The Autosar SOME/IP Specification states the following two statements:
"[PRS_SOMEIP_00927] A server shall not send a response message for a request with a specific Request ID until the corresponding request message has been received."
"[PRS_SOMEIP_00539] A SOME/IP error message (i.e. return code 0x01 - 0x1f) shall not be answered with an error message.
Why do we need the second requirement? Would the first requirement not be sufficient, as it already makes sure that we only should receive an error message after a request? An Error after an Error would not comply with this already, as I understand.
Or is the second requirement created for the case that a client would reply with an error message to a server for example, after the server sent an error already? In which legitimate cases would a client send an response/ error message back to the server? Is the client not only sending Requests to the Server?
Thank you very much for reading!
I did not find anything in the specefication going into more detail about when a client would send error messages or if a server can send requests to the client.