So what's the surprise here? this is exactly why you use locks in the code, because you don't know what the compiler is going to do with your code, and you don't want to know all the details of that. The solution is not to know all those asm details, but to use tools like locks correctly.
edit: after writing lock-free code years ago, and having very subtle bugs like the ones described here, I don't think it is a good idea anymore, unless you are in a very specific scenario.
Comments
So what's the surprise here? this is exactly why you use locks in the code, because you don't know what the compiler is going to do with your code, and you don't want to know all the details of that. The solution is not to know all those asm details, but to use tools like locks correctly.
edit: after writing lock-free code years ago, and having very subtle bugs like the ones described here, I don't think it is a good idea anymore, unless you are in a very specific scenario.
> ...unless you are in a very specific scenario.
Locks can be very slow (relatively). At my last job using lock-free code was necessary for performance in many cases.