Suppose you have two threads, one creates a TSX transaction, and modifies some data structure. The other thread does no synchronization of any kind and reads the same data structure. Is the transaction atomic to it? I can't actually imagine that it can be true, since there is no way afaik to block or restart it if it tries reading a cache line modified by the transaction.
If the transaction is not atomic, then are the write ordering rules on x86 still respected? If it sees write #2, then it is guaranteed that it must be able to see the previous write #1. Does this still hold for writes that happen as part of a transaction?
I could not find answers to these questions anywhere, and I kind of doubt anyone on SO would know either, but at least when somebody finds out this is a Google friendly place to put an answer.