE_QT4)
FIND_PACKAGE(Qt4 REQUIRED QtCore QtGui QtNetwork)
IF(QT_FOUND)
INCLUDE(${QT_USE_FILE})
ENDIF(QT_FOUND)
ENDIF(ENABLE_QT4)
.
.
.
and also add to wtwithqt examples cmakelist.txt ${QT_QTNETWORK_LIBRARY}
FIND_PACKAGE(Qt4 COMPONENTS QtCore QtGui QtNetwork )
SET(QT_USE_QTNETWORK true)
INCLUDE(${QT_USE_FILE})
to below
IF(COMMAND cmake_policy)
CMAKE_POLICY(SET CMP0003 NEW)
ENDIF(COMMAND cmake_policy)
SET(BUILD_WTWITHQT true)
IF (NOT MULTI_THREADED_BUILD)
SET(BUILD_WTWITHQT false)
ENDIF (NOT MULTI_THREADED_BUILD)
IF (NOT QT_FOUND)
SET(BUILD_WTWITHQT false)
ENDIF (NOT QT_FOUND)
IF (NOT BUILD_WTWITHQT)
MESSAGE(STATUS "** Not building wtwithqt example.")
MESSAGE(STATUS " wtwithqt example requires a Qt4 installation.")
ELSE (NOT BUILD_WTWITHQT)
MESSAGE("\n\n " + ${QT_QTCORE_LIBRARY} + " \n" + ${QT_QTGUI_LIBRARY} + "\n" + ${QT_QTNETWORK_LIBRARY} + "\n" + ${QT_LIBRARIES} + "\n\n" )
FIND_PACKAGE(Qt4 COMPONENTS QtCore QtGui QtNetwork )
SET(QT_USE_QTNETWORK true)
INCLUDE(${QT_USE_FILE})
SUBDIRS(lib)
ADD_DEFINITIONS(-DWT_NO_SLOT_MACROS)
QT4_GENERATE_MOC(${CMAKE_CURRENT_SOURCE_DIR}/QtObject.h
${CMAKE_CURRENT_BINARY_DIR}/moccedQtObject.C)
WT_ADD_EXAMPLE(helloqt.wt
hello.C
QtObject.C
${CMAKE_CURRENT_BINARY_DIR}/moccedQtObject.C
)
TARGET_LINK_LIBRARIES(helloqt.wt
wtwithqt
${QT_QTCORE_LIBRARY}
${QT_QTGUI_LIBRARY}
${QT_QTNETWORK_LIBRARY}
${QT_LIBRARIES}
)
#
# If you have Wt installed somehwere, you should use the
# installed Wt header files for your own Wt projects.
# e.g. INCLUDE_DIRECTORIES(/usr/local/wt/include)
# instead of the following:
#
INCLUDE_DIRECTORIES(
${WT_SOURCE_DIR}/src
${CMAKE_CURRENT_SOURCE_DIR}/lib
${QT_QTCORE_INCLUDE_DIR}
${QT_QTNETWORK_INCLUDE_DIR}
${QT_INCLUDE_DIR}
)
ENDIF (NOT BUILD_WTWITHQT)
and add to QTcpSocket to function below
QtObject.h
// This may look like C code, but it's really -- C++ --
#ifndef QTOBJECT_H_
#define QTOBJECT_H_
#include <QThread>
#include <QTcpSocket>
class Dictionary;
/*! \class QtObject
* \brief A simple Qt object with sample signal and slot.
*
* This simple object class demonstrates that the Qt signal/slot
* mechanism may be used alonglisde Wt's signal/slot mechanism.
*/
class QtObject : public QObject
{
Q_OBJECT;
public:
QtObject(Dictionary *wt_, QObject *parent = 0);
void passGreet(const QString&);
QTcpSocket* socket;
signals:
void greet(const QString&);
public slots:
void doGreet(const QString&);
void Connected();
private:
Dictionary *wt_;
};
#endif // QTOBJECT_H_
QtObject.C file
#include "HelloApplication.h"
#include "QtObject.h"
#include <QHostAddress>
QtObject::QtObject(Dictionary *wt, QObject *parent)
: QObject(parent),
wt_(wt)
{
socket = new QTcpSocket();
QHostAddress adr;
adr.setAddress("192.168.0.2");
socket->connectToHost(adr,17776);
QObject::connect(socket,SIGNAL(connected()),this,SLOT(Connected()));
}
void QtObject::passGreet(const QString& name)
{
emit greet(name);
}
void QtObject::doGreet(const QString& name)
{
wt_->doGreet(name);
}
void QtObject::Connected(){
std::cout << "\n\nCONNNECTED\n\n";
emit greet(QString("QString"));
}
From this time
cml#cml-All-Series:~/wt-3.3.4/build$ make clean
cml#cml-All-Series:~/wt-3.3.4/build$ cmake ..
cml#cml-All-Series:~/wt-3.3.4/build$ make -j8
cml#cml-All-Series:~/wt-3.3.4/build$ make -C examples/wtwithqt
cml#cml-All-Series:~/wt-3.3.4/build/examples/wtwithqt$ ./helloqt.wt charts.wt --http-port 10000 --http-addr 0.0.0.0 --docroot .
[2015-Aug-22 10:34:04.692004] 3116 - [info] "WServer/wthttp: initializing built-in wthttpd"
[2015-Aug-22 10:34:04.693292] 3116 - [info] "wthttp: started server: http://0.0.0.0:10000"
when click on browser 0.0.0.0:10000
page is incoming and
socket emitting Connected() signals and Connected() SLOT Work
print screen to std::cout << "\n\nCONNNECTED\n\n";
and application
crashed. Segmentation fault and Core Dumped
I can not find what is wrong?
I Debug Qt Creator
WWebWidget.C file stopped there
bool WWebWidget::canOptimizeUpdates()
{
-> return WApplication::instance()->session()->renderer().preLearning();
}
Qt Creator Debugger says ->
The inferior stopped because it received a signal from the Operating System.
Signal name :
SIGSEGV
Signal meaning :
Segmentation fault

Answer 1

There talking about the solution
in my code I delete WText object after there is no fail seg fault...
this is not solution for me but I can use it

Answer 2

Wt::WApplication* app = Wt::WApplication::instance();
app->enableUpdates(true);
Wt::WApplication::UpdateLock uilock(app);
if( uilock ){
button->setText("Test"); //Here is Editable Widget
app->trigerUpdate();
app->enableUpdates(false);
}
For a big work you lock application and
control if locked change any thing
ServerPUSH.c