tdf#111994 WIN workaround PostMessage delays

Fixes the "Multiple timers in queue" assertion by effectively
removing it.

When debugging it became obvious, that PostMessage returns, even
if the message was not yet added to the message queue.

The assert happens, because we start the timer in the Scheduler
before Invoke(), so it fires, if we block in Invoke(), and then
reset the timer after Invoke, if there were changes to the Task
list.

In this case it fires during Invoke(), the message is added. We
restart the timer, first by stopping it (we wait in
DeleteTimerQueueTimer, to be sure the timer function has either
finished or was not run). And the try to remove the message with
PeekMessageW, which doesn't remove the posted message.

Then the timer is restarted, and when the event is processed, we
end up with an additional timer event, which was asserted.

As a fix this adds a (microsecond) timestamp to the timer message,
which is validated in the WinProc function. So if we stop the
timer too fast, the event is ignored based on the timestamp.

And while at it, the patch moves timer related variables from
SalData into WinSalTimer.

Change-Id: Ib840a421e8bd040d40f39473e1d44491e5b332bd
Reviewed-on: https://gerrit.libreoffice.org/42575
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

2 files changed, 26 insertions, 7 deletions

diff --git a/vcl/inc/win/saldata.hxx b/vcl/inc/win/saldata.hxx
index bc5b9c5db1eb..245d986915b1 100644
--- a/vcl/inc/win/saldata.hxx
+++ b/vcl/inc/win/saldata.hxx
@@ -84,8 +84,6 @@ public:
     long*                   mpDitherDiff;           // Dither mapping table
     BYTE*                   mpDitherLow;            // Dither mapping table
     BYTE*                   mpDitherHigh;           // Dither mapping table
-    HANDLE                  mnTimerId;              ///< Windows timer id
-    bool                    mbOnIdleRunScheduler;   ///< Run yield until the scheduler processed the idle
     HHOOK                   mhSalObjMsgHook;        // hook to get interesting msg for SalObject
     HWND                    mhWantLeaveMsg;         // window handle, that want a MOUSELEAVE message
     AutoTimer*              mpMouseLeaveTimer;      // Timer for MouseLeave Test
@@ -178,8 +176,6 @@ void ImplSalYieldMutexRelease();
 
 LRESULT CALLBACK SalFrameWndProcW( HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam );
 
-void EmitTimerCallback();
-
 void SalTestMouseLeave();
 
 bool ImplHandleSalObjKeyMsg( HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam );
diff --git a/vcl/inc/win/saltimer.h b/vcl/inc/win/saltimer.h
index 084a25745b87..9107dd1a0b19 100644
--- a/vcl/inc/win/saltimer.h
+++ b/vcl/inc/win/saltimer.h
@@ -24,16 +24,39 @@
 
 class WinSalTimer : public SalTimer
 {
+    HANDLE       m_nTimerId;          ///< Windows timer id
+    sal_uInt32   m_nTimerStartTicks;  ///< system ticks at timer start % SAL_MAX_UINT32
+    bool         m_bPollForMessage;   ///< Run yield until a message is caught (most likely the 0ms timer)
+
 public:
-    WinSalTimer() {}
+    WinSalTimer();
     virtual ~WinSalTimer() override;
 
     virtual void Start(sal_uIntPtr nMS) override;
     virtual void Stop() override;
+
+    inline bool IsValidWPARAM( WPARAM wParam ) const;
+
+    inline bool PollForMessage() const;
+
+    // The Impl functions are just public to be called from the static
+    // SalComWndProc on main thread redirect! Otherwise they would be private.
+    // They must be called from the main application thread only!
+
+    void ImplStart( sal_uIntPtr nMS );
+    void ImplStop();
+    void ImplEmitTimerCallback();
 };
 
-void ImplSalStartTimer( sal_uIntPtr nMS );
-void ImplSalStopTimer();
+inline bool WinSalTimer::IsValidWPARAM( WPARAM aWPARAM ) const
+{
+    return aWPARAM == m_nTimerStartTicks;
+}
+
+inline bool WinSalTimer::PollForMessage() const
+{
+    return m_bPollForMessage;
+}
 
 #endif