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Jeong, YunWon
d474353be5
* Keep slot values freelist-eligible Member cells now sit in the object allocation ahead of the extension header, so a slot read is one pointer instead of a boxed slice. A value stored in a slot is not marked published. With threading, only the value that leaves the slot is, so its free can wait out a reader. Without threading a slot read is a single incref. Assisted-by: Grok:4.7 * Address slot members by byte offset A slot member's offset is the byte distance from the object to its inline pointer cell. Loads and stores, including the specialized instructions, use that address. A relative C offset is resolved by adding the object header and the type's basic size. Assisted-by: Grok:4.7 * Keep base slot offsets stable on subclasses Cell 0 sits directly in front of the extension header. Further slots extend away from the object, so a member offset computed for a base class still addresses the same cell on a subclass. Assisted-by: Grok:4.7 * Pack slot cells flush against the extension header On 32-bit targets an odd slot count is not a multiple of ObjExt's alignment. The padding now sits in front of the cells, so cell 0 stays immediately before the header. The non-threading slot load is also the function's return value. Assisted-by: Grok:4.7 * Place weakref lists in front of slot cells A subclass that adds a weakref list no longer inserts it between ObjExt and the object, so inherited member offsets stay valid. Assisted-by: Grok:4.7