Motivation:
Sometimes it can be helpful to limit the number of times a connection
can be used before discarding it. AHC has no such support for this at
the moment.
Modifications:
- Add a `maximumUsesPerConnection` configuration option which defaults
to `nil` (i.e. no limit).
- For HTTP1 we count down uses in the state machine and close the
connection if it hits zero.
- For HTTP2, each use maps to a stream so we count down remaining uses
in the state machine which we combine with max concurrent streams to
limit how many streams are available per connection. We also count
remaining uses in the HTTP2 idle handler: we treat no remaining uses
as receiving a GOAWAY frame and notify the pool which then drains the
streams and replaces the connection.
Result:
Users can control how many times each connection can be used.
If a request times out because no connection could be attained, we should fail the request with the last connection creation error. If no connection creation error is present and there is no active connection, we fail the request with a connectTimeout error.
George Barnett
David Nadoba
Fabian Fett