15.4.4 CancelRequest Message

   CancelRequest messages may be sent, in GIOP versions 1.0 and 1.1, only from clients to servers. CancelRequest messages notify a server that the client is no longer expecting a reply for a specified pending Request or LocateRequest message.

   CancelRequest messages have two elements, encoded in this order:

• A GIOP message header

• A CancelRequestHeader

   15.4.4.1 Cancel Request Header

   The cancel request header is defined as follows:

   module GIOP { // IDL struct CancelRequestHeader { unsigned long request_id; }; };

   The request_id member identifies the Request or LocateRequest message to which the cancel applies. This value is the same as the request_id value specified in the original Request or LocateRequest message.

   When a client issues a cancel request message, it serves in an advisory capacity only. The server is not required to acknowledge the cancellation, and may subsequently send the corresponding reply. The client should have no expectation about whether a reply (including an exceptional one) arrives.