The primary signal is desiredSize on the controller. It can be positive (wants data), zero (at capacity), negative (over capacity), or null (closed). Producers are supposed to check this value and stop enqueueing when it's not positive. But there's nothing enforcing this: controller.enqueue() always succeeds, even when desiredSize is deeply negative.
（本报记者亓玉昆、刘军国、魏哲哲、宋飞、常钦、吴未、沈童睿、向子丰、胡婧怡），更多细节参见新收录的资料
。新收录的资料对此有专业解读
Amanda Silberling
NYT Connections hints today: Clues, answers for March 2, 2026，更多细节参见新收录的资料