A stream created using open-tcp-stream.
Code to be executed while the stream is "noticed".
If you do a process-wait inside the body of some code, and the Lispworks system has no more processes to run, it will wait for some external event. This macro alerts the system to the fact that any event on the socket associated with the given stream should cause the system wake and check the predicates for processes doing a process-wait.
The net effect is that, without using this macro, data coming into the socket will not cause a wake-up. The socket will only be checked again when another event (such as a mouse event) causes the system to wake and re-check the wait function for each waiting processes.
The macro is designed to be used with streams created by the function