How to lock several objects?

Question

I want to lock on two objects at the same time. Why can't I write like such code?

lock (obj1, obj2) 

Should I always write like that?

lock (obj1) {     lock (obj2)     {     } } 

Probably this could be made simpler? Likely it would be better to introduce special private object, and use it for a lock...

Answer 1

Well, this question is way too old but, here is a compact one I figured out, both codes will end up to the same compiled statements (this and the one in the question description):

    lock (obj1) lock (obj2)     {         // your code     }