1 files changed, 24 insertions, 41 deletions

diff --git a/MediaBrowser.MediaEncoding/Subtitles/SubtitleEncoder.cs b/MediaBrowser.MediaEncoding/Subtitles/SubtitleEncoder.cs
index 8fd1f9fc1..8f1cc3f64 100644
--- a/MediaBrowser.MediaEncoding/Subtitles/SubtitleEncoder.cs
+++ b/MediaBrowser.MediaEncoding/Subtitles/SubtitleEncoder.cs
@@ -1,7 +1,6 @@
 #pragma warning disable CS1591
 
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
@@ -12,6 +11,7 @@ using System.Net.Http;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using AsyncKeyedLock;
 using MediaBrowser.Common;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Extensions;
@@ -28,7 +28,7 @@ using UtfUnknown;
 
 namespace MediaBrowser.MediaEncoding.Subtitles
 {
-    public sealed class SubtitleEncoder : ISubtitleEncoder
+    public sealed class SubtitleEncoder : ISubtitleEncoder, IDisposable
     {
         private readonly ILogger<SubtitleEncoder> _logger;
         private readonly IApplicationPaths _appPaths;
@@ -41,8 +41,11 @@ namespace MediaBrowser.MediaEncoding.Subtitles
         /// <summary>
         /// The _semaphoreLocks.
         /// </summary>
-        private readonly ConcurrentDictionary<string, SemaphoreSlim> _semaphoreLocks =
-            new ConcurrentDictionary<string, SemaphoreSlim>();
+        private readonly AsyncKeyedLocker<string> _semaphoreLocks = new(o =>
+        {
+            o.PoolSize = 20;
+            o.PoolInitialFill = 1;
+        });
 
         public SubtitleEncoder(
             ILogger<SubtitleEncoder> logger,
@@ -294,16 +297,6 @@ namespace MediaBrowser.MediaEncoding.Subtitles
         }
 
         /// <summary>
-        /// Gets the lock.
-        /// </summary>
-        /// <param name="filename">The filename.</param>
-        /// <returns>System.Object.</returns>
-        private SemaphoreSlim GetLock(string filename)
-        {
-            return _semaphoreLocks.GetOrAdd(filename, _ => new SemaphoreSlim(1, 1));
-        }
-
-        /// <summary>
         /// Converts the text subtitle to SRT.
         /// </summary>
         /// <param name="subtitleStream">The subtitle stream.</param>
@@ -313,21 +306,13 @@ namespace MediaBrowser.MediaEncoding.Subtitles
         /// <returns>Task.</returns>
         private async Task ConvertTextSubtitleToSrt(MediaStream subtitleStream, MediaSourceInfo mediaSource, string outputPath, CancellationToken cancellationToken)
         {
-            var semaphore = GetLock(outputPath);
-
-            await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
-
-            try
+            using (await _semaphoreLocks.LockAsync(outputPath, cancellationToken).ConfigureAwait(false))
             {
                 if (!File.Exists(outputPath))
                 {
                     await ConvertTextSubtitleToSrtInternal(subtitleStream, mediaSource, outputPath, cancellationToken).ConfigureAwait(false);
                 }
             }
-            finally
-            {
-                semaphore.Release();
-            }
         }
 
         /// <summary>
@@ -472,7 +457,7 @@ namespace MediaBrowser.MediaEncoding.Subtitles
         /// <returns>Task.</returns>
         private async Task ExtractAllTextSubtitles(MediaSourceInfo mediaSource, CancellationToken cancellationToken)
         {
-            var semaphores = new List<SemaphoreSlim>();
+            var locks = new List<AsyncKeyedLockReleaser<string>>();
             var extractableStreams = new List<MediaStream>();
 
             try
@@ -484,16 +469,16 @@ namespace MediaBrowser.MediaEncoding.Subtitles
                 {
                     var outputPath = GetSubtitleCachePath(mediaSource, subtitleStream.Index, "." + GetTextSubtitleFormat(subtitleStream));
 
-                    var semaphore = GetLock(outputPath);
-                    await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
+                    var @lock = _semaphoreLocks.GetOrAdd(outputPath);
+                    await @lock.SemaphoreSlim.WaitAsync(cancellationToken).ConfigureAwait(false);
 
                     if (File.Exists(outputPath))
                     {
-                        semaphore.Release();
+                        @lock.Dispose();
                         continue;
                     }
 
-                    semaphores.Add(semaphore);
+                    locks.Add(@lock);
                     extractableStreams.Add(subtitleStream);
                 }
 
@@ -508,9 +493,9 @@ namespace MediaBrowser.MediaEncoding.Subtitles
             }
             finally
             {
-                foreach (var semaphore in semaphores)
+                foreach (var @lock in locks)
                 {
-                    semaphore.Release();
+                    @lock.Dispose();
                 }
             }
         }
@@ -657,16 +642,12 @@ namespace MediaBrowser.MediaEncoding.Subtitles
             string outputPath,
             CancellationToken cancellationToken)
         {
-            var semaphore = GetLock(outputPath);
-
-            await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
-
-            var subtitleStreamIndex = EncodingHelper.FindIndex(mediaSource.MediaStreams, subtitleStream);
-
-            try
+            using (await _semaphoreLocks.LockAsync(outputPath, cancellationToken).ConfigureAwait(false))
             {
                 if (!File.Exists(outputPath))
                 {
+                    var subtitleStreamIndex = EncodingHelper.FindIndex(mediaSource.MediaStreams, subtitleStream);
+
                     var args = _mediaEncoder.GetInputArgument(mediaSource.Path, mediaSource);
 
                     if (subtitleStream.IsExternal)
@@ -682,10 +663,6 @@ namespace MediaBrowser.MediaEncoding.Subtitles
                         cancellationToken).ConfigureAwait(false);
                 }
             }
-            finally
-            {
-                semaphore.Release();
-            }
         }
 
         private async Task ExtractTextSubtitleInternal(
@@ -901,6 +878,12 @@ namespace MediaBrowser.MediaEncoding.Subtitles
             }
         }
 
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            _semaphoreLocks.Dispose();
+        }
+
 #pragma warning disable CA1034 // Nested types should not be visible
         // Only public for the unit tests
         public readonly record struct SubtitleInfo