Fix ping recommendation (#1082)

* don't block tokio

* more

* more

* more

* more

* more

src/device/vi.rs

@@ -221,6 +221,7 @@ fn speed_limiter(device: &mut device::Device) {
             if now < deadline {
                 let dur = deadline - now;
                 spin_sleep::sleep(dur);
+
                 if dur < device.speed_limiter.min_wait_time {
                     device.speed_limiter.min_wait_time = dur;
                 }

src/netplay.rs

@@ -294,6 +294,9 @@ pub fn process_requests(
         } else {
             // unsafe { sdl3_sys::events::SDL_PumpEvents() }; // so the screen doesn't freeze
             process_netplay(device);
+            if device.netplay.as_ref().unwrap().requests.is_empty() {
+                std::thread::sleep(std::time::Duration::from_millis(1));
+            }
         }
     }
 }

src/savestates.rs

@@ -237,6 +237,7 @@ pub fn load_savestate(device: &mut device::Device, rewind: bool, rewind_frame: O
                 if now.elapsed() > timeout {
                     break None;
                 }
+                std::thread::sleep(std::time::Duration::from_millis(1));
             }
         } else if let Ok(mut pool) = device.savestate.rewind_pool.lock()
             && let Some((_key, state)) = pool.pop_last()

src/ui/gui/netplay_wait.slint

@@ -105,7 +105,7 @@ export component NetplayWait inherits Page {
 
                     SpinBox {
                         minimum: 0;
-                        maximum: 16;
+                        maximum: 32;
                         value: NetplayWaitData.input_delay;
                         enabled: NetplayWaitData.recommended_delay != 0;
                         edited => {

src/ui/netplay.rs

@@ -649,7 +649,9 @@ fn update_ping(
                                     .duration_since(std::time::UNIX_EPOCH)
                                     .unwrap()
                                     .as_millis();
-                                let ping = (now - message.timestamp) as f64 / 2.0; // calculate one-way latency
+                                // for lockstep, we need to calculate the two-way latency
+                                // for rollback, this would be the one-way latency (divide by 2)
+                                let ping = (now - message.timestamp) as f64;
                                 pings.push(ping);
                                 if pings.len() > message.num_of_peers * 4 {
                                     // once we have enough samples, average the 3 highest values
@@ -666,7 +668,7 @@ fn update_ping(
                                             };
                                             let latency_frames = (ping_avg / (1000.0 / refresh_rate)).ceil() as i32;
                                             let recommendation =
-                                                (latency_frames + 1).min(16);
+                                                (latency_frames + 1).min(32);
 
                                             if handle.get_netplay_recommended_delay() == 0 {
                                                 handle.set_netplay_input_delay(recommendation);