Use IXCSRVR to define the server that is to process requests and send responses. The IXCSRVR macro completes a parameter with data and then calls the XCF service routine. When starting a server, the XCF service routine does not return to the caller until the server stops or fails; that is, the XCF service routine repeatedly calls the server exit routine as long as there are requests to process. Each time it is called, the exit routine of the server processes the request and, as needed, invokes the IXCSEND macro to send a response with the results of the processing. When the server exit routine returns, XCF either calls it again to process the next request or suspends the server task until there is a request to process.