Details
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Bug
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Resolution: Invalid
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P2: Important
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None
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5.12.12
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None
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Linux/X11
Description
I have already read from https://bugreports.qt.io/browse/QTBUG-13505
The problem I encountered is quite different from 13505
I want to implement the plugin hot update function by using QFileSystemWatcher and QPluginLoader,like this:
{
m_pluginPath = "libtestplugin.so";
m_pfilewatcher = new QFileSystemWatcher(this);
m_pfilewatcher->addPath(m_pluginPath);
m_ploader = new QPluginLoader(m_pluginPath);
m_ploader->setLoadHints(0);
if(m_ploader->load()){
if(m_pinstance= m_ploader->instance()){
m_pabs = dynamic_cast<AbstractProcess *>(m_pinstance);
m_pwgt = m_pabs->GetWidget();
}
}else{
qDebug()<<m_ploader->errorString();
}
m_pwgt->show();
this->setCentralWidget(m_pwgt);
connect(m_pfilewatcher,
&QFileSystemWatcher::fileChanged,
this,
&MainWindow::slotfilechange);
}
void MainWindow::slotfilechange(const QString &path)
{
QTimer::singleShot(2000, this, [=](){
m_pfilewatcher->addPath(m_pluginPath);
if(m_pinstance){
delete m_pinstance;
m_pinstance = nullptr;
}
if (m_ploader) {
bool flag = m_ploader->unload();
qDebug() << "unload result =" << flag;
delete m_ploader;
m_ploader = nullptr;
m_pabs = nullptr;
m_pwgt = nullptr;
}
m_ploader = new QPluginLoader(m_pluginPath);
m_ploader->setLoadHints(0);
if(m_ploader->load()){
if(m_pinstance = m_ploader->instance()){
m_pabs = dynamic_cast<AbstractProcess *>(m_pinstance);
m_pwgt = m_pabs->GetWidget();
}
}else{
qDebug()<<m_ploader->errorString();
}
m_pwgt->show();
this->setCentralWidget(m_pwgt);
});
}
Operation process
1. Start the main program and load the. so file
2. Delete the. so file
3. Copy a new. so file to the directory
4. Observation results
Can browse attachment videos, a success ,a fail (unload res is always true)
When the. so file is deleted and an unload is triggered, it is found that( use cat /proc/pid/maps | grep libdisplay.so)
7f8a92a000-7f8a931000 r-xp 00000000 103:05 7355231 libdisplay.so (deleted) , Always output this when it fails
It seems that libdisplay.so has not been completely uninstalled
I don't think it's a Qt issue, it should be a problem with the dynamic library code(Business code cannot be uploaded)
I deleted most of the business code and was able to achieve hot updates, but I couldn't find the root cause
I would like to ask, in this situation, which direction should I investigate the problem from? Thank you
