From ca81c65eaeafb7134bd1e8809a247d5116ab070b Mon Sep 17 00:00:00 2001
From: Mathew Sutcliffe <oktal3700@gmail.com>
Date: Sat, 6 May 2017 23:46:25 +0100
Subject: [PATCH] T66 CContinuousWorker tracks whether it has been started, and
 when starting checks that it was not already started.

---
 src/blackmisc/worker.cpp | 8 +++++++-
 src/blackmisc/worker.h   | 9 +++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/blackmisc/worker.cpp b/src/blackmisc/worker.cpp
index 9860d5114..13484882c 100644
--- a/src/blackmisc/worker.cpp
+++ b/src/blackmisc/worker.cpp
@@ -9,6 +9,7 @@
 
 #include "blackmisc/threadutils.h"
 #include "blackmisc/worker.h"
+#include "blackmisc/verify.h"
 
 #include <future>
 
@@ -54,8 +55,9 @@ namespace BlackMisc
 
     CWorker *CWorker::fromTaskImpl(QObject *owner, const QString &name, int typeId, std::function<CVariant()> task)
     {
-        auto *thread = new CRegularThread(owner);
         auto *worker = new CWorker(task);
+        worker->setStarted();
+        auto *thread = new CRegularThread(owner);
 
         if (typeId != QMetaType::Void) { worker->m_result = CVariant(typeId, nullptr); }
 
@@ -115,8 +117,12 @@ namespace BlackMisc
 
     void CContinuousWorker::start(QThread::Priority priority)
     {
+        BLACK_VERIFY_X(!hasStarted(), Q_FUNC_INFO, "Tried to start a worker that was already started");
+        if (hasStarted()) { return; }
+
         if (m_name.isEmpty()) { m_name = metaObject()->className(); }
 
+        setStarted();
         auto *thread = new CRegularThread(m_owner);
 
         Q_ASSERT(m_owner); // must not be null, see (9) https://dev.vatsim-germany.org/issues/402
diff --git a/src/blackmisc/worker.h b/src/blackmisc/worker.h
index 8886a785d..9de5d58c3 100644
--- a/src/blackmisc/worker.h
+++ b/src/blackmisc/worker.h
@@ -166,6 +166,12 @@ namespace BlackMisc
         //! \threadsafe
         bool isAbandoned() const;
 
+        //! True if the worker has started.
+        bool hasStarted() const { return m_started; }
+
+        //! Mark the task as started.
+        void setStarted() { m_started = true; }
+
         //! Mark the task as finished.
         void setFinished()
         {
@@ -178,6 +184,7 @@ namespace BlackMisc
         virtual void quit() noexcept {}
         virtual void quitAndWait() noexcept { waitForFinished(); }
 
+        bool m_started = false;
         bool m_finished = false;
         mutable QMutex m_finishedMutex { QMutex::Recursive };
     };
@@ -285,6 +292,8 @@ namespace BlackMisc
         void ps_finish();
 
     private:
+        using CWorkerBase::hasStarted;
+        using CWorkerBase::setStarted;
         using CWorkerBase::setFinished;
 
         QObject *m_owner = nullptr;