Merge pull request #108 from hadashiA/ku/perf-scalar-pool

Optimize ScalarPool
hadashiA · Jun 1, 2024 · 887eb8e · 887eb8e
2 parents bc05817 + a7edd07
commit 887eb8e
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Showing 2 changed files with 36 additions and 12 deletions.
diff --git a/VYaml.Unity/Assets/VYaml/Runtime/Internal/Scalar.cs b/VYaml.Unity/Assets/VYaml/Runtime/Internal/Scalar.cs
@@ -1,9 +1,9 @@
-#nullable enable
 using System;
 using System.Buffers;
 using System.Buffers.Text;
 using System.Collections.Concurrent;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using VYaml.Internal;
 
 namespace VYaml.Parser
@@ -12,21 +12,33 @@ class ScalarPool
     {
         public static readonly ScalarPool Shared = new();
 
-        readonly ConcurrentQueue<Scalar> queue = new();
+        readonly ConcurrentQueue<Scalar> items = new();
+        Scalar? fastItem;
 
         public Scalar Rent()
         {
-            if (queue.TryDequeue(out var value))
+            var value = fastItem;
+            if (value != null &&
+                Interlocked.CompareExchange(ref fastItem, null, value) == value)
+            {
+                return value;
+            }
+            if (items.TryDequeue(out value))
             {
                 return value;
             }
             return new Scalar(256);
         }
 
-        public void Return(Scalar scalar)
+        public void Return(Scalar value)
         {
-            scalar.Clear();
-            queue.Enqueue(scalar);
+            value.Clear();
+
+            if (fastItem != null ||
+                Interlocked.CompareExchange(ref fastItem, value, null) != null)
+            {
+                items.Enqueue(value);
+            }
         }
     }
 

diff --git a/VYaml/Internal/Scalar.cs b/VYaml/Internal/Scalar.cs
@@ -1,9 +1,9 @@
-#nullable enable
 using System;
 using System.Buffers;
 using System.Buffers.Text;
 using System.Collections.Concurrent;
 using System.Runtime.CompilerServices;
+using System.Threading;
 using VYaml.Internal;
 
 namespace VYaml.Parser
@@ -12,21 +12,33 @@ class ScalarPool
     {
         public static readonly ScalarPool Shared = new();
 
-        readonly ConcurrentQueue<Scalar> queue = new();
+        readonly ConcurrentQueue<Scalar> items = new();
+        Scalar? fastItem;
 
         public Scalar Rent()
         {
-            if (queue.TryDequeue(out var value))
+            var value = fastItem;
+            if (value != null &&
+                Interlocked.CompareExchange(ref fastItem, null, value) == value)
+            {
+                return value;
+            }
+            if (items.TryDequeue(out value))
             {
                 return value;
             }
             return new Scalar(256);
         }
 
-        public void Return(Scalar scalar)
+        public void Return(Scalar value)
         {
-            scalar.Clear();
-            queue.Enqueue(scalar);
+            value.Clear();
+
+            if (fastItem != null ||
+                Interlocked.CompareExchange(ref fastItem, value, null) != null)
+            {
+                items.Enqueue(value);
+            }
         }
     }