Interlocked internals

To understand how interlocked internals work under the hood, we're going to see what machine code is being generated when compiling the Interlocked.Increment method. If we just run the program in debug mode and look at the disassembly window, we will see the usual method call.

To see what is really going on, we have to enable all optimizations:

If everything is set, you will see the following code in the disassembly window:

Interlocked.Increment(ref counter);

00007FFEF22B49AE  lea         rcx,[rsi+20h]
00007FFEF22B49B2  lock add    dword ptr [rcx],1