It's a big deal that we're not setting the dirty bit for variable C in the cache line. This is in order to maintain the principle of isolation, namely, because our transaction hasn't committed, we should not be doing anything to indicate that the cache line is being written to. The state of the cache line mid-transaction must be isolated, so the dirty bit should only be set upon the commit!

Do we have a write buffer here to store the value that need to be written to C when the transaction commits?