Clang: Fix crash on exit

There were threads running but the instances they called were already
deleted. Now we delete the scheduler first which is the thread holder and
which is waiting that all threads are finished.

Task-number: QTCREATORBUG-21882
Change-Id: I2e9f4d8381d79fab9a93346cef6598ab8e8f7850
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangpchmanagerbackend/clangpchmanagerbackendmain.cpp

@@ -183,16 +183,6 @@ struct Data // because we have a cycle dependency
     PrecompiledHeaderStorage<> preCompiledHeaderStorage{database};
     ClangBackEnd::ProgressCounter progressCounter{
         [&](int progress, int total) { clangPchManagerServer.setProgress(progress, total); }};
-    TaskScheduler systemTaskScheduler{pchCreatorManager,
-                                      pchTaskQueue,
-                                      progressCounter,
-                                      std::thread::hardware_concurrency(),
-                                      ClangBackEnd::CallDoInMainThreadAfterFinished::No};
-    TaskScheduler projectTaskScheduler{pchCreatorManager,
-                                       pchTaskQueue,
-                                       progressCounter,
-                                       std::thread::hardware_concurrency(),
-                                       ClangBackEnd::CallDoInMainThreadAfterFinished::Yes};
     ClangBackEnd::PchTaskQueue pchTaskQueue{systemTaskScheduler,
                                             projectTaskScheduler,
                                             progressCounter,
@@ -212,6 +202,16 @@ struct Data // because we have a cycle dependency
                                                                     database};
     ClangBackEnd::PchTaskGenerator pchTaskGenerator{buildDependencyProvider, pchTaskMerger};
     PchManagerServer clangPchManagerServer{includeWatcher, pchTaskGenerator, projectParts, generatedFiles};
+    TaskScheduler systemTaskScheduler{pchCreatorManager,
+                                      pchTaskQueue,
+                                      progressCounter,
+                                      std::thread::hardware_concurrency(),
+                                      ClangBackEnd::CallDoInMainThreadAfterFinished::No};
+    TaskScheduler projectTaskScheduler{pchCreatorManager,
+                                       pchTaskQueue,
+                                       progressCounter,
+                                       std::thread::hardware_concurrency(),
+                                       ClangBackEnd::CallDoInMainThreadAfterFinished::Yes};
 };
 
 int main(int argc, char *argv[])

src/tools/clangpchmanagerbackend/source/taskscheduler.h

@@ -80,6 +80,11 @@ public:
         , m_callDoInMainThreadAfterFinished(callDoInMainThreadAfterFinished)
     {}
 
+    ~TaskScheduler()
+    {
+        syncTasks();
+    }
+
     void addTasks(std::vector<Task> &&tasks)
     {
         for (auto &task : tasks) {

src/tools/clangrefactoringbackend/clangrefactoringbackendmain.cpp

@@ -93,8 +93,8 @@ struct Data // because we have a cycle dependency
     RefactoringDatabaseInitializer<Sqlite::Database> databaseInitializer{database};
     FilePathCaching filePathCache{database};
     GeneratedFiles generatedFiles;
-    SymbolIndexing symbolIndexing{database, filePathCache, generatedFiles, [&] (int progress, int total) { clangCodeModelServer.setProgress(progress, total); }};
     RefactoringServer clangCodeModelServer{symbolIndexing, filePathCache, generatedFiles};
+    SymbolIndexing symbolIndexing{database, filePathCache, generatedFiles, [&] (int progress, int total) { clangCodeModelServer.setProgress(progress, total); }};
 };
 
 int main(int argc, char *argv[])

src/tools/clangrefactoringbackend/source/symbolindexing.h

@@ -124,8 +124,6 @@ private:
     FileStatusCache m_fileStatusCache{m_filePathCache};
     SymbolsCollectorManager m_collectorManger;
     ProgressCounter m_progressCounter;
-    SymbolIndexerTaskScheduler m_indexerScheduler;
-    SymbolIndexerTaskQueue m_indexerQueue{m_indexerScheduler, m_progressCounter};
     SymbolIndexer m_indexer{m_indexerQueue,
                             m_symbolStorage,
                             m_buildDependencyStorage,
@@ -133,6 +131,8 @@ private:
                             m_filePathCache,
                             m_fileStatusCache,
                             m_symbolStorage.m_database};
+    SymbolIndexerTaskQueue m_indexerQueue{m_indexerScheduler, m_progressCounter};
+    SymbolIndexerTaskScheduler m_indexerScheduler;
 };
 
 } // namespace ClangBackEnd

tests/unit/unittest/symbolindexer-test.cpp

@@ -241,12 +241,6 @@ protected:
     Manager collectorManger{generatedFiles};
     NiceMock<MockFunction<void(int, int)>> mockSetProgressCallback;
     ClangBackEnd::ProgressCounter progressCounter{mockSetProgressCallback.AsStdFunction()};
-    Scheduler indexerScheduler{collectorManger,
-                               indexerQueue,
-                               progressCounter,
-                               1,
-                               ClangBackEnd::CallDoInMainThreadAfterFinished::Yes};
-    SymbolIndexerTaskQueue indexerQueue{indexerScheduler, progressCounter};
     ClangBackEnd::SymbolIndexer indexer{indexerQueue,
                                         mockSymbolStorage,
                                         mockBuildDependenciesStorage,
@@ -254,6 +248,12 @@ protected:
                                         filePathCache,
                                         fileStatusCache,
                                         mockSqliteTransactionBackend};
+    SymbolIndexerTaskQueue indexerQueue{indexerScheduler, progressCounter};
+    Scheduler indexerScheduler{collectorManger,
+                               indexerQueue,
+                               progressCounter,
+                               1,
+                               ClangBackEnd::CallDoInMainThreadAfterFinished::Yes};
     MockSymbolsCollector &mockCollector{static_cast<MockSymbolsCollector&>(collectorManger.unusedProcessor())};
 };