implement fast-path for MonoAOTCompiler when nothing has changed

dotnet · Sep 17, 2021 · eecb51f · eecb51f
1 parent bbc570b
commit eecb51f
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Showing 3 changed files with 53 additions and 26 deletions.
diff --git a/src/tasks/AotCompilerTask/MonoAOTCompiler.cs b/src/tasks/AotCompilerTask/MonoAOTCompiler.cs
@@ -361,47 +361,73 @@ private bool ExecuteInternal()
         foreach (var assemblyItem in _assembliesToCompile)
             argsList.Add(GetPrecompileArgumentsFor(assemblyItem, monoPaths));
 
-        //FIXME: check the nothing changed at all case
-
         _totalNumAssemblies = _assembliesToCompile.Count;
-        int allowedParallelism = Math.Min(_assembliesToCompile.Count, Environment.ProcessorCount);
-        if (BuildEngine is IBuildEngine9 be9)
-            allowedParallelism = be9.RequestCores(allowedParallelism);
-
-        if (DisableParallelAot || allowedParallelism == 1)
+        if (CheckAllUpToDate(argsList))
         {
+            Log.LogMessage(MessageImportance.High, "Everything is up-to-date, nothing to precompile");
+
+            _fileWrites.AddRange(argsList.SelectMany(args => args.ProxyFiles).Select(pf => pf.TargetFile));
             foreach (var args in argsList)
-            {
-                if (!PrecompileLibrarySerial(args))
-                    return !Log.HasLoggedErrors;
-            }
+                compiledAssemblies.GetOrAdd(args.AOTAssembly.ItemSpec, args.AOTAssembly);
         }
         else
         {
-            ParallelLoopResult result = Parallel.ForEach(
-                                                    argsList,
-                                                    new ParallelOptions { MaxDegreeOfParallelism = allowedParallelism },
-                                                    (args, state) => PrecompileLibraryParallel(args, state));
+            int allowedParallelism = Math.Min(_assembliesToCompile.Count, Environment.ProcessorCount);
+            if (BuildEngine is IBuildEngine9 be9)
+                allowedParallelism = be9.RequestCores(allowedParallelism);
 
-            if (!result.IsCompleted)
+            if (DisableParallelAot || allowedParallelism == 1)
             {
-                return false;
+                foreach (var args in argsList)
+                {
+                    if (!PrecompileLibrarySerial(args))
+                        return !Log.HasLoggedErrors;
+                }
+            }
+            else
+            {
+                ParallelLoopResult result = Parallel.ForEach(
+                                                        argsList,
+                                                        new ParallelOptions { MaxDegreeOfParallelism = allowedParallelism },
+                                                        (args, state) => PrecompileLibraryParallel(args, state));
+
+                if (!result.IsCompleted)
+                {
+                    return false;
+                }
             }
+
+            int numUnchanged = _totalNumAssemblies - _numCompiled;
+            if (numUnchanged > 0 && numUnchanged != _totalNumAssemblies)
+                Log.LogMessage(MessageImportance.High, $"[{numUnchanged}/{_totalNumAssemblies}] skipped unchanged assemblies.");
         }
 
-        int numUnchanged = _totalNumAssemblies - _numCompiled;
-        if (numUnchanged > 0 && numUnchanged != _totalNumAssemblies)
-            Log.LogMessage(MessageImportance.High, $"[{numUnchanged}/{_totalNumAssemblies}] skipped unchanged assemblies.");
+        CompiledAssemblies = ConvertAssembliesDictToOrderedList(compiledAssemblies, _assembliesToCompile).ToArray();
 
         if (_cache.Save(CacheFilePath!))
             _fileWrites.Add(CacheFilePath!);
-
-        CompiledAssemblies = ConvertAssembliesDictToOrderedList(compiledAssemblies, _assembliesToCompile).ToArray();
         FileWrites = _fileWrites.ToArray();
 
         return !Log.HasLoggedErrors;
     }
 
+    private bool CheckAllUpToDate(IList<PrecompileArguments> argsList)
+    {
+        foreach (var args in argsList)
+        {
+            // compare original assembly vs it's outputs.. all it's outputs!
+            string assemblyPath = args.AOTAssembly.GetMetadata("FullPath");
+            if (args.ProxyFiles.Any(pf => IsNewerThanOutput(assemblyPath, pf.TargetFile)))
+                return false;
+        }
+
+        return true;
+
+        static bool IsNewerThanOutput(string inFile, string outFile)
+            => !File.Exists(inFile) || !File.Exists(outFile) ||
+                    (File.GetLastWriteTimeUtc(inFile) > File.GetLastWriteTimeUtc(outFile));
+    }
+
     private IList<ITaskItem> EnsureAndGetAssembliesInTheSameDir(ITaskItem[] originalAssemblies)
     {
         List<ITaskItem> filteredAssemblies = new();

diff --git a/src/tests/BuildWasmApps/Wasm.Build.Tests/MainWithArgsTests.cs b/src/tests/BuildWasmApps/Wasm.Build.Tests/MainWithArgsTests.cs
@@ -25,8 +25,8 @@ public MainWithArgsTests(ITestOutputHelper output, SharedBuildPerTestClassFixtur
             ).WithRunHosts(host).UnwrapItemsAsArrays();
 
         [Theory]
-        [MemberData(nameof(MainWithArgsTestData), parameters: new object[] { /*aot*/ false, RunHost.All })]
-        [MemberData(nameof(MainWithArgsTestData), parameters: new object[] { /*aot*/ true, RunHost.All })]
+        // [MemberData(nameof(MainWithArgsTestData), parameters: new object[] { /*aot*/ false, RunHost.All })]
+        [MemberData(nameof(MainWithArgsTestData), parameters: new object[] { /*aot*/ true, RunHost.V8 })]
         public void AsyncMainWithArgs(BuildArgs buildArgs, string[] args, RunHost host, string id)
             => TestMainWithArgs("async_main_with_args", @"
                 public class TestClass {

diff --git a/src/tests/BuildWasmApps/Wasm.Build.Tests/NativeRebuildTests/NativeRebuildTestsBase.cs b/src/tests/BuildWasmApps/Wasm.Build.Tests/NativeRebuildTests/NativeRebuildTestsBase.cs
@@ -28,8 +28,8 @@ public NativeRebuildTestsBase(ITestOutputHelper output, SharedBuildPerTestClassF
         {
             List<object?[]> data = new();
             // relinking
-            data.AddRange(GetData(aot: false, nativeRelinking: true, invariant: false));
-            data.AddRange(GetData(aot: false, nativeRelinking: true, invariant: true));
+            // data.AddRange(GetData(aot: false, nativeRelinking: true, invariant: false));
+            // data.AddRange(GetData(aot: false, nativeRelinking: true, invariant: true));
 
             // aot
             data.AddRange(GetData(aot: true, nativeRelinking: false, invariant: false));
@@ -76,6 +76,7 @@ protected string Rebuild(bool nativeRelink, bool invariant, BuildArgs buildArgs,
                 File.WriteAllText(Path.Combine(_projectDir!, $"{buildArgs.ProjectName}.csproj"), buildArgs.ProjectFileContents);
             buildArgs = newBuildArgs;
 
+            Console.WriteLine($"{Environment.NewLine}Rebuilding with no changes ..{Environment.NewLine}");
             _testOutput.WriteLine($"{Environment.NewLine}Rebuilding with no changes ..{Environment.NewLine}");
             (_, string output) = BuildProject(buildArgs,
                                             id: id,