Changeset 86323 in vbox for trunk/src/VBox/Frontends/VirtualBox

Timestamp:

Sep 28, 2020 2:59:10 PM (4 years ago)

Author:

vboxsync

Message:

FE/Qt: bugref:9653: Extending UIMainEventListener with possibility to provide listener object with escape event types which should command listener to shutdown corresponding thread properly; Besides that, if no listening thread remain, listener will notify parent about listening was effectively finished and it's safe to perform cleanup.

Location:

trunk/src/VBox/Frontends/VirtualBox/src/globals

Files:

• UIMainEventListener.cpp (modified) (8 diffs)
• UIMainEventListener.h (modified) (4 diffs)

trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMainEventListener.cpp

@@ -81 +81 @@
 
     /** Constructs Main events listener thread redirecting events from @a comSource to @a comListener.
-      * @param  comSource    Brings event source we are creating this thread for.
-      * @param  comListener  Brings event listener we are creating this thread for. */
+      * @param  comSource         Brings event source we are creating this thread for.
+      * @param  comListener       Brings event listener we are creating this thread for.
+      * @param  escapeEventTypes  Brings a set of escape event types which commands this thread to finish. */
     UIMainEventListeningThread(const CEventSource &comSource,
-                               const CEventListener &comListener);
+                               const CEventListener &comListener,
+                               const QSet<KVBoxEventType> &escapeEventTypes);
     /** Destructs Main events listener thread. */
     virtual ~UIMainEventListeningThread() /* override */;
@@ -104 +106 @@
     /** Holds the Main event listener reference. */
     CEventListener        m_comListener;
+    /** Holds a set of event types this thread should finish job on. */
+    QSet<KVBoxEventType>  m_escapeEventTypes;
 
     /** Holds the mutex instance which protects thread access. */
@@ -117 +121 @@
 
 UIMainEventListeningThread::UIMainEventListeningThread(const CEventSource &comSource,
-                                                       const CEventListener &comListener)
+                                                       const CEventListener &comListener,
+                                                       const QSet<KVBoxEventType> &escapeEventTypes)
     : m_comSource(comSource)
     , m_comListener(comListener)
+    , m_escapeEventTypes(escapeEventTypes)
     , m_fShutdown(false)
 {
@@ -162 +168 @@
                 LogRel(("GUI: UIMainEventListener/ThreadRun: EventProcessed set for waitable event\n"));
             }
+
+            /* Check whether we should finish our job on this event: */
+            if (m_escapeEventTypes.contains(comEvent.GetType()))
+                setShutdown(true);
         }
     }
@@ -206 +216 @@
 
 void UIMainEventListener::registerSource(const CEventSource &comSource,
-                                         const CEventListener &comListener)
+                                         const CEventListener &comListener,
+                                         const QSet<KVBoxEventType> &escapeEventTypes /* = QSet<KVBoxEventType>() */)
 {
     /* Make sure source and listener are valid: */
@@ -213 +224 @@
 
     /* Create thread for passed source: */
-    UIMainEventListeningThread *pThread = new UIMainEventListeningThread(comSource, comListener);
+    UIMainEventListeningThread *pThread = new UIMainEventListeningThread(comSource, comListener, escapeEventTypes);
     if (pThread)
     {
+        /* Listen for thread finished signal: */
+        connect(pThread, &UIMainEventListeningThread::finished,
+                this, &UIMainEventListener::sltHandleThreadFinished);
         /* Register & start it: */
         m_threads << pThread;
@@ -224 +238 @@
 void UIMainEventListener::unregisterSources()
 {
+    /* Stop listening for thread finished thread signals,
+     * we are about to destroy these threads anyway: */
+    foreach (UIMainEventListeningThread *pThread, m_threads)
+        disconnect(pThread, &UIMainEventListeningThread::finished,
+                   this, &UIMainEventListener::sltHandleThreadFinished);
+
     /* Wipe out the threads: */
     /** @todo r=bird: The use of qDeleteAll here is unsafe because it won't take
@@ -576 +596 @@
 }
 
+void UIMainEventListener::sltHandleThreadFinished()
+{
+    /* We have received a signal about thread finished, that means we were
+     * patiently waiting for it, instead of killing UIMainEventListener object. */
+    UIMainEventListeningThread *pSender = qobject_cast<UIMainEventListeningThread*>(sender());
+    AssertPtrReturnVoid(pSender);
+
+    /* We should remove corresponding thread from the list: */
+    const int iIndex = m_threads.indexOf(pSender);
+    delete m_threads.value(iIndex);
+    m_threads.removeAt(iIndex);
+
+    /* And notify listeners we have really finished: */
+    if (m_threads.isEmpty())
+        emit sigListeningFinished();
+}
+
 #include "UIMainEventListener.moc"

trunk/src/VBox/Frontends/VirtualBox/src/globals/UIMainEventListener.h

@@ -26 +26 @@
 #include <QObject>
 #include <QRect>
+#include <QSet>
 
 /* GUI includes: */
@@ -71 +72 @@
 
 signals:
+
+    /** @name General signals
+      * @{ */
+        /** Notifies about listening has finished. */
+        void sigListeningFinished();
+    /** @} */
 
     /** @name VirtualBoxClient related signals
@@ -210 +217 @@
 
     /** Registers event source for passive event listener by creating a listening thread.
-      * @param  comSource    Brings event source we are creating listening thread for.
-      * @param  comListener  Brings event listener we are creating listening thread for. */
+      * @param  comSource         Brings event source we are creating listening thread for.
+      * @param  comListener       Brings event listener we are creating listening thread for.
+      * @param  escapeEventTypes  Brings a set of escape event types which commands listener to finish. */
     void registerSource(const CEventSource &comSource,
-                        const CEventListener &comListener);
+                        const CEventListener &comListener,
+                        const QSet<KVBoxEventType> &escapeEventTypes = QSet<KVBoxEventType>());
     /** Unregisters event sources. */
     void unregisterSources();
@@ -222 +231 @@
     /** Holds the list of threads handling passive event listening. */
     QList<UIMainEventListeningThread*> m_threads;
+
+private slots:
+
+    /** Handles thread finished signal. */
+    void sltHandleThreadFinished();
 };