CDB being slowed down by QSetting::sync()

Debugging in QtCreator on windows requires use of CDB. Note, however, this bug is not specific to QtCreator - it also happens if you run CDB on the command line.

Now try debugging the following program:

#include <QSettings>
#include <QDir>

int main(int, char *[])
 {
     for (int i=0; i<1000;++i) {
         QSettings settings(QDir::temp().absoluteFilePath("test.ini"), QSettings::IniFormat);
         settings.setValue("what", i);
         settings.sync();
     }
}
  

If you do it from within QtCreator, ensure you have the debugger log open.

What you will notice is that every single call to sync result in this line being printed:

Module loaded: C:\WINDOWS\System32\psapi.DLL

Which might slow down usage of CDB a lot.

I don't really know what is going on insite sync() (and I ran out of attention span before debugging in there), but I wonder if the above load could be avoided.