Make ark stop crashing here on every startup due to threading problems.

Now only the interface object is moved to the worker thread, and then
returned back to the original thread.
TODO: ThreadExecution knows too much about the internals of Job, so a
refactoring is welcome.

svn path=/trunk/KDE/kdeutils/ark/; revision=956398

kerfuffle/jobs.cpp

@@ -68,16 +68,15 @@ namespace Kerfuffle
 #ifdef KERFUFFLE_NOJOBTHREADING
 		QTimer::singleShot(0, this, SLOT(doWork()));
 #else
-		m_workerThread = new ThreadExecution(this);
-
 		//we want the event handling to happen in the work thread to avoid
 		//unsafe data access due to events while work is being done
 		kDebug() << "Moving from " << QObject::thread() << " to " << m_workerThread;
+
 		m_previousInterfaceParent = m_interface->parent();
-		m_interface->setParent(NULL);
-		m_interface->moveToThread(m_workerThread);
-		moveToThread(m_workerThread);
 
+		m_workerThread = new ThreadExecution(this);
+		connect(m_workerThread, SIGNAL(finished()), this, SLOT(returnToMainThread()));
+		connect(m_workerThread, SIGNAL(terminated()), this, SLOT(returnToMainThread()));
 		m_workerThread->start();
 #endif
 	}
@@ -116,15 +115,18 @@ namespace Kerfuffle
 		m_interface->removeObserver( this );
 
 		setError(!result);
+	}
+
+	void Job::returnToMainThread()
+	{
+		kDebug();
 
 #ifndef KERFUFFLE_NOJOBTHREADING
-		kDebug() << "Moving from " << QObject::thread()<< " to " << QApplication::instance()->thread();
-		m_interface->moveToThread(QApplication::instance()->thread());
+		Q_ASSERT(m_interface->thread() != m_workerThread);
+		Q_ASSERT(m_previousInterfaceParent);
+
 		m_interface->setParent(m_previousInterfaceParent);
-		moveToThread(QApplication::instance()->thread());
 #endif
-
-		emitResult();
 	}
 
 	void Job::onUserQuery(Query *query)
@@ -157,6 +159,7 @@ namespace Kerfuffle
 		m_interface->registerObserver( this );
 		bool ret = m_interface->list();
 
+		emitResult();
 		if (!m_interface->waitForFinishedSignal()) m_interface->finished(ret);
 	}
 
@@ -220,6 +223,8 @@ namespace Kerfuffle
 					;
 
 		bool ret = m_interface->copyFiles( m_files, m_destinationDir, m_options );
+
+		emitResult();
 		if (!m_interface->waitForFinishedSignal()) m_interface->finished(ret);
 
 	}
@@ -247,6 +252,7 @@ namespace Kerfuffle
 		m_writeInterface->registerObserver( this );
 		bool ret = m_writeInterface->addFiles( m_files, m_options );
 
+		emitResult();
 		if (!m_interface->waitForFinishedSignal()) m_interface->finished(ret);
 	}
 

kerfuffle/jobs.h

@@ -62,6 +62,9 @@ namespace Kerfuffle
 		public slots:
 			virtual void doWork() = 0;
 
+		private slots:
+			void returnToMainThread();
+
 		signals:
 			void userQuery( Query* );
 			void newEntry( const ArchiveEntry & );
@@ -74,10 +77,11 @@ namespace Kerfuffle
 
 			ReadOnlyArchiveInterface* m_interface;
 			QObject *m_previousInterfaceParent;
-			ThreadExecution *m_workerThread;
 
 			virtual bool doKill();
 
+		private:
+			ThreadExecution *m_workerThread;
 	};
 
 	class KERFUFFLE_EXPORT ListJob: public Job

kerfuffle/threading.cpp

@@ -32,7 +32,12 @@ namespace Kerfuffle
 {
 	ThreadExecution::ThreadExecution(Kerfuffle::Job *job)
 		: m_job(job)
+		, m_interface(job->interface())
 	{
+		m_interface->setParent(NULL);
+		m_interface->moveToThread(this);
+
+		moveToThread(this);
 	}
 
 	void ThreadExecution::run()
@@ -42,14 +47,19 @@ namespace Kerfuffle
 		QTimer::singleShot(0, m_job, SLOT(doWork()));
 
 		//and when finished, quit the event loop
-		connect(m_job, SIGNAL(result(KJob*)),
-				this, SLOT(quit()));
+		connect(m_job, SIGNAL(result(KJob*)), this, SLOT(slotJobFinished()));
+		connect(m_job, SIGNAL(result(KJob*)), this, SLOT(quit()));
 
 		//start the event loop
 		exec();
 
 		kDebug(1601) << "Finished exec";
 	}
+
+	void ThreadExecution::slotJobFinished()
+	{
+		m_interface->moveToThread(QApplication::instance()->thread());
+	}
 }
 
 #include "threading.moc"

kerfuffle/threading.h

@@ -43,6 +43,10 @@ namespace Kerfuffle
 
 		private:
 			Kerfuffle::Job *m_job;
+			QObject *m_interface;
+
+		private slots:
+			void slotJobFinished();
 	};
 }