From 2f1e3f47f983356c92864c3fc88a43378c4a01bb Mon Sep 17 00:00:00 2001
From: Mat Sutcliffe <oktal3700@gmail.com>
Date: Sat, 28 Mar 2020 22:09:25 +0000
Subject: [PATCH] Track worker construction and destruction

Added debug log messages in case a worker still exists when the `qApp` is destroyed.
This would mean that a `quitAndWait` is missing or is being skipped somewhere.
---
 src/blackcore/application.cpp |  8 ++++++++
 src/blackmisc/worker.cpp      | 12 ++++++++++++
 src/blackmisc/worker.h        | 10 ++++++++++
 3 files changed, 30 insertions(+)

diff --git a/src/blackcore/application.cpp b/src/blackcore/application.cpp
index 20b153cd0..341098288 100644
--- a/src/blackcore/application.cpp
+++ b/src/blackcore/application.cpp
@@ -173,6 +173,14 @@ namespace BlackCore
                 m_inputManager = new CInputManager(this);
                 m_inputManager->createDevices();
             }
+
+            connect(this, &QObject::destroyed, [cat = CLogCategoryList(this)]
+            {
+                for (CWorkerBase *worker : CWorkerBase::allWorkers())
+                {
+                    CLogMessage(cat).debug(u"Worker named '%1' still exists after application destroyed") << worker->objectName();
+                }
+            });
         }
     }
 
diff --git a/src/blackmisc/worker.cpp b/src/blackmisc/worker.cpp
index 0536e0c5f..52ad1fc94 100644
--- a/src/blackmisc/worker.cpp
+++ b/src/blackmisc/worker.cpp
@@ -22,6 +22,8 @@
 
 namespace BlackMisc
 {
+    QSet<CWorkerBase *> CWorkerBase::s_allWorkers;
+
     void CRegularThread::run()
     {
 #ifdef Q_OS_WIN32
@@ -105,6 +107,16 @@ namespace BlackMisc
         // must not access the worker beyond this point, as it now lives in the owner's thread and could be deleted at any moment
     }
 
+    CWorkerBase::CWorkerBase()
+    {
+        s_allWorkers.insert(this);
+    }
+
+    CWorkerBase::~CWorkerBase()
+    {
+        s_allWorkers.remove(this);
+    }
+
     const CLogCategoryList &CWorkerBase::getLogCategories()
     {
         static const BlackMisc::CLogCategoryList cats { CLogCategory::worker() };
diff --git a/src/blackmisc/worker.h b/src/blackmisc/worker.h
index 9f5af21a9..e6b70a382 100644
--- a/src/blackmisc/worker.h
+++ b/src/blackmisc/worker.h
@@ -163,6 +163,9 @@ namespace BlackMisc
         //! Convenience to call abandon() followed by waitForFinished().
         void abandonAndWait() noexcept;
 
+        //! All workers currently existing.
+        static const QSet<CWorkerBase *> &allWorkers() { return s_allWorkers; }
+
     signals:
         //! Emitted when the task is about to start.
         void aboutToStart();
@@ -172,6 +175,12 @@ namespace BlackMisc
         void finished();
 
     protected:
+        //! Constructor.
+        CWorkerBase();
+
+        //! Destructor.
+        virtual ~CWorkerBase() override;
+
         //! For the task to check whether it can finish early.
         //! \threadsafe
         bool isAbandoned() const;
@@ -197,6 +206,7 @@ namespace BlackMisc
         bool m_started = false;
         bool m_finished = false;
         mutable QMutex m_finishedMutex { QMutex::Recursive };
+        static QSet<CWorkerBase *> s_allWorkers;
     };
 
     /*!