Bug 318559 - MouseTrailer holds XPCOM references past shutdown, r=ere sr=roc

widget/src/windows/nsToolkit.cpp

@@ -92,8 +92,6 @@ DEFINE_GUID(IID_IActiveIMMMessagePumpOwner,
 IActiveIMMApp* nsToolkit::gAIMMApp   = NULL;
 PRInt32        nsToolkit::gAIMMCount = 0;
 
-MouseTrailer MouseTrailer::mSingleton;
-
 #if !defined(MOZ_STATIC_COMPONENT_LIBS) && !defined(MOZ_ENABLE_LIBXUL)
 //
 // Dll entry point. Keep the dll instance
@@ -695,6 +693,8 @@ NS_CreateWindowEx   nsToolkit::mCreateWindowEx = nsCreateWindowEx;
 NS_RegisterClass    nsToolkit::mRegisterClass = nsRegisterClass; 
 NS_UnregisterClass  nsToolkit::mUnregisterClass = nsUnregisterClass; 
 
+MouseTrailer*       nsToolkit::gMouseTrailer;
+
 #ifndef WINCE
 NS_SHGetPathFromIDList  nsToolkit::mSHGetPathFromIDList = nsSHGetPathFromIDList; 
 NS_SHBrowseForFolder    nsToolkit::mSHBrowseForFolder = nsSHBrowseForFolder; 
@@ -751,6 +751,8 @@ nsToolkit::nsToolkit()
 #if defined(MOZ_STATIC_COMPONENT_LIBS) || defined (WINCE)
     nsToolkit::Startup(GetModuleHandle(NULL));
 #endif
+
+    gMouseTrailer = new MouseTrailer();
 }
 
 
@@ -784,6 +786,12 @@ nsToolkit::~nsToolkit()
     // Remove reference to cached event queue
     gEventQueueService = nsnull;
 
+    if (gMouseTrailer) {
+      gMouseTrailer->DestroyTimer();
+      delete gMouseTrailer;
+      gMouseTrailer = nsnull;
+    }
+
     // Unhook the filter used to determine when
     // the user is moving a top-level window.
 #ifndef WINCE
@@ -1212,46 +1220,48 @@ void MouseTrailer::DestroyTimer()
 //-------------------------------------------------------------------------
 void MouseTrailer::TimerProc(nsITimer* aTimer, void* aClosure)
 {
+  MouseTrailer *mtrailer = nsToolkit::gMouseTrailer;
+  NS_ASSERTION(mtrailer, "MouseTrailer still firing after deletion!");
+
   // Check to see if we are in mouse capture mode,
   // Once capture ends we could still get back one more timer event.
   // Capture could end outside our window.
   // Also, for some reason when the mouse is on the frame it thinks that
   // it is inside the window that is being captured.
-  if (mSingleton.mCaptureWindow) {
-    if (mSingleton.mCaptureWindow != mSingleton.mMouseTrailerWindow) {
+  if (mtrailer->mCaptureWindow) {
+    if (mtrailer->mCaptureWindow != mtrailer->mMouseTrailerWindow) {
       return;
     }
   } else {
-    if (mSingleton.mIsInCaptureMode) {
+    if (mtrailer->mIsInCaptureMode) {
       // mMouseTrailerWindow could be bad from rolling over the frame, so clear 
       // it if we were capturing and now this is the first timer callback 
       // since we canceled the capture
-      mSingleton.mMouseTrailerWindow = nsnull;
-      mSingleton.mIsInCaptureMode = PR_FALSE;
+      mtrailer->mMouseTrailerWindow = nsnull;
+      mtrailer->mIsInCaptureMode = PR_FALSE;
       return;
     }
   }
 
-  if (mSingleton.mMouseTrailerWindow && ::IsWindow(mSingleton.mMouseTrailerWindow)) {
+  if (mtrailer->mMouseTrailerWindow && ::IsWindow(mtrailer->mMouseTrailerWindow)) {
     POINT mp;
     DWORD pos = ::GetMessagePos();
     mp.x = GET_X_LPARAM(pos);
     mp.y = GET_Y_LPARAM(pos);
-
     HWND mouseWnd = ::WindowFromPoint(mp);
-    if (mSingleton.mMouseTrailerWindow != mouseWnd) {
+    if (mtrailer->mMouseTrailerWindow != mouseWnd) {
 #ifndef WINCE
       // Notify someone that a mouse exit happened.
-      PostMessage(mSingleton.mMouseTrailerWindow, WM_MOUSELEAVE, NULL, NULL);
+      PostMessage(mtrailer->mMouseTrailerWindow, WM_MOUSELEAVE, NULL, NULL);
 #endif
 
       // we are out of this window, destroy timer
-      mSingleton.DestroyTimer();
-      mSingleton.mMouseTrailerWindow = nsnull;
+      mtrailer->DestroyTimer();
+      mtrailer->mMouseTrailerWindow = nsnull;
     }
   } else {
-    mSingleton.DestroyTimer();
-    mSingleton.mMouseTrailerWindow = nsnull;
+    mtrailer->DestroyTimer();
+    mtrailer->mMouseTrailerWindow = nsnull;
   }
 }
 

widget/src/windows/nsToolkit.h

@@ -50,6 +50,7 @@
 
 struct MethodInfo;
 class nsIEventQueue;
+class MouseTrailer;
 
 // we used to use MAX_PATH
 // which works great for one file
@@ -138,6 +139,8 @@ public:
 #ifndef WINCE
     static NS_SHBrowseForFolder   mSHBrowseForFolder;
 #endif
+
+    static MouseTrailer *gMouseTrailer;
 };
 
 #define WM_CALLMETHOD   (WM_USER+1)
@@ -160,8 +163,6 @@ class  nsWindow;
 class MouseTrailer 
 {
 public:
-    static MouseTrailer  &GetSingleton() { return mSingleton; }
-    
     HWND                  GetMouseTrailerWindow() { return mMouseTrailerWindow; }
     HWND                  GetCaptureWindow() { return mCaptureWindow; }
 
@@ -170,18 +171,15 @@ public:
     void                  Disable() { mEnabled = PR_FALSE; DestroyTimer(); }
     void                  Enable() { mEnabled = PR_TRUE; CreateTimer(); }
     void                  DestroyTimer();
-                          ~MouseTrailer();
 
-private:
                           MouseTrailer();
+                          ~MouseTrailer();
+private:
 
     nsresult              CreateTimer();
 
     static void           TimerProc(nsITimer* aTimer, void* aClosure);
 
-    // Global nsToolkit Instance
-    static MouseTrailer   mSingleton;
-
     // Information for mouse enter/exit events
     HWND                  mMouseTrailerWindow;
     HWND                  mCaptureWindow;

widget/src/windows/nsWindow.cpp

@@ -789,11 +789,13 @@ nsWindow::~nsWindow()
     gCurrentWindow = nsnull;
   }
 
-  if (MouseTrailer::GetSingleton().GetMouseTrailerWindow() == mWnd) {
-    MouseTrailer::GetSingleton().DestroyTimer();
-  }
-  if (MouseTrailer::GetSingleton().GetCaptureWindow() == mWnd) {
-    MouseTrailer::GetSingleton().SetCaptureWindow(nsnull);
+  MouseTrailer* mtrailer = nsToolkit::gMouseTrailer;
+  if (mtrailer) {
+    if (mtrailer->GetMouseTrailerWindow() == mWnd)
+      mtrailer->DestroyTimer();
+
+    if (mtrailer->GetCaptureWindow() == mWnd)
+      mtrailer->SetCaptureWindow(nsnull);
   }
 
   // If the widget was released without calling Destroy() then the native
@@ -834,11 +836,16 @@ nsWindow::~nsWindow()
 
 NS_METHOD nsWindow::CaptureMouse(PRBool aCapture)
 {
+  if (!nsToolkit::gMouseTrailer) {
+    NS_ERROR("nsWindow::CaptureMouse called after nsToolkit destroyed");
+    return NS_OK;
+  }
+
   if (aCapture) {
-    MouseTrailer::GetSingleton().SetCaptureWindow(mWnd);
+    nsToolkit::gMouseTrailer->SetCaptureWindow(mWnd);
     ::SetCapture(mWnd);
   } else {
-    MouseTrailer::GetSingleton().SetCaptureWindow(NULL);
+    nsToolkit::gMouseTrailer->SetCaptureWindow(NULL);
     ::ReleaseCapture();
   }
   mIsInMouseCapture = aCapture;
@@ -5933,10 +5940,11 @@ PRBool nsWindow::DispatchMouseEvent(PRUint32 aEventType, WPARAM wParam, LPARAM l
 
   // call the event callback
   if (nsnull != mEventCallback) {
-    MouseTrailer::GetSingleton().Disable();
+    if (nsToolkit::gMouseTrailer)
+      nsToolkit::gMouseTrailer->Disable();
     if (aEventType == NS_MOUSE_MOVE) {
-      if (!mIsInMouseCapture) {
-        MouseTrailer::GetSingleton().SetMouseTrailerWindow(mWnd);
+      if (nsToolkit::gMouseTrailer && !mIsInMouseCapture) {
+        nsToolkit::gMouseTrailer->SetMouseTrailerWindow(mWnd);
       }
       nsRect rect;
       GetBounds(rect);
@@ -5964,7 +5972,8 @@ PRBool nsWindow::DispatchMouseEvent(PRUint32 aEventType, WPARAM wParam, LPARAM l
 
     result = DispatchWindowEvent(&event);
 
-    MouseTrailer::GetSingleton().Enable();
+    if (nsToolkit::gMouseTrailer)
+      nsToolkit::gMouseTrailer->Enable();
 
     // Release the widget with NS_IF_RELEASE() just in case
     // the context menu key code in nsEventListenerManager::HandleEvent()