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

I am not sure if I understand you concern right. Are you saying you would expect lower performance through the use of shared locks?

Here is an example why I started to think about this:
I needed a mechanism to lock out all threads from vdpau in order to be able to clear down all resources. I protected all methods with a shared lock and clear down would grab the exclusive lock. So far no problem but this process is tightly related to error recovery. A thread enters vdpau, grabs the shared lock and needs to check/set the error state. Most of the time it would only check the state but what if a write is required. To work around this issue I needed an additional section for the state variable.