I don't recall anyone mentioning a very common usage in a client-server protocol.
Consider a "server" that either suspends its client or has the client wait on an ECB for completion of the request. The client PC's (space-switch) to the server. The server queues the requests, and has the client thread wait (or suspend) Upon completion of the request the server -- schedules an SRB back to the client's home space with which to resume the client thread or -- issues XM Post back to the client's home space to POST (if it truly knows that the space is still valid) and the system in many cases will schedule an SRB to that space. "Truly knowing" may not be possible. or -- implements a safe XM Post protocol, such as scheduling an SRB with STOKEN to the client's home space, validating the client's TCBTOKEN, then issuing branch-entry POST All of these result in an SRB running in the client's space on behalf of the server.. Peter Relson z/OS Core Technology Design
