tree e5df4d9cf7db0cf4e700fe53b959f5b9d8df485d
parent 5570c7c9931d32f7558e08143d32125a745ec56b
author Viktor Dick <vd@perfact.de> 1597173034 +0200
committer Viktor Dick <vd@perfact.de> 1603614994 +0100

Allow tasks to notice if client disconnected

This inserts a callable `waitress.client_disconnected` into the
environment that allows the task to check if the client disconnected
while waiting for the response at strategic points in the execution,
allowing to cancel the operation.

It requires setting the new adjustment `channel_request_lookahead` to a
value larger than 0, which continues to read requests from a channel
even if a request is already being processed on that channel, up to the
given count, since a client disconnect is detected by reading from a
readable socket and receiving an empty result.