Speedup destruction of sheets with too many listeners & broadcasters.

Listeners and broadcasters are M:N relationship.  If you want to
destruct them, you easily end up in O(M*N) situation; where for every
listener, you iterate all broadcasters, to remove that one listener.

To avoid that, announce to the broadcasters that they are going to die, and the
listeners do not have to bother with removing themselves from the broadcaster.
The broadcaster will not broadcast anything after the PrepareForDesctruction()
call anyway.

Change-Id: I68d78b23e73bcbb944de9139448b2c20dfa14f62

include/svl/broadcast.hxx

@@ -60,8 +60,21 @@ public:
 
     bool HasListeners() const;
 
+    /**
+     * Listeners and broadcasters are M:N relationship.  If you want to
+     * destruct them, you easily end up in O(M*N) situation; where for every
+     * listener, you iterate all broadcasters, to remove that one listener.
+     *
+     * To avoid that, use this call to announce to the broadcaster it is going
+     * to die, and the listeners do not have to bother with removing
+     * themselves from the broadcaster - the broadcaster will not broadcast
+     * anything after the PrepareForDesctruction() call anyway.
+     */
+    void PrepareForDestruction() { mbAboutToDie = true; }
+
 private:
     ListenersType maListeners;
+    bool mbAboutToDie:1;
     bool mbDisposing:1;
     bool mbNormalized:1;
 };

sc/inc/column.hxx

@@ -491,6 +491,7 @@ public:
     SvtBroadcaster* GetBroadcaster( SCROW nRow );
     const SvtBroadcaster* GetBroadcaster( SCROW nRow ) const;
     void DeleteBroadcasters( sc::ColumnBlockPosition& rBlockPos, SCROW nRow1, SCROW nRow2 );
+    void PrepareBroadcastersForDestruction();
     bool HasBroadcaster() const;
 
     void Broadcast( SCROW nRow );

sc/source/core/data/column2.cxx

@@ -1962,6 +1962,21 @@ void ScColumn::DeleteBroadcasters( sc::ColumnBlockPosition& rBlockPos, SCROW nRo
         maBroadcasters.set_empty(rBlockPos.miBroadcasterPos, nRow1, nRow2);
 }
 
+void ScColumn::PrepareBroadcastersForDestruction()
+{
+    sc::BroadcasterStoreType::iterator itPos = maBroadcasters.begin(), itPosEnd = maBroadcasters.end();
+    for (; itPos != itPosEnd; ++itPos)
+    {
+        if (itPos->type == sc::element_type_broadcaster)
+        {
+            sc::broadcaster_block::iterator it = sc::broadcaster_block::begin(*itPos->data);
+            sc::broadcaster_block::iterator itEnd = sc::broadcaster_block::end(*itPos->data);
+            for (; it != itEnd; ++it)
+                (*it)->PrepareForDestruction();
+        }
+    }
+}
+
 bool ScColumn::HasBroadcaster() const
 {
     sc::BroadcasterStoreType::const_iterator it = maBroadcasters.begin(), itEnd = maBroadcasters.end();

sc/source/core/data/table1.cxx

@@ -341,6 +341,9 @@ ScTable::~ScTable()
     delete mpRangeName;
     delete pDBDataNoName;
     DestroySortCollator();
+
+    for (SCCOL k=0; k<=MAXCOL; k++)
+        aCol[k].PrepareBroadcastersForDestruction();
 }
 
 void ScTable::GetName( OUString& rName ) const

svl/source/notify/broadcast.cxx

@@ -81,7 +81,7 @@ void SvtBroadcaster::Add( SvtListener* p )
 
 void SvtBroadcaster::Remove( SvtListener* p )
 {
-    if (mbDisposing)
+    if (mbAboutToDie || mbDisposing)
         return;
 
     Normalize();
@@ -94,10 +94,10 @@ void SvtBroadcaster::Remove( SvtListener* p )
         ListenersGone();
 }
 
-SvtBroadcaster::SvtBroadcaster() : mbDisposing(false), mbNormalized(false) {}
+SvtBroadcaster::SvtBroadcaster() : mbAboutToDie(false), mbDisposing(false), mbNormalized(false) {}
 
 SvtBroadcaster::SvtBroadcaster( const SvtBroadcaster &rBC ) :
-    maListeners(rBC.maListeners), mbDisposing(false), mbNormalized(rBC.mbNormalized)
+    maListeners(rBC.maListeners), mbAboutToDie(false), mbDisposing(false), mbNormalized(rBC.mbNormalized)
 {
     std::for_each(maListeners.begin(), maListeners.end(), StartListeningHandler(*this));
 }
@@ -113,6 +113,9 @@ SvtBroadcaster::~SvtBroadcaster()
 
 void SvtBroadcaster::Broadcast( const SfxHint &rHint )
 {
+    if (mbAboutToDie)
+        return;
+
     Normalize();
     ListenersType listeners(maListeners);
     std::for_each(listeners.begin(), listeners.end(), NotifyHandler(*this, rHint));