Fix a crash when closing the main Ui

Also make sure to dispose the OpenAL context to not leak memory when
unloading the emulation context.

Ryujinx.Audio/Renderers/OpenAL/OpenALAudioOut.cs

@@ -101,6 +101,7 @@ namespace Ryujinx.Audio
             }
 
             _tracks.Clear();
+            _context.Dispose();
         }
 
         /// <summary>

Ryujinx.HLE/HOS/Horizon.cs

@@ -107,6 +107,7 @@ namespace Ryujinx.HLE.HOS
         public Keyset KeySet => Device.FileSystem.KeySet;
 
         private bool _hasStarted;
+        private bool _isDisposed;
 
         public BlitStruct<ApplicationControlProperty> ControlData { get; set; }
 
@@ -741,8 +742,10 @@ namespace Ryujinx.HLE.HOS
 
         protected virtual void Dispose(bool disposing)
         {
-            if (disposing)
+            if (!_isDisposed && disposing)
             {
+                _isDisposed = true;
+
                 KProcess terminationProcess = new KProcess(this);
 
                 KThread terminationThread = new KThread(this);

Ryujinx/Ui/MainWindow.cs

@@ -31,6 +31,8 @@ namespace Ryujinx.Ui
 
         private static GlScreen _screen;
 
+        private static AutoResetEvent _screenExitStatus = new AutoResetEvent(false);
+
         private static ListStore _tableStore;
 
         private static bool _updatingGameTable;
@@ -299,6 +301,8 @@ namespace Ryujinx.Ui
 
                 _emulationContext = device;
 
+                _screenExitStatus.Reset();
+
 #if MACOS_BUILD
                 CreateGameWindow(device);
 #else
@@ -337,6 +341,8 @@ namespace Ryujinx.Ui
 
             DiscordIntegrationModule.SwitchToMainMenu();
 
+            _screenExitStatus.Set();
+
             Application.Invoke(delegate
             {
                 _stopEmulation.Sensitive            = false;
@@ -371,12 +377,17 @@ namespace Ryujinx.Ui
             if (device != null)
             {
                 UpdateGameMetadata(device.System.TitleIdText);
+
+                if (_screen != null)
+                {
+                    _screen.Exit();
+                    _screenExitStatus.WaitOne();
+                }
             }
 
             Dispose();
 
             Profile.FinishProfiling();
-            device?.Dispose();
             DiscordIntegrationModule.Exit();
             Logger.Shutdown();
             Application.Quit();
@@ -510,13 +521,11 @@ namespace Ryujinx.Ui
 
         private void Exit_Pressed(object sender, EventArgs args)
         {
-            _screen?.Exit();
             End(_emulationContext);
         }
 
         private void Window_Close(object sender, DeleteEventArgs args)
         {
-            _screen?.Exit();
             End(_emulationContext);
         }