WIN guarantee direct timeout handling

The code did acccount processing of an invaild timeout system
message as a valid timeout event.

Change-Id: I3c31f8b9cec592631b4089411163dadecffde816
Reviewed-on: https://gerrit.libreoffice.org/43529
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

4 files changed, 54 insertions, 18 deletions

diff --git a/vcl/README.scheduler b/vcl/README.scheduler
index 17648ae3b439..80c14b032c54 100644
--- a/vcl/README.scheduler
+++ b/vcl/README.scheduler
@@ -89,6 +89,35 @@ can be added to the scheduler reasonably.
 
 = Implementation details =
 
+== General: event priority for DoYield ==
+
+There are three types of events, with different priority:
+
+1. LO user events
+2. System events
+3. LO Scheduler event
+
+They should be processed according to the following code:
+
+bool DoYield( bool bWait, bool bAllCurrent )
+{
+    bool bWasEvent = ProcessUserEvents( bAllCurrent );
+    if ( !bAllCurrent && bWasEvent )
+        return true;
+    bWasEvent = ProcessSystemEvents( bAllCurrent, &bWasSchedulerEvent ) || bWasEvent;
+    if ( !bWasSchedulerEvent && IsSchedulerEvent() )
+    {
+        ProcessSchedulerEvent()
+        bWasEvent = true;
+    }
+    if ( !bWasEvent && bWait )
+    {
+        WaitForSystemEvents();
+        bWasEvent = true;
+    }
+    return bWasEvent;
+}
+
 == General: main thread deferral ==
 
 Currently for Mac and Windows, we run main thread deferrals by disabling the
diff --git a/vcl/inc/win/saltimer.h b/vcl/inc/win/saltimer.h
index d762b51b6716..b7d1a1e0d0f1 100644
--- a/vcl/inc/win/saltimer.h
+++ b/vcl/inc/win/saltimer.h
@@ -42,9 +42,9 @@ class WinSalTimer final : public SalTimer, protected VersionedEvent
 
     void ImplStart( sal_uIntPtr nMS );
     void ImplStop();
-    void ImplHandleTimerEvent( WPARAM aWPARAM );
+    bool ImplHandleTimerEvent( WPARAM aWPARAM );
     void ImplHandleElapsedTimer();
-    void ImplHandle_WM_TIMER( WPARAM aWPARAM );
+    bool ImplHandle_WM_TIMER( WPARAM aWPARAM );
 
 public:
     WinSalTimer();
diff --git a/vcl/win/app/salinst.cxx b/vcl/win/app/salinst.cxx
index d1fc8adb6272..693411a0583c 100644
--- a/vcl/win/app/salinst.cxx
+++ b/vcl/win/app/salinst.cxx
@@ -459,17 +459,15 @@ void WinSalInstance::AcquireYieldMutex( sal_uInt32 nCount )
     mpSalYieldMutex->acquire( nCount );
 }
 
-static void ImplSalDispatchMessage( MSG* pMsg )
+static LRESULT ImplSalDispatchMessage( MSG* pMsg )
 {
     SalData* pSalData = GetSalData();
-    if ( pSalData->mpFirstObject )
-    {
-        if ( ImplSalPreDispatchMsg( pMsg ) )
-            return;
-    }
+    if ( pSalData->mpFirstObject && ImplSalPreDispatchMsg( pMsg ) )
+        return 0;
     LRESULT lResult = DispatchMessageW( pMsg );
     if ( pSalData->mpFirstObject )
         ImplSalPostDispatchMsg( pMsg, lResult );
+    return lResult;
 }
 
 bool ImplSalYield( bool bWait, bool bHandleAllCurrentEvents )
@@ -491,10 +489,13 @@ bool ImplSalYield( bool bWait, bool bHandleAllCurrentEvents )
         if ( bOneEvent )
         {
             bWasMsg = true;
-            if ( !bWasTimeoutMsg )
-                bWasTimeoutMsg = (SAL_MSG_TIMER_CALLBACK == aMsg.message);
             TranslateMessage( &aMsg );
-            ImplSalDispatchMessage( &aMsg );
+            LRESULT nRet = ImplSalDispatchMessage( &aMsg );
+
+            if ( !bWasTimeoutMsg )
+                bWasTimeoutMsg = (SAL_MSG_TIMER_CALLBACK == aMsg.message)
+                    && static_cast<bool>( nRet );
+
             if ( bHandleAllCurrentEvents
                     && !bHadNewerEvent && aMsg.time > nCurTicks
                     && (nLastTicks <= nCurTicks || aMsg.time < nLastTicks) )
@@ -666,14 +667,16 @@ LRESULT CALLBACK SalComWndProc( HWND, UINT nMsg, WPARAM wParam, LPARAM lParam, i
         {
             WinSalTimer *const pTimer = static_cast<WinSalTimer*>( ImplGetSVData()->maSchedCtx.mpSalTimer );
             assert( pTimer != nullptr );
-            pTimer->ImplHandleTimerEvent( wParam );
+            nRet = static_cast<LRESULT>( pTimer->ImplHandleTimerEvent( wParam ) );
+            rDef = FALSE;
             break;
         }
         case WM_TIMER:
         {
             WinSalTimer *const pTimer = static_cast<WinSalTimer*>( ImplGetSVData()->maSchedCtx.mpSalTimer );
             assert( pTimer != nullptr );
-            pTimer->ImplHandle_WM_TIMER( wParam );
+            nRet = static_cast<LRESULT>( pTimer->ImplHandle_WM_TIMER( wParam ) );
+            rDef = FALSE;
             break;
         }
     }
diff --git a/vcl/win/app/saltimer.cxx b/vcl/win/app/saltimer.cxx
index 9d20c70bdb5a..9c67e841956e 100644
--- a/vcl/win/app/saltimer.cxx
+++ b/vcl/win/app/saltimer.cxx
@@ -158,13 +158,14 @@ void WinSalTimer::ImplHandleElapsedTimer()
     ImplSalYieldMutexRelease();
 }
 
-void WinSalTimer::ImplHandleTimerEvent( const WPARAM aWPARAM )
+bool WinSalTimer::ImplHandleTimerEvent( const WPARAM aWPARAM )
 {
     assert( aWPARAM <= SAL_MAX_INT32 );
     if ( !IsValidEventVersion( static_cast<sal_Int32>( aWPARAM ) ) )
-        return;
+        return false;
 
     ImplHandleElapsedTimer();
+    return true;
 }
 
 void WinSalTimer::SetForceRealTimer( const bool bVal )
@@ -179,11 +180,14 @@ void WinSalTimer::SetForceRealTimer( const bool bVal )
         Start( 0 );
 }
 
-void WinSalTimer::ImplHandle_WM_TIMER( const WPARAM aWPARAM )
+bool WinSalTimer::ImplHandle_WM_TIMER( const WPARAM aWPARAM )
 {
     assert( m_aWmTimerId == aWPARAM );
-    if ( m_aWmTimerId == aWPARAM && m_bDirectTimeout && m_bForceRealTimer )
-        ImplHandleElapsedTimer();
+    if ( !(m_aWmTimerId == aWPARAM && m_bDirectTimeout && m_bForceRealTimer) )
+        return false;
+
+    ImplHandleElapsedTimer();
+    return true;
 }
 
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