Unify SalUserEvent handling

Merges the various SalUserEvent structs and their handling into
a single class. This includes a common SalFrame* hash map, as all
backends use such a map to verify alive SalFrames.

It also reverts the "FIXME: lousy workaround" for i#90083, which
was part of commit d6f7c94e5c27ba02ff5c3229760c9808cc9b5bea.

At least on my current OSX box application based window switching
"just works" "out of the box", even without the code.

Change-Id: I188b567e44fd79c162b2d9cabbd771d1f66c7dc4
Reviewed-on: https://gerrit.libreoffice.org/42845
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

33 files changed, 507 insertions, 589 deletions

diff --git a/vcl/Library_vcl.mk b/vcl/Library_vcl.mk
index 1aa3095d0a6c..5d62542e8b13 100644
--- a/vcl/Library_vcl.mk
+++ b/vcl/Library_vcl.mk
@@ -321,6 +321,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/app/help \
     vcl/source/app/i18nhelp \
 	vcl/source/app/idle \
+	vcl/source/app/salusereventlist \
     vcl/source/app/salvtables \
 	vcl/source/app/scheduler \
     vcl/source/app/session \
diff --git a/vcl/headless/svpframe.cxx b/vcl/headless/svpframe.cxx
index 9a086c0b3d6a..7fc7c3a88eb0 100644
--- a/vcl/headless/svpframe.cxx
+++ b/vcl/headless/svpframe.cxx
@@ -94,10 +94,9 @@ SvpSalFrame::~SvpSalFrame()
         // pass focus to another frame, preferably a document style window
         if( s_pFocusFrame == nullptr )
         {
-            const std::list< SalFrame* >& rFrames( m_pInstance->getFrames() );
-            for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+            for (auto pSalFrame : m_pInstance->getFrames() )
             {
-                SvpSalFrame* pFrame = static_cast<SvpSalFrame*>(*it);
+                SvpSalFrame* pFrame = static_cast<SvpSalFrame*>( pSalFrame );
                 if( pFrame->m_bVisible        &&
                     pFrame->m_pParent == nullptr &&
                     (pFrame->m_nStyle & (SalFrameStyleFlags::MOVEABLE |
diff --git a/vcl/headless/svpinst.cxx b/vcl/headless/svpinst.cxx
index ab8f91eac31f..5153c8952f4a 100644
--- a/vcl/headless/svpinst.cxx
+++ b/vcl/headless/svpinst.cxx
@@ -47,19 +47,6 @@
 // FIXME: remove when we re-work the svp mainloop
 #include "unx/salunxtime.h"
 
-bool SvpSalInstance::isFrameAlive( const SalFrame* pFrame ) const
-{
-    for( std::list< SalFrame* >::const_iterator it = m_aFrames.begin();
-         it != m_aFrames.end(); ++it )
-    {
-        if( *it == pFrame )
-        {
-            return true;
-        }
-    }
-    return false;
-}
-
 SvpSalInstance* SvpSalInstance::s_pDefaultInstance = nullptr;
 
 #if !defined(ANDROID) && !defined(IOS)
@@ -165,12 +152,8 @@ void SvpSalInstance::CreateWakeupPipe(bool log)
 
 #endif
 
-void SvpSalInstance::PostEvent(const SalFrame* pFrame, ImplSVEvent* pData, SalEvent nEvent)
+void SvpSalInstance::TriggerUserEventProcessing()
 {
-    {
-        osl::MutexGuard g(m_aEventGuard);
-        m_aUserEvents.emplace_back( pFrame, pData, nEvent );
-    }
     Wakeup();
 }
 
@@ -186,31 +169,6 @@ bool SvpSalInstance::PostedEventsInQueue()
 }
 #endif
 
-void SvpSalInstance::deregisterFrame( SalFrame* pFrame )
-{
-    m_aFrames.remove( pFrame );
-
-    osl::MutexGuard g(m_aEventGuard);
-    // cancel outstanding events for this frame
-    if( ! m_aUserEvents.empty() )
-    {
-        std::list< SalUserEvent >::iterator it = m_aUserEvents.begin();
-        do
-        {
-            if( it->m_pFrame == pFrame )
-            {
-                if (it->m_nEvent == SalEvent::UserEvent)
-                {
-                    delete it->m_pData;
-                }
-                it = m_aUserEvents.erase( it );
-            }
-            else
-                ++it;
-        } while( it != m_aUserEvents.end() );
-    }
-}
-
 void SvpSalInstance::Wakeup()
 {
 #ifndef IOS
@@ -304,44 +262,24 @@ SalBitmap* SvpSalInstance::CreateSalBitmap()
 #endif
 }
 
-bool SvpSalInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents)
+void SvpSalInstance::ProcessEvent( SalUserEvent aEvent )
 {
-    // first, check for already queued events.
-    std::list< SalUserEvent > aEvents;
+    aEvent.m_pFrame->CallCallback( aEvent.m_nEvent, aEvent.m_pData );
+    if( aEvent.m_nEvent == SalEvent::Resize )
     {
-        osl::MutexGuard g(m_aEventGuard);
-        if( ! m_aUserEvents.empty() )
-        {
-            if( bHandleAllCurrentEvents )
-            {
-                aEvents = m_aUserEvents;
-                m_aUserEvents.clear();
-            }
-            else
-            {
-                aEvents.push_back( m_aUserEvents.front() );
-                m_aUserEvents.pop_front();
-            }
-        }
+        // this would be a good time to post a paint
+        const SvpSalFrame* pSvpFrame = static_cast<const SvpSalFrame*>( aEvent.m_pFrame);
+        pSvpFrame->PostPaint();
     }
+}
 
-    bool bEvent = !aEvents.empty();
-    if( bEvent )
-    {
-        for( std::list<SalUserEvent>::const_iterator it = aEvents.begin(); it != aEvents.end(); ++it )
-        {
-            if ( isFrameAlive( it->m_pFrame ) )
-            {
-                it->m_pFrame->CallCallback( it->m_nEvent, it->m_pData );
-                if( it->m_nEvent == SalEvent::Resize )
-                {
-                    // this would be a good time to post a paint
-                    const SvpSalFrame* pSvpFrame = static_cast<const SvpSalFrame*>(it->m_pFrame);
-                    pSvpFrame->PostPaint();
-                }
-            }
-        }
-    }
+
+bool SvpSalInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents)
+{
+    // first, process current user events
+    bool bEvent = DispatchUserEvents( bHandleAllCurrentEvents );
+    if ( !bHandleAllCurrentEvents &&bEvent )
+        return true;
 
     bEvent = CheckTimeout() || bEvent;
 
diff --git a/vcl/headless/svpprn.cxx b/vcl/headless/svpprn.cxx
index 488f17bb4084..2afb52502300 100644
--- a/vcl/headless/svpprn.cxx
+++ b/vcl/headless/svpprn.cxx
@@ -257,10 +257,9 @@ OUString SvpSalInstance::GetDefaultPrinter()
 
 void SvpSalInstance::PostPrintersChanged()
 {
-    const std::list< SalFrame* >& rList = SvpSalInstance::s_pDefaultInstance->getFrames();
-    for( std::list< SalFrame* >::const_iterator it = rList.begin();
-         it != rList.end(); ++it )
-        SvpSalInstance::s_pDefaultInstance->PostEvent( *it, nullptr, SalEvent::PrinterChanged );
+    SvpSalInstance *pInst = SvpSalInstance::s_pDefaultInstance;
+    for (auto pSalFrame : pInst->getFrames() )
+        pInst->PostEvent( pSalFrame, nullptr, SalEvent::PrinterChanged );
 }
 
 GenPspGraphics *SvpSalInstance::CreatePrintGraphics()
diff --git a/vcl/inc/headless/svpinst.hxx b/vcl/inc/headless/svpinst.hxx
index 0883981c4406..80566be18248 100644
--- a/vcl/inc/headless/svpinst.hxx
+++ b/vcl/inc/headless/svpinst.hxx
@@ -25,6 +25,7 @@
 #include <salinst.hxx>
 #include <salwtype.hxx>
 #include <saltimer.hxx>
+#include <salusereventlist.hxx>
 #include <unx/geninst.h>
 #include <unx/genprn.h>
 
@@ -57,35 +58,18 @@ class GenPspGraphics;
 
 SalInstance* svp_create_SalInstance();
 
-class VCL_DLLPUBLIC SvpSalInstance : public SalGenericInstance
+class VCL_DLLPUBLIC SvpSalInstance : public SalGenericInstance, public SalUserEventList
 {
     timeval                 m_aTimeout;
     sal_uLong               m_nTimeoutMS;
     int                     m_pTimeoutFDS[2];
 
-    // internal event queue
-    struct SalUserEvent
-    {
-        const SalFrame*     m_pFrame;
-        ImplSVEvent*        m_pData;
-        SalEvent            m_nEvent;
-
-        SalUserEvent( const SalFrame* pFrame, ImplSVEvent* pData, SalEvent nEvent )
-                : m_pFrame( pFrame ),
-                  m_pData( pData ),
-                  m_nEvent( nEvent )
-        {}
-    };
-
-    osl::Mutex              m_aEventGuard;
-    std::list< SalUserEvent > m_aUserEvents;
-
-    std::list< SalFrame* >  m_aFrames;
-
-    bool                    isFrameAlive( const SalFrame* pFrame ) const;
-
     void                    DoReleaseYield( int nTimeoutMS );
 
+    virtual void            TriggerUserEventProcessing() override;
+    virtual void            ProcessEvent( SalUserEvent aEvent ) override;
+    void                    Wakeup();
+
 public:
     static SvpSalInstance*  s_pDefaultInstance;
 
@@ -95,20 +79,15 @@ public:
     void                    CloseWakeupPipe(bool log);
     void                    CreateWakeupPipe(bool log);
 
-    void                    PostEvent(const SalFrame* pFrame, ImplSVEvent* pData, SalEvent nEvent);
-
 #ifdef ANDROID
     bool                    PostedEventsInQueue();
 #endif
 
     void                    StartTimer( sal_uLong nMS );
     void                    StopTimer();
-    void                    Wakeup();
 
-    void                    registerFrame( SalFrame* pFrame ) { m_aFrames.push_back( pFrame ); }
-    void                    deregisterFrame( SalFrame* pFrame );
-    const std::list< SalFrame* >&
-                            getFrames() const { return m_aFrames; }
+    inline void             registerFrame( SalFrame* pFrame );
+    inline void             deregisterFrame( SalFrame* pFrame );
 
     bool                    CheckTimeout( bool bExecuteTimers = true );
 
@@ -171,6 +150,16 @@ public:
     virtual GenPspGraphics *CreatePrintGraphics() override;
 };
 
+inline void SvpSalInstance::registerFrame( SalFrame* pFrame )
+{
+    insertFrame( pFrame );
+}
+
+inline void SvpSalInstance::deregisterFrame( SalFrame* pFrame )
+{
+    eraseFrame( pFrame );
+}
+
 #endif // INCLUDED_VCL_INC_HEADLESS_SVPINST_HXX
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/osx/saldata.hxx b/vcl/inc/osx/saldata.hxx
index fbc28e05391d..5ec684b83973 100644
--- a/vcl/inc/osx/saldata.hxx
+++ b/vcl/inc/osx/saldata.hxx
@@ -45,6 +45,7 @@
 
 #include "apple_remote/RemoteMainController.h"
 
+class AquaSalFrame;
 class AquaSalInstance;
 class SalObject;
 class SalFrame;
@@ -53,14 +54,6 @@ class SalPrinter;
 class SystemFontList;
 
 #define SAL_CLIPRECT_COUNT 16
-
-class AquaSalFrame;
-struct FrameHash : public std::hash<sal_IntPtr>
-{
-    size_t operator()(const AquaSalFrame* frame) const
-    { return std::hash<sal_IntPtr>::operator()( reinterpret_cast<const sal_IntPtr>(frame) ); }
-};
-
 #define INVALID_CURSOR_PTR reinterpret_cast<NSCursor*>(0xdeadbeef)
 
 // Singleton, instantiated from Application::Application() in
@@ -71,8 +64,6 @@ class SalData
 public:
     SALTIMERPROC                                  mpTimerProc;      // timer callback proc
     AquaSalInstance                              *mpFirstInstance;  // pointer of first instance
-    std::list<AquaSalFrame*>                      maFrames;         // list of all frames
-    std::unordered_set<const AquaSalFrame*,FrameHash>  maFrameCheck;// for fast check of frame existence
     std::list<AquaSalFrame*>                      maPresentationFrames;  // list of frames in presentation mode
     SalObject                                    *mpFirstObject;    // pointer of first object window
     SalVirtualDevice                             *mpFirstVD;        // first VirDev
diff --git a/vcl/inc/osx/salframe.h b/vcl/inc/osx/salframe.h
index e99a3175876d..f8cef1834106 100644
--- a/vcl/inc/osx/salframe.h
+++ b/vcl/inc/osx/salframe.h
@@ -26,6 +26,7 @@
 
 #include <vcl/sysdata.hxx>
 
+#include "osx/salinst.h"
 #include "osx/salmenu.h"
 #include "osx/saldata.hxx"
 #include "osx/osxvcltypes.h"
@@ -163,8 +164,7 @@ public:
     // trigger painting of the window
     void SendPaintEvent( const tools::Rectangle* pRect = nullptr );
 
-    static bool isAlive( const AquaSalFrame* pFrame )
-    { return GetSalData()->maFrameCheck.find( pFrame ) != GetSalData()->maFrameCheck.end(); }
+    static inline bool isAlive( const AquaSalFrame* pFrame );
 
     static AquaSalFrame* GetCaptureFrame() { return s_pCaptureFrame; }
 
@@ -204,6 +204,12 @@ private: // data
     AquaSalFrame& operator=(const AquaSalFrame&) = delete;
 };
 
+inline bool AquaSalFrame::isAlive( const AquaSalFrame* pFrame )
+{
+    AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
+    return pInst && pInst->isFrameAlive( pFrame );
+}
+
 #endif // INCLUDED_VCL_INC_OSX_SALFRAME_H
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/osx/salinst.h b/vcl/inc/osx/salinst.h
index 0e30dfafb693..272cfc722d64 100644
--- a/vcl/inc/osx/salinst.h
+++ b/vcl/inc/osx/salinst.h
@@ -34,6 +34,8 @@
 
 #include "osx/runinmain.hxx"
 
+#include "salusereventlist.hxx"
+
 class AquaSalFrame;
 class SalFrame;
 class SalObject;
@@ -59,27 +61,18 @@ public:
     virtual bool IsCurrentThread() const override;
 };
 
-class AquaSalInstance : public SalInstance
+class AquaSalInstance : public SalInstance, public SalUserEventList
 {
-    struct SalUserEvent
-    {
-        AquaSalFrame*   mpFrame;
-        void*           mpData;
-        SalEvent        mnType;
-
-        SalUserEvent( AquaSalFrame* pFrame, void* pData, SalEvent nType ) :
-            mpFrame( pFrame ), mpData( pData ), mnType( nType )
-        {}
-    };
-
     bool RunInMainYield( bool bHandleAllCurrentEvents );
 
+    virtual void TriggerUserEventProcessing() override;
+    virtual void ProcessEvent( SalUserEvent aEvent ) override;
+
 public:
     SalYieldMutex*                          mpSalYieldMutex;        // Sal-Yield-Mutex
     OUString                                maDefaultPrinter;
     oslThreadIdentifier                     maMainThread;
     int                                     mnActivePrintJobs;
-    std::list< SalUserEvent >               maUserEvents;
     osl::Mutex                              maUserEventListMutex;
     osl::Condition                          maWaitingYieldCond;
     bool                                    mbIsLiveResize;
@@ -145,7 +138,6 @@ public:
 public:
     friend class AquaSalFrame;
 
-    void PostUserEvent( AquaSalFrame* pFrame, SalEvent nType, void* pData );
     void delayedSettingsChanged( bool bInvalidate );
 
     // Is this the NSAppThread?
diff --git a/vcl/inc/osx/vclnsapp.h b/vcl/inc/osx/vclnsapp.h
index c899ffce59d1..39bd3170abaf 100644
--- a/vcl/inc/osx/vclnsapp.h
+++ b/vcl/inc/osx/vclnsapp.h
@@ -61,8 +61,6 @@ class AquaSalFrame;
 #endif
 -(BOOL)applicationShouldHandleReopen: (NSApplication*)pApp hasVisibleWindows: (BOOL)bWinVisible;
 -(void)setDockIconClickHandler: (NSObject*)pHandler;
--(void)cycleFrameForward: (AquaSalFrame*)pCurFrame;
--(void)cycleFrameBackward: (AquaSalFrame*)pCurFrame;
 @end
 
 #endif // INCLUDED_VCL_INC_OSX_VCLNSAPP_H
diff --git a/vcl/inc/salusereventlist.hxx b/vcl/inc/salusereventlist.hxx
new file mode 100644
index 000000000000..1f689fb5cbf7
--- /dev/null
+++ b/vcl/inc/salusereventlist.hxx
@@ -0,0 +1,126 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_VCL_INC_SALUSEREVENTLIST_HXX
+#define INCLUDED_VCL_INC_SALUSEREVENTLIST_HXX
+
+#include <sal/config.h>
+#include <vcl/dllapi.h>
+#include <osl/mutex.hxx>
+
+#include <assert.h>
+
+#include <list>
+#include <unordered_set>
+
+class SalFrame;
+enum class SalEvent;
+
+struct SalFrameHash : public std::hash<sal_IntPtr>
+{
+    size_t operator()(const SalFrame* frame) const
+        { return std::hash<sal_IntPtr>::operator()( reinterpret_cast<const sal_IntPtr>(frame) ); }
+};
+
+typedef std::unordered_set< SalFrame*, SalFrameHash > SalFrameSet;
+
+class VCL_PLUGIN_PUBLIC SalUserEventList
+{
+public:
+    struct SalUserEvent
+    {
+        SalFrame*     m_pFrame;
+        void*         m_pData;
+        SalEvent      m_nEvent;
+
+        SalUserEvent( SalFrame* pFrame, void* pData, SalEvent nEvent )
+                : m_pFrame( pFrame ),
+                  m_pData( pData ),
+                  m_nEvent( nEvent )
+        {}
+
+        bool operator==(const SalUserEvent &aEvent) const
+        {
+            return m_pFrame == aEvent.m_pFrame
+                && m_pData == aEvent.m_pData
+                && m_nEvent== aEvent.m_nEvent;
+        }
+    };
+
+protected:
+    mutable osl::Mutex         m_aUserEventsMutex;
+    std::list< SalUserEvent >  m_aUserEvents;
+    std::list< SalUserEvent >  m_aProcessingUserEvents;
+    SalFrameSet                m_aFrames;
+
+    virtual void ProcessEvent( SalUserEvent aEvent ) = 0;
+    virtual void TriggerUserEventProcessing() = 0;
+    virtual void TriggerAllUserEventsProcessed() {};
+
+public:
+    SalUserEventList();
+    virtual ~SalUserEventList();
+
+    inline const SalFrameSet& getFrames() const;
+    inline SalFrame* anyFrame() const;
+    void insertFrame( SalFrame* pFrame );
+    void eraseFrame( SalFrame* pFrame );
+    inline bool isFrameAlive( const SalFrame* pFrame ) const;
+
+    void PostEvent( SalFrame* pFrame, void* pData, SalEvent nEvent );
+    bool RemoveEvent( SalFrame* pFrame, void* pData, SalEvent nEvent );
+    inline bool HasUserEvents() const;
+
+    bool DispatchUserEvents( bool bHandleAllCurrentEvents );
+};
+
+inline SalFrame* SalUserEventList::anyFrame() const
+{
+    if ( m_aFrames.empty() )
+        return nullptr;
+    return *m_aFrames.begin();
+}
+
+inline bool SalUserEventList::isFrameAlive( const SalFrame* pFrame ) const
+{
+    auto it = m_aFrames.find( const_cast<SalFrame*>( pFrame ) );
+    return it != m_aFrames.end();
+}
+
+inline bool SalUserEventList::HasUserEvents() const
+{
+    osl::MutexGuard aGuard( m_aUserEventsMutex );
+    return !(m_aUserEvents.empty() && m_aProcessingUserEvents.empty());
+}
+
+inline void SalUserEventList::PostEvent( SalFrame* pFrame, void* pData, SalEvent nEvent )
+{
+    osl::MutexGuard aGuard( m_aUserEventsMutex );
+    m_aUserEvents.push_back( SalUserEvent( pFrame, pData, nEvent ) );
+    TriggerUserEventProcessing();
+}
+
+inline const SalFrameSet& SalUserEventList::getFrames() const
+{
+    return m_aFrames;
+}
+
+#endif // INCLUDED_VCL_INC_SALUSEREVENTLIST_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/unx/gendisp.hxx b/vcl/inc/unx/gendisp.hxx
index 64564237a232..5c8f5113c300 100644
--- a/vcl/inc/unx/gendisp.hxx
+++ b/vcl/inc/unx/gendisp.hxx
@@ -27,45 +27,27 @@
 #include <vcl/dllapi.h>
 #include <list>
 #include <vector>
+#include <salusereventlist.hxx>
 
 class SalFrame;
-class VCL_DLLPUBLIC SalGenericDisplay
+class VCL_DLLPUBLIC SalGenericDisplay : public SalUserEventList
 {
-    mutable osl::Mutex m_aEventGuard;
-    struct SalUserEvent
-    {
-        SalFrame*  m_pFrame;
-        void*      m_pData;
-        SalEvent   m_nEvent;
-
-        SalUserEvent( SalFrame* pFrame, void* pData,
-                      SalEvent nEvent )
-                : m_pFrame( pFrame ),
-                  m_pData( pData ),
-                  m_nEvent( nEvent )
-        {}
-    };
-    std::list< SalUserEvent > m_aUserEvents;
 protected:
     SalFrame* m_pCapture;
-    std::list<SalFrame*> m_aFrames;
+
+    virtual void ProcessEvent( SalUserEvent aEvent ) override;
+
 public:
                  SalGenericDisplay();
-    virtual      ~SalGenericDisplay();
-
-    osl::Mutex& getEventGuardMutex() { return m_aEventGuard; }
+    virtual      ~SalGenericDisplay() override;
 
     void registerFrame( SalFrame* pFrame );
     virtual void deregisterFrame( SalFrame* pFrame );
     void emitDisplayChanged();
 
-    // Event handling
-    virtual void PostUserEvent() = 0;
-
     void SendInternalEvent( SalFrame* pFrame, void* pData, SalEvent nEvent = SalEvent::UserEvent );
-    void CancelInternalEvent( SalFrame const * pFrame, void const * pData, SalEvent nEvent );
+    void CancelInternalEvent( SalFrame* pFrame, void* pData, SalEvent nEvent );
     bool DispatchInternalEvent();
-    bool HasUserEvents() const;
 
     bool     MouseCaptured( const SalFrame *pFrameData ) const
                         { return m_pCapture == pFrameData; }
diff --git a/vcl/inc/unx/gtk/gtkdata.hxx b/vcl/inc/unx/gtk/gtkdata.hxx
index 4f4d520fc141..01b5c46b8dca 100644
--- a/vcl/inc/unx/gtk/gtkdata.hxx
+++ b/vcl/inc/unx/gtk/gtkdata.hxx
@@ -117,9 +117,9 @@ public:
     static void initNWF();
     static void deInitNWF();
 
-    static gboolean userEventFn( gpointer data );
+    void TriggerUserEventProcessing();
+    void TriggerAllUserEventsProcessed();
 
-    void PostUserEvent();
     bool Yield( bool bWait, bool bHandleAllCurrentEvents );
     inline GdkDisplay *GetGdkDisplay();
 
@@ -146,6 +146,7 @@ class GtkSalDisplay : public SalDisplay
 
     GdkCursor* getFromXBM( const unsigned char *pBitmap, const unsigned char *pMask,
                            int nWidth, int nHeight, int nXHot, int nYHot );
+
 public:
              GtkSalDisplay( GdkDisplay* pDisplay );
     virtual ~GtkSalDisplay() override;
@@ -180,7 +181,8 @@ public:
     void screenSizeChanged( GdkScreen const * );
     void monitorsChanged( GdkScreen const * );
 
-    virtual void PostUserEvent() override;
+    virtual void TriggerUserEventProcessing() override;
+    virtual void TriggerAllUserEventsProcessed() override;
 
 #if !GTK_CHECK_VERSION(3,0,0)
     virtual bool Dispatch( XEvent *pEvent ) override;
diff --git a/vcl/inc/unx/saldisp.hxx b/vcl/inc/unx/saldisp.hxx
index 0ec4e10e7d65..8f96e03630b0 100644
--- a/vcl/inc/unx/saldisp.hxx
+++ b/vcl/inc/unx/saldisp.hxx
@@ -168,7 +168,7 @@ public:
 
     virtual bool    Yield( bool bWait, bool bHandleAllCurrentEvents );
     virtual void    Wakeup();
-    virtual void    PostUserEvent();
+    void            TriggerUserEventProcessing();
 
     virtual void    Insert( int fd, void* data,
                             YieldFunc   pending,
@@ -371,12 +371,10 @@ public:
             { return getDataForScreen( nXScreen ).m_aRoot; }
     unsigned int GetXScreenCount() const { return m_aScreens.size(); }
 
-    const std::list< SalFrame* >& getFrames() const { return m_aFrames; }
+    const SalFrameSet& getFrames() const { return m_aFrames; }
     bool            IsNumLockFromXS() const { return bNumLockFromXS_; }
 
     std::list< SalObject* >& getSalObjects() { return m_aSalObjects; }
-
-    virtual void    PostUserEvent() override = 0;
 };
 
 inline  Display *SalColormap::GetXDisplay() const
@@ -390,7 +388,7 @@ public:
 
     virtual bool        Dispatch( XEvent *pEvent ) override;
     virtual void        Yield();
-    virtual void        PostUserEvent() override;
+    virtual void        TriggerUserEventProcessing() override;
 
     bool                IsEvent();
     void                SetupInput();
diff --git a/vcl/osx/salframe.cxx b/vcl/osx/salframe.cxx
index e54073cdf4f1..dcdfe6d9c936 100644
--- a/vcl/osx/salframe.cxx
+++ b/vcl/osx/salframe.cxx
@@ -87,8 +87,7 @@ AquaSalFrame::AquaSalFrame( SalFrame* pParent, SalFrameStyleFlags salFrameStyle
     initWindowAndView();
 
     SalData* pSalData = GetSalData();
-    pSalData->maFrames.push_front( this );
-    pSalData->maFrameCheck.insert( this );
+    pSalData->mpFirstInstance->insertFrame( this );
 }
 
 AquaSalFrame::~AquaSalFrame()
@@ -106,8 +105,7 @@ AquaSalFrame::~AquaSalFrame()
     [SalFrameView unsetMouseFrame: this];
 
     SalData* pSalData = GetSalData();
-    pSalData->maFrames.remove( this );
-    pSalData->maFrameCheck.erase( this );
+    pSalData->mpFirstInstance->eraseFrame( this );
     pSalData->maPresentationFrames.remove( this );
 
     SAL_WARN_IF( this == s_pCaptureFrame, "vcl", "capture frame destroyed" );
@@ -296,7 +294,7 @@ void AquaSalFrame::ReleaseGraphics( SalGraphics *pGraphics )
 
 bool AquaSalFrame::PostEvent(ImplSVEvent* pData)
 {
-    GetSalData()->mpFirstInstance->PostUserEvent( this, SalEvent::UserEvent, pData );
+    GetSalData()->mpFirstInstance->PostEvent( this, pData, SalEvent::UserEvent );
     return TRUE;
 }
 
diff --git a/vcl/osx/salinst.cxx b/vcl/osx/salinst.cxx
index 855dac645e41..89e3ae6d4e82 100644
--- a/vcl/osx/salinst.cxx
+++ b/vcl/osx/salinst.cxx
@@ -79,7 +79,8 @@ static bool bLeftMain = false;
 class AquaDelayedSettingsChanged : public Idle
 {
     bool            mbInvalidate;
-    public:
+
+public:
     AquaDelayedSettingsChanged( bool bInvalidate ) :
         mbInvalidate( bInvalidate )
     {
@@ -87,20 +88,20 @@ class AquaDelayedSettingsChanged : public Idle
 
     virtual void Invoke() override
     {
-        SalData* pSalData = GetSalData();
-        if( ! pSalData->maFrames.empty() )
-            pSalData->maFrames.front()->CallCallback( SalEvent::SettingsChanged, nullptr );
+        AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
+        SalFrame *pAnyFrame = pInst->anyFrame();
+        if( pAnyFrame )
+            pAnyFrame->CallCallback( SalEvent::SettingsChanged, nullptr );
 
         if( mbInvalidate )
         {
-            for( std::list< AquaSalFrame* >::iterator it = pSalData->maFrames.begin();
-                it != pSalData->maFrames.end(); ++it )
+            for( auto pSalFrame : pInst->getFrames() )
             {
-                if( (*it)->mbShown )
-                    (*it)->SendPaintEvent();
+                AquaSalFrame* pFrame = static_cast<AquaSalFrame*>( const_cast<SalFrame*>( pSalFrame ) );
+                if( pFrame->mbShown )
+                    pFrame->SendPaintEvent();
             }
         }
-        Stop();
         delete this;
     }
 };
@@ -390,17 +391,19 @@ AquaSalInstance::~AquaSalInstance()
     delete mpSalYieldMutex;
 }
 
-void AquaSalInstance::PostUserEvent( AquaSalFrame* pFrame, SalEvent nType, void* pData )
+void AquaSalInstance::TriggerUserEventProcessing()
 {
-    {
-        osl::MutexGuard g( maUserEventListMutex );
-        maUserEvents.push_back( SalUserEvent( pFrame, pData, nType ) );
-    }
     dispatch_async(dispatch_get_main_queue(),^{
         ImplNSAppPostEvent( AquaSalInstance::YieldWakeupEvent, NO );
     });
 }
 
+void AquaSalInstance::ProcessEvent( SalUserEvent aEvent )
+{
+    aEvent.m_pFrame->CallCallback( aEvent.m_nEvent, aEvent.m_pData );
+    maWaitingYieldCond.set();
+}
+
 comphelper::SolarMutex* AquaSalInstance::GetYieldMutex()
 {
     return mpSalYieldMutex;
@@ -453,15 +456,17 @@ void AquaSalInstance::handleAppDefinedEvent( NSEvent* pEvent )
     case AppleRemoteControlEvent: // Defined in <apple_remote/RemoteMainController.h>
     {
         MediaCommand nCommand;
-        SalData* pSalData = GetSalData();
+        AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
         bool bIsFullScreenMode = false;
 
-        std::list<AquaSalFrame*>::iterator it = pSalData->maFrames.begin();
-        while( it != pSalData->maFrames.end() )
+        for( auto pSalFrame : pInst->getFrames() )
         {
-            if ( (*it) && (*it)->mbFullScreen )
+            const AquaSalFrame* pFrame = static_cast<const AquaSalFrame*>( pSalFrame );
+            if ( pFrame->mbFullScreen )
+            {
                 bIsFullScreenMode = true;
-            ++it;
+                break;
+            }
         }
 
         switch ([pEvent data1])
@@ -497,9 +502,8 @@ void AquaSalInstance::handleAppDefinedEvent( NSEvent* pEvent )
             default:
                 break;
         }
-        AquaSalFrame* pFrame = pSalData->maFrames.front();
+        AquaSalFrame* pFrame = static_cast<AquaSalFrame*>( pInst->anyFrame() );
         vcl::Window* pWindow = pFrame ? pFrame->GetWindow() : nullptr;
-
         if( pWindow )
         {
             const Point aPoint;
@@ -532,6 +536,7 @@ bool AquaSalInstance::RunInMainYield( bool bHandleAllCurrentEvents )
     return false;
 
 }
+
 static bool isWakeupEvent( NSEvent *pEvent )
 {
 SAL_WNODEPRECATED_DECLARATIONS_PUSH
@@ -542,8 +547,6 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
 
 bool AquaSalInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents)
 {
-    bool bHadEvent = false;
-
     // ensure that the per thread autorelease pool is top level and
     // will therefore not be destroyed by cocoa implicitly
     SalData::ensureThreadAutoreleasePool();
@@ -552,36 +555,10 @@ bool AquaSalInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents)
     // an own pool for each yield level
     ReleasePoolHolder aReleasePool;
 
-    // Release all locks so that we don't deadlock when we pull pending
-    // events from the event queue
-    bool bDispatchUser = true;
-    while( bDispatchUser )
-    {
-        // get one user event
-        SalUserEvent aEvent( nullptr, nullptr, SalEvent::NONE );
-        {
-            osl::MutexGuard g( maUserEventListMutex );
-            if( ! maUserEvents.empty() )
-            {
-                aEvent = maUserEvents.front();
-                maUserEvents.pop_front();
-                bHadEvent = true;
-            }
-            else
-                bDispatchUser = false;
-        }
-
-        // dispatch it
-        if( aEvent.mpFrame && AquaSalFrame::isAlive( aEvent.mpFrame ) )
-        {
-            aEvent.mpFrame->CallCallback( aEvent.mnType, aEvent.mpData );
-            maWaitingYieldCond.set();
-        }
-
-        // return if only one event is asked for
-        if( !bHandleAllCurrentEvents && bDispatchUser )
-            return true;
-    }
+    // first, process current user events
+    bool bHadEvent = DispatchUserEvents( bHandleAllCurrentEvents );
+    if ( !bHandleAllCurrentEvents && bHadEvent )
+        return true;
 
     // handle cocoa event queue
     // cocoa events may be only handled in the thread the NSApp was created
@@ -639,13 +616,13 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
         }
 
         // collect update rectangles
-        const std::list< AquaSalFrame* > rFrames( GetSalData()->maFrames );
-        for( std::list< AquaSalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+        for( auto pSalFrame : GetSalData()->mpFirstInstance->getFrames() )
         {
-            if( (*it)->mbShown && ! (*it)->maInvalidRect.IsEmpty() )
+            AquaSalFrame* pFrame = static_cast<AquaSalFrame*>( const_cast<SalFrame*>( pSalFrame ) );
+            if( pFrame->mbShown && ! pFrame->maInvalidRect.IsEmpty() )
             {
-                (*it)->Flush( (*it)->maInvalidRect );
-                (*it)->maInvalidRect.SetEmpty();
+                pFrame->Flush( pFrame->maInvalidRect );
+                pFrame->maInvalidRect.SetEmpty();
             }
         }
 
diff --git a/vcl/osx/vclnsapp.mm b/vcl/osx/vclnsapp.mm
index 651fa2a014cc..dafcdb97aca5 100644
--- a/vcl/osx/vclnsapp.mm
+++ b/vcl/osx/vclnsapp.mm
@@ -136,24 +136,6 @@ SAL_WNODEPRECATED_DECLARATIONS_PUSH
                 }
             }
 
-            // #i90083# handle frame switching
-            // FIXME: lousy workaround
-            if( (nModMask & (NSControlKeyMask|NSAlternateKeyMask)) == 0 )
-            {
-                if( [[pEvent characters] isEqualToString: @"<"] ||
-                    [[pEvent characters] isEqualToString: @"~"] )
-                {
-                    [self cycleFrameForward: pFrame];
-                    return;
-                }
-                else if( [[pEvent characters] isEqualToString: @">"] ||
-                         [[pEvent characters] isEqualToString: @"`"] )
-                {
-                    [self cycleFrameBackward: pFrame];
-                    return;
-                }
-            }
-
             // get information whether the event was handled; keyDown returns nothing
             GetSalData()->maKeyEventAnswer[ pEvent ] = false;
             bool bHandled = false;
@@ -245,84 +227,6 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
     [super sendEvent: pEvent];
 }
 
--(void)cycleFrameForward: (AquaSalFrame*)pCurFrame
-{
-    // find current frame in list
-    std::list< AquaSalFrame* >& rFrames( GetSalData()->maFrames );
-    std::list< AquaSalFrame* >::iterator it = rFrames.begin();
-    for( ; it != rFrames.end() && *it != pCurFrame; ++it )
-        ;
-    if( it != rFrames.end() )
-    {
-        // now find the next frame (or end)
-        do
-        {
-            ++it;
-            if( it != rFrames.end() )
-            {
-                if( (*it)->mpDockMenuEntry != nullptr &&
-                    (*it)->mbShown )
-                {
-                    [(*it)->getNSWindow() makeKeyAndOrderFront: NSApp];
-                    return;
-                }
-            }
-        } while( it != rFrames.end() );
-        // cycle around, find the next up to pCurFrame
-        it = rFrames.begin();
-        while( *it != pCurFrame )
-        {
-            if( (*it)->mpDockMenuEntry != nullptr &&
-                (*it)->mbShown )
-            {
-                [(*it)->getNSWindow() makeKeyAndOrderFront: NSApp];
-                return;
-            }
-            ++it;
-        }
-    }
-}
-
--(void)cycleFrameBackward: (AquaSalFrame*)pCurFrame
-{
-    // do the same as cycleFrameForward only with a reverse iterator
-
-    // find current frame in list
-    std::list< AquaSalFrame* >& rFrames( GetSalData()->maFrames );
-    std::list< AquaSalFrame* >::reverse_iterator it = rFrames.rbegin();
-    for( ; it != rFrames.rend() && *it != pCurFrame; ++it )
-        ;
-    if( it != rFrames.rend() )
-    {
-        // now find the next frame (or end)
-        do
-        {
-            ++it;
-            if( it != rFrames.rend() )
-            {
-                if( (*it)->mpDockMenuEntry != nullptr &&
-                    (*it)->mbShown )
-                {
-                    [(*it)->getNSWindow() makeKeyAndOrderFront: NSApp];
-                    return;
-                }
-            }
-        } while( it != rFrames.rend() );
-        // cycle around, find the next up to pCurFrame
-        it = rFrames.rbegin();
-        while( *it != pCurFrame )
-        {
-            if( (*it)->mpDockMenuEntry != nullptr &&
-                (*it)->mbShown )
-            {
-                [(*it)->getNSWindow() makeKeyAndOrderFront: NSApp];
-                return;
-            }
-            ++it;
-        }
-    }
-}
-
 -(NSMenu*)applicationDockMenu:(NSApplication *)sender
 {
     (void)sender;
@@ -413,12 +317,13 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
     {
         SolarMutexGuard aGuard;
 
-        SalData* pSalData = GetSalData();
-        if( ! pSalData->maFrames.empty() )
+        AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
+        SalFrame *pAnyFrame = pInst->anyFrame();
+        if( pAnyFrame )
         {
             // the following QueryExit will likely present a message box, activate application
             [NSApp activateIgnoringOtherApps: YES];
-            aReply = pSalData->maFrames.front()->CallCallback( SalEvent::Shutdown, nullptr ) ? NSTerminateCancel : NSTerminateNow;
+            aReply = pAnyFrame->CallCallback( SalEvent::Shutdown, nullptr ) ? NSTerminateCancel : NSTerminateNow;
         }
 
         if( aReply == NSTerminateNow )
@@ -439,9 +344,10 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
     (void)pNotification;
     SolarMutexGuard aGuard;
 
-    const SalData* pSalData = GetSalData();
-    if( !pSalData->maFrames.empty() )
-        pSalData->maFrames.front()->CallCallback( SalEvent::SettingsChanged, nullptr );
+    AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
+    SalFrame *pAnyFrame = pInst->anyFrame();
+    if(  pAnyFrame )
+        pAnyFrame->CallCallback( SalEvent::SettingsChanged, nullptr );
 }
 
 -(void)screenParametersChanged: (NSNotification*) pNotification
@@ -449,11 +355,10 @@ SAL_WNODEPRECATED_DECLARATIONS_POP
     (void)pNotification;
     SolarMutexGuard aGuard;
 
-    SalData* pSalData = GetSalData();
-    std::list< AquaSalFrame* >::iterator it;
-    for( it = pSalData->maFrames.begin(); it != pSalData->maFrames.end(); ++it )
+    for( auto pSalFrame : GetSalData()->mpFirstInstance->getFrames() )
     {
-        (*it)->screenParametersChanged();
+        AquaSalFrame *pFrame = static_cast<AquaSalFrame*>( const_cast<SalFrame*>( pSalFrame ) );
+        pFrame->screenParametersChanged();
     }
 }
 
diff --git a/vcl/quartz/salvd.cxx b/vcl/quartz/salvd.cxx
index 3110398b8784..fe48f0b80326 100644
--- a/vcl/quartz/salvd.cxx
+++ b/vcl/quartz/salvd.cxx
@@ -255,19 +255,10 @@ bool AquaSalVirtualDevice::SetSize( long nDX, long nDY )
         AquaSalFrame* pSalFrame = mpGraphics->getGraphicsFrame();
         if( !pSalFrame || !AquaSalFrame::isAlive( pSalFrame ))
         {
-            if( !GetSalData()->maFrames.empty() )
-            {
-                // get the first matching frame
-                pSalFrame = *GetSalData()->maFrames.begin();
-            }
-            else
-            {
-                // ensure we don't reuse a dead AquaSalFrame on the very
-                // unlikely case of no other frame to use
-                pSalFrame = nullptr;
-            }
-            // update the frame reference
-            mpGraphics->setGraphicsFrame( pSalFrame );
+            pSalFrame = static_cast<AquaSalFrame*>( GetSalData()->mpFirstInstance->anyFrame() );
+            if ( pSalFrame )
+                // update the frame reference
+                mpGraphics->setGraphicsFrame( pSalFrame );
         }
         if( pSalFrame )
         {
diff --git a/vcl/source/app/salusereventlist.cxx b/vcl/source/app/salusereventlist.cxx
new file mode 100644
index 000000000000..af588e4bb151
--- /dev/null
+++ b/vcl/source/app/salusereventlist.cxx
@@ -0,0 +1,119 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <salusereventlist.hxx>
+#include <salwtype.hxx>
+
+#include <algorithm>
+
+SalUserEventList::SalUserEventList()
+{
+}
+
+SalUserEventList::~SalUserEventList()
+{
+}
+
+void SalUserEventList::insertFrame( SalFrame* pFrame )
+{
+    auto aPair = m_aFrames.insert( pFrame );
+    assert( aPair.second ); (void) aPair;
+}
+
+void SalUserEventList::eraseFrame( SalFrame* pFrame )
+{
+    auto it = m_aFrames.find( pFrame );
+    assert( it != m_aFrames.end() );
+    if ( it != m_aFrames.end() )
+        m_aFrames.erase( it );
+}
+
+bool SalUserEventList::DispatchUserEvents( bool bHandleAllCurrentEvents )
+{
+    bool bWasEvent = false;
+
+    {
+        osl::MutexGuard aGuard( m_aUserEventsMutex );
+        if( ! m_aUserEvents.empty() )
+        {
+            if( bHandleAllCurrentEvents )
+                m_aProcessingUserEvents.swap( m_aUserEvents );
+            else
+            {
+                m_aProcessingUserEvents.push_back( m_aUserEvents.front() );
+                m_aUserEvents.pop_front();
+            }
+            bWasEvent = true;
+        }
+    }
+
+    if( bWasEvent )
+    {
+        SalUserEvent aEvent( nullptr, nullptr, SalEvent::NONE );
+        do {
+            {
+                osl::MutexGuard aGuard( m_aUserEventsMutex );
+                if ( m_aProcessingUserEvents.empty() )
+                    break;
+                aEvent = m_aProcessingUserEvents.front();
+                m_aProcessingUserEvents.pop_front();
+            }
+
+            if ( isFrameAlive( aEvent.m_pFrame ) )
+                ProcessEvent( aEvent );
+        }
+        while( true );
+    }
+
+    osl::MutexGuard aGuard( m_aUserEventsMutex );
+    if ( !HasUserEvents() )
+        TriggerAllUserEventsProcessed();
+
+    return bWasEvent;
+}
+
+bool SalUserEventList::RemoveEvent( SalFrame* pFrame, void* pData, SalEvent nEvent )
+{
+    SalUserEvent aEvent( pFrame, pData, nEvent );
+    bool bResult = false;
+
+    osl::MutexGuard aGuard( m_aUserEventsMutex );
+    auto it = std::find( m_aUserEvents.begin(), m_aUserEvents.end(), aEvent );
+    if ( it != m_aUserEvents.end() )
+    {
+        m_aUserEvents.erase( it );
+        bResult = true;
+    }
+    else
+    {
+        it = std::find( m_aProcessingUserEvents.begin(), m_aProcessingUserEvents.end(), aEvent );
+        if ( it != m_aProcessingUserEvents.end() )
+        {
+            m_aProcessingUserEvents.erase( it );
+            bResult = true;
+        }
+    }
+
+    if ( bResult && !HasUserEvents() )
+        TriggerAllUserEventsProcessed();
+
+    return bResult;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/unx/generic/app/gendisp.cxx b/vcl/unx/generic/app/gendisp.cxx
index edaf0e6ffb95..1be8606602e0 100644
--- a/vcl/unx/generic/app/gendisp.cxx
+++ b/vcl/unx/generic/app/gendisp.cxx
@@ -22,7 +22,6 @@
 #include <unx/geninst.h>
 
 SalGenericDisplay::SalGenericDisplay()
- : m_aEventGuard()
 {
     m_pCapture = nullptr;
 }
@@ -33,94 +32,39 @@ SalGenericDisplay::~SalGenericDisplay()
 
 void SalGenericDisplay::registerFrame( SalFrame* pFrame )
 {
-    m_aFrames.push_front( pFrame );
+    insertFrame( pFrame );
 }
 
 void SalGenericDisplay::deregisterFrame( SalFrame* pFrame )
 {
-    {
-        osl::MutexGuard g( m_aEventGuard );
-        std::list< SalUserEvent >::iterator it = m_aUserEvents.begin();
-        while ( it != m_aUserEvents.end() )
-        {
-            if( it->m_pFrame == pFrame )
-            {
-                if (it->m_nEvent == SalEvent::UserEvent) {
-                    delete static_cast<ImplSVEvent *>(it->m_pData);
-                }
-                it = m_aUserEvents.erase( it );
-            }
-            else
-                ++it;
-        }
-    }
-
-    m_aFrames.remove( pFrame );
+    eraseFrame( pFrame );
 }
 
 void SalGenericDisplay::emitDisplayChanged()
 {
-    if( !m_aFrames.empty() )
-        m_aFrames.front()->CallCallback( SalEvent::DisplayChanged, nullptr );
+    SalFrame *pAnyFrame = anyFrame();
+    if( pAnyFrame )
+        pAnyFrame->CallCallback( SalEvent::DisplayChanged, nullptr );
 }
 
 bool SalGenericDisplay::DispatchInternalEvent()
 {
-    void* pData = nullptr;
-    SalFrame* pFrame = nullptr;
-    SalEvent nEvent = SalEvent::NONE;
-
-    {
-        osl::MutexGuard g( m_aEventGuard );
-        if( !m_aUserEvents.empty() )
-        {
-            pFrame  = m_aUserEvents.front().m_pFrame;
-            pData   = m_aUserEvents.front().m_pData;
-            nEvent  = m_aUserEvents.front().m_nEvent;
-
-            m_aUserEvents.pop_front();
-        }
-    }
-
-    if( pFrame )
-        pFrame->CallCallback( nEvent, pData );
-
-    return pFrame != nullptr;
+    return DispatchUserEvents( false );
 }
 
 void SalGenericDisplay::SendInternalEvent( SalFrame* pFrame, void* pData, SalEvent nEvent )
 {
-    osl::MutexGuard g( m_aEventGuard );
-
-    m_aUserEvents.emplace_back( pFrame, pData, nEvent );
-
-    PostUserEvent(); // wakeup the concrete mainloop
+    PostEvent( pFrame, pData, nEvent );
 }
 
-void SalGenericDisplay::CancelInternalEvent( SalFrame const * pFrame, void const * pData, SalEvent nEvent )
+void SalGenericDisplay::CancelInternalEvent( SalFrame* pFrame, void* pData, SalEvent nEvent )
 {
-    osl::MutexGuard g( m_aEventGuard );
-    if( ! m_aUserEvents.empty() )
-    {
-        std::list< SalUserEvent >::iterator it = m_aUserEvents.begin();
-        while (it != m_aUserEvents.end())
-        {
-            if( it->m_pFrame    == pFrame   &&
-                it->m_pData     == pData    &&
-                it->m_nEvent    == nEvent )
-            {
-                it = m_aUserEvents.erase( it );
-            }
-            else
-                ++it;
-        }
-    }
+    RemoveEvent( pFrame, pData, nEvent );
 }
 
-bool SalGenericDisplay::HasUserEvents() const
+void SalGenericDisplay::ProcessEvent( SalUserEvent aEvent )
 {
-    osl::MutexGuard g( m_aEventGuard );
-    return !m_aUserEvents.empty();
+    aEvent.m_pFrame->CallCallback( aEvent.m_nEvent, aEvent.m_pData );
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/unx/generic/app/i18n_status.cxx b/vcl/unx/generic/app/i18n_status.cxx
index f2be4d7b47a2..81ce3a5450b2 100644
--- a/vcl/unx/generic/app/i18n_status.cxx
+++ b/vcl/unx/generic/app/i18n_status.cxx
@@ -170,12 +170,9 @@ bool XIMStatusWindow::checkLastParent() const
 {
     if( m_pLastParent )
     {
-        const std::list< SalFrame* >& rFrames = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames();
-        for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
-        {
-            if( *it == m_pLastParent )
-                return true;
-        }
+        auto rFrameList = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames();
+        auto it = rFrameList.find( m_pLastParent );
+        return it != rFrameList.end();
     }
     return false;
 }
diff --git a/vcl/unx/generic/app/saldata.cxx b/vcl/unx/generic/app/saldata.cxx
index 930356b76992..4ad2c02db54f 100644
--- a/vcl/unx/generic/app/saldata.cxx
+++ b/vcl/unx/generic/app/saldata.cxx
@@ -786,7 +786,7 @@ void SalXLib::Wakeup()
     OSL_VERIFY(write (m_pTimeoutFDS[1], "", 1) == 1);
 }
 
-void SalXLib::PostUserEvent()
+void SalXLib::TriggerUserEventProcessing()
 {
     Wakeup();
 }
diff --git a/vcl/unx/generic/app/saldisp.cxx b/vcl/unx/generic/app/saldisp.cxx
index cd96818420ad..6afeeb81739a 100644
--- a/vcl/unx/generic/app/saldisp.cxx
+++ b/vcl/unx/generic/app/saldisp.cxx
@@ -431,10 +431,10 @@ SalX11Display::~SalX11Display()
     }
 }
 
-void SalX11Display::PostUserEvent()
+void SalX11Display::TriggerUserEventProcessing()
 {
     if( pXLib_ )
-        pXLib_->PostUserEvent();
+        pXLib_->TriggerUserEventProcessing();
 }
 
 SalDisplay::ScreenData *
@@ -1935,17 +1935,16 @@ bool SalX11Display::Dispatch( XEvent *pEvent )
     {
         ::Window aWindow = pEvent->xkey.window;
 
-        std::list< SalFrame* >::const_iterator it;
-        for( it = m_aFrames.begin(); it != m_aFrames.end(); ++it )
+        for (auto pSalFrame : m_aFrames )
         {
-            const X11SalFrame* pFrame = static_cast< const X11SalFrame* >(*it);
+            const X11SalFrame* pFrame = static_cast< const X11SalFrame* >( pSalFrame );
             if( pFrame->GetWindow() == aWindow || pFrame->GetShellWindow() == aWindow )
             {
                 aWindow = pFrame->GetWindow();
                 break;
             }
         }
-        if( it != m_aFrames.end() )
+        if( aWindow != pEvent->xkey.window )
         {
             if ( pInputMethod && pInputMethod->FilterEvent( pEvent , aWindow ) )
                 return false;
@@ -1975,9 +1974,8 @@ bool SalX11Display::Dispatch( XEvent *pEvent )
                 {
                     if( pEvent->xproperty.window == rScreen.m_aRefWindow )
                     {
-                        std::list< SalFrame* >::const_iterator it;
-                        for( it = m_aFrames.begin(); it != m_aFrames.end(); ++it )
-                            (*it)->CallCallback( SalEvent::SettingsChanged, nullptr );
+                        for (auto pSalFrame : m_aFrames )
+                             pSalFrame->CallCallback( SalEvent::SettingsChanged, nullptr );
                         return false;
                     }
                 }
@@ -2009,10 +2007,10 @@ bool SalX11Display::Dispatch( XEvent *pEvent )
             break;
     }
 
-    std::list< SalFrame* >::iterator it;
-    for( it = m_aFrames.begin(); it != m_aFrames.end(); ++it )
+    for (auto pSalFrame : m_aFrames )
     {
-        X11SalFrame* pFrame = static_cast< X11SalFrame* >(*it);
+        X11SalFrame* pFrame = static_cast<X11SalFrame*>( pSalFrame );
+
         ::Window aDispatchWindow = pEvent->xany.window;
         if( pFrame->GetWindow() == aDispatchWindow
             || pFrame->GetShellWindow() == aDispatchWindow
diff --git a/vcl/unx/generic/app/salinst.cxx b/vcl/unx/generic/app/salinst.cxx
index e38164ee247b..abd29a78c077 100644
--- a/vcl/unx/generic/app/salinst.cxx
+++ b/vcl/unx/generic/app/salinst.cxx
@@ -225,10 +225,8 @@ void X11SalInstance::AddToRecentDocumentList(const OUString& rFileUrl, const OUS
 void X11SalInstance::PostPrintersChanged()
 {
     SalDisplay* pDisp = vcl_sal::getSalDisplay(GetGenericUnixSalData());
-    const std::list< SalFrame* >& rList = pDisp->getFrames();
-    for( std::list< SalFrame* >::const_iterator it = rList.begin();
-         it != rList.end(); ++it )
-        pDisp->SendInternalEvent( *it, nullptr, SalEvent::PrinterChanged );
+    for (auto pSalFrame : pDisp->getFrames() )
+        pDisp->PostEvent( pSalFrame, nullptr, SalEvent::PrinterChanged );
 }
 
 GenPspGraphics *X11SalInstance::CreatePrintGraphics()
diff --git a/vcl/unx/generic/app/sm.cxx b/vcl/unx/generic/app/sm.cxx
index e6da11244074..4beb1d58b2c3 100644
--- a/vcl/unx/generic/app/sm.cxx
+++ b/vcl/unx/generic/app/sm.cxx
@@ -293,10 +293,9 @@ IMPL_STATIC_LINK( SessionManagerClient, SaveYourselfHdl, void*, pStateVal, void
           task of the quick-starter)
         */
         *pSmRestartHint = SmRestartNever;
-        const std::list< SalFrame* >& rFrames = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames();
-        for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+        for (auto pSalFrame : vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames() )
         {
-            vcl::Window *pWindow = (*it)->GetWindow();
+            vcl::Window *pWindow = pSalFrame->GetWindow();
             if (pWindow && pWindow->IsVisible())
             {
                 *pSmRestartHint = SmRestartIfRunning;
@@ -394,11 +393,10 @@ IMPL_STATIC_LINK_NOARG( SessionManagerClient, ShutDownHdl, void*, void )
         m_pSession->CallCallback( &aEvent );
     }
 
-    const std::list< SalFrame* >& rFrames = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames();
-
-    SAL_INFO("vcl.sm.debug", "  rFrames.empty() = " << (rFrames.empty() ? "true" : "false"));
-    if( !rFrames.empty() )
-        rFrames.front()->CallCallback( SalEvent::Shutdown, nullptr );
+    SalFrame *pAnyFrame = vcl_sal::getSalDisplay(GetGenericUnixSalData())->anyFrame();
+    SAL_INFO("vcl.sm.debug", "  rFrames.empty() = " << (pAnyFrame ? "true" : "false"));
+    if( pAnyFrame )
+        pAnyFrame->CallCallback( SalEvent::Shutdown, nullptr );
 }
 
 void SessionManagerClient::DieProc(
diff --git a/vcl/unx/generic/gdi/salgdi2.cxx b/vcl/unx/generic/gdi/salgdi2.cxx
index 6c4aba94f9d4..76fe85451f86 100644
--- a/vcl/unx/generic/gdi/salgdi2.cxx
+++ b/vcl/unx/generic/gdi/salgdi2.cxx
@@ -127,12 +127,11 @@ void X11SalGraphics::YieldGraphicsExpose()
     ::Window aWindow = GetDrawable();
     if( ! pFrame )
     {
-        const std::list< SalFrame* >& rFrames = vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames();
-        for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end() && ! pFrame; ++it )
+        for (auto pSalFrame : vcl_sal::getSalDisplay(GetGenericUnixSalData())->getFrames() )
         {
-            const SystemEnvData* pEnvData = (*it)->GetSystemData();
+            const SystemEnvData* pEnvData = pSalFrame->GetSystemData();
             if( Drawable(pEnvData->aWindow) == aWindow )
-                pFrame = *it;
+                pFrame = pSalFrame;
         }
         if( ! pFrame )
             return;
diff --git a/vcl/unx/generic/window/salframe.cxx b/vcl/unx/generic/window/salframe.cxx
index b89a736581d2..e2eb2ee2d237 100644
--- a/vcl/unx/generic/window/salframe.cxx
+++ b/vcl/unx/generic/window/salframe.cxx
@@ -492,15 +492,14 @@ void X11SalFrame::Init( SalFrameStyleFlags nSalFrameStyle, SalX11Screen nXScreen
 
         // check if this is really one of our own frames
         // do not change the input mask in that case
-        const std::list< SalFrame* >& rFrames = GetDisplay()->getFrames();
-        std::list< SalFrame* >::const_iterator it = rFrames.begin();
-        while( it != rFrames.end() && mhForeignParent != static_cast<const X11SalFrame*>(*it)->GetWindow() )
-            ++it;
-
-        if( it == rFrames.end() )
+        for (auto pSalFrame : GetDisplay()->getFrames() )
         {
-            XSelectInput( GetDisplay()->GetDisplay(), mhForeignParent, StructureNotifyMask | FocusChangeMask );
-            XSelectInput( GetDisplay()->GetDisplay(), mhShellWindow, StructureNotifyMask | FocusChangeMask );
+            if ( static_cast<const X11SalFrame*>( pSalFrame )->GetWindow() == mhForeignParent )
+            {
+                XSelectInput( GetDisplay()->GetDisplay(), mhForeignParent, StructureNotifyMask | FocusChangeMask );
+                XSelectInput( GetDisplay()->GetDisplay(), mhShellWindow, StructureNotifyMask | FocusChangeMask );
+                break;
+            }
         }
     }
     else
@@ -521,11 +520,9 @@ void X11SalFrame::Init( SalFrameStyleFlags nSalFrameStyle, SalX11Screen nXScreen
             {
                 // find the last document window (if any)
                 const X11SalFrame* pFrame = nullptr;
-                const std::list< SalFrame* >& rFrames = GetDisplay()->getFrames();
-                std::list< SalFrame* >::const_iterator it = rFrames.begin();
-                while( it != rFrames.end() )
+                for (auto pSalFrame : GetDisplay()->getFrames() )
                 {
-                    pFrame = static_cast< const X11SalFrame* >(*it);
+                    pFrame = static_cast< const X11SalFrame* >( pSalFrame );
                     if( ! ( pFrame->mpParent
                             || pFrame->mbFullScreen
                             || ! ( pFrame->nStyle_ & SalFrameStyleFlags::SIZEABLE )
@@ -534,10 +531,9 @@ void X11SalFrame::Init( SalFrameStyleFlags nSalFrameStyle, SalX11Screen nXScreen
                             )
                         )
                         break;
-                    ++it;
                 }
 
-                if( it != rFrames.end() )
+                if( pFrame )
                 {
                     // set a document position and size
                     // the first frame gets positioned by the window manager
@@ -954,13 +950,12 @@ X11SalFrame::~X11SalFrame()
      *  check if there is only the status frame left
      *  if so, free it
      */
-    if( ! GetDisplay()->getFrames().empty() && vcl::I18NStatus::exists() )
+    auto &rFrames = GetDisplay()->getFrames();
+    if( ! rFrames.empty() && vcl::I18NStatus::exists() )
     {
         SalFrame* pStatusFrame = vcl::I18NStatus::get().getStatusFrame();
-        std::list< SalFrame* >::const_iterator sit = GetDisplay()->getFrames().begin();
-        if( pStatusFrame
-            && *sit == pStatusFrame
-            && ++sit == GetDisplay()->getFrames().end() )
+        auto sit = rFrames.begin();
+        if( pStatusFrame && *sit == pStatusFrame && ++sit == rFrames.end() )
             vcl::I18NStatus::free();
     }
 }
@@ -1204,10 +1199,9 @@ void X11SalFrame::Show( bool bVisible, bool bNoActivate )
         if( ! (nStyle_ & SalFrameStyleFlags::INTRO) )
         {
             // hide all INTRO frames
-            const std::list< SalFrame* >& rFrames = GetDisplay()->getFrames();
-            for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+            for (auto pSalFrame : GetDisplay()->getFrames() )
             {
-                const X11SalFrame* pFrame = static_cast< const X11SalFrame* >(*it);
+                const X11SalFrame* pFrame = static_cast< const X11SalFrame* >( pSalFrame );
                 // look for intro bit map; if present, hide it
                 if( pFrame->nStyle_ & SalFrameStyleFlags::INTRO )
                 {
@@ -2698,10 +2692,9 @@ bool X11SalFrame::HandleMouseEvent( XEvent *pEvent )
             // see if the user clicks outside all of the floats
             // if yes release the grab
             bool bInside = false;
-            const std::list< SalFrame* >& rFrames = GetDisplay()->getFrames();
-            for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+            for (auto pSalFrame : GetDisplay()->getFrames() )
             {
-                const X11SalFrame* pFrame = static_cast< const X11SalFrame* >(*it);
+                const X11SalFrame* pFrame = static_cast< const X11SalFrame* >( pSalFrame );
                 if( pFrame->IsFloatGrabWindow()                                     &&
                     pFrame->bMapped_                                                &&
                     pEvent->xbutton.x_root >= pFrame->maGeometry.nX                             &&
@@ -2738,9 +2731,9 @@ bool X11SalFrame::HandleMouseEvent( XEvent *pEvent )
                     && aChild // pointer may not be in any child
                     )
                 {
-                    for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+                    for (auto pSalFrame : GetDisplay()->getFrames() )
                     {
-                        const X11SalFrame* pFrame = static_cast< const X11SalFrame* >(*it);
+                        const X11SalFrame* pFrame = static_cast< const X11SalFrame* >( pSalFrame );
                         if( ! pFrame->IsFloatGrabWindow()
                             && ( pFrame->GetWindow() == aChild ||
                                  pFrame->GetShellWindow() == aChild ||
diff --git a/vcl/unx/gtk/gtkdata.cxx b/vcl/unx/gtk/gtkdata.cxx
index eaa34d9461e5..da70c0fbd62c 100644
--- a/vcl/unx/gtk/gtkdata.cxx
+++ b/vcl/unx/gtk/gtkdata.cxx
@@ -133,19 +133,17 @@ GdkFilterReturn GtkSalDisplay::filterGdkEvent( GdkXEvent* sys_event )
         // so we need to listen for corresponding property notifications here
         // these should be rare enough so that we can assume that the settings
         // actually change when a corresponding PropertyNotify occurs
-        if( pEvent->type == PropertyNotify &&
-            pEvent->xproperty.atom == getWMAdaptor()->getAtom( WMAdaptor::XSETTINGS ) &&
-            ! m_aFrames.empty()
-           )
+        SalFrame *pAnyFrame = anyFrame();
+        if( pAnyFrame && pEvent->type == PropertyNotify &&
+            pEvent->xproperty.atom == getWMAdaptor()->getAtom( WMAdaptor::XSETTINGS ) )
         {
-            SendInternalEvent( m_aFrames.front(), nullptr, SalEvent::SettingsChanged );
+            PostEvent( pAnyFrame, nullptr, SalEvent::SettingsChanged );
         }
         // let's see if one of our frames wants to swallow these events
         // get the frame
-        for( std::list< SalFrame* >::const_iterator it = m_aFrames.begin();
-                 it != m_aFrames.end(); ++it )
+        for (auto pSalFrame : m_aFrames )
         {
-            GtkSalFrame* pFrame = static_cast<GtkSalFrame*>(*it);
+            GtkSalFrame* pFrame = static_cast<GtkSalFrame*>( pSalFrame );
             if( pFrame->GetSystemData()->aWindow == pEvent->xany.window ||
                 ( pFrame->getForeignParent() && pFrame->getForeignParentWindow() == pEvent->xany.window ) ||
                 ( pFrame->getForeignTopLevel() && pFrame->getForeignTopLevelWindow() == pEvent->xany.window )
@@ -213,11 +211,10 @@ bool GtkSalDisplay::Dispatch( XEvent* pEvent )
     {
         // let's see if one of our frames wants to swallow these events
         // get the child frame
-        for( std::list< SalFrame* >::const_iterator it = m_aFrames.begin();
-             it != m_aFrames.end(); ++it )
+        for (auto pSalFrame : m_aFrames )
         {
-            if ((*it)->GetSystemData()->aWindow == pEvent->xany.window)
-                return static_cast<GtkSalFrame*>(*it)->Dispatch( pEvent );
+            if (pSalFrame->GetSystemData()->aWindow == pEvent->xany.window)
+                return static_cast<GtkSalFrame*>( pSalFrame )->Dispatch( pEvent );
         }
     }
 
@@ -816,47 +813,23 @@ void GtkSalTimer::Stop()
     }
 }
 
-gboolean GtkSalData::userEventFn( gpointer data )
-{
-    gboolean bContinue = FALSE;
-    GtkSalData *pThis = static_cast<GtkSalData *>(data);
-    GenericUnixSalData *pData = GetGenericUnixSalData();
-    SolarMutexGuard aGuard;
-    const SalGenericDisplay *pDisplay = pData->GetDisplay();
-    if (pDisplay)
-    {
-        OSL_ASSERT(static_cast<const SalGenericDisplay *>(pThis->GetGtkDisplay()) == pDisplay);
-        {
-            osl::MutexGuard g (pThis->GetGtkDisplay()->getEventGuardMutex());
-
-            if( !pThis->GetGtkDisplay()->HasUserEvents() )
-            {
-                if( pThis->m_pUserEvent )
-                {
-                    g_source_unref (pThis->m_pUserEvent);
-                    pThis->m_pUserEvent = nullptr;
-                }
-                bContinue = FALSE;
-            }
-            else
-                bContinue = TRUE;
-        }
-        pThis->GetGtkDisplay()->DispatchInternalEvent();
-    }
-
-    return bContinue;
-}
-
 extern "C" {
     static gboolean call_userEventFn( void *data )
     {
+        GtkSalData *pThis = static_cast<GtkSalData *>(data);
         SolarMutexGuard aGuard;
-        return GtkSalData::userEventFn( data );
+        const SalGenericDisplay *pDisplay = GetGenericUnixSalData()->GetDisplay();
+        if ( pDisplay )
+        {
+            GtkSalDisplay *pThisDisplay = pThis->GetGtkDisplay();
+            assert(static_cast<const SalGenericDisplay *>(pThisDisplay) == pDisplay);
+            pThisDisplay->DispatchInternalEvent();
+        }
+        return TRUE;
     }
 }
 
-// hEventGuard_ held during this invocation
-void GtkSalData::PostUserEvent()
+void GtkSalData::TriggerUserEventProcessing()
 {
     if (m_pUserEvent)
         g_main_context_wakeup (nullptr); // really needed ?
@@ -871,16 +844,28 @@ void GtkSalData::PostUserEvent()
     }
 }
 
-void GtkSalDisplay::PostUserEvent()
+void GtkSalData::TriggerAllUserEventsProcessed()
+{
+    assert( m_pUserEvent );
+    g_source_destroy( m_pUserEvent );
+    g_source_unref( m_pUserEvent );
+    m_pUserEvent = nullptr;
+}
+
+void GtkSalDisplay::TriggerUserEventProcessing()
+{
+    GetGtkSalData()->TriggerUserEventProcessing();
+}
+
+void GtkSalDisplay::TriggerAllUserEventsProcessed()
 {
-    GetGtkSalData()->PostUserEvent();
+    GetGtkSalData()->TriggerAllUserEventsProcessed();
 }
 
 GtkWidget* GtkSalDisplay::findGtkWidgetForNativeHandle(sal_uIntPtr hWindow) const
 {
-    for (auto it = m_aFrames.begin(); it != m_aFrames.end(); ++it)
+    for (auto pFrame : m_aFrames)
     {
-        SalFrame* pFrame = *it;
         const SystemEnvData* pEnvData = pFrame->GetSystemData();
         if (pEnvData->aWindow == hWindow)
             return GTK_WIDGET(pEnvData->pWidget);
diff --git a/vcl/unx/gtk/gtksalframe.cxx b/vcl/unx/gtk/gtksalframe.cxx
index 3ca2b4816ad8..0077a056bb53 100644
--- a/vcl/unx/gtk/gtksalframe.cxx
+++ b/vcl/unx/gtk/gtksalframe.cxx
@@ -2180,10 +2180,9 @@ void GtkSalFrame::grabPointer( bool bGrab, bool bOwnerEvents )
     if( bGrab )
     {
         bool bUseGdkGrab = true;
-        const std::list< SalFrame* >& rFrames = getDisplay()->getFrames();
-        for( std::list< SalFrame* >::const_iterator it = rFrames.begin(); it != rFrames.end(); ++it )
+        for (auto pSalFrame : getDisplay()->getFrames() )
         {
-            const GtkSalFrame* pFrame = static_cast< const GtkSalFrame* >(*it);
+            const GtkSalFrame* pFrame = static_cast< const GtkSalFrame* >( pSalFrame );
             if( pFrame->m_bWindowIsGtkPlug )
             {
                 bUseGdkGrab = false;
diff --git a/vcl/unx/gtk3/gtk3gtkdata.cxx b/vcl/unx/gtk3/gtk3gtkdata.cxx
index 844dc77f20c1..fbd449ef4ec6 100644
--- a/vcl/unx/gtk3/gtk3gtkdata.cxx
+++ b/vcl/unx/gtk3/gtk3gtkdata.cxx
@@ -778,47 +778,23 @@ void GtkSalTimer::Stop()
     }
 }
 
-gboolean GtkSalData::userEventFn( gpointer data )
-{
-    gboolean bContinue = FALSE;
-    GtkSalData *pThis = static_cast<GtkSalData *>(data);
-    GenericUnixSalData *pData = GetGenericUnixSalData();
-    SolarMutexGuard aGuard;
-    const SalGenericDisplay *pDisplay = pData->GetDisplay();
-    if (pDisplay)
-    {
-        OSL_ASSERT(static_cast<const SalGenericDisplay *>(pThis->GetGtkDisplay()) == pDisplay);
-        {
-            osl::MutexGuard g (pThis->GetGtkDisplay()->getEventGuardMutex());
-
-            if( !pThis->GetGtkDisplay()->HasUserEvents() )
-            {
-                if( pThis->m_pUserEvent )
-                {
-                    g_source_unref (pThis->m_pUserEvent);
-                    pThis->m_pUserEvent = nullptr;
-                }
-                bContinue = FALSE;
-            }
-            else
-                bContinue = TRUE;
-        }
-        pThis->GetGtkDisplay()->DispatchInternalEvent();
-    }
-
-    return bContinue;
-}
-
 extern "C" {
     static gboolean call_userEventFn( void *data )
     {
+        GtkSalData *pThis = static_cast<GtkSalData *>(data);
         SolarMutexGuard aGuard;
-        return GtkSalData::userEventFn( data );
+        const SalGenericDisplay *pDisplay = GetGenericUnixSalData()->GetDisplay();
+        if ( pDisplay )
+        {
+            GtkSalDisplay *pThisDisplay = pThis->GetGtkDisplay();
+            assert(static_cast<const SalGenericDisplay *>(pThisDisplay) == pDisplay);
+            pThisDisplay->DispatchInternalEvent();
+        }
+        return TRUE;
     }
 }
 
-// hEventGuard_ held during this invocation
-void GtkSalData::PostUserEvent()
+void GtkSalData::TriggerUserEventProcessing()
 {
     if (m_pUserEvent)
         g_main_context_wakeup (nullptr); // really needed ?
@@ -836,17 +812,29 @@ void GtkSalData::PostUserEvent()
     }
 }
 
-void GtkSalDisplay::PostUserEvent()
+void GtkSalData::TriggerAllUserEventsProcessed()
+{
+    assert( m_pUserEvent );
+    g_source_destroy( m_pUserEvent );
+    g_source_unref( m_pUserEvent );
+    m_pUserEvent = nullptr;
+}
+
+void GtkSalDisplay::TriggerUserEventProcessing()
+{
+    GetGtkSalData()->TriggerUserEventProcessing();
+}
+
+void GtkSalDisplay::TriggerAllUserEventsProcessed()
 {
-    GetGtkSalData()->PostUserEvent();
+    GetGtkSalData()->TriggerAllUserEventsProcessed();
 }
 
 GtkWidget* GtkSalDisplay::findGtkWidgetForNativeHandle(sal_uIntPtr hWindow) const
 {
-    for (auto it = m_aFrames.begin(); it != m_aFrames.end(); ++it)
+    for (auto pSalFrame : m_aFrames )
     {
-        SalFrame* pFrame = *it;
-        const SystemEnvData* pEnvData = pFrame->GetSystemData();
+        const SystemEnvData* pEnvData = pSalFrame->GetSystemData();
         if (pEnvData->aWindow == hWindow)
             return GTK_WIDGET(pEnvData->pWidget);
     }
diff --git a/vcl/unx/kde4/KDESalDisplay.cxx b/vcl/unx/kde4/KDESalDisplay.cxx
index 4647b3d111c8..8a2422a3918d 100644
--- a/vcl/unx/kde4/KDESalDisplay.cxx
+++ b/vcl/unx/kde4/KDESalDisplay.cxx
@@ -86,4 +86,9 @@ bool SalKDEDisplay::checkDirectInputEvent( XEvent* ev )
     return false;
 }
 
+void SalKDEDisplay::TriggerUserEventProcessing()
+{
+    static_cast<KDEXLib*>(GetXLib())->TriggerUserEventProcessing();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/unx/kde4/KDESalDisplay.hxx b/vcl/unx/kde4/KDESalDisplay.hxx
index 4a0458dcc5c2..07b5ca3dadf5 100644
--- a/vcl/unx/kde4/KDESalDisplay.hxx
+++ b/vcl/unx/kde4/KDESalDisplay.hxx
@@ -23,15 +23,18 @@
 
 class SalKDEDisplay : public SalX11Display
 {
-    public:
-        explicit SalKDEDisplay( Display* pDisp );
-        virtual ~SalKDEDisplay() override;
-        static SalKDEDisplay* self();
-        virtual void Yield() override;
-        bool checkDirectInputEvent( XEvent* ev );
-    private:
-        Atom xim_protocol;
-        static SalKDEDisplay* selfptr;
+    Atom xim_protocol;
+    static SalKDEDisplay* selfptr;
+
+protected:
+    virtual void TriggerUserEventProcessing() override;
+
+public:
+    explicit SalKDEDisplay( Display* pDisp );
+    virtual ~SalKDEDisplay() override;
+    static SalKDEDisplay* self();
+    virtual void Yield() override;
+    bool checkDirectInputEvent( XEvent* ev );
 };
 
 inline SalKDEDisplay* SalKDEDisplay::self()
diff --git a/vcl/unx/kde4/KDEXLib.cxx b/vcl/unx/kde4/KDEXLib.cxx
index 402461e45bc6..f047ed9fce65 100644
--- a/vcl/unx/kde4/KDEXLib.cxx
+++ b/vcl/unx/kde4/KDEXLib.cxx
@@ -357,10 +357,10 @@ void KDEXLib::Wakeup()
     QAbstractEventDispatcher::instance( qApp->thread())->wakeUp(); // main thread event loop
 }
 
-void KDEXLib::PostUserEvent()
+void KDEXLib::TriggerUserEventProcessing()
 {
     if( !m_isGlibEventLoopType )
-        return SalXLib::PostUserEvent();
+        return SalXLib::TriggerUserEventProcessing();
     QApplication::postEvent(this, new QEvent(QEvent::Type( m_postUserEventId )));
 }
 
diff --git a/vcl/unx/kde4/KDEXLib.hxx b/vcl/unx/kde4/KDEXLib.hxx
index 2fe497d019fa..4c06104b4c59 100644
--- a/vcl/unx/kde4/KDEXLib.hxx
+++ b/vcl/unx/kde4/KDEXLib.hxx
@@ -83,7 +83,7 @@ class KDEXLib : public QObject, public SalXLib
         virtual void StartTimer( sal_uLong nMS ) override;
         virtual void StopTimer() override;
         virtual void Wakeup() override;
-        virtual void PostUserEvent() override;
+        void TriggerUserEventProcessing();
 
         void doStartup();
         bool allowKdeDialogs() { return m_allowKdeDialogs; }