Changeset 57364 in vbox

Timestamp:

Aug 14, 2015 5:28:03 PM (10 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

102127

Message:

FE/Qt: Main event handling: Protect COM cleanup procedure with read-write lock.

Location:

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

Files:

• UIMainEventListener.cpp (modified) (3 diffs)
• VBoxGlobal.cpp (modified) (1 diff)
• VBoxGlobal.h (modified) (2 diffs)

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

@@ -22 +22 @@
 /* GUI includes: */
 # include "UIMainEventListener.h"
+# include "VBoxGlobal.h"
 
 /* COM includes: */
@@ -67 +68 @@
 STDMETHODIMP UIMainEventListener::HandleEvent(VBoxEventType_T /* type */, IEvent *pEvent)
 {
+    /* Try to acquire COM cleanup protection token first: */
+    if (!vboxGlobal().comTokenTryLockForRead())
+        return S_OK;
+
     CEvent event(pEvent);
     // printf("Event received: %d\n", event.GetType());
@@ -264 +269 @@
         default: break;
     }
+
+    /* Unlock COM cleanup protection token: */
+    vboxGlobal().comTokenUnlock();
+
     return S_OK;
 }

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

@@ -4382 +4382 @@
     mTypes.clear();
 
-    /* the last steps to ensure we don't use COM any more */
-    m_host.detach();
-    m_vbox.detach();
-    m_client.detach();
-
-    /* There may be UIMedium(s)EnumeratedEvent instances still in the message
-     * queue which reference COM objects. Remove them to release those objects
-     * before uninitializing the COM subsystem. */
-    QApplication::removePostedEvents (this);
-
-    COMBase::CleanupCOM();
+    /* Starting COM cleanup: */
+    m_comCleanupProtectionToken.lockForWrite();
+    {
+        /* First, make sure we don't use COM any more: */
+        m_host.detach();
+        m_vbox.detach();
+        m_client.detach();
+
+        /* There may be UIMedium(s)EnumeratedEvent instances still in the message
+         * queue which reference COM objects. Remove them to release those objects
+         * before uninitializing the COM subsystem. */
+        QApplication::removePostedEvents(this);
+
+        /* Finally cleanup COM itself: */
+        COMBase::CleanupCOM();
+    }
+    /* Finishing COM cleanup: */
+    m_comCleanupProtectionToken.unlock();
 
     /* Destroy popup-center: */

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

@@ -120 +120 @@
 #endif /* Q_WS_MAC */
 
+    /** Try to acquire COM cleanup protection token for reading. */
+    bool comTokenTryLockForRead() { return m_comCleanupProtectionToken.tryLockForRead(); }
+    /** Unlock previously acquired COM cleanup protection token. */
+    void comTokenUnlock() { return m_comCleanupProtectionToken.unlock(); }
+
     /** Returns the copy of VirtualBox client wrapper. */
     CVirtualBoxClient virtualBoxClient() const { return m_client; }
@@ -481 +486 @@
 
     bool mValid;
+
+    /** COM cleanup protection token. */
+    QReadWriteLock m_comCleanupProtectionToken;
 
     /** Holds the instance of VirtualBox client wrapper. */