Original title: Customers not getting the widgets they paid for if they click too fast -or- In C#, the += operator is not merely not guaranteed to be atomic, it is guaranteed not to be atomic
Original title: Customers not getting the widgets they paid for if they click too fast -or- In C#, the += operator is not merely not guaranteed to be atomic, it is guaranteed not to be atomic
A cool bit of foolishness. :)
A C compiler has considerable flexibility here, and would probably do the opposite, evaluating the function first, then x. Probably how one would expect it to go as well. The c# ordering seems strange, but makes sense given a little thought. They went to considerable effort to define the order of such edge cases to make an overall less surprising language.
It is more surprising behavior if it is unexpected. How many people can honestly admit to have read the full language spec??
The less surprising part is perhaps not that it does what you immediately expect, but that it always does the same thing on 32-bit and 64-bit and on x86 and arm, etc. Everywhere the C spec says implementation defined, the C# spec says defined as follows…