Add ImmutableListTest

Author: jerviscui

src/Tests/CollectionTest/ImmutableListTest.cs

@@ -0,0 +1,61 @@
+using System.Collections.Immutable;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace CollectionTest;
+
+internal class ImmutableListTest
+{
+
+    #region Constants & Statics
+
+    public static void CopyOnWriteTest()
+    {
+        var array = new[] { 1, 2, 3, 4 };
+        var immutable = array.ToImmutableList();
+
+        var asImmutable = ImmutableCollectionsMarshal.AsImmutableArray(array);
+        var as2 = Unsafe.As<int[], ImmutableArray<int>>(ref array);
+        var as3 = ImmutableArray.Create(array);
+
+        array[0] = 100;
+        Console.WriteLine(immutable[0]); // 1 发生复制
+        Console.WriteLine(asImmutable[0]); // 100
+        Console.WriteLine(as2[0]); // 100
+        Console.WriteLine(as3[0]); // 1 发生复制
+
+        Console.WriteLine();
+        var newImmutable = asImmutable.SetItem(1, 200);
+        Console.WriteLine(array[1]); // 2
+        Console.WriteLine(newImmutable[1]); // 200
+    }
+
+    public static void ImmutableInterlockedTest()
+    {
+        var list = ImmutableList<int>.Empty;
+
+        // 多线程安全添加
+        ImmutableInterlocked.Update(ref list, l => l.Add(1));
+        ImmutableInterlocked.Update(ref list, l => l.Add(2));
+
+        Console.WriteLine(string.Join(", ", list)); // 1, 2
+    }
+
+    public static void Test()
+    {
+        var list = new List<int>();
+        var readOnly = list.AsReadOnly();
+        var immutable = list.ToImmutableList();
+
+        list.Add(1);
+        Console.WriteLine(readOnly.Count);  // 1
+        Console.WriteLine(immutable.Count); // 0
+
+        var newList = immutable.Add(2);
+        Console.WriteLine(immutable.Count); // 0
+        Console.WriteLine(newList.Count); // 1
+    }
+
+    #endregion
+
+}

src/Tests/CollectionTest/Program.cs

@@ -1,5 +1,3 @@
-using BenchmarkDotNet.Running;
-
 namespace CollectionTest;
 
 internal sealed class Program
@@ -17,7 +15,11 @@ private static void Main(string[] args)
 
         //Console.ReadLine();
 
-        BenchmarkRunner.Run<FrozenCollectionBenchmark>();
+        //BenchmarkRunner.Run<FrozenCollectionBenchmark>();
+
+        //ImmutableListTest.Test();
+        //ImmutableListTest.CopyOnWriteTest();
+        ImmutableListTest.ImmutableInterlockedTest();
     }
 
     #endregion