WiP

src/dotnet/MulticoreJitProfilePathCalculator.cs

@@ -0,0 +1,57 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using Microsoft.DotNet.Cli.Utils;
+using Microsoft.Extensions.PlatformAbstractions;
+
+namespace Microsoft.DotNet.Cli
+{
+    internal class MulticoreJitProfilePathCalculator
+    {
+        private string _multicoreJitProfilePath;
+
+        public string MulticoreJitProfilePath
+        {
+            get
+            {
+                if (_multicoreJitProfilePath == null)
+                {
+                    CalculateProfileRootPath();
+                }
+
+                return _multicoreJitProfilePath;
+            }
+        }
+
+        private void CalculateProfileRootPath()
+        {
+            var profileRoot = GetRuntimeDataRootPath();
+
+            var version = Product.Version;
+
+            var rid = PlatformServices.Default.Runtime.GetRuntimeIdentifier();
+
+            _multicoreJitProfilePath = Path.Combine(profileRoot, "sdk", version, rid, "optimizationdata");
+        }
+
+        private string GetRuntimeDataRootPath()
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? GetWindowsRuntimeDataRoot()
+                : GetNonWindowsRuntimeDataRoot();
+        }
+
+        private static string GetWindowsRuntimeDataRoot()
+        {
+            return $@"{(Environment.GetEnvironmentVariable("LocalAppData"))}\Microsoft\dotnet\";
+        }
+
+        private static string GetNonWindowsRuntimeDataRoot()
+        {
+            return $"{(Environment.GetEnvironmentVariable("HOME"))}/.dotnet/";
+        }
+    }
+}

src/dotnet/Program.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.Loader;
 using System.Text;
 using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.InternalAbstractions;
@@ -42,6 +43,10 @@ namespace Microsoft.DotNet.Cli
         {
             DebugHelper.HandleDebugSwitch(ref args);
 
+            AssemblyLoadContext.Default.SetProfileOptimizationRoot(
+                new MulticoreJitProfilePathCalculator().MulticoreJitProfilePath);
+            AssemblyLoadContext.Default.StartProfileOptimization("dotnet");
+
             if (Env.GetEnvironmentVariableAsBool("DOTNET_CLI_CAPTURE_TIMING", false))
             {
                 PerfTrace.Enabled = true;

src/dotnet/Telemetry.cs

@@ -1,3 +1,6 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;

test/dotnet.Tests/GivenThatIWantToManageMulticoreJIT.cs

@@ -0,0 +1,76 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. 
+// Licensed under the MIT license. See LICENSE file in the project root for full license information. 
+
+using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.Tools.Test.Utilities;
+using Microsoft.Extensions.PlatformAbstractions;
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using Xunit;
+using Xunit.Abstractions;
+using FluentAssertions;
+
+namespace Microsoft.DotNet.Tests
+{
+    public class GivenThatIWantToManageMulticoreJIT : TestBase
+    {
+        ITestOutputHelper _output;
+        private const string OptimizationProfileFileName = "dotnet.";
+        private readonly string _optimizationProfileFilePath;
+        
+        public GivenThatIWantToManageMulticoreJIT(ITestOutputHelper output)
+        {
+            _output = output;
+            _optimizationProfileFilePath = GetOptimizationProfileFilePath();
+        }
+
+        [Fact]
+        public void When_invoked_it_writes_optimization_data_to_the_profile_root()
+        {
+            var testStartTime = DateTime.UtcNow;
+
+            new TestCommand("dotnet")
+                .Execute("--version");
+
+            File.Exists(_optimizationProfileFilePath)
+                .Should().BeTrue("Because dotnet CLI creates it after each run");
+
+            File.GetLastWriteTimeUtc(_optimizationProfileFilePath)
+                .Should().BeOnOrAfter(testStartTime, "Because dotnet CLI was executed after that time.");
+        }
+
+        private static string GetOptimizationProfileFilePath()
+        {
+            Console.WriteLine(GetOptimizationRootPath(GetDotnetVersion()));
+            return Path.Combine(GetOptimizationRootPath(GetDotnetVersion()),
+                OptimizationProfileFileName);
+        }
+
+        private static string GetOptimizationRootPath(string version)
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? GetWindowsProfileRoot(version)
+                : GetNonWindowsProfileRoot(version);
+        }
+
+        private static string GetWindowsProfileRoot(string version)
+        {
+            return $@"{(Environment.GetEnvironmentVariable("LocalAppData"))}\Microsoft\dotnet\sdk\{version}\optimizationdata";
+        }
+
+        private static string GetNonWindowsProfileRoot(string version)
+        {
+            return $"{(Environment.GetEnvironmentVariable("HOME"))}/.dotnet/sdk/{version}/optimizationdata";
+        }
+
+        private static string GetDotnetVersion()
+        {
+            return Command.Create("dotnet", new[] { "--version" })
+                .CaptureStdOut()
+                .Execute()
+                .StdOut
+                .Trim();
+        }
+    }
+}

test/dotnet.Tests/project.json

@@ -16,6 +16,7 @@
       "target": "project",
       "type": "build"
     },
+    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-rc2-20100",
     "xunit": "2.1.0",
     "dotnet-test-xunit": "1.0.0-rc2-173361-36"
   },