Multithreading

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Donotalo

Trainee

Posts: 39

Location: Bangladesh

Thursday, May 8th 2008, 3:00pm

Multithreading

I've some computational tasks to do. Like generating 1 million vector<short> by computation and displaying them in a QTableWidget. I want that whenever a vector<short> is generated, it will be added at the last of QTableWidget and shown immediately. So that the so-far progress is always known. What is the proper way to do that?

Here is what I tried.

I've subclassed QThread for the computation and passed QTableWidget* to it for displaying purpose. Here is the subclass' cpp file:

Source code

void CodewordThread::initialize(int order, int vc, int vs, const short* _R, QTableWidget* tW) {
	vector_size = vs;
	tableWidget = tW;
	cgen.initialize(order, vc, vector_size, _R);
}

void CodewordThread::run() {
	long long i, j, k;
	pair< set< vector<short> >::iterator, bool> pr;
	QString str;
	QTableWidgetItem *item;

	k = cgen.getCount();
	tableWidget->setRowCount(k);
	for (i = 0; i < k; i++) {
		pr = codewords.insert(cgen.getData());
		if (pr.second) {
			str = "";
			for (j = 0; j < vector_size; j++)
				str += QString("%1").arg((*(pr.first))[j]);
			item = new QTableWidgetItem(str);
			tableWidget->setItem(i, 0, item);
		}
	}
}

The QTableWidget* is initialized in a QDialog subclass. I tested run()'s functionality there and the QTableWidget was properly shown with all the values. But nothing is shown if I use it here.

~Donotalo()