Improve test:

* skip on aot platforms
* add current thread test for coreclr

src/libraries/System.Runtime/tests/System/Runtime/JitInfoTests.cs

@@ -1,21 +1,67 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Microsoft.DotNet.XUnitExtensions;
+using System.Threading;
 using Xunit;
 
 namespace System.Runtime.Tests
 {
-    // NOTE: DependentHandle is already heavily tested indirectly through ConditionalWeakTable<,>.
-    // This class contains some specific tests for APIs that are only relevant when used directly.
     public class JitInfoTests
     {
-        // TODO(josalem): disable test on iOS/Android/browser
+        private const TestPlatforms AotPlatforms = TestPlatforms.Browser | TestPlatforms.iOS | TestPlatforms.tvOS | TestPlatforms.Android;
+
         [Fact]
+        [SkipOnPlatform(AotPlatforms, "JitInfo metrics will be 0 in AOT scenarios.")]
         public void JitInfoIsPopulated()
         {
+            Func<string> theFunc = () => "JIT compile this!";
+            Assert.True(theFunc().Equals("JIT compile this!"));
             Assert.True(System.Runtime.JitInfo.GetCompilationTime() > TimeSpan.Zero);
             Assert.True(System.Runtime.JitInfo.GetCompiledILBytes() > 0);
             Assert.True(System.Runtime.JitInfo.GetCompiledMethodCount() > 0);
         }
+
+        [Fact]
+        [SkipOnMono("Mono does not track thread specific JIT information")]
+        public void JitInfoCurrentThreadIsPopulated()
+        {
+            TimeSpan t1_compilationTime = TimeSpan.Zero;
+            long t1_compiledILBytes = 0;
+            long t1_compiledMethodCount = 0;
+
+            TimeSpan t2_compilationTime = TimeSpan.Zero;
+            long t2_compiledILBytes = 0;
+            long t2_compiledMethodCount = 0;
+
+            var t1 = new Thread(() => {
+                Func<string> theFunc = () => "JIT compile this!";
+                Assert.True(theFunc().Equals("JIT compile this!"));
+                t1_compilationTime = System.Runtime.JitInfo.GetCompilationTime(currentThread: true);
+                t1_compiledILBytes = System.Runtime.JitInfo.GetCompiledILBytes(currentThread: true);
+                t1_compiledMethodCount = System.Runtime.JitInfo.GetCompiledMethodCount(currentThread: true);
+            });
+
+            var t2 = new Thread(() => {
+                Func<string> theFunc2 = () => "Also JIT compile this!";
+                Assert.True(theFunc2().Equals("Also JIT compile this!"));
+                t2_compilationTime = System.Runtime.JitInfo.GetCompilationTime(currentThread: true);
+                t2_compiledILBytes = System.Runtime.JitInfo.GetCompiledILBytes(currentThread: true);
+                t2_compiledMethodCount = System.Runtime.JitInfo.GetCompiledMethodCount(currentThread: true);
+            });
+
+            t1.Start();
+            t2.Start();
+            t1.Join();
+            t2.Join();
+
+            Assert.True(t1_compilationTime > TimeSpan.Zero);
+            Assert.True(t1_compiledILBytes > 0);
+            Assert.True(t1_compiledMethodCount > 0);
+
+            Assert.True(t2_compilationTime > TimeSpan.Zero);
+            Assert.True(t2_compiledILBytes > 0);
+            Assert.True(t2_compiledMethodCount > 0);
+        }
     }
 }