Merge pull request #378 from benaadams/thread-count

Network thread count defaults

src/Microsoft.AspNet.Server.Kestrel/KestrelServer.cs

@@ -75,14 +75,37 @@ namespace Microsoft.AspNet.Server.Kestrel
                 _disposables.Push(engine);
                 _disposables.Push(dateHeaderValueManager);
 
+                // Actual core count would be a better number 
+                // rather than logical cores which includes hyper-threaded cores.
+                // Divide by 2 for hyper-threading, and good defaults (still need threads to do webserving).
+                // Can be user overriden using IKestrelServerInformation.ThreadCount
+                var threadCount = Environment.ProcessorCount >> 1;
+
+                if (threadCount < 1)
+                {
+                    // Ensure shifted value is at least one
+                    threadCount = 1;
+                }
+                else if (threadCount > 16)
+                {
+                    // Receive Side Scaling RSS Processor count currently maxes out at 16
+                    // would be better to check the NIC's current hardware queues; but xplat...
+                    threadCount = 16;
+                }
+
                 if (information.ThreadCount < 0)
                 {
                     throw new ArgumentOutOfRangeException(nameof(information.ThreadCount),
                         information.ThreadCount,
                         "ThreadCount cannot be negative");
                 }
+                else if (information.ThreadCount > 0)
+                {
+                    // ThreadCount has been user set, use that value
+                    threadCount = information.ThreadCount;
+                }
 
-                engine.Start(information.ThreadCount == 0 ? 1 : information.ThreadCount);
+                engine.Start(threadCount);
                 var atLeastOneListener = false;
 
                 foreach (var address in information.Addresses)

test/Microsoft.AspNet.Server.Kestrel.FunctionalTests/ThreadCountTests.cs

@@ -15,7 +15,6 @@ namespace Microsoft.AspNet.Server.Kestrel.FunctionalTests
 {
     public class ThreadCountTests
     {
-        [Theory(Skip = "https://github.com/aspnet/KestrelHttpServer/issues/232"), MemberData(nameof(OneToTen))]
         public async Task ZeroToTenThreads(int threadCount)
         {
             var config = new ConfigurationBuilder()

test/Microsoft.AspNet.Server.KestrelTests/MultipleLoopTests.cs

@@ -21,7 +21,6 @@ namespace Microsoft.AspNet.Server.KestrelTests
             _logger = engine.Log;
         }
 
-        [Fact(Skip = "Waiting for adding support for multi loop in libuv")]
         public void InitAndCloseServerPipe()
         {
             var loop = new UvLoopHandle(_logger);
@@ -39,7 +38,6 @@ namespace Microsoft.AspNet.Server.KestrelTests
 
         }
 
-        [Fact(Skip = "Waiting for adding support for multi loop in libuv")]
         public void ServerPipeListenForConnections()
         {
             var loop = new UvLoopHandle(_logger);
@@ -112,7 +110,6 @@ namespace Microsoft.AspNet.Server.KestrelTests
         }
 
 
-        [Fact(Skip = "Waiting for adding support for multi loop in libuv")]
         public void ServerPipeDispatchConnections()
         {
             var pipeName = @"\\.\pipe\ServerPipeDispatchConnections" + Guid.NewGuid().ToString("n");