Do I need MemoryBarrier with ReaderWriterLockSlim?

Question

It looks like the mono implementation has no MemoryBarrier calls inside the ReaderWriterLockSlim methods. So when I make any changes inside a write lock, I can receive old cached values in another thread which uses a read lock.

Is it really possible? Should I insert MemoryBarrier before and after the code inside Read and Write lock?

Answer 1

Looking at (what I think is) the mono source, the Mono ReaderWriterLockSlim is implemented using Interlocked calls.

These calls include a memory barrier on x86, so you shouldn't need to add one.