From cb79618316bc21589374ed183363b4c8749cacde Mon Sep 17 00:00:00 2001
From: Koundinya Veluri <kouvel@microsoft.com>
Date: Fri, 3 Nov 2017 23:16:34 -0700
Subject: [PATCH] Add test for setting min worker threads in thread pool to 1

Related to https://github.com/dotnet/coreclr/issues/14239
Depends on https://github.com/dotnet/coreclr/pull/14864
---
 .../tests/ThreadPoolTests.cs                  | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/src/System.Threading.ThreadPool/tests/ThreadPoolTests.cs b/src/System.Threading.ThreadPool/tests/ThreadPoolTests.cs
index e86ff390cfbf..5e42a9693665 100644
--- a/src/System.Threading.ThreadPool/tests/ThreadPoolTests.cs
+++ b/src/System.Threading.ThreadPool/tests/ThreadPoolTests.cs
@@ -194,6 +194,47 @@ private static void VerifyMaxThreads(int expectedMaxw, int expectedMaxc)
             Assert.Equal(expectedMaxc, maxc);
         }
 
+        [Fact]
+        private static void SetMinThreadsTo0Test()
+        {
+            int minw, minc, maxw, maxc;
+            ThreadPool.GetMinThreads(out minw, out minc);
+            ThreadPool.GetMaxThreads(out maxw, out maxc);
+            void ResetThreadCounts()
+            {
+                Assert.True(ThreadPool.SetMaxThreads(maxw, maxc));
+                Assert.True(ThreadPool.SetMinThreads(minw, minc));
+            }
+
+            try
+            {
+                Assert.True(ThreadPool.SetMinThreads(0, minc));
+                Assert.True(ThreadPool.SetMaxThreads(1, maxc));
+
+                int count = 0;
+                var done = new ManualResetEvent(false);
+                WaitCallback callback = null;
+                callback = state =>
+                {
+                    ++count;
+                    if (count > 100)
+                    {
+                        done.Set();
+                    }
+                    else
+                    {
+                        ThreadPool.QueueUserWorkItem(callback);
+                    }
+                };
+                ThreadPool.QueueUserWorkItem(callback);
+                done.WaitOne(ThreadTestHelpers.UnexpectedTimeoutMilliseconds);
+            }
+            finally
+            {
+                ResetThreadCounts();
+            }
+        }
+
         [Fact]
         public static void QueueRegisterPositiveAndFlowTest()
         {