Orderlock: A New Type of Deadlock and its Implications on HPN Protocol Design#

Weihao Jiang et al. (SJTU, Nanjing U.)

Why: A genuine impossibility result is the kind of conceptual lever that outlasts any benchmark and reshapes how to reason about transport feature combinations.

What: Proves that in-order delivery + lossless transmission + out-of-order capability are jointly impossible without risking a new deadlock class ("Orderlock"), and explores Orderlock-free designs.

How: Formal necessary-and-sufficient-condition proof, plus a case study tuning AI-workload performance under Orderlock-free protocols.

Where applicable: General theory for HPN protocol/hardware co-design — a reasoning tool, not a system.