Is "Finished Receiving message without Finished Sending" protocol violation?

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FIXP - FIX performance session layer specification

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Is "Finished Receiving message without Finished Sending" protocol violation? #61

Closed ujos closed 6 years ago

ujos commented 6 years ago

What if remote peer sends Finished Receiving message while local peer did not send Finished Sending message. Is this Protocol Violation case?

donmendelson commented 6 years ago

I think yes. This should be added to a list of protocol violations.

adkapur commented 6 years ago

Yes generally speaking any thing received out of sequence will be terminated such as sending FinishedReceiving before FinishedSending, sending Terminate after FinsihedSending but before FinishedReceiving etc

ujos commented 6 years ago

sending Terminate after FinsihedSending but before FinishedReceiving etc

Why Terminate before FinishedReceiving is a protocol violation?

donmendelson commented 6 years ago

@ujos , an edge case: if the peer sent FinishedSending but then violated the protocol by sending another application message, it seems you would be obligated to terminate immediately. But that might be counter to your best interests if you had other messages queued up before responding with FinishedReceiving. A bit of a mess. Bad behavior should have consequences.

ujos commented 6 years ago

I'm not sure if I understand the case.

If initiator of Finalization sends Terminate before receiving FinishedReceiving - it is OK. It requires to close connection for some reason.
If acceptor of Finalization sends Terminate before sending FinishedReceiving - it is also OK as Terminate message can be sent in parallel to sending FInishedSending.