fix segmenter semaphore (#1676)

* disable dead air watermarks by default

* fix session worker semaphore

* update changelog

CHANGELOG.md

@@ -23,6 +23,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 - Fix some cases of 404s from Plex when files were replaced and scanning the library from ETV didn't help
 - Fix more wildcard search phrase queries (when wildcards are used in quotes, like `title:"law & order*"`)
+- Fix bug where channels would unnecessarily wait on each other
+  - e.g. in-progress streams would delay responding with a playlist when new streams were starting
 
 ## [0.8.6-beta] - 2024-04-03
 ### Added

ErsatzTV.Application/Streaming/HlsSessionWorker.cs

@@ -20,8 +20,8 @@ namespace ErsatzTV.Application.Streaming;
 
 public class HlsSessionWorker : IHlsSessionWorker
 {
-    private static readonly SemaphoreSlim Slim = new(1, 1);
     private static int _workAheadCount;
+    private readonly SemaphoreSlim _slim = new(1, 1);
     private readonly IClient _client;
     private readonly IConfigElementRepository _configElementRepository;
     private readonly IHlsPlaylistFilter _hlsPlaylistFilter;
@@ -66,14 +66,14 @@ public class HlsSessionWorker : IHlsSessionWorker
     {
         _logger.LogInformation("API termination request for HLS session for channel {Channel}", _channelNumber);
 
-        await Slim.WaitAsync(cancellationToken);
+        await _slim.WaitAsync(cancellationToken);
         try
         {
             await _cancellationTokenSource.CancelAsync();
         }
         finally
         {
-            Slim.Release();
+            _slim.Release();
         }
     }
 
@@ -97,7 +97,7 @@ public class HlsSessionWorker : IHlsSessionWorker
         try
         {
             var sw = Stopwatch.StartNew();
-            await Slim.WaitAsync(cancellationToken);
+            await _slim.WaitAsync(cancellationToken);
             try
             {
                 Option<string[]> maybeLines = await ReadPlaylistLines(cancellationToken);
@@ -117,7 +117,7 @@ public class HlsSessionWorker : IHlsSessionWorker
             }
             finally
             {
-                Slim.Release();
+                _slim.Release();
                 sw.Stop();
                 // _logger.LogDebug("TrimPlaylist took {Duration}", sw.Elapsed);
             }
@@ -535,7 +535,7 @@ public class HlsSessionWorker : IHlsSessionWorker
 
     private async Task TrimAndDelete(CancellationToken cancellationToken)
     {
-        await Slim.WaitAsync(cancellationToken);
+        await _slim.WaitAsync(cancellationToken);
         try
         {
             Option<string[]> maybeLines = await ReadPlaylistLines(cancellationToken);
@@ -555,7 +555,7 @@ public class HlsSessionWorker : IHlsSessionWorker
         }
         finally
         {
-            Slim.Release();
+            _slim.Release();
         }
     }
 
@@ -606,7 +606,7 @@ public class HlsSessionWorker : IHlsSessionWorker
 
     private async Task<long> GetPtsOffset(string channelNumber, CancellationToken cancellationToken)
     {
-        await Slim.WaitAsync(cancellationToken);
+        await _slim.WaitAsync(cancellationToken);
         try
         {
             long result = 0;
@@ -635,7 +635,7 @@ public class HlsSessionWorker : IHlsSessionWorker
         }
         finally
         {
-            Slim.Release();
+            _slim.Release();
         }
     }
 

ErsatzTV.Application/Streaming/HlsSessionWorkerV2.cs

@@ -18,7 +18,7 @@ namespace ErsatzTV.Application.Streaming;
 
 public class HlsSessionWorkerV2 : IHlsSessionWorker
 {
-    private static readonly SemaphoreSlim Slim = new(1, 1);
+    private readonly SemaphoreSlim _slim = new(1, 1);
 
     //private static int _workAheadCount;
     private readonly IConfigElementRepository _configElementRepository;
@@ -65,14 +65,14 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
     {
         _logger.LogInformation("API termination request for HLS session for channel {Channel}", _channelNumber);
 
-        await Slim.WaitAsync(cancellationToken);
+        await _slim.WaitAsync(cancellationToken);
         try
         {
             await _cancellationTokenSource.CancelAsync();
         }
         finally
         {
-            Slim.Release();
+            _slim.Release();
         }
     }
 
@@ -369,7 +369,7 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
 
     private async Task<long> GetPtsOffset(string channelNumber, CancellationToken cancellationToken)
     {
-        await Slim.WaitAsync(cancellationToken);
+        await _slim.WaitAsync(cancellationToken);
         try
         {
             long result = 0;
@@ -398,7 +398,7 @@ public class HlsSessionWorkerV2 : IHlsSessionWorker
         }
         finally
         {
-            Slim.Release();
+            _slim.Release();
         }
     }
 

ErsatzTV.Application/Streaming/Queries/GetPlayoutItemProcessByChannelNumberHandler.cs

@@ -466,7 +466,7 @@ public class GetPlayoutItemProcessByChannelNumberHandler : FFmpegProcessHandler<
             case CustomDeadAirFallback custom:
                 maybeFallback = new FillerPreset
                 {
-                    AllowWatermarks = true,
+                    AllowWatermarks = false, // TODO: does this need to be configurable?
                     CollectionType = custom.CollectionType,
                     CollectionId = custom.CollectionId,
                     MediaItemId = custom.MediaItemId,