On x86 you can. When xchg is used with a memory parameter it locks the bus. This is true even in the absence of a lock prefix. I included a spinlock implementat

On x86 you can. When xchg is used with a memory parameter it locks the bus. This is true even in the absence of a lock prefix. I included a spinlock implementation in the blog post. If you see any errors with it, then please let me know!