> When the object is locked by a stack-lock or monitor, or if the object is forwarded by the GC (all of which is indicated by the lowest two bits of the header)

> When the object is locked by a stack-lock or monitor, or if the object is forwarded by the GC (all of which is indicated by the lowest two bits of the header), the upper 62 bits of the first word of the header are interpreted as a pointer to the stack-lock, object monitor or the forwarded location of the object. The term "stack-lock" is new to me. What's that? Is that just when the lock record is stored on the stack? In which case, what is being locked by a monitor, because i would expect the lock record to always be on the stack. Is this about thin vs inflated lock states?