[cs63201] clarification on Ricart-Agrawala

[Mikhail Nesterenko]

AOS students,

The original paper is available in the additional reading material
section. Ricart-Agrawala's algorithm does not need to maintain the
explicit queue of CS requests because the only comparison is done when
the node decides whether to delay the request or not. For this
decision, the node compares its own timestamp with that of the
requester. Thus, no need for the queue.

Thanks,
-- 
Mikhail