[pavon]

In C++ I would consider the best option in those cases would be for the function that performs the operation to return an error rather than throw an exception. That way you avoid the race condition, but also don't have to worry about the overhead of calling it in a tight loop.

If the library you are using does throw exceptions, then I would probably start with just using exception handling. Then if I notice poor performance, add an initial check, purely as an optimization, while keeping the exception handling to deal with race condition.