Enable VSTHRD200 (Use "Async" suffix for async methods)

.editorconfig

@@ -7,9 +7,6 @@ dotnet_sort_system_directives_first = true
 # VSTHRD002: Avoid problematic synchronous waits
 dotnet_diagnostic.VSTHRD002.severity = none
 
-# VSTHRD200: Use "Async" suffix for async methods
-dotnet_diagnostic.VSTHRD200.severity = none
-
 [test/**/*.cs]
 
 # MSML_GeneralName: This name should be PascalCased
@@ -25,3 +22,7 @@ dotnet_diagnostic.MSML_NoInstanceInitializers.severity = none
 # BaseTestClass does not apply for analyzer testing.
 # MSML_ExtendBaseTestClass: Test classes should be derived from BaseTestClass
 dotnet_diagnostic.MSML_ExtendBaseTestClass.severity = none
+
+# The MSML_RelaxTestNaming suppressor for VSTHRD200 is not active for CodeAnalyzer.Tests, so we disable it altogether.
+# VSTHRD200: Use "Async" suffix for async methods
+dotnet_diagnostic.VSTHRD200.severity = none

src/Microsoft.Extensions.ML/ModelLoaders/UriModelLoader.cs

@@ -46,7 +46,7 @@ internal void Start(Uri uri, TimeSpan period)
         {
             _timerPeriod = period;
             _uri = uri;
-            if (LoadModel().ConfigureAwait(false).GetAwaiter().GetResult())
+            if (LoadModelAsync().ConfigureAwait(false).GetAwaiter().GetResult())
             {
                 StartReloadTimer();
             }
@@ -78,10 +78,10 @@ internal async Task RunAsync()
                 cancellation.CancelAfter(TimeoutMilliseconds);
                 Logger.UriReloadBegin(_logger, _uri);
 
-                var eTagMatches = await MatchEtag(_uri, _eTag);
+                var eTagMatches = await MatchEtagAsync(_uri, _eTag);
                 if (!eTagMatches)
                 {
-                    await LoadModel();
+                    await LoadModelAsync();
                     var previousToken = Interlocked.Exchange(ref _reloadToken, new ModelReloadToken());
                     previousToken.OnReload();
                 }
@@ -102,7 +102,7 @@ internal async Task RunAsync()
             }
         }
 
-        internal virtual async Task<bool> MatchEtag(Uri uri, string eTag)
+        internal virtual async Task<bool> MatchEtagAsync(Uri uri, string eTag)
         {
             using (var client = new HttpClient())
             {
@@ -133,7 +133,7 @@ internal void StopReloadTimer()
             }
         }
 
-        internal virtual async Task<bool> LoadModel()
+        internal virtual async Task<bool> LoadModelAsync()
         {
             //TODO: We probably need some sort of retry policy for this.
             try

src/Microsoft.ML.Core/Utilities/ResourceManagerUtils.cs

@@ -98,7 +98,7 @@ public static string GetUrl(string suffix)
         /// <param name="timeout">An integer indicating the number of milliseconds to wait before timing out while downloading a resource.</param>
         /// <returns>The download results, containing the file path where the resources was (or should have been) downloaded to, and an error message
         /// (or null if there was no error).</returns>
-        public async Task<ResourceDownloadResults> EnsureResource(IHostEnvironment env, IChannel ch, string relativeUrl, string fileName, string dir, int timeout)
+        public async Task<ResourceDownloadResults> EnsureResourceAsync(IHostEnvironment env, IChannel ch, string relativeUrl, string fileName, string dir, int timeout)
         {
             var filePath = GetFilePath(ch, fileName, dir, out var error);
             if (File.Exists(filePath) || !string.IsNullOrEmpty(error))
@@ -120,7 +120,7 @@ private async Task<string> DownloadFromUrlWithRetryAsync(IHostEnvironment env, I
 
             for (int i = 0; i < retryTimes; ++i)
             {
-                var thisDownloadResult = await DownloadFromUrl(env, ch, url, fileName, timeout, filePath);
+                var thisDownloadResult = await DownloadFromUrlAsync(env, ch, url, fileName, timeout, filePath);
 
                 if (string.IsNullOrEmpty(thisDownloadResult))
                     return thisDownloadResult;
@@ -134,7 +134,7 @@ private async Task<string> DownloadFromUrlWithRetryAsync(IHostEnvironment env, I
         }
 
         /// <returns>Returns the error message if an error occurred, null if download was successful.</returns>
-        private async Task<string> DownloadFromUrl(IHostEnvironment env, IChannel ch, string url, string fileName, int timeout, string filePath)
+        private async Task<string> DownloadFromUrlAsync(IHostEnvironment env, IChannel ch, string url, string fileName, int timeout, string filePath)
         {
             using (var webClient = new WebClient())
             using (var downloadCancel = new CancellationTokenSource())

src/Microsoft.ML.Core/Utilities/ThreadUtils.cs

@@ -12,11 +12,11 @@ namespace Microsoft.ML.Internal.Utilities
 {
     internal static partial class Utils
     {
-        public static Task RunOnBackgroundThread(Action start) =>
-            ImmediateBackgroundThreadPool.Queue(start);
+        public static Task RunOnBackgroundThreadAsync(Action start) =>
+            ImmediateBackgroundThreadPool.QueueAsync(start);
 
-        public static Task RunOnBackgroundThread(Action<object> start, object obj) =>
-            ImmediateBackgroundThreadPool.Queue(start, obj);
+        public static Task RunOnBackgroundThreadAsync(Action<object> start, object obj) =>
+            ImmediateBackgroundThreadPool.QueueAsync(start, obj);
 
         public static Thread RunOnForegroundThread(ParameterizedThreadStart start) =>
             new Thread(start) { IsBackground = false };
@@ -42,17 +42,17 @@ private static class ImmediateBackgroundThreadPool
             /// always end in the <see cref="TaskStatus.RanToCompletion"/> state; if the delegate throws
             /// an exception, it'll be allowed to propagate on the thread, crashing the process.
             /// </summary>
-            public static Task Queue(Action threadStart) => Queue((Delegate)threadStart, null);
+            public static Task QueueAsync(Action threadStart) => QueueAsync((Delegate)threadStart, null);
 
             /// <summary>
             /// Queues an <see cref="Action{Object}"/> delegate and associated state to be executed immediately on another thread,
             /// and returns a <see cref="Task"/> that represents its eventual completion. The task will
             /// always end in the <see cref="TaskStatus.RanToCompletion"/> state; if the delegate throws
             /// an exception, it'll be allowed to propagate on the thread, crashing the process.
             /// </summary>
-            public static Task Queue(Action<object> threadStart, object state) => Queue((Delegate)threadStart, state);
+            public static Task QueueAsync(Action<object> threadStart, object state) => QueueAsync((Delegate)threadStart, state);
 
-            private static Task Queue(Delegate threadStart, object state)
+            private static Task QueueAsync(Delegate threadStart, object state)
             {
                 // Create the TaskCompletionSource used to represent this work.
                 // Call sites only care about completion, not about the distinction between

src/Microsoft.ML.Data/Data/DataViewUtils.cs

@@ -367,7 +367,7 @@ private static DataViewRowCursor ConsolidateCore(IChannelProvider provider, Data
                     ch.Assert(localCursor.Position < 0);
                     // Note that these all take ownership of their respective cursors,
                     // so they all handle their disposal internal to the thread.
-                    workers[t] = Utils.RunOnBackgroundThread(() =>
+                    workers[t] = Utils.RunOnBackgroundThreadAsync(() =>
                     {
                             // This will be the last batch sent in the finally. If iteration proceeds without
                             // error, it will remain null, and be sent as a sentinel. If iteration results in
@@ -557,7 +557,7 @@ private DataViewRowCursor[] SplitCore(IChannelProvider ch, DataViewRowCursor inp
                 // Set up and start the thread that consumes the input, and utilizes the InPipe
                 // instances to compose the Batch objects. The thread takes ownership of the
                 // cursor, and so handles its disposal.
-                Task thread = Utils.RunOnBackgroundThread(
+                Task thread = Utils.RunOnBackgroundThreadAsync(
                     () =>
                     {
                         Batch lastBatch = null;

src/Microsoft.ML.Data/DataLoadSave/Binary/BinaryLoader.cs

@@ -1333,9 +1333,9 @@ public Cursor(BinaryLoader parent, IEnumerable<DataViewSchema.Column> columnsNee
                     _pipeGetters[c] = _pipes[c].GetGetter();
                 }
                 // The data structures are initialized. Now set up the workers.
-                _readerThread = Utils.RunOnBackgroundThread(ReaderWorker);
+                _readerThread = Utils.RunOnBackgroundThreadAsync(ReaderWorker);
 
-                _pipeTask = SetupDecompressTask();
+                _pipeTask = DecompressAsync();
             }
 
             protected override void Dispose(bool disposing)
@@ -1405,14 +1405,14 @@ protected override void Dispose(bool disposing)
                 base.Dispose(disposing);
             }
 
-            private Task SetupDecompressTask()
+            private Task DecompressAsync()
             {
                 Task[] pipeWorkers = new Task[_parent._threads];
                 long decompressSequence = -1;
                 long decompressSequenceLim = (long)_numBlocks * _actives.Length;
                 for (int w = 0; w < pipeWorkers.Length; ++w)
                 {
-                    pipeWorkers[w] = Utils.RunOnBackgroundThread(() =>
+                    pipeWorkers[w] = Utils.RunOnBackgroundThreadAsync(() =>
                     {
                         try
                         {

src/Microsoft.ML.Data/DataLoadSave/Binary/BinarySaver.cs

@@ -664,15 +664,15 @@ public void SaveData(Stream stream, IDataView data, params int[] colIndices)
                     Task[] compressionThreads = new Task[Environment.ProcessorCount];
                     for (int i = 0; i < compressionThreads.Length; ++i)
                     {
-                        compressionThreads[i] = Utils.RunOnBackgroundThread(
+                        compressionThreads[i] = Utils.RunOnBackgroundThreadAsync(
                             () => CompressionWorker(toCompress, toWrite, activeColumns.Length, waiter, exMarshaller));
                     }
                     compressionTask = Task.WhenAll(compressionThreads);
                 }
 
                 // While there is an advantage to putting the IO into a separate thread, there is not an
                 // advantage to having more than one worker.
-                Task writeThread = Utils.RunOnBackgroundThread(
+                Task writeThread = Utils.RunOnBackgroundThreadAsync(
                     () => WriteWorker(stream, toWrite, activeColumns, data.Schema, rowsPerBlock, _host, exMarshaller));
                 sw.Start();
 

src/Microsoft.ML.Data/DataLoadSave/Text/TextLoaderCursor.cs

@@ -427,7 +427,7 @@ public LineReader(IMultiStreamSource files, int batchSize, int bufSize, bool has
                     _cref = cref;
 
                     _queue = new BlockingQueue<LineBatch>(bufSize);
-                    _thdRead = Utils.RunOnBackgroundThread(ThreadProc);
+                    _thdRead = Utils.RunOnBackgroundThreadAsync(ThreadProc);
                 }
 
                 public void Release()
@@ -691,7 +691,7 @@ public ParallelState(Cursor curs, out RowSet rows, int cthd)
 
                     for (int tid = 0; tid < _threads.Length; tid++)
                     {
-                        _threads[tid] = Utils.RunOnBackgroundThread(ThreadProc, tid);
+                        _threads[tid] = Utils.RunOnBackgroundThreadAsync(ThreadProc, tid);
                     }
                 }
 

src/Microsoft.ML.Data/DataView/CacheDataView.cs

@@ -364,7 +364,7 @@ private void KickoffFiller(int[] columns)
             // They will not be caught by the big catch in the main thread, as filler is not running
             // in the main thread. Some sort of scheme by which these exceptions could be
             // cleanly handled would be more appropriate. See task 3740.
-            var fillerThread = Utils.RunOnBackgroundThread(() => Filler(cursor, caches, waiter));
+            var fillerThread = Utils.RunOnBackgroundThreadAsync(() => Filler(cursor, caches, waiter));
             _cacheFillerThreads.Add(fillerThread);
         }
 

src/Microsoft.ML.Data/Transforms/RowShufflingTransformer.cs

@@ -546,7 +546,7 @@ public Cursor(IChannelProvider provider, int poolRows, DataViewRowCursor input,
                 for (int i = 1; i < _bufferDepth; ++i)
                     PostAssert(_toProduce, _blockSize);
 
-                _producerTask = LoopProducerWorker();
+                _producerTask = ProduceAsync();
             }
 
             protected override void Dispose(bool disposing)
@@ -586,7 +586,7 @@ public override ValueGetter<DataViewRowId> GetIdGetter()
                 return _idGetter;
             }
 
-            private async Task LoopProducerWorker()
+            private async Task ProduceAsync()
             {
                 try
                 {

src/Microsoft.ML.Sweeper/AsyncSweeper.cs

@@ -47,7 +47,7 @@ public interface IAsyncSweeper
         /// Propose a <see cref="ParameterSet"/>.
         /// </summary>
         /// <returns>A future <see cref="ParameterSet"/> and its id. Null if unavailable or cancelled.</returns>
-        Task<ParameterSetWithId> Propose();
+        Task<ParameterSetWithId> ProposeAsync();
 
         /// <summary>
         /// Notify the sweeper of a finished run.
@@ -108,7 +108,7 @@ public void Update(int id, IRunResult result)
             }
         }
 
-        public Task<ParameterSetWithId> Propose()
+        public Task<ParameterSetWithId> ProposeAsync()
         {
             if (_canceled)
                 return Task.FromResult<ParameterSetWithId>(null);
@@ -272,7 +272,7 @@ private void UpdateBarrierStatus(int id)
             }
         }
 
-        public async Task<ParameterSetWithId> Propose()
+        public async Task<ParameterSetWithId> ProposeAsync()
         {
             if (_cts.IsCancellationRequested)
                 return null;

src/Microsoft.ML.TensorFlow/TensorflowUtils.cs

@@ -180,7 +180,7 @@ internal static void DownloadIfNeeded(IHostEnvironment env, string url, string d
         {
             using (var ch = env.Start("Ensuring meta files are present."))
             {
-                var ensureModel = ResourceManagerUtils.Instance.EnsureResource(env, ch, url, fileName, dir, timeout);
+                var ensureModel = ResourceManagerUtils.Instance.EnsureResourceAsync(env, ch, url, fileName, dir, timeout);
                 ensureModel.Wait();
                 var errorResult = ResourceManagerUtils.GetErrorMessage(out var errorMessage, ensureModel.Result);
                 if (errorResult != null)

src/Microsoft.ML.Transforms/Text/WordEmbeddingsExtractor.cs

@@ -628,7 +628,7 @@ private string EnsureModelFile(IHostEnvironment env, out int linesToSkip, WordEm
                 {
                     string dir = kind == WordEmbeddingEstimator.PretrainedModelKind.SentimentSpecificWordEmbedding ? Path.Combine("Text", "Sswe") : "WordVectors";
                     var url = $"{dir}/{modelFileName}";
-                    var ensureModel = ResourceManagerUtils.Instance.EnsureResource(Host, ch, url, modelFileName, dir, Timeout);
+                    var ensureModel = ResourceManagerUtils.Instance.EnsureResourceAsync(Host, ch, url, modelFileName, dir, Timeout);
                     ensureModel.Wait();
                     var errorResult = ResourceManagerUtils.GetErrorMessage(out var errorMessage, ensureModel.Result);
                     if (errorResult != null)

test/Microsoft.Extensions.ML.Tests/UriLoaderTests.cs

@@ -92,12 +92,12 @@ public override ITransformer GetModel()
             return null;
         }
 
-        internal override Task<bool> LoadModel()
+        internal override Task<bool> LoadModelAsync()
         {
             return Task.FromResult(true);
         }
 
-        internal override Task<bool> MatchEtag(Uri uri, string eTag)
+        internal override Task<bool> MatchEtagAsync(Uri uri, string eTag)
         {
             return Task.FromResult(ETagMatches(uri, eTag));
         }

test/Microsoft.ML.Sweeper.Tests/TestSweeper.cs

@@ -145,7 +145,7 @@ public void TestSimpleSweeperAsync()
             var paramSets = new List<ParameterSet>();
             for (int i = 0; i < sweeps; i++)
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 Assert.True(task.IsCompleted);
                 paramSets.Add(task.Result.ParameterSet);
                 var result = new RunResult(task.Result.ParameterSet, random.NextDouble(), true);
@@ -166,7 +166,7 @@ public void TestSimpleSweeperAsync()
             paramSets.Clear();
             for (int i = 0; i < sweeps; i++)
             {
-                var task = gridSweeper.Propose();
+                var task = gridSweeper.ProposeAsync();
                 Assert.True(task.IsCompleted);
                 paramSets.Add(task.Result.ParameterSet);
             }
@@ -202,7 +202,7 @@ public async Task TestDeterministicSweeperAsyncCancellation()
             int numCompleted = 0;
             for (int i = 0; i < sweeps; i++)
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 if (i < args.BatchSize - args.Relaxation)
                 {
                     Assert.True(task.IsCompleted);
@@ -252,7 +252,7 @@ public async Task TestDeterministicSweeperAsync()
             var paramSets = new List<ParameterSet>();
             for (int i = 0; i < sweeps; i++)
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 Assert.True(task.IsCompleted);
                 paramSets.Add(task.CompletedResult().ParameterSet);
                 var result = new RunResult(task.CompletedResult().ParameterSet, random.NextDouble(), true);
@@ -270,7 +270,7 @@ public async Task TestDeterministicSweeperAsync()
             var results = new List<KeyValuePair<int, IRunResult>>();
             for (int i = 0; i < args.BatchSize; i++)
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 Assert.True(task.IsCompleted);
                 tasks[i] = task;
                 if (task.CompletedResult() == null)
@@ -281,7 +281,7 @@ public async Task TestDeterministicSweeperAsync()
             // in the previous batch has been posted to the sweeper.
             for (int i = args.BatchSize; i < 2 * args.BatchSize; i++)
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 Assert.False(task.IsCompleted);
                 tasks[i] = task;
             }
@@ -328,7 +328,7 @@ public void TestDeterministicSweeperAsyncParallel()
                 sleeps[i] = random.Next(10, 100);
             var r = Task.Run(() => Parallel.For(0, sweeps, options, (int i) =>
             {
-                var task = sweeper.Propose();
+                var task = sweeper.ProposeAsync();
                 task.Wait();
                 Assert.Equal(TaskStatus.RanToCompletion, task.Status);
                 var paramWithId = task.Result;
@@ -386,7 +386,7 @@ public async Task TestNelderMeadSweeperAsync()
 
             for (int i = 0; i < sweeps; i++)
             {
-                var paramWithId = await sweeper.Propose();
+                var paramWithId = await sweeper.ProposeAsync();
                 if (paramWithId == null)
                     return;
                 var result = new RunResult(paramWithId.ParameterSet, metrics[i], true);