Queueing of slots in QT

Couldn't seem to find an answer in the documentation, however I'm not entirely sure I was looking in the right places. I have a signal connected to a slot, for example with my QIODevice connect(port, SIGNAL(readyRead()), SLOT(handleReadyRead())); If the signal readyRead() is emitted twice in quick succession, say before the slot has finished processing, will the slot be called concurrently or queued and run one after the other?