Qt

Qt is a relatively high-level framework, which also reflects in its multithreading API. Another defining feature of Qt is that it wraps its own code (QApplication and QMainWindow) along with the use of a meta-compiler (qmake) to implement its signal-slot architecture and other defining features of the framework.

As a result, Qt's threading support cannot be added into existing code as-is, but requires one to adapt one's code to fit the framework.

QThread

A QThread class in Qt is not a thread, but an extensive wrapper around a thread instance, which adds signal-slot communication, runtime support, and other features. This is reflected in the basic usage of a QThread, as shown in the following code:

class Worker : public QObject { 
    Q_OBJECT 

    public: 
        Worker(); 
        ~Worker(); 

    public slots: 
        void process(); 

    signals: 
        void finished(); 
        void error(QString err); 

    private: 
}; 

This preceding code is a basic Worker class, which will contain...