chain_head_listener: Add comment on reason for `spawn`
@@ -89,6 +89,10 @@ impl ChainHeadUpdateListener {
let logger = logger.clone();
let subscribers = subscribers.clone();
+ // A subgraph that's syncing will not regularly pull
+ // chain head updates from the channel, to prevent a
+ // full channel from stopping all updates each update is
+ // sent in its own task.
tokio::spawn(sender.send(update.clone()).then(move |result| {
if result.is_err() {
// If sending to a subscriber fails, we'll assume that
