When use QReadWriteLock and when use QMutex?

[Momergil]

Hello!

I just discovered the existence of this class, QReadWriteLock, and when reading the Qt Assistant files, I noticed it seems very much like QMutex. In fact, the documentation states "In many cases, QReadWriteLock is a direct competitor to QMutex." The problem is that no comparison table was provided to learn when it's appropriate to use which of them, nor teeling in which situations there is no difference between using one or the other.

My question is, therefore: when should one use QReadWriteLock instead of QMutex, and when the contrary should be done?

Thanks,

Momergil