diff --git a/Algorithm/Eocron.Algorithms.csproj b/Algorithm/Eocron.Algorithms.csproj
index 51fa35a..452f19e 100644
--- a/Algorithm/Eocron.Algorithms.csproj
+++ b/Algorithm/Eocron.Algorithms.csproj
@@ -22,6 +22,7 @@
 	</PropertyGroup>
 
 	<ItemGroup>
+		<PackageReference Include="AsyncKeyedLock" Version="6.3.4" />
 		<PackageReference Include="Microsoft.Extensions.Configuration" Version="7.0.0" />
 		<PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
 		<PackageReference Include="System.Memory" Version="4.5.5" />
@@ -36,4 +37,4 @@
 	    <Link>README.md</Link>
 	  </Content>
 	</ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/Algorithm/FileCache/Async/FileCacheAsync.cs b/Algorithm/FileCache/Async/FileCacheAsync.cs
index 65335d7..d3e3448 100644
--- a/Algorithm/FileCache/Async/FileCacheAsync.cs
+++ b/Algorithm/FileCache/Async/FileCacheAsync.cs
@@ -1,4 +1,5 @@
-using Eocron.Algorithms.Disposing;
+using AsyncKeyedLock;
+using Eocron.Algorithms.Disposing;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -14,79 +15,6 @@ public sealed class FileCacheAsync<TKey> : IFileCacheAsync<TKey>, IDisposable
         #region Private helper classes
         private delegate Task CancellableAction(CancellationToken token);
 
-        private sealed class PerKeySemaphoreSlim : IDisposable
-        {
-            private sealed class RefCounted<T>
-            {
-                public RefCounted(T value)
-                {
-                    RefCount = 1;
-                    Value = value;
-                }
-
-                public int RefCount { get; set; }
-                public T Value { get; private set; }
-            }
-
-            private readonly SemaphoreSlim _lock = new SemaphoreSlim(1);
-            private readonly Dictionary<object, RefCounted<SemaphoreSlim>> _dict = new Dictionary<object, RefCounted<SemaphoreSlim>>();
-
-            private async Task<RefCounted<SemaphoreSlim>> GetOrCreate(object key, CancellationToken token)
-            {
-                RefCounted<SemaphoreSlim> item;
-                await _lock.WaitAsync(token);
-                try
-                {
-                    if (_dict.TryGetValue(key, out item))
-                    {
-                        ++item.RefCount;
-                    }
-                    else
-                    {
-                        item = new RefCounted<SemaphoreSlim>(new SemaphoreSlim(1, 1));
-                        _dict[key] = item;
-                    }
-                }
-                finally
-                {
-                    _lock.Release();
-                }
-
-                return item;
-            }
-
-            public async Task<IDisposable> LockAsync(object key, CancellationToken token)
-            {
-                var item = await GetOrCreate(key, token);
-                await item.Value.WaitAsync(CancellationToken.None);
-                return new Disposable(() =>
-                {
-                    _lock.Wait(CancellationToken.None);
-                    try
-                    {
-                        --item.RefCount;
-                        if (item.RefCount == 0)
-                            _dict.Remove(key);
-                    }
-                    finally
-                    {
-                        _lock.Release();
-                    }
-
-                    item.Value.Release();
-                });
-            }
-
-            public void Dispose()
-            {
-                _lock.Dispose();
-                foreach (var v in _dict.Values)
-                {
-                    v.Value.Dispose();
-                }
-            }
-        }
-
         private sealed class CFileCacheEntry : AnyExpirationPolicy
         {
             public string FilePath { get; set; }
@@ -168,7 +96,7 @@ public void Dispose()
 
         private readonly int _gcIntervalMs = 5 * 1000;
         private readonly int _gcFailRetryIntervalMs = 10 * 1000;
-        private readonly PerKeySemaphoreSlim _perKeyLock;
+        private readonly AsyncKeyedLocker<TKey> _perKeyLock;
         private readonly IFileSystemAsync _fs;
         private readonly string _baseFolder;
         private readonly AsyncReaderWriterLock _cacheLock;
@@ -203,7 +131,11 @@ public FileCacheAsync(string baseFolder, IFileSystemAsync fileSystem = null, boo
         {
             if (baseFolder == null)
                 throw new ArgumentNullException(nameof(baseFolder));
-            _perKeyLock = new PerKeySemaphoreSlim();
+            _perKeyLock = new AsyncKeyedLocker<TKey>(o =>
+            {
+                o.PoolSize = 20;
+                o.PoolInitialFill = 1;
+            });
             _cacheLock = new AsyncReaderWriterLock();
             _fs = fileSystem ?? FileSystemAsync.Instance;
             _baseFolder = baseFolder;
@@ -464,7 +396,7 @@ private async Task<CFileCacheEntry> InternalGetOrAdd(TKey key, Func<TKey, Task<C
 
             //per key mutex required to avoid multiple file upload to cache by same key.
             //files are very large objects, so unnecessary actions with them should be avoided if possible.
-            using (await _perKeyLock.LockAsync(key, token))
+            using (await _perKeyLock.LockAsync(key, token).ConfigureAwait(false))
             {
                 if (_entries.TryGetValue(key, out cacheEntry))
                     return cacheEntry.Pulse(policy);
@@ -749,7 +681,6 @@ public void Dispose()
         {
             _cts?.Dispose();
             _gc?.Wait();
-            _perKeyLock.Dispose();
             //_cacheLock.Dispose();
         }
     }
diff --git a/Algorithm/FileCache/FileCache.cs b/Algorithm/FileCache/FileCache.cs
index e5450f4..8a59d3c 100644
--- a/Algorithm/FileCache/FileCache.cs
+++ b/Algorithm/FileCache/FileCache.cs
@@ -1,4 +1,5 @@
-using Eocron.Algorithms.Disposing;
+using AsyncKeyedLock;
+using Eocron.Algorithms.Disposing;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -14,79 +15,6 @@ public sealed class FileCache<TKey> : IFileCache<TKey>, IDisposable
         #region Private helper classes
         private delegate void CancellableAction(CancellationToken token);
 
-        private sealed class PerKeySemaphoreSlim : IDisposable
-        {
-            private sealed class RefCounted<T>
-            {
-                public RefCounted(T value)
-                {
-                    RefCount = 1;
-                    Value = value;
-                }
-
-                public int RefCount { get; set; }
-                public T Value { get; private set; }
-            }
-
-            private readonly SemaphoreSlim _lock = new SemaphoreSlim(1);
-            private readonly Dictionary<object, RefCounted<SemaphoreSlim>> _dict = new Dictionary<object, RefCounted<SemaphoreSlim>>();
-
-            private RefCounted<SemaphoreSlim> GetOrCreate(object key, CancellationToken token)
-            {
-                RefCounted<SemaphoreSlim> item;
-                _lock.Wait(token);
-                try
-                {
-                    if (_dict.TryGetValue(key, out item))
-                    {
-                        ++item.RefCount;
-                    }
-                    else
-                    {
-                        item = new RefCounted<SemaphoreSlim>(new SemaphoreSlim(1, 1));
-                        _dict[key] = item;
-                    }
-                }
-                finally
-                {
-                    _lock.Release();
-                }
-
-                return item;
-            }
-
-            public IDisposable Lock(object key, CancellationToken token)
-            {
-                var item = GetOrCreate(key, token);
-                item.Value.Wait(CancellationToken.None);
-                return new Disposable(() =>
-                {
-                    _lock.Wait(CancellationToken.None);
-                    try
-                    {
-                        --item.RefCount;
-                        if (item.RefCount == 0)
-                            _dict.Remove(key);
-                    }
-                    finally
-                    {
-                        _lock.Release();
-                    }
-
-                    item.Value.Release();
-                });
-            }
-
-            public void Dispose()
-            {
-                _lock.Dispose();
-                foreach (var v in _dict.Values)
-                {
-                    v.Value.Dispose();
-                }
-            }
-        }
-
         private sealed class CFileCacheEntry : AnyExpirationPolicy
         {
             public string FilePath { get; set; }
@@ -168,7 +96,7 @@ public void Dispose()
 
         private readonly int _gcIntervalMs = 5 * 1000;
         private readonly int _gcFailRetryIntervalMs = 10 * 1000;
-        private readonly PerKeySemaphoreSlim _perKeyLock;
+        private readonly AsyncKeyedLocker<TKey> _perKeyLock;
         private readonly IFileSystem _fs;
         private readonly string _baseFolder;
         private readonly ReaderWriterLockSlim _cacheLock;
@@ -203,7 +131,11 @@ public FileCache(string baseFolder, IFileSystem fileSystem = null, bool disableG
         {
             if (baseFolder == null)
                 throw new ArgumentNullException(nameof(baseFolder));
-            _perKeyLock = new PerKeySemaphoreSlim();
+            _perKeyLock = new AsyncKeyedLocker<TKey>(o =>
+            {
+                o.PoolSize = 20;
+                o.PoolInitialFill = 1;
+            });
             _cacheLock = new ReaderWriterLockSlim();
             _fs = fileSystem ?? FileSystem.Instance;
             _baseFolder = baseFolder;
@@ -750,7 +682,6 @@ public void Dispose()
         {
             _cts?.Dispose();
             _gc?.Join();
-            _perKeyLock.Dispose();
             //_cacheLock.Dispose();
         }
     }