Signals to the client that the server started graceful shutdown procedure.
This function is only usable for server. If this function is called with client side session, this function returns
To gracefully shutdown HTTP/2 session, server should call this function to send GOAWAY with last_stream_id (1u << 31) - 1. And after some delay (e.g., 1 RTT), send another GOAWAY with the stream ID that the server has some processing using
nghttp2_submit_goaway(). See also
nghttp2_submit_goaway(), this function just sends GOAWAY and does nothing more. This is a mere indication to the client that session shutdown is imminent. The application should call
nghttp2_submit_goaway()with appropriate last_stream_id after this call.
This function returns 0 if it succeeds, or one of the following negative error codes: