Fix modules reload leak

src/Analysis/Engine/Impl/Infrastructure/Extensions/StringBuilderExtensions.cs

@@ -37,7 +37,15 @@ public static StringBuilder EnsureEndsWithWhiteSpace(this StringBuilder sb, int
             if (whiteSpaceCount > 0) {
                 sb.Append(' ', whiteSpaceCount);
             }
-
+
+            return sb;
+        }
+
+        public static StringBuilder AppendIf(this StringBuilder sb, bool condition, string value) {
+            if (condition) {
+                sb.Append(value);
+            }
+
             return sb;
         }
     }

src/Analysis/Engine/Impl/Interpreter/Ast/AstPythonInterpreter.cs

@@ -274,6 +274,7 @@ public void Initialize(PythonAnalyzer state) {
             }
 
             _analyzer = state;
+            RemoveImportedModules();
 
             if (state != null) {
                 lock (_userSearchPathsLock) {
@@ -289,19 +290,23 @@ public void Initialize(PythonAnalyzer state) {
 
         private void Analyzer_SearchPathsChanged(object sender, EventArgs e) {
             lock (_userSearchPathsLock) {
-                // Remove imported modules from search paths so we will
-                // import them again.
-                foreach (var name in _userSearchPathImported.MaybeEnumerate()) {
-                    IPythonModule mod;
-                    _modules.TryRemove(name, out mod);
-                }
+                RemoveImportedModules();
                 _userSearchPathImported = null;
                 _userSearchPathPackages = null;
                 _userSearchPaths = _analyzer.GetSearchPaths();
             }
             ModuleNamesChanged?.Invoke(this, EventArgs.Empty);
         }
 
+        private void RemoveImportedModules() {
+            lock (_userSearchPathsLock) {
+                // Remove imported modules from search paths so we will import them again.
+                foreach (var name in _userSearchPathImported.MaybeEnumerate()) {
+                    _modules.TryRemove(name, out var mod);
+                }
+            }
+        }
+
         public IEnumerable<string> GetModulesNamed(string name) {
             var usp = GetUserSearchPathPackagesAsync(CancellationToken.None).WaitAndUnwrapExceptions();
             var ssp = _factory.GetImportableModulesAsync(CancellationToken.None).WaitAndUnwrapExceptions();

src/Analysis/Engine/Impl/ModuleTable.cs

@@ -172,7 +172,7 @@ public ModuleReference GetOrAdd(string name) {
         /// Modules that are already in the table as builtins are replaced or
         /// removed, but no new modules are added.
         /// </summary>
-        public void ReInit() {
+        internal void Reload() {
             var newNames = new HashSet<string>(_interpreter.GetModuleNames(), StringComparer.Ordinal);
 
             foreach (var keyValue in _modules) {

src/Analysis/Engine/Impl/PythonAnalyzer.cs

@@ -174,16 +174,16 @@ private async Task LoadKnownTypesAsync(CancellationToken token) {
             }
 
             try {
-                _interpreterFactory.NotifyImportNamesChanged();
-                _modules.ReInit();
+                _modules.Reload();
                 _interpreter.Initialize(this);
 
                 await LoadKnownTypesAsync(token);
-
                 foreach (var mod in _modulesByFilename.Values) {
                     mod.Clear();
                     mod.EnsureModuleVariables(this);
                 }
+
+                _interpreterFactory.NotifyImportNamesChanged();
             } finally {
                 _reloadLock.Release();
             }

src/Analysis/Engine/Impl/Values/Protocols.cs

@@ -17,6 +17,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using Microsoft.PythonTools.Analysis.Infrastructure;
 using Microsoft.PythonTools.Interpreter;
 using Microsoft.PythonTools.Parsing;
@@ -389,9 +390,32 @@ class TupleProtocol : IterableProtocol {
 
         public TupleProtocol(ProtocolInfo self, IEnumerable<IAnalysisSet> values) : base(self, AnalysisSet.UnionAll(values)) {
             _values = values.Select(s => s.AsUnion(1)).ToArray();
+            Name = GetNameFromValues();
+        }
+
+        private string GetNameFromValues() {
+            // Enumerate manually since SelectMany drops empty/unknown values
+            var sb = new StringBuilder("tuple[");
+            for (var i = 0; i < _values.Length; i++) {
+               sb.AppendIf(i > 0, ", ");
+               AppendParameterString(sb, _values[i].ToArray());
+            }
+            sb.Append(']');
+            return sb.ToString();
+        }
+
+        private void AppendParameterString(StringBuilder sb, AnalysisValue[] sets) {
+            if (sets.Length == 0) {
+                sb.Append('?');
+                return;
+            }
 
-            var argTypes = _values.SelectMany(e => e.Select(v => v is IHasQualifiedName qn ? qn.FullyQualifiedName : v.ShortDescription));
-            Name = "tuple[{0}]".FormatInvariant(string.Join(", ", argTypes));
+            sb.AppendIf(sets.Length > 1, "[");
+            for (var i = 0; i < sets.Length; i++) {
+                sb.AppendIf(i > 0, ", ");
+                sb.Append(sets[i] is IHasQualifiedName qn ? qn.FullyQualifiedName : sets[i].ShortDescription);
+            }
+            sb.AppendIf(sets.Length > 1, "]");
         }
 
         protected override void EnsureMembers(IDictionary<string, IAnalysisSet> members) {
@@ -419,6 +443,7 @@ public override IAnalysisSet GetIndex(Node node, AnalysisUnit unit, IAnalysisSet
         }
 
         public override string Name { get; }
+        public override BuiltinTypeId TypeId => BuiltinTypeId.Tuple;
 
         public override IEnumerable<KeyValuePair<string, string>> GetRichDescription() {
             if (_values.Any()) {
@@ -437,7 +462,7 @@ public override IEnumerable<KeyValuePair<string, string>> GetRichDescription() {
             }
         }
 
-        protected override bool Equals(Protocol other) => 
+        protected override bool Equals(Protocol other) =>
             other is TupleProtocol tp &&
             _values.Zip(tp._values, (x, y) => x.SetEquals(y)).All(b => b);
 
@@ -524,6 +549,7 @@ public override IAnalysisSet GetIndex(Node node, AnalysisUnit unit, IAnalysisSet
         }
 
         public override string Name => "dict";
+        public override BuiltinTypeId TypeId => BuiltinTypeId.Dict;
 
         public override IEnumerable<KeyValuePair<string, string>> GetRichDescription() {
             if (_valueType.Any()) {
@@ -576,14 +602,13 @@ protected override void EnsureMembers(IDictionary<string, IAnalysisSet> members)
         }
 
         public override string Name => "generator";
-
+        public override BuiltinTypeId TypeId => BuiltinTypeId.Generator;
+
         public IAnalysisSet Yielded => _yielded;
         public IAnalysisSet Sent { get; }
         public IAnalysisSet Returned { get; }
 
-        public override IAnalysisSet GetReturnForYieldFrom(Node node, AnalysisUnit unit) {
-            return Returned;
-        }
+        public override IAnalysisSet GetReturnForYieldFrom(Node node, AnalysisUnit unit) => Returned;
 
         public override IEnumerable<KeyValuePair<string, string>> GetRichDescription() {
             if (_yielded.Any() || Sent.Any() || Returned.Any()) {

src/LanguageServer/Impl/Implementation/Server.Completion.cs

@@ -22,7 +22,6 @@
 using Microsoft.Python.LanguageServer.Extensions;
 using Microsoft.PythonTools;
 using Microsoft.PythonTools.Analysis;
-using Microsoft.PythonTools.Analysis.Infrastructure;
 using Microsoft.PythonTools.Parsing;
 using Microsoft.PythonTools.Parsing.Ast;
 

src/LanguageServer/Impl/Implementation/Server.cs

@@ -40,12 +40,12 @@ public sealed partial class Server : ServerBase, ILogger, IPythonLanguageServer,
         /// Implements ability to execute module reload on the analyzer thread
         /// </summary>
         private sealed class ReloadModulesQueueItem : IAnalyzable {
-            private readonly PythonAnalyzer _analyzer;
+            private readonly Server _server;
             private TaskCompletionSource<bool> _tcs = new TaskCompletionSource<bool>();
             public Task Task => _tcs.Task;
 
-            public ReloadModulesQueueItem(PythonAnalyzer analyzer) {
-                _analyzer = analyzer;
+            public ReloadModulesQueueItem(Server server) {
+                _server = server;
             }
             public void Analyze(CancellationToken cancel) {
                 if (cancel.IsCancellationRequested) {
@@ -54,7 +54,10 @@ public void Analyze(CancellationToken cancel) {
 
                 var currentTcs = Interlocked.Exchange(ref _tcs, new TaskCompletionSource<bool>());
                 try {
-                    _analyzer.ReloadModulesAsync(cancel).WaitAndUnwrapExceptions();
+                    _server.Analyzer.ReloadModulesAsync(cancel).WaitAndUnwrapExceptions();
+                    foreach (var entry in _server.Analyzer.ModulesByFilename) {
+                        _server.AnalysisQueue.Enqueue(entry.Value.ProjectEntry, AnalysisPriority.Normal);
+                    }
                     currentTcs.TrySetResult(true);
                 } catch (OperationCanceledException oce) {
                     currentTcs.TrySetCanceled(oce.CancellationToken);
@@ -374,7 +377,7 @@ private async Task DoInitializeAsync(InitializeParams @params, CancellationToken
             _analysisUpdates = @params.initializationOptions.analysisUpdates;
 
             Analyzer.EnableDiagnostics = _clientCaps?.python?.liveLinting ?? false;
-            _reloadModulesQueueItem = new ReloadModulesQueueItem(Analyzer);
+            _reloadModulesQueueItem = new ReloadModulesQueueItem(this);
 
             if (@params.initializationOptions.displayOptions != null) {
                 DisplayOptions = @params.initializationOptions.displayOptions;
@@ -391,8 +394,6 @@ private async Task DoInitializeAsync(InitializeParams @params, CancellationToken
 
             SetSearchPaths(@params.initializationOptions.searchPaths);
             SetTypeStubSearchPaths(@params.initializationOptions.typeStubSearchPaths);
-
-            Analyzer.Interpreter.ModuleNamesChanged += Interpreter_ModuleNamesChanged;
         }
 
         private void DisplayStartupInfo() {
@@ -403,13 +404,6 @@ private void DisplayStartupInfo() {
                 : Resources.InitializingForPythonInterpreter.FormatInvariant(Analyzer.InterpreterFactory.Configuration.InterpreterPath));
         }
 
-        private void Interpreter_ModuleNamesChanged(object sender, EventArgs e) {
-            Analyzer.Modules.ReInit();
-            foreach (var entry in Analyzer.ModulesByFilename) {
-                AnalysisQueue.Enqueue(entry.Value.ProjectEntry, AnalysisPriority.Normal);
-            }
-        }
-
         private T ActivateObject<T>(string assemblyName, string typeName, Dictionary<string, object> properties) {
             if (string.IsNullOrEmpty(assemblyName) || string.IsNullOrEmpty(typeName)) {
                 return default(T);