wait-for-wait-state-collection waits for one of the states in collection to become active, or until some message arrives from another process. Such messages may be a result of creating a new async-io-state associated with the collection, or a result of a call to apply-in-wait-state-collection-process.
wait-for-wait-state-collection returns once any of the states in collection is ready or there is a message.
Typically you would not call
wait-for-wait-state-collection yourself, but it will be called by loop-processing-wait-state-collection. However, sometimes you may want to create the looping code yourself. In the latter case, once
wait-for-wait-state-collection returns, you will need to call call-wait-state-collection to handle the active states or messages in collection.
LispWorks User Guide and Reference Manual - 20 Sep 2017