Fixed rare race condition (thanks for pointing it out Theodor Zoulias…

…), added limit to avoid unnecessary attempts to fill pool when initialFill > capacity.
MarkCiliaVincenti · Dec 29, 2022 · 825c673 · 825c673
1 parent 8af2c93
commit 825c673
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Showing 4 changed files with 10 additions and 16 deletions.
diff --git a/AsyncKeyedLock.Tests/OriginalTests.cs b/AsyncKeyedLock.Tests/OriginalTests.cs
@@ -118,9 +118,7 @@ public async Task BasicTestGenerics()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / concurrency));
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });
@@ -170,9 +168,7 @@ public async Task BasicTestGenericsPooling50k()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / concurrency));
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });
@@ -226,9 +222,7 @@ public async Task BasicTestGenericsPooling50kUnfilled()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / concurrency));
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });
@@ -278,9 +272,7 @@ public async Task BasicTestGenericsPoolingProcessorCount()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / concurrency));
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });
@@ -330,9 +322,7 @@ public async Task BasicTestGenericsPooling10k()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / concurrency));
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });
@@ -382,9 +372,7 @@ public async Task BasicTestGenericsString()
                     var key = Convert.ToInt32(Math.Ceiling((double)i / 5)).ToString();
                     using (await asyncKeyedLocker.LockAsync(key))
                     {
-                        await Task.Delay(20);
                         concurrentQueue.Enqueue((true, key));
-                        await Task.Delay(80);
                         concurrentQueue.Enqueue((false, key));
                     }
                 });

diff --git a/AsyncKeyedLock/AsyncKeyedLock.csproj b/AsyncKeyedLock/AsyncKeyedLock.csproj
@@ -8,16 +8,16 @@
 		<PackageProjectUrl>https://github.com/MarkCiliaVincenti/AsyncKeyedLock</PackageProjectUrl>
 		<Copyright>MIT</Copyright>
 		<PackageLicenseExpression>MIT</PackageLicenseExpression>
-		<Version>6.0.2</Version>
+		<Version>6.0.3</Version>
 		<PackageIcon>logo.png</PackageIcon>
-		<PackageReleaseNotes>Fixed critical parameter validation issue, optimizations on timeouts, added out parameters for synchronous locks with timeouts, improved tests.</PackageReleaseNotes>
+		<PackageReleaseNotes>Fixed rare race condition (thanks for pointing it out Theodor Zoulias), added limit to avoid unnecessary attempts to fill pool when initialFill > capacity.</PackageReleaseNotes>
 		<Description>An asynchronous .NET Standard 2.0 library that allows you to lock based on a key (keyed semaphores), limiting concurrent threads sharing the same key to a specified number.</Description>
 		<Copyright>© 2022 Mark Cilia Vincenti</Copyright>
 		<PackageTags>async,lock,key,keyed,semaphore,dictionary,pooling,duplicate,synchronization</PackageTags>
 		<RepositoryType>git</RepositoryType>
 		<GeneratePackageOnBuild>false</GeneratePackageOnBuild>
-		<AssemblyVersion>6.0.2.0</AssemblyVersion>
-		<FileVersion>6.0.2.0</FileVersion>
+		<AssemblyVersion>6.0.3.0</AssemblyVersion>
+		<FileVersion>6.0.3.0</FileVersion>
 		<PackageReadmeFile>README.md</PackageReadmeFile>
 		<IsPackable>true</IsPackable>
 		<IsTrimmable>true</IsTrimmable>

diff --git a/AsyncKeyedLock/AsyncKeyedLockPool.cs b/AsyncKeyedLock/AsyncKeyedLockPool.cs
@@ -44,6 +44,7 @@ public AsyncKeyedLockReleaser<TKey> GetObject(TKey key)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void PutObject(AsyncKeyedLockReleaser<TKey> item)
         {
+            item.ReferenceCount = 1;
             _objects.TryAdd(item);
         }
     }

diff --git a/AsyncKeyedLock/AsyncKeyedLockReleaser.cs b/AsyncKeyedLock/AsyncKeyedLockReleaser.cs
@@ -52,6 +52,11 @@ internal bool TryIncrement()
         {
             if (Monitor.TryEnter(this))
             {
+                if (_referenceCount == 0) // rare race condition
+                {
+                    Monitor.Exit(this);
+                    return false;
+                }
                 ++_referenceCount;
                 Monitor.Exit(this);
                 return true;