tdf#109085: don't assume MtaOleReq window is still valid at shutdown

The window can be destroyed by e.g. WM_QUERYENDSESSION/WM_ENDSESSION
sequence, and then the message MSG_REGCLIPVIEWER handler would not run
and the condition would never be set.

Since we need to wait for the message processed, let's just use sendMessage
which would return only after the message has been processed anyway, and
also will return immediately on failure (e.g., window handle invalid).

Also this changes other cases where postMessage + wait pattern was used,
and removes the condition from MsgContext.

Change-Id: Ic12deafbaedd1cc99b9d6145650d99069c618f0e
Reviewed-on: https://gerrit.libreoffice.org/62881
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

1 files changed, 5 insertions, 95 deletions

diff --git a/dtrans/source/win32/clipb/MtaOleClipb.cxx b/dtrans/source/win32/clipb/MtaOleClipb.cxx
index 7dc5c7e38a53..79983edd5b16 100644
--- a/dtrans/source/win32/clipb/MtaOleClipb.cxx
+++ b/dtrans/source/win32/clipb/MtaOleClipb.cxx
@@ -66,81 +66,8 @@ namespace /* private */
     const bool MANUAL_RESET                     = true;
     const bool INIT_NONSIGNALED                 = false;
 
-    /*  Cannot use osl conditions because they are blocking
-        without waking up on messages sent by another thread
-        this leads to deadlocks because we are blocking the
-        communication between inter-thread marshalled COM
-        pointers.
-        COM Proxy-Stub communication uses SendMessages for
-        synchronization purposes.
-    */
-    class Win32Condition
-    {
-        public:
-            // ctor
-            Win32Condition()
-            {
-                m_hEvent = CreateEventW(
-                    nullptr, /* no security */
-                    true,   /* manual reset */
-                    false,  /* initial state not signaled */
-                    nullptr); /* automatic name */
-            }
-
-            // dtor
-            ~Win32Condition()
-            {
-                CloseHandle(m_hEvent);
-            }
-
-            // wait infinite for event be signaled
-            // leave messages sent through
-            void wait()
-            {
-                while(true)
-                {
-                    DWORD dwResult =
-                        MsgWaitForMultipleObjects(1, &m_hEvent, FALSE, INFINITE, QS_SENDMESSAGE);
-
-                       switch (dwResult)
-                    {
-                        case WAIT_OBJECT_0:
-                            return;
-
-                        case WAIT_OBJECT_0 + 1:
-                        {
-                            /* PeekMessage processes all messages in the SendMessage
-                               queue that's what we want, messages from the PostMessage
-                               queue stay untouched */
-                            MSG msg;
-                            PeekMessageW(&msg, nullptr, 0, 0, PM_NOREMOVE);
-
-                            break;
-                        }
-                    }
-                }
-            }
-
-            // reset the event
-            void set()
-            {
-                SetEvent(m_hEvent);
-            }
-
-        private:
-            HANDLE m_hEvent;
-
-        // prevent copy/assignment
-        private:
-            Win32Condition(const Win32Condition&) = delete;
-            Win32Condition& operator=(const Win32Condition&) = delete;
-    };
-
-    // we use one condition for every request
-
     struct MsgCtx
     {
-        Win32Condition  aCondition;
         HRESULT         hr;
     };
 
@@ -329,12 +256,10 @@ HRESULT CMtaOleClipboard::flushClipboard( )
 
     MsgCtx  aMsgCtx;
 
-    postMessage( MSG_FLUSHCLIPBOARD,
+    sendMessage( MSG_FLUSHCLIPBOARD,
                  static_cast< WPARAM >( 0 ),
                  reinterpret_cast< LPARAM >( &aMsgCtx ) );
 
-    aMsgCtx.aCondition.wait( /* infinite */ );
-
     return aMsgCtx.hr;
 }
 
@@ -357,12 +282,10 @@ HRESULT CMtaOleClipboard::getClipboard( IDataObject** ppIDataObject )
 
     MsgCtx    aMsgCtx;
 
-    postMessage( MSG_GETCLIPBOARD,
+    sendMessage( MSG_GETCLIPBOARD,
                  reinterpret_cast< WPARAM >( &lpStream ),
                  reinterpret_cast< LPARAM >( &aMsgCtx ) );
 
-    aMsgCtx.aCondition.wait( /* infinite */ );
-
     HRESULT hr = aMsgCtx.hr;
 
     if ( SUCCEEDED( hr ) )
@@ -422,13 +345,7 @@ bool CMtaOleClipboard::registerClipViewer( LPFNC_CLIPVIEWER_CALLBACK_t pfncClipV
 
     OSL_ENSURE( GetCurrentThreadId( ) != m_uOleThreadId, "registerClipViewer from within the OleThread called" );
 
-    MsgCtx  aMsgCtx;
-
-    postMessage( MSG_REGCLIPVIEWER,
-                 reinterpret_cast<WPARAM>( pfncClipViewerCallback ),
-                 reinterpret_cast<LPARAM>( &aMsgCtx ) );
-
-    aMsgCtx.aCondition.wait( /* infinite */ );
+    sendMessage(MSG_REGCLIPVIEWER, reinterpret_cast<WPARAM>(pfncClipViewerCallback), 0);
 
     return false;
 }
@@ -609,7 +526,6 @@ LRESULT CALLBACK CMtaOleClipboard::mtaOleReqWndProc( HWND hWnd, UINT uMsg, WPARA
             OSL_ASSERT( aMsgCtx );
 
             aMsgCtx->hr = CMtaOleClipboard::onGetClipboard( reinterpret_cast< LPSTREAM* >(wParam) );
-            aMsgCtx->aCondition.set( );
         }
         break;
 
@@ -619,18 +535,12 @@ LRESULT CALLBACK CMtaOleClipboard::mtaOleReqWndProc( HWND hWnd, UINT uMsg, WPARA
             OSL_ASSERT( aMsgCtx );
 
             aMsgCtx->hr = CMtaOleClipboard::onFlushClipboard( );
-            aMsgCtx->aCondition.set( );
         }
         break;
 
     case MSG_REGCLIPVIEWER:
-        {
-            MsgCtx* aMsgCtx = reinterpret_cast< MsgCtx* >( lParam );
-            OSL_ASSERT( aMsgCtx );
-
-            pImpl->onRegisterClipViewer( reinterpret_cast<CMtaOleClipboard::LPFNC_CLIPVIEWER_CALLBACK_t>(wParam) );
-            aMsgCtx->aCondition.set( );
-        }
+        pImpl->onRegisterClipViewer(
+            reinterpret_cast<CMtaOleClipboard::LPFNC_CLIPVIEWER_CALLBACK_t>(wParam));
         break;
 
     case WM_CHANGECBCHAIN: