Hi,sirs, I learning this book too, and be happy to know you guys are doing something interesting on this book
my question is about the directory MSEI protocol in the Table8.4 implemented by directory controller.
when directory controller recoreds a block is in E state, how can the directory controller recieve a putS-NonLast or a putS-Last message ? in what situation this sernario will happen ?
from my point of view, directory controller can be in E state when and only when the previous state of dir controller is I and all the caches in the system do NOT have a copy of tbe cache block, and the putS should be a massage send by a cache which have the block in S state, the two condition conflict!!
hope your reply , thanks~