Thread Help

[tntcoda]

Hi,

Im having some problems with cross thread communication, basically i get an assert error:

"ASSERT failure in QCoreApplication::sendEvent: "Cannot send events to objects owned by a different thread. Current thread 72fc768. Receiver 'ProDialog' (of type 'progressDlg') was created in thread 50d4058", file kernel\qcoreapplication.cpp, line 296"

Im using signals/slots to send data from the new thread to the ProDialog instance, and im not sure why it doesn't like it :confused the only shared object is the container instance, i havent bothered locking/unlocking this as I know its not in use while the thread is executing, hopefully thats good enough.

Heres some code extracts:

Main window code:

// Create progress dialog
	pro = new progressDlg();
	pro->show();
 
	// Spawn a new worker thread
	enc = new TEnc;
 
       // Connect signals/slots
       connect(enc, SIGNAL(StartingFile(QString)), pro, SLOT(setProgressLabel(const QString&)), Qt::DirectConnection);
	connect(enc, SIGNAL(AddFilesDone(bool)), this, SLOT(AddFilesComplete(bool)));
	connect(enc, SIGNAL(Progress(int, int)), pro, SLOT(setProgress(int, int)), Qt::DirectConnection);
 
	enc->setParams(container, files);
	enc->start(); // start the thread

// Create progress dialog
	pro = new progressDlg();
	pro->show();
	
	// Spawn a new worker thread
	enc = new TEnc;
	
       // Connect signals/slots
       connect(enc, SIGNAL(StartingFile(QString)), pro, SLOT(setProgressLabel(const QString&)), Qt::DirectConnection);
	connect(enc, SIGNAL(AddFilesDone(bool)), this, SLOT(AddFilesComplete(bool)));
	connect(enc, SIGNAL(Progress(int, int)), pro, SLOT(setProgress(int, int)), Qt::DirectConnection);

	enc->setParams(container, files);
	enc->start(); // start the thread

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The TEnc object (QThread subclass)

void TEnc::run()
{
	emit Progress(files.size(), 0);
	QStringList bits;
 
	// do the work
	for(int i = 0; i < files.size(); i++)
	{
		bits = files.at(i).split("/"); // extract file name from path
		if(bits.size() == 0)
			bits = files.at(i).split("\\");
 
		if(bits.size() != 0)
			emit StartingFile("[" + QString::number(i+1) + "/" + QString::number(files.size()) + "] " + bits.at(bits.size() - 1)); // send signal out that we are starting
 
		if(!container->AddItem(files.at(i).toAscii(), NULL))
		{
			emit AddFilesDone(false); // fail with error
			return;
		}
 
		emit Progress(files.size(), i + 1); // update progress
	}	
 
// all done signal
	emit AddFilesDone(true); // singal -> all files done
}

void TEnc::run()
{
	emit Progress(files.size(), 0);
	QStringList bits;
	
	// do the work
	for(int i = 0; i < files.size(); i++)
	{
		bits = files.at(i).split("/"); // extract file name from path
		if(bits.size() == 0)
			bits = files.at(i).split("\\");
			
		if(bits.size() != 0)
			emit StartingFile("[" + QString::number(i+1) + "/" + QString::number(files.size()) + "] " + bits.at(bits.size() - 1)); // send signal out that we are starting
		
		if(!container->AddItem(files.at(i).toAscii(), NULL))
		{
			emit AddFilesDone(false); // fail with error
			return;
		}
		
		emit Progress(files.size(), i + 1); // update progress
	}	
	
// all done signal
	emit AddFilesDone(true); // singal -> all files done
}

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Any ideas what silly mistake ive made this time

Thanks,

Jack

[jpn]

Removed the Qt::DirectConnection parameter. You don't want to invoke direct calls from the worker thread to the GUI thread.