Always schedule with the same time

No need to always update the time - scheduling should be fast!

Change-Id: Ic4c01f5a5759ef4970f1385aab6ef93cd67f33b6

4 files changed, 21 insertions, 26 deletions

diff --git a/vcl/inc/saltimer.hxx b/vcl/inc/saltimer.hxx
index 9a71eace286f..72b1eb8e14fa 100644
--- a/vcl/inc/saltimer.hxx
+++ b/vcl/inc/saltimer.hxx
@@ -70,7 +70,7 @@ struct ImplSchedulerData
     void Invoke();
 
     const char *GetDebugName() const;
-    static ImplSchedulerData *GetMostImportantTask( bool bTimer );
+    static ImplSchedulerData *GetMostImportantTask( bool bTimerOnly, sal_uInt64 nTimeNow );
 };
 
 #endif // INCLUDED_VCL_INC_SALTIMER_HXX
diff --git a/vcl/source/app/idle.cxx b/vcl/source/app/idle.cxx
index 10a7a495a92f..faf499ed440b 100644
--- a/vcl/source/app/idle.cxx
+++ b/vcl/source/app/idle.cxx
@@ -74,7 +74,7 @@ bool Idle::IsIdle() const
     return true;
 }
 
-sal_uInt64 Idle::UpdateMinPeriod( sal_uInt64 /* nMinPeriod */, sal_uInt64 /* nTime */ ) const
+sal_uInt64 Idle::UpdateMinPeriod( sal_uInt64 /* nMinPeriod */, sal_uInt64 /* nTimeNow */ ) const
 {
     assert(false); // idles currently don't hit this.
     return ImmediateTimeoutMs;
diff --git a/vcl/source/app/scheduler.cxx b/vcl/source/app/scheduler.cxx
index c9aa2b1b3c2d..cc4e14ac4a1d 100644
--- a/vcl/source/app/scheduler.cxx
+++ b/vcl/source/app/scheduler.cxx
@@ -49,12 +49,11 @@ void ImplSchedulerData::Invoke()
     mbInScheduler = false;
 }
 
-ImplSchedulerData *ImplSchedulerData::GetMostImportantTask( bool bTimerOnly )
+ImplSchedulerData *ImplSchedulerData::GetMostImportantTask( bool bTimerOnly, sal_uInt64 nTimeNow )
 {
     ImplSVData*     pSVData = ImplGetSVData();
     ImplSchedulerData *pMostUrgent = nullptr;
 
-    sal_uInt64 nTimeNow = tools::Time::GetSystemTicks();
     for ( ImplSchedulerData *pSchedulerData = pSVData->mpFirstSchedulerData; pSchedulerData; pSchedulerData = pSchedulerData->mpNext )
     {
         if ( !pSchedulerData->mpScheduler || pSchedulerData->mbDelete || pSchedulerData->mbInScheduler ||
@@ -173,13 +172,16 @@ void Scheduler::CallbackTaskScheduling(bool)
 
 bool Scheduler::ProcessTaskScheduling( bool bTimerOnly )
 {
+    ImplSchedulerData* pSchedulerData;
+    sal_uInt64         nTime = tools::Time::GetSystemTicks();
+
     DBG_TESTSOLARMUTEX();
 
-    if (ImplSchedulerData * pSchedulerData = ImplSchedulerData::GetMostImportantTask(bTimerOnly))
+    if ((pSchedulerData = ImplSchedulerData::GetMostImportantTask(bTimerOnly, nTime)))
     {
         SAL_INFO("vcl.schedule", "Invoke task " << pSchedulerData->GetDebugName());
 
-        pSchedulerData->mnUpdateTime = tools::Time::GetSystemTicks();
+        pSchedulerData->mnUpdateTime = nTime;
         pSchedulerData->Invoke();
         return true;
     }
@@ -243,6 +245,13 @@ sal_uInt64 Scheduler::CalculateMinimumTimeout( bool &bHasActiveIdles )
                              pSchedulerData->GetDebugName() <<
                              "' update min period from " << nOldMinPeriod <<
                              " to " << nMinPeriod);
+                    assert( nMinPeriod <= nOldMinPeriod );
+                    if ( nMinPeriod > nOldMinPeriod )
+                    {
+                        nMinPeriod = nOldMinPeriod;
+                        SAL_WARN("vcl.schedule",
+                             "New update min period > old period - using old");
+                    }
                 }
                 else
                 {
diff --git a/vcl/source/app/timer.cxx b/vcl/source/app/timer.cxx
index accd92734746..aabfbb28a211 100644
--- a/vcl/source/app/timer.cxx
+++ b/vcl/source/app/timer.cxx
@@ -41,30 +41,16 @@ bool Timer::IsIdle() const
     return false;
 }
 
-sal_uInt64 Timer::UpdateMinPeriod( sal_uInt64 nMinPeriod, sal_uInt64 nTime ) const
+sal_uInt64 Timer::UpdateMinPeriod( sal_uInt64 nMinPeriod, sal_uInt64 nTimeNow ) const
 {
-    sal_uInt64 nDeltaTime;
-    //determine smallest time slot
-    if( mpSchedulerData->mnUpdateTime == nTime )
-    {
-       nDeltaTime = mnTimeout;
-       if( nDeltaTime < nMinPeriod )
-           nMinPeriod = nDeltaTime;
-    }
+    sal_uInt64 nWakeupTime = mpSchedulerData->mnUpdateTime + mnTimeout;
+    if( nWakeupTime <= nTimeNow )
+        return ImmediateTimeoutMs;
     else
     {
-        nDeltaTime = mpSchedulerData->mnUpdateTime + mnTimeout;
-        if( nDeltaTime < nTime )
-            nMinPeriod = ImmediateTimeoutMs;
-        else
-        {
-            nDeltaTime -= nTime;
-            if( nDeltaTime < nMinPeriod )
-                nMinPeriod = nDeltaTime;
-        }
+        sal_uInt64 nSleepTime = nWakeupTime - nTimeNow;
+        return ( nSleepTime < nMinPeriod ) ? nSleepTime : nMinPeriod;
     }
-
-    return nMinPeriod;
 }
 
 Timer::Timer(const sal_Char *pDebugName) :