Change new ThreadPool.QueueUserWorkItem overload to be generic

2 files changed, 41 insertions, 11 deletions

diff --git a/src/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.cs b/src/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.cs
index bb4b87c06c..7d1911d50a 100644
--- a/src/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.cs
+++ b/src/System.Threading.ThreadPool/ref/System.Threading.ThreadPool.cs
@@ -23,7 +23,7 @@ namespace System.Threading
         public static void GetMinThreads(out int workerThreads, out int completionPortThreads) { throw null; }
         public static bool QueueUserWorkItem(System.Threading.WaitCallback callBack) { throw null; }
         public static bool QueueUserWorkItem(System.Threading.WaitCallback callBack, object state) { throw null; }
-        public static bool QueueUserWorkItem(System.Threading.WaitCallback callBack, object state, bool preferLocal) { throw null; }
+        public static bool QueueUserWorkItem<TState>(System.Action<TState> callBack, TState state, bool preferLocal) { throw null; }
         public static System.Threading.RegisteredWaitHandle RegisterWaitForSingleObject(System.Threading.WaitHandle waitObject, System.Threading.WaitOrTimerCallback callBack, object state, int millisecondsTimeOutInterval, bool executeOnlyOnce) { throw null; }
         public static System.Threading.RegisteredWaitHandle RegisterWaitForSingleObject(System.Threading.WaitHandle waitObject, System.Threading.WaitOrTimerCallback callBack, object state, long millisecondsTimeOutInterval, bool executeOnlyOnce) { throw null; }
         public static System.Threading.RegisteredWaitHandle RegisterWaitForSingleObject(System.Threading.WaitHandle waitObject, System.Threading.WaitOrTimerCallback callBack, object state, System.TimeSpan timeout, bool executeOnlyOnce) { throw null; }
diff --git a/src/System.Threading.ThreadPool/tests/ThreadPoolTests.netcoreapp.cs b/src/System.Threading.ThreadPool/tests/ThreadPoolTests.netcoreapp.cs
index c3b9a92c3a..4aac66daed 100644
--- a/src/System.Threading.ThreadPool/tests/ThreadPoolTests.netcoreapp.cs
+++ b/src/System.Threading.ThreadPool/tests/ThreadPoolTests.netcoreapp.cs
@@ -14,7 +14,7 @@ namespace System.Threading.ThreadPools.Tests
         [InlineData(true)]
         public void QueueUserWorkItem_PreferLocal_InvalidArguments_Throws(bool preferLocal)
         {
-            Assert.Throws<ArgumentNullException>(() => ThreadPool.QueueUserWorkItem(null, new object(), preferLocal));
+            AssertExtensions.Throws<ArgumentNullException>("callBack", () => ThreadPool.QueueUserWorkItem(null, new object(), preferLocal));
         }
 
         [Theory]
@@ -23,24 +23,54 @@ namespace System.Threading.ThreadPools.Tests
         public async Task QueueUserWorkItem_PreferLocal_NullValidForState(bool preferLocal)
         {
             var tcs = new TaskCompletionSource<int>();
-            ThreadPool.QueueUserWorkItem(s =>
-            {
-                tcs.SetResult(84);
-            }, null, preferLocal);
+            ThreadPool.QueueUserWorkItem(s => tcs.SetResult(84), (object)null, preferLocal);
             Assert.Equal(84, await tcs.Task);
         }
 
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
-        public async Task QueueUserWorkItem_PreferLocal_StateObjectPassedThrough(bool preferLocal)
+        public async Task QueueUserWorkItem_PreferLocal_ReferenceTypeStateObjectPassedThrough(bool preferLocal)
         {
             var tcs = new TaskCompletionSource<int>();
-            ThreadPool.QueueUserWorkItem(s =>
-            {
-                ((TaskCompletionSource<int>)s).SetResult(84);
-            }, tcs, preferLocal);
+            ThreadPool.QueueUserWorkItem(s => s.SetResult(84), tcs, preferLocal);
             Assert.Equal(84, await tcs.Task);
         }
+
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public async Task QueueUserWorkItem_PreferLocal_ValueTypeStateObjectPassedThrough(bool preferLocal)
+        {
+            var tcs = new TaskCompletionSource<int>();
+            ThreadPool.QueueUserWorkItem(s => s.tcs.SetResult(s.value), (tcs, value: 42), preferLocal);
+            Assert.Equal(42, await tcs.Task);
+        }
+
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public async Task QueueUserWorkItem_PreferLocal_RunsAsynchronously(bool preferLocal)
+        {
+            await Task.Factory.StartNew(() =>
+            {
+                int origThread = Environment.CurrentManagedThreadId;
+                var tcs = new TaskCompletionSource<int>();
+                ThreadPool.QueueUserWorkItem(s => s.SetResult(Environment.CurrentManagedThreadId), tcs, preferLocal);
+                Assert.NotEqual(origThread, tcs.Task.GetAwaiter().GetResult());
+            }, CancellationToken.None, TaskCreationOptions.LongRunning, TaskScheduler.Default);
+        }
+
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public async Task QueueUserWorkItem_PreferLocal_ExecutionContextFlowed(bool preferLocal)
+        {
+            var tcs = new TaskCompletionSource<int>();
+            var asyncLocal = new AsyncLocal<int>() { Value = 42 };
+            ThreadPool.QueueUserWorkItem(s => s.SetResult(asyncLocal.Value), tcs, preferLocal);
+            asyncLocal.Value = 0;
+            Assert.Equal(42, await tcs.Task);
+        }
     }
 }