feat: deprecate KeepAlive in favor of connection keepalives

The connection-level pings introduced in
95ddb3d are a better mechanism, and
apply to any stream.

mm-client-common/src/lib.rs

@@ -466,20 +466,9 @@ async fn spawn_conn(
     // Spawn a second thread to fulfill request/response futures and drive
     // the attachment delegates.
 
-    let outgoing_clone = outgoing_tx.clone();
-    let waker_clone = waker.clone();
     let _ = std::thread::Builder::new()
         .name("mmclient reactor".to_string())
-        .spawn(move || {
-            conn_reactor(
-                incoming_rx,
-                outgoing_clone,
-                waker_clone,
-                roundtrips_rx,
-                attachments_rx,
-                client,
-            )
-        })
+        .spawn(move || conn_reactor(incoming_rx, roundtrips_rx, attachments_rx, client))
         .unwrap();
 
     if ready_rx.await.is_err() {
@@ -509,8 +498,6 @@ struct InFlight {
 
 fn conn_reactor(
     incoming: flume::Receiver<conn::ConnEvent>,
-    outgoing: flume::Sender<conn::OutgoingMessage>,
-    conn_waker: Arc<mio::Waker>,
     roundtrips: flume::Receiver<(u64, Roundtrip)>,
     attachments: flume::Receiver<(u64, AttachmentState)>,
     client: Arc<AsyncMutex<InnerClient>>,
@@ -537,19 +524,6 @@ fn conn_reactor(
                 let Roundtrip { tx, .. } = in_flight.roundtrips.remove(id).unwrap();
                 let _ = tx.send(Err(ClientError::RequestTimeout));
             }
-
-            // Send keepalives.
-            if !in_flight.attachments.is_empty() {
-                for (sid, _) in in_flight.attachments.iter() {
-                    let _ = outgoing.send(conn::OutgoingMessage {
-                        sid: *sid,
-                        msg: protocol::KeepAlive {}.into(),
-                        fin: false,
-                    });
-                }
-
-                let _ = conn_waker.wake();
-            }
         }
 
         enum SelectResult {

mm-server/src/server/handlers/attachment.rs

@@ -45,7 +45,6 @@ struct AttachmentHandler<'a> {
 
     last_video_frame_recvd: time::Instant,
     last_audio_frame_recvd: time::Instant,
-    keepalive_timer: crossbeam_channel::Receiver<time::Instant>,
 
     // For saving the bitstream to disk in bug reports.
     bug_report_dir: Option<PathBuf>,
@@ -60,9 +59,6 @@ enum AttachmentError {
     ServerError(ErrorCode, Option<String>),
 }
 
-/// How long to wait before kicking the client for inactivity.
-const KEEPALIVE_TIMEOUT: time::Duration = time::Duration::from_secs(30);
-
 pub fn attach(ctx: &super::Context, msg: protocol::Attach) -> Result<(), ServerError> {
     let session_id = msg.session_id;
     let handler = AttachmentHandler::new(ctx, msg)?;
@@ -182,7 +178,6 @@ impl<'a> AttachmentHandler<'a> {
 
         let pointer_lock = None;
 
-        let keepalive_timer = crossbeam_channel::after(KEEPALIVE_TIMEOUT);
         let now = time::Instant::now();
 
         Ok(Self {
@@ -197,7 +192,6 @@ impl<'a> AttachmentHandler<'a> {
 
             last_video_frame_recvd: now,
             last_audio_frame_recvd: now,
-            keepalive_timer,
 
             bug_report_dir,
             bug_report_files: BTreeMap::default(),
@@ -229,9 +223,6 @@ impl<'a> AttachmentHandler<'a> {
                 recv(self.ctx.incoming) -> msg => {
                     match msg {
                         Ok(m) => {
-                            // Reset timer.
-                            self.keepalive_timer = crossbeam_channel::after(KEEPALIVE_TIMEOUT);
-
                             match self.handle_attachment_message(m) {
                                 Ok(_) => (),
                                 Err(AttachmentError::Finished) => return Ok(()),
@@ -267,10 +258,6 @@ impl<'a> AttachmentHandler<'a> {
                         }
                     }
                 },
-                recv(self.keepalive_timer) -> _ => {
-                    debug!("client hung; ending attachment");
-                    return Ok(());
-                }
             }
         }
     }