Le 15/12/12 19:16, Fredrik Orderud a écrit :

The current "fair" shared_mutex implementation is great in the sense that it neither favors readers nor writers. This is probably a good property in most situations.

However, there are situations where either reader or writer prioritization can be beneficial. In particular, I'm working on a project where the locking could be significantly stricter without risking introducing deadlocks if read-locks could be guaranteed to have priority over write-locks. I fully understand that a read- or write-priority implementation might have a bigger overhead compared to the existing "fair" shared_mutex implementation, but that is unlikely to be a problem for me.

Is anyone in the boost community experiencing similar problems and/or is there any interest in extending shared_mutex with support for different priority policies?

I think that it will be better to create specific shared mutex classes with read/write/fifo priorities. The interface of these classes must mimic boost::shared_mutex so that we are able to use them with the shared_lock and upgrade_lock.

I have no time to work on this now but if you provide a first implementation I could help you to finish it so that it can be introduced in Boost.Thread.