Suppose I have a std::vector<Item> class member variable where Item is some class with getters and setters.
It is created in one thread (#1) but is filled from the other thread (#2) with push_backs. In the end it is read in the thread #1. The access to it is synchronized only with Windows event objects. The event is set to a signaled state when the vector is filled up.
Should I beware of cross-thread visibility issues (getting stale values) in this scenario? If yes, how could these issues be prevented?
Microsoft says waiting on event objects is enough.
According to MSDN:
The following synchronization functions use the appropriate barriers to ensure memory ordering:
- Functions that enter or leave critical sections
- Functions that signal synchronization objects
- Wait functions
- Interlocked functions
This means if Thread #1 sees the side effect of the event object signaled, it must see the side effect of Thread #2's modification of the vector.