Don't keep MTP process alive if pipe disconnects by @Youssef1313 in #6477 (backport to rel/3.10)

src/Platform/Microsoft.Testing.Extensions.HangDump/HangDumpActivityIndicator.cs

@@ -65,7 +65,7 @@ public HangDumpActivityIndicator(
             string pipeNameEnvironmentVariable = $"{HangDumpConfiguration.PipeName}_{FNV_1aHashHelper.ComputeStringHash(testApplicationModuleInfo.GetCurrentTestApplicationFullPath())}_{namedPipeSuffix}";
             string namedPipeName = _environment.GetEnvironmentVariable(pipeNameEnvironmentVariable)
                 ?? throw new InvalidOperationException($"Expected {pipeNameEnvironmentVariable} environment variable set.");
-            _namedPipeClient = new NamedPipeClient(namedPipeName);
+            _namedPipeClient = new NamedPipeClient(namedPipeName, _environment);
             _namedPipeClient.RegisterSerializer(new ActivityIndicatorMutexNameRequestSerializer(), typeof(ActivityIndicatorMutexNameRequest));
             _namedPipeClient.RegisterSerializer(new VoidResponseSerializer(), typeof(VoidResponse));
             _namedPipeClient.RegisterSerializer(new SessionEndSerializerRequestSerializer(), typeof(SessionEndSerializerRequest));

src/Platform/Microsoft.Testing.Extensions.HangDump/HangDumpProcessLifetimeHandler.cs

@@ -159,7 +159,7 @@ private async Task<IResponse> CallbackAsync(IRequest request)
         else if (request is ConsumerPipeNameRequest consumerPipeNameRequest)
         {
             await _logger.LogDebugAsync($"Consumer pipe name received '{consumerPipeNameRequest.PipeName}'").ConfigureAwait(false);
-            _namedPipeClient = new NamedPipeClient(consumerPipeNameRequest.PipeName);
+            _namedPipeClient = new NamedPipeClient(consumerPipeNameRequest.PipeName, _environment);
             _namedPipeClient.RegisterSerializer(new GetInProgressTestsResponseSerializer(), typeof(GetInProgressTestsResponse));
             _namedPipeClient.RegisterSerializer(new GetInProgressTestsRequestSerializer(), typeof(GetInProgressTestsRequest));
             _namedPipeClient.RegisterSerializer(new ExitSignalActivityIndicatorTaskRequestSerializer(), typeof(ExitSignalActivityIndicatorTaskRequest));

src/Platform/Microsoft.Testing.Extensions.TrxReport/TrxTestApplicationLifecycleCallbacks.cs

@@ -63,7 +63,7 @@ public async Task BeforeRunAsync(CancellationToken cancellationToken)
             {
                 string namedPipeName = _environment.GetEnvironmentVariable(TrxEnvironmentVariableProvider.TRXNAMEDPIPENAME)
                     ?? throw new InvalidOperationException(string.Format(CultureInfo.InvariantCulture, ExtensionResources.TrxReportGeneratorMissingTrxNamedPipeEnvironmentVariable, TrxEnvironmentVariableProvider.TRXNAMEDPIPENAME));
-                NamedPipeClient = new NamedPipeClient(namedPipeName);
+                NamedPipeClient = new NamedPipeClient(namedPipeName, _environment);
                 NamedPipeClient.RegisterSerializer(new ReportFileNameRequestSerializer(), typeof(ReportFileNameRequest));
                 NamedPipeClient.RegisterSerializer(new TestAdapterInformationRequestSerializer(), typeof(TestAdapterInformationRequest));
                 NamedPipeClient.RegisterSerializer(new VoidResponseSerializer(), typeof(VoidResponse));

src/Platform/Microsoft.Testing.Platform/Hosts/TestHostBuilder.cs

@@ -545,7 +545,7 @@ await LogTestHostCreatedAsync(
         environment.SetEnvironmentVariable(pipeEnvironmentVariable, string.Empty);
 
         // Create client to connect to the monitor
-        NamedPipeClient client = new(pipeName);
+        NamedPipeClient client = new(pipeName, environment);
         client.RegisterAllSerializers();
 
         // Connect to the monitor

src/Platform/Microsoft.Testing.Platform/IPC/NamedPipeClient.cs

@@ -3,12 +3,12 @@
 
 #if NETCOREAPP
 using System.Buffers;
-
-using Microsoft.Testing.Platform.Helpers;
 #endif
 
 using System.IO.Pipes;
 
+using Microsoft.Testing.Platform.Helpers;
+
 #if NET
 using Microsoft.Testing.Platform.Resources;
 #endif
@@ -24,14 +24,21 @@ internal sealed class NamedPipeClient : NamedPipeBase, IClient
     private readonly MemoryStream _serializationBuffer = new();
     private readonly MemoryStream _messageBuffer = new();
     private readonly byte[] _readBuffer = new byte[250000];
+    private readonly IEnvironment _environment;
 
     private bool _disposed;
 
     public NamedPipeClient(string name)
+        : this(name, new SystemEnvironment())
+    {
+    }
+
+    public NamedPipeClient(string name, IEnvironment environment)
     {
         Guard.NotNull(name);
         _namedPipeClientStream = new(".", name, PipeDirection.InOut);
         PipeName = name;
+        _environment = environment;
     }
 
     public string PipeName { get; }
@@ -144,6 +151,16 @@ public async Task<TResponse> RequestReplyAsync<TRequest, TResponse>(TRequest req
                 int currentReadBytes = await _namedPipeClientStream.ReadAsync(_readBuffer, currentReadIndex, _readBuffer.Length, cancellationToken).ConfigureAwait(false);
 #endif
 
+                if (currentReadBytes == 0)
+                {
+                    // We are reading a message response.
+                    // If we cannot get a response, there is no way we can recover and continue executing.
+                    // This can happen if the other processes gets killed or crashes while while it's sending the response.
+                    // This is especially important for 'dotnet test', where the user can simply kill the dotnet.exe process themselves.
+                    // In that case, we want the MTP process to also die.
+                    _environment.FailFast("[NamedPipeClient] Connection lost with the other side.");
+                }
+
                 // Reset the current chunk size
                 int missingBytesToReadOfCurrentChunk = currentReadBytes;
 

src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestConnection.cs

@@ -56,7 +56,7 @@ public async Task AfterCommonServiceSetupAsync()
                 _environment.SetEnvironmentVariable(EnvironmentVariableConstants.TESTINGPLATFORM_DOTNETTEST_EXECUTIONID, Guid.NewGuid().ToString("N"));
             }
 
-            _dotnetTestPipeClient = new(arguments[0]);
+            _dotnetTestPipeClient = new(arguments[0], _environment);
             _dotnetTestPipeClient.RegisterAllSerializers();
 
             await _dotnetTestPipeClient.ConnectAsync(_cancellationTokenSource.CancellationToken).ConfigureAwait(false);