The recently added ProcessWindowFunction has a Context object that allows querying some additional information about the window firing that we are processing. Right now, this is only the window for which the firing is happening. We should extends this with methods that allow querying the current processing time and the current watermark.
Original text by issue creator: This is similar to
FLINK-3674 but exposing time information in window functions. Currently when a timer is fired, all states in a window will be returned to users, including those after the timer. This change will allow users to filter out states after the timer based on time info.