Disable heartbeat warning when debugger is attached (#2258)

src/Kestrel.Core/Internal/Infrastructure/Heartbeat.cs

@@ -13,14 +13,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure
 
         private readonly IHeartbeatHandler[] _callbacks;
         private readonly ISystemClock _systemClock;
+        private readonly IDebugger _debugger;
         private readonly IKestrelTrace _trace;
         private Timer _timer;
         private int _executingOnHeartbeat;
 
-        public Heartbeat(IHeartbeatHandler[] callbacks, ISystemClock systemClock, IKestrelTrace trace)
+        public Heartbeat(IHeartbeatHandler[] callbacks, ISystemClock systemClock, IDebugger debugger, IKestrelTrace trace)
         {
             _callbacks = callbacks;
             _systemClock = systemClock;
+            _debugger = debugger;
             _trace = trace;
         }
 
@@ -59,7 +61,10 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure
             }
             else
             {
-                _trace.HeartbeatSlow(Interval, now);
+                if (!_debugger.IsAttached)
+                {
+                    _trace.HeartbeatSlow(Interval, now);
+                }
             }
         }
 

src/Kestrel.Core/KestrelServer.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Hosting.Server;
@@ -47,7 +48,9 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core
             var httpHeartbeatManager = new HttpHeartbeatManager(serviceContext.ConnectionManager);
             _heartbeat = new Heartbeat(
                 new IHeartbeatHandler[] { serviceContext.DateHeaderValueManager, httpHeartbeatManager },
-                serviceContext.SystemClock, Trace);
+                serviceContext.SystemClock,
+                DebuggerWrapper.Singleton,
+                Trace);
 
             Features = new FeatureCollection();
             _serverAddresses = new ServerAddressesFeature();

test/Kestrel.Core.Tests/DateHeaderValueManagerTests.cs

@@ -46,7 +46,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var dateHeaderValueManager = new DateHeaderValueManager(systemClock);
             var testKestrelTrace = new TestKestrelTrace();
 
-            using (var heartbeat = new Heartbeat(new IHeartbeatHandler[] { dateHeaderValueManager }, systemClock, testKestrelTrace))
+            using (var heartbeat = new Heartbeat(new IHeartbeatHandler[] { dateHeaderValueManager }, systemClock, DebuggerWrapper.Singleton, testKestrelTrace))
             {
                 Assert.Equal(now.ToString(Rfc1123DateFormat), dateHeaderValueManager.GetDateHeaderValues().String);
                 systemClock.UtcNow = future;
@@ -71,7 +71,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 
             var mockHeartbeatHandler = new Mock<IHeartbeatHandler>();
 
-            using (var heartbeat = new Heartbeat(new[] { dateHeaderValueManager, mockHeartbeatHandler.Object }, systemClock, testKestrelTrace))
+            using (var heartbeat = new Heartbeat(new[] { dateHeaderValueManager, mockHeartbeatHandler.Object }, systemClock, DebuggerWrapper.Singleton, testKestrelTrace))
             {
                 heartbeat.OnHeartbeat();
 
@@ -100,7 +100,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             var dateHeaderValueManager = new DateHeaderValueManager(systemClock);
             var testKestrelTrace = new TestKestrelTrace();
 
-            using (var heatbeat = new Heartbeat(new IHeartbeatHandler[] { dateHeaderValueManager }, systemClock, testKestrelTrace))
+            using (var heatbeat = new Heartbeat(new IHeartbeatHandler[] { dateHeaderValueManager }, systemClock, DebuggerWrapper.Singleton, testKestrelTrace))
             {
                 heatbeat.OnHeartbeat();
                 Assert.Equal(now.ToString(Rfc1123DateFormat), dateHeaderValueManager.GetDateHeaderValues().String);

test/Kestrel.Core.Tests/HeartbeatTests.cs

@@ -26,14 +26,16 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         {
             var systemClock = new MockSystemClock();
             var heartbeatHandler = new Mock<IHeartbeatHandler>();
+            var debugger = new Mock<IDebugger>();
             var kestrelTrace = new Mock<IKestrelTrace>();
             var handlerMre = new ManualResetEventSlim();
             var traceMre = new ManualResetEventSlim();
 
             heartbeatHandler.Setup(h => h.OnHeartbeat(systemClock.UtcNow)).Callback(() => handlerMre.Wait());
+            debugger.Setup(d => d.IsAttached).Returns(false);
             kestrelTrace.Setup(t => t.HeartbeatSlow(Heartbeat.Interval, systemClock.UtcNow)).Callback(() => traceMre.Set());
 
-            using (var heartbeat = new Heartbeat(new[] { heartbeatHandler.Object }, systemClock, kestrelTrace.Object))
+            using (var heartbeat = new Heartbeat(new[] { heartbeatHandler.Object }, systemClock, debugger.Object, kestrelTrace.Object))
             {
                 Task.Run(() => heartbeat.OnHeartbeat());
                 Task.Run(() => heartbeat.OnHeartbeat());
@@ -46,6 +48,33 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             kestrelTrace.Verify(t => t.HeartbeatSlow(Heartbeat.Interval, systemClock.UtcNow), Times.Once());
         }
 
+        [Fact]
+        public void BlockedHeartbeatIsNotLoggedAsErrorIfDebuggerAttached()
+        {
+            var systemClock = new MockSystemClock();
+            var heartbeatHandler = new Mock<IHeartbeatHandler>();
+            var debugger = new Mock<IDebugger>();
+            var kestrelTrace = new Mock<IKestrelTrace>();
+            var handlerMre = new ManualResetEventSlim();
+            var traceMre = new ManualResetEventSlim();
+
+            heartbeatHandler.Setup(h => h.OnHeartbeat(systemClock.UtcNow)).Callback(() => handlerMre.Wait());
+            debugger.Setup(d => d.IsAttached).Returns(true);
+            kestrelTrace.Setup(t => t.HeartbeatSlow(Heartbeat.Interval, systemClock.UtcNow)).Callback(() => traceMre.Set());
+
+            using (var heartbeat = new Heartbeat(new[] { heartbeatHandler.Object }, systemClock, debugger.Object, kestrelTrace.Object))
+            {
+                Task.Run(() => heartbeat.OnHeartbeat());
+                Task.Run(() => heartbeat.OnHeartbeat());
+                Assert.False(traceMre.Wait(TimeSpan.FromSeconds(10)));
+            }
+
+            handlerMre.Set();
+
+            heartbeatHandler.Verify(h => h.OnHeartbeat(systemClock.UtcNow), Times.Once());
+            kestrelTrace.Verify(t => t.HeartbeatSlow(Heartbeat.Interval, systemClock.UtcNow), Times.Never());
+        }
+
         [Fact]
         public void ExceptionFromHeartbeatHandlerIsLoggedAsError()
         {
@@ -56,7 +85,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
 
             heartbeatHandler.Setup(h => h.OnHeartbeat(systemClock.UtcNow)).Throws(ex);
 
-            using (var heartbeat = new Heartbeat(new[] { heartbeatHandler.Object }, systemClock, kestrelTrace))
+            using (var heartbeat = new Heartbeat(new[] { heartbeatHandler.Object }, systemClock, DebuggerWrapper.Singleton, kestrelTrace))
             {
                 heartbeat.OnHeartbeat();
             }