Write process and pipe information to a pid file

src/Microsoft.AspNetCore.Razor.Tools/MetadataReaderExtensions.cs

@@ -1,4 +1,5 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
 using System.Collections.Generic;

src/Microsoft.AspNetCore.Razor.Tools/MutexName.cs

@@ -12,7 +12,11 @@ namespace Microsoft.AspNetCore.Razor.Tools
 
         public static string GetServerMutexName(string pipeName)
         {
-            return $"{pipeName}.server";
+            // We want to prefix this with Global\ because we want this mutex to be visible
+            // across terminal sessions which is useful for cases like shutdown.
+            // https://msdn.microsoft.com/en-us/library/system.threading.mutex(v=vs.110).aspx#Remarks
+            // This still wouldn't allow other users to access the server because the pipe will fail to connect.
+            return $"Global\\{pipeName}.server";
         }
     }
 }

src/Microsoft.AspNetCore.Razor.Tools/ServerCommand.cs

@@ -2,6 +2,10 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.CommandLineUtils;
@@ -17,6 +21,18 @@ namespace Microsoft.AspNetCore.Razor.Tools
             KeepAlive = Option("-k|--keep-alive", "sets the default idle timeout for the server in seconds", CommandOptionType.SingleValue);
         }
 
+        // For testing purposes only.
+        internal ServerCommand(Application parent, string pipeName, int? keepAlive = null)
+            : this(parent)
+        {
+            Pipe.Values.Add(pipeName);
+
+            if (keepAlive.HasValue)
+            {
+                KeepAlive.Values.Add(keepAlive.Value.ToString());
+            }
+        }
+
         public CommandOption Pipe { get; }
 
         public CommandOption KeepAlive { get; }
@@ -61,8 +77,20 @@ namespace Microsoft.AspNetCore.Razor.Tools
                 return Task.FromResult(1);
             }
 
+            FileStream pidFileStream = null;
             try
             {
+                try
+                {
+                    // Write the process and pipe information to a file in a well-known location.
+                    pidFileStream = WritePidFile();
+                }
+                catch (Exception ex)
+                {
+                    // Something happened when trying to write to the pid file. Log and move on.
+                    ServerLogger.LogException(ex, "Failed to create PID file.");
+                }
+
                 TimeSpan? keepAlive = null;
                 if (KeepAlive.HasValue() && int.TryParse(KeepAlive.Value(), out var result))
                 {
@@ -79,6 +107,7 @@ namespace Microsoft.AspNetCore.Razor.Tools
             {
                 serverMutex.ReleaseMutex();
                 serverMutex.Dispose();
+                pidFileStream?.Close();
             }
 
             return Task.FromResult(0);
@@ -89,5 +118,49 @@ namespace Microsoft.AspNetCore.Razor.Tools
             var dispatcher = RequestDispatcher.Create(host, compilerHost, cancellationToken, eventBus, keepAlive);
             dispatcher.Run();
         }
+
+        internal FileStream WritePidFile()
+        {
+            // To make all the running rzc servers more discoverable, We want to write the process Id and pipe name to a file.
+            // The file contents will be in the following format,
+            //
+            // <PID>
+            // rzc
+            // path/to/rzc.dll
+            // <pipename>
+
+            const int DefaultBufferSize = 4096;
+            var processId = Process.GetCurrentProcess().Id;
+            var fileName = $"rzc-{processId}";
+
+            var path = Environment.GetEnvironmentVariable("DOTNET_BUILD_PIDFILE_DIRECTORY");
+            if (string.IsNullOrEmpty(path))
+            {
+                var homeEnvVariable = PlatformInformation.IsWindows ? "USERPROFILE" : "HOME";
+                var homePath = Environment.GetEnvironmentVariable(homeEnvVariable);
+                if (string.IsNullOrEmpty(homePath))
+                {
+                    // Couldn't locate the user profile directory. Bail.
+                    return null;
+                }
+
+                path = Path.Combine(homePath, ".dotnet", "pids", "build");
+            }
+
+            // Make sure the directory exists.
+            Directory.CreateDirectory(path);
+
+            path = Path.Combine(path, fileName);
+            var fileStream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.Read, DefaultBufferSize, FileOptions.DeleteOnClose);
+
+            using (var writer = new StreamWriter(fileStream, Encoding.UTF8, DefaultBufferSize, leaveOpen: true))
+            {
+                var rzcPath = Assembly.GetExecutingAssembly().Location;
+                var content = $"{processId}{Environment.NewLine}rzc{Environment.NewLine}{rzcPath}{Environment.NewLine}{Pipe.Value()}";
+                writer.Write(content);
+            }
+
+            return fileStream;
+        }
     }
 }

src/Microsoft.AspNetCore.Razor.Tools/ServerProtocol/NativeMethods.cs

@@ -1,4 +1,5 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
 using System.Runtime.InteropServices;

src/Microsoft.AspNetCore.Razor.Tools/ServerProtocol/ServerConnection.cs

@@ -1,4 +1,5 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
 using System.Collections.Generic;
@@ -21,6 +22,9 @@ namespace Microsoft.AspNetCore.Razor.Tools
         // Spend up to 20s connecting to a new process, to allow time for it to start.
         private const int TimeOutMsNewProcess = 20000;
 
+        // Custom delegate that contains an out param to use with TryCreateServerCore method.
+        private delegate TResult TryCreateServerCoreDelegate<T1, T2, T3, T4, out TResult>(T1 arg1, T2 arg2, out T3 arg3, T4 arg4);
+
         public static bool WasServerMutexOpen(string mutexName)
         {
             Mutex mutex = null;
@@ -118,7 +122,7 @@ namespace Microsoft.AspNetCore.Razor.Tools
             string pipeName,
             string keepAlive,
             int? timeoutOverride,
-            Func<string, string, bool, bool> tryCreateServerFunc,
+            TryCreateServerCoreDelegate<string, string, int?, bool, bool> tryCreateServerFunc,
             CancellationToken cancellationToken,
             bool debug)
         {
@@ -181,7 +185,7 @@ namespace Microsoft.AspNetCore.Razor.Tools
                 var wasServerRunning = WasServerMutexOpen(serverMutexName);
                 var timeout = wasServerRunning ? timeoutExistingProcess : timeoutNewProcess;
 
-                if (wasServerRunning || tryCreateServerFunc(clientDir, pipeName, debug))
+                if (wasServerRunning || tryCreateServerFunc(clientDir, pipeName, out var _, debug))
                 {
                     pipeTask = Client.ConnectAsync(pipeName, TimeSpan.FromMilliseconds(timeout), cancellationToken);
                 }
@@ -277,10 +281,11 @@ namespace Microsoft.AspNetCore.Razor.Tools
         }
 
         // Internal for testing.
-        internal static bool TryCreateServerCore(string clientDir, string pipeName, bool debug = false)
+        internal static bool TryCreateServerCore(string clientDir, string pipeName, out int? processId, bool debug = false)
         {
             string expectedPath;
             string processArguments;
+            processId = null;
 
             // The server should be in the same directory as the client
             var expectedCompilerPath = Path.Combine(clientDir, ServerName);
@@ -328,6 +333,7 @@ namespace Microsoft.AspNetCore.Razor.Tools
                     ServerLogger.Log("Successfully created process with process id {0}", processInfo.dwProcessId);
                     NativeMethods.CloseHandle(processInfo.hProcess);
                     NativeMethods.CloseHandle(processInfo.hThread);
+                    processId = processInfo.dwProcessId;
                 }
                 else
                 {
@@ -351,7 +357,9 @@ namespace Microsoft.AspNetCore.Razor.Tools
                         CreateNoWindow = true
                     };
 
-                    Process.Start(startInfo);
+                    var process = Process.Start(startInfo);
+                    processId = process.Id;
+
                     return true;
                 }
                 catch

src/Microsoft.AspNetCore.Razor.Tools/ServerProtocol/ServerLogger.cs

@@ -1,4 +1,5 @@
-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
 using System.Diagnostics;

src/Microsoft.AspNetCore.Razor.Tools/ShutdownCommand.cs

@@ -44,8 +44,13 @@ namespace Microsoft.AspNetCore.Razor.Tools
 
             try
             {
-                using (var client = await Client.ConnectAsync(Pipe.Value(), timeout: null, cancellationToken: Cancelled))
+                using (var client = await Client.ConnectAsync(Pipe.Value(), timeout: TimeSpan.FromSeconds(5), cancellationToken: Cancelled))
                 {
+                    if (client == null)
+                    {
+                        throw new InvalidOperationException("Couldn't connect to the server.");
+                    }
+
                     var request = ServerRequest.CreateShutdown();
                     await request.WriteAsync(client.Stream, Cancelled).ConfigureAwait(false);
 

test/Microsoft.AspNetCore.Razor.Design.Test/IntegrationTests/BuildServerIntegrationTest.cs

@@ -1,6 +1,8 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+using System.Diagnostics;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -15,9 +17,12 @@ namespace Microsoft.AspNetCore.Razor.Design.IntegrationTests
 {
     public class BuildServerIntegrationTest : MSBuildIntegrationTestBase, IClassFixture<BuildServerTestFixture>
     {
+        private BuildServerTestFixture _buildServer;
+
         public BuildServerIntegrationTest(BuildServerTestFixture buildServer)
             : base(buildServer)
         {
+            _buildServer = buildServer;
         }
 
         [Fact]

test/Microsoft.AspNetCore.Razor.Design.Test/IntegrationTests/BuildServerTestFixture.cs

@@ -18,14 +18,18 @@ namespace Microsoft.AspNetCore.Razor.Design.IntegrationTests
         {
             PipeName = Guid.NewGuid().ToString();
 
-            if (!ServerConnection.TryCreateServerCore(Environment.CurrentDirectory, PipeName))
+            if (!ServerConnection.TryCreateServerCore(Environment.CurrentDirectory, PipeName, out var processId))
             {
                 throw new InvalidOperationException($"Failed to start the build server at pipe {PipeName}.");
             }
+
+            ProcessId = processId;
         }
 
         public string PipeName { get; }
 
+        public int? ProcessId { get; }
+
         public void Dispose()
         {
             // Shutdown the build server.

test/Microsoft.AspNetCore.Razor.Tools.Test/ServerCommandTest.cs

@@ -0,0 +1,69 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Threading;
+using Microsoft.CodeAnalysis;
+using Moq;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Razor.Tools
+{
+    public class ServerCommandTest
+    {
+        [Fact]
+        public void WritePidFile_WorksAsExpected()
+        {
+            // Arrange
+            var expectedProcessId = Process.GetCurrentProcess().Id;
+            var expectedRzcPath = typeof(ServerCommand).Assembly.Location;
+            var expectedFileName = $"rzc-{expectedProcessId}";
+            var homeEnvVariable = PlatformInformation.IsWindows ? "USERPROFILE" : "HOME";
+            var path = Path.Combine(Environment.GetEnvironmentVariable(homeEnvVariable), ".dotnet", "pids", "build", expectedFileName);
+
+            var pipeName = Guid.NewGuid().ToString();
+            var server = GetServerCommand(pipeName);
+
+            // Act & Assert
+            try
+            {
+                using (var _ = server.WritePidFile())
+                {
+                    Assert.True(File.Exists(path));
+
+                    // Make sure another stream can be opened while the write stream is still open.
+                    using (var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Write | FileShare.Delete))
+                    using (var reader = new StreamReader(fileStream))
+                    {
+                        var lines = reader.ReadToEnd().Split(Environment.NewLine);
+                        Assert.Equal(new[] { expectedProcessId.ToString(), "rzc", expectedRzcPath, pipeName }, lines);
+                    }
+                }
+
+                // Make sure the file is deleted on dispose.
+                Assert.False(File.Exists(path));
+            }
+            finally
+            {
+                // Delete the file in case the test fails.
+                if (File.Exists(path))
+                {
+                    File.Delete(path);
+                }
+            }
+        }
+
+        private ServerCommand GetServerCommand(string pipeName)
+        {
+            var application = new Application(
+                CancellationToken.None,
+                Mock.Of<ExtensionAssemblyLoader>(),
+                Mock.Of<ExtensionDependencyChecker>(),
+                (path, properties) => MetadataReference.CreateFromFile(path, properties));
+
+            return new ServerCommand(application, pipeName);
+        }
+    }
+}