xbmc/xbmc — comment on commit fc67f9f1f01626f94e011a0bc95e07c5da37bd0b
File:  line 0
By elupus:

The code above will deadlock I think. Upgrading shared locks is very tricky.
On essence one must exit the shared locks one have then reenter. With the
risk of another thread gets an exclusive lock inbetween.