Sleep thread if yield fails

main/OpenCover.Framework/Manager/ProfilerManager.cs

@@ -151,7 +151,7 @@ private WaitCallback SaveVisitData(EventWaitHandle queueMgmt)
                 {
                     byte[] data;
                     while (!_messageQueue.TryDequeue(out data))
-                        Thread.Yield();
+                        ThreadHelper.YieldOrSleep(100);
 
                     _perfCounters.CurrentMemoryQueueSize = _messageQueue.Count;
                     _perfCounters.IncrementBlocksReceived();
@@ -289,7 +289,7 @@ private WaitCallback ProcessBlock(ManagedBufferBlock block,
                             {
                                 do
                                 {
-                                    Thread.Yield();
+                                    ThreadHelper.YieldOrSleep(100);
                                 } while (_messageQueue.Count > 200);
                             }
                             break;

main/OpenCover.Framework/OpenCover.Framework.csproj

@@ -148,6 +148,7 @@
     <Compile Include="Utility\CodeCoverageStringTextSource.cs" />
     <Compile Include="Utility\IPerfCounters.cs" />
     <Compile Include="Utility\PerfCounters.cs" />
+    <Compile Include="Utility\ThreadHelper.cs" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="log4net.config">

main/OpenCover.Framework/Utility/ThreadHelper.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+
+namespace OpenCover.Framework.Utility
+{
+    internal static class ThreadHelper
+    {
+        public static void YieldOrSleep(int millisecondsInTimeout)
+        {
+            if (!Thread.Yield())
+            {
+                Thread.Sleep(millisecondsInTimeout);
+            }
+        }
+
+        public static void YieldOrSleep(TimeSpan timespan)
+        {
+            if (!Thread.Yield())
+            {
+                Thread.Sleep(timespan);
+            }
+        }
+    }
+}