[EMAIL PROTECTED] wrote on Tue, 22 Aug 2006 09:52 -0400:
> What is the purpose of the Request To Send (RTS) and Clear To Send
> (CTS) messages in the IB and other BMI implementations? Is it to
> check if resources are available on the receiver (i.e. to see if a
> matching receive has been posted) or to explicitly tell the receiver
> to post a receive?
The former. I'm sure Patrick would be happy to quote from his rant
on how much IB sucks in imposing this netowrk semantic. :)
> From my discussions with Sam and Murali, they mentioned that in any
> exchange the first message is always unexpected. These messages are
> guaranteed to below a preset size (determined by the BMI method). Any
> expected message should then find a matching receive on the peer. If
> so, why use the RTS and CTS messages?
BMI does not guarantee that receives be preposted. It also does not
look into message contents to divine that, for instance, an
unexpected message implies a following expected message. Even if we
did integrate BMI into the server protocol, there are situations
where you wouldn't know the response size in advance.
-- Pete
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