GTK+ simplifiy system timer implementation

Instead of implementing an own GSource, this implements the glib
based system timer using the g_timeout_source_new() function.

It removes the vector of GtkSalTimer and changes the remaining
timer to be single-shot, just like the Windows and KDE platforms.

The ownership handling is a little bit strange and should generally
be changed to use std::shared_ptr as the result of CreateSalTimer
for all backends.

Change-Id: Iea40a6284bdc5c121235af5a6079a92a679391ca

2 files changed, 38 insertions, 135 deletions

diff --git a/vcl/unx/gtk/gtkdata.cxx b/vcl/unx/gtk/gtkdata.cxx
index e5278f157698..76c9fed0e733 100644
--- a/vcl/unx/gtk/gtkdata.cxx
+++ b/vcl/unx/gtk/gtkdata.cxx
@@ -652,161 +652,71 @@ bool GtkData::ErrorTrapPop( bool bIgnoreError )
     return gdk_error_trap_pop () != 0;
 }
 
-extern "C" {
-
-    struct SalGtkTimeoutSource {
-        GSource      aParent;
-        GTimeVal     aFireTime;
-        GtkSalTimer *pInstance;
-    };
-
-    static void sal_gtk_timeout_defer( SalGtkTimeoutSource *pTSource )
-    {
-        g_get_current_time( &pTSource->aFireTime );
-        g_time_val_add( &pTSource->aFireTime, pTSource->pInstance->m_nTimeoutMS * 1000 );
-    }
-
-    static gboolean sal_gtk_timeout_expired( SalGtkTimeoutSource *pTSource,
-                                             gint *nTimeoutMS, GTimeVal *pTimeNow )
-    {
-        glong nDeltaSec = pTSource->aFireTime.tv_sec - pTimeNow->tv_sec;
-        glong nDeltaUSec = pTSource->aFireTime.tv_usec - pTimeNow->tv_usec;
-        if( nDeltaSec < 0 || ( nDeltaSec == 0 && nDeltaUSec < 0) )
-        {
-            *nTimeoutMS = 0;
-            return TRUE;
-        }
-        if( nDeltaUSec < 0 )
-        {
-            nDeltaUSec += 1000000;
-            nDeltaSec -= 1;
-        }
-        // if the clock changes backwards we need to cope ...
-        if( (unsigned long) nDeltaSec > 1 + ( pTSource->pInstance->m_nTimeoutMS / 1000 ) )
-        {
-            sal_gtk_timeout_defer( pTSource );
-            return TRUE;
-        }
-
-        *nTimeoutMS = MIN( G_MAXINT, ( nDeltaSec * 1000 + (nDeltaUSec + 999) / 1000 ) );
-
-        return *nTimeoutMS == 0;
-    }
-
-    static gboolean sal_gtk_timeout_prepare( GSource *pSource, gint *nTimeoutMS )
-    {
-        SalGtkTimeoutSource *pTSource = reinterpret_cast<SalGtkTimeoutSource *>(pSource);
-
-        GTimeVal aTimeNow;
-        g_get_current_time( &aTimeNow );
-
-        return sal_gtk_timeout_expired( pTSource, nTimeoutMS, &aTimeNow );
-    }
-
-    static gboolean sal_gtk_timeout_check( GSource *pSource )
-    {
-        SalGtkTimeoutSource *pTSource = reinterpret_cast<SalGtkTimeoutSource *>(pSource);
-
-        GTimeVal aTimeNow;
-        g_get_current_time( &aTimeNow );
-
-        return ( pTSource->aFireTime.tv_sec < aTimeNow.tv_sec ||
-                 ( pTSource->aFireTime.tv_sec == aTimeNow.tv_sec &&
-                   pTSource->aFireTime.tv_usec < aTimeNow.tv_usec ) );
-    }
+#if !GLIB_CHECK_VERSION(2,32,0)
+#define G_SOURCE_REMOVE FALSE
+#endif
 
-    static gboolean sal_gtk_timeout_dispatch( GSource *pSource, GSourceFunc, gpointer )
+extern "C" {
+    static gboolean sal_gtk_timeout_function( gpointer )
     {
-        SalGtkTimeoutSource *pTSource = reinterpret_cast<SalGtkTimeoutSource *>(pSource);
-
-        if( !pTSource->pInstance )
-            return FALSE;
-
         GtkData *pSalData = static_cast< GtkData* >( GetSalData());
-
         osl::Guard< comphelper::SolarMutex > aGuard( pSalData->m_pInstance->GetYieldMutex() );
 
-        sal_gtk_timeout_defer( pTSource );
-
         ImplSVData* pSVData = ImplGetSVData();
         if( pSVData->maSchedCtx.mpSalTimer )
             pSVData->maSchedCtx.mpSalTimer->CallCallback();
-
-        return TRUE;
+        return G_SOURCE_REMOVE;
     }
-
-    static GSourceFuncs sal_gtk_timeout_funcs =
-    {
-        sal_gtk_timeout_prepare,
-        sal_gtk_timeout_check,
-        sal_gtk_timeout_dispatch,
-        nullptr, nullptr, nullptr
-    };
-}
-
-static SalGtkTimeoutSource *
-create_sal_gtk_timeout( GtkSalTimer *pTimer )
-{
-  GSource *pSource = g_source_new( &sal_gtk_timeout_funcs, sizeof( SalGtkTimeoutSource ) );
-  SalGtkTimeoutSource *pTSource = reinterpret_cast<SalGtkTimeoutSource *>(pSource);
-  pTSource->pInstance = pTimer;
-
-  // #i36226# timers should be executed with lower priority
-  // than XEvents like in generic plugin
-  g_source_set_priority( pSource, G_PRIORITY_LOW );
-  g_source_set_can_recurse( pSource, TRUE );
-  g_source_set_callback( pSource,
-                         /* unused dummy */ g_idle_remove_by_data,
-                         nullptr, nullptr );
-  g_source_attach( pSource, g_main_context_default() );
-#ifdef DBG_UTIL
-  g_source_set_name( pSource, "VCL timeout source" );
-#endif
-
-  sal_gtk_timeout_defer( pTSource );
-
-  return pTSource;
 }
 
 GtkSalTimer::GtkSalTimer()
     : m_pTimeout(nullptr)
-    , m_nTimeoutMS(0)
 {
 }
 
 GtkSalTimer::~GtkSalTimer()
 {
     GtkInstance *pInstance = static_cast<GtkInstance *>(GetSalData()->m_pInstance);
-    pInstance->RemoveTimer( this );
+    pInstance->RemoveTimer();
     Stop();
 }
 
 bool GtkSalTimer::Expired()
 {
-    if( !m_pTimeout )
+    if( !m_pTimeout || g_source_is_destroyed( m_pTimeout ) )
         return false;
-
-    gint nDummy = 0;
-    GTimeVal aTimeNow;
-    g_get_current_time( &aTimeNow );
-    return !!sal_gtk_timeout_expired( m_pTimeout, &nDummy, &aTimeNow);
+    return (g_get_monotonic_time() > g_source_get_ready_time( m_pTimeout ));
 }
 
 void GtkSalTimer::Start( sal_uLong nMS )
 {
     // glib is not 64bit safe in this regard.
-    assert( nMS <= G_MAXINT );
-    m_nTimeoutMS = nMS; // for restarting
-    Stop(); // FIXME: ideally re-use an existing m_pTimeout
-    m_pTimeout = create_sal_gtk_timeout( this );
+    if ( nMS > G_MAXINT )
+        nMS = G_MAXINT;
+
+    Stop();
+    assert( nullptr == m_pTimeout );
+
+    m_pTimeout = g_timeout_source_new ( nMS );
+    // #i36226# timers should be executed with lower priority
+    // than XEvents like in generic plugin
+    g_source_set_priority( m_pTimeout, G_PRIORITY_LOW );
+    g_source_set_can_recurse( m_pTimeout, TRUE );
+    g_source_set_callback( m_pTimeout,
+                           sal_gtk_timeout_function,
+                           this, nullptr );
+    g_source_attach( m_pTimeout, g_main_context_default() );
+#ifdef DBG_UTIL
+    g_source_set_name( m_pTimeout, "VCL timeout source" );
+#endif
 }
 
 void GtkSalTimer::Stop()
 {
     if( m_pTimeout )
     {
-        g_source_destroy( &m_pTimeout->aParent );
-        g_source_unref( &m_pTimeout->aParent );
+        g_source_destroy( m_pTimeout );
+        g_source_unref( m_pTimeout );
         m_pTimeout = nullptr;
     }
 }
diff --git a/vcl/unx/gtk/gtkinst.cxx b/vcl/unx/gtk/gtkinst.cxx
index 034b634a0f79..caaa2af2499f 100644
--- a/vcl/unx/gtk/gtkinst.cxx
+++ b/vcl/unx/gtk/gtkinst.cxx
@@ -156,6 +156,7 @@ GtkInstance::GtkInstance( SalYieldMutex* pMutex )
 #else
     : X11SalInstance( pMutex )
 #endif
+    , m_pTimer(nullptr)
     , bNeedsInit(true)
     , m_pLastCairoFontOptions(nullptr)
 {
@@ -194,8 +195,7 @@ void GtkInstance::EnsureInit()
 
 GtkInstance::~GtkInstance()
 {
-    while( !m_aTimers.empty() )
-        delete *m_aTimers.begin();
+    assert( nullptr == m_pTimer );
     DeInitAtkBridge();
     ResetLastSeenCairoFontOptions();
 }
@@ -397,18 +397,16 @@ void         GtkInstance::DestroyMenuItem( SalMenuItem* )        {}
 SalTimer* GtkInstance::CreateSalTimer()
 {
     EnsureInit();
-    GtkSalTimer *pTimer = new GtkSalTimer();
-    m_aTimers.push_back( pTimer );
-    return pTimer;
+    assert( nullptr == m_pTimer );
+    if ( nullptr == m_pTimer )
+        m_pTimer = new GtkSalTimer();
+    return m_pTimer;
 }
 
-void GtkInstance::RemoveTimer (SalTimer *pTimer)
+void GtkInstance::RemoveTimer()
 {
     EnsureInit();
-    std::vector<GtkSalTimer *>::iterator it;
-    it = std::find( m_aTimers.begin(), m_aTimers.end(), pTimer );
-    if( it != m_aTimers.end() )
-        m_aTimers.erase( it );
+    m_pTimer = nullptr;
 }
 
 bool GtkInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents, sal_uLong const nReleased)
@@ -422,12 +420,7 @@ bool GtkInstance::DoYield(bool bWait, bool bHandleAllCurrentEvents, sal_uLong co
 bool GtkInstance::IsTimerExpired()
 {
     EnsureInit();
-    for( std::vector<GtkSalTimer *>::iterator it = m_aTimers.begin();
-         it != m_aTimers.end(); ++it )
-        if( (*it)->Expired() )
-            return true;
-
-    return false;
+    return (m_pTimer && m_pTimer->Expired());
 }
 
 bool GtkInstance::AnyInput( VclInputFlags nType )