`dbus-crossroads` backend does not immediately apply updates about souvlaki

[Sinono3]

Okay. I think this is because we use a MPSC channel internally (std::sync::mpsc) and we check for these messages using if let instead of while let. This causes us to only get one message every 500 ms which is very bad. We can fix this in two ways:

1. The quick way is changing that if let for a while let, which I think should work. If it blocks the thread for too long we might have to find a way to make it non-blocking.
2. Switching our thread-shared state management to use Arc<Mutex<T>> or Arc<RwLock<T>>. The switch shouldn't be difficult.

Can you try doing one of this fixes on a local copy of souvlaki and see if it works?

[Beinsezii]

Why is conn.process() set to 1000ms by default? In fact why does it even need a duration?

Setting conn.process(Duration::from_millis(0))?; lets me read playback position in real-time like on zbus and so far there's no adverse side effects.

[Beinsezii]

I also don't get the whole loop{if let} vs while let thing. Shouldn't they be functionally equivalent? Where's the 500ms come from?

[Beinsezii]

Okay I see what you meant with while let.

diff --git a/src/platform/mpris/dbus/controls.rs b/src/platform/mpris/dbus/controls.rs
index 6aa5123..a59e228 100644
--- a/src/platform/mpris/dbus/controls.rs
+++ b/src/platform/mpris/dbus/controls.rs
@@ -242,10 +242,10 @@ where
         }),
     );
 
-    loop {
-        if let Ok(event) = event_channel.recv_timeout(Duration::from_millis(10)) {
+    'outer: loop {
+        while let Ok(event) = event_channel.recv_timeout(Duration::from_millis(10)) {
             if event == InternalEvent::Kill {
-                break;
+                break 'outer;
             }
 
             let mut changed_properties = HashMap::new();

To consume all the events at once before processing. That also works. I still find the 1000ms wild though.