Why can't we lock on a value type?

Question

I was trying to lock a Boolean variable when I encountered the following error :

\'bool\' is not a reference type as require

Answer 1

I think this is one of those cases where the answer to why is "because a Microsoft engineer implemented it that way".

The way locking works under the hood is by creating a table of lock structures in memory and then using the objects vtable to remember the position in the table where the required lock is. This gives the appearance that every object has a lock when in fact they don't. Only those that have been locked do. As value types don't have a reference there is no vtable to store the locks position in.

Why Microsoft chose this strange way of doing things is anyone's guess. They could have made Monitor a class you had to instantiate. I'm sure I have seen an article by an MS employee that said that on reflection this design pattern was a mistake, but I can't seem to find it now.