prevent concurrent access while creating iterators and updating cache…

… info (#3224) #mutexmania kudos to @m-kuhn
qgis · Jun 21, 2016 · 7eacd44 · 7eacd44
1 parent b443627
commit 7eacd44
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Showing 4 changed files with 9 additions and 0 deletions.
diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -2211,6 +2211,8 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
 
     QgsAttributeTableConfig mAttributeTableConfig;
 
+    QMutex mFeatureSourceConstructorMutex;
+
     friend class QgsVectorLayerFeatureSource;
 };
 

diff --git a/src/core/qgsvectorlayerfeatureiterator.cpp b/src/core/qgsvectorlayerfeatureiterator.cpp
@@ -29,6 +29,7 @@
 QgsVectorLayerFeatureSource::QgsVectorLayerFeatureSource( QgsVectorLayer *layer )
     : mCrsId( 0 )
 {
+  QMutexLocker locker( &layer->mFeatureSourceConstructorMutex );
   mProviderFeatureSource = layer->dataProvider()->featureSource();
   mFields = layer->fields();
 

diff --git a/src/core/qgsvectorlayerjoinbuffer.cpp b/src/core/qgsvectorlayerjoinbuffer.cpp
@@ -62,6 +62,7 @@ static bool _hasCycleDFS( QgsVectorLayer* n, QHash<QgsVectorLayer*, int>& mark )
 
 bool QgsVectorLayerJoinBuffer::addJoin( const QgsVectorJoinInfo& joinInfo )
 {
+  QMutexLocker locker( &mMutex );
   mVectorJoins.push_back( joinInfo );
 
   // run depth-first search to detect cycles in the graph of joins between layers.
@@ -97,6 +98,7 @@ bool QgsVectorLayerJoinBuffer::addJoin( const QgsVectorJoinInfo& joinInfo )
 
 bool QgsVectorLayerJoinBuffer::removeJoin( const QString& joinLayerId )
 {
+  QMutexLocker locker( &mMutex );
   bool res = false;
   for ( int i = 0; i < mVectorJoins.size(); ++i )
   {
@@ -259,6 +261,7 @@ void QgsVectorLayerJoinBuffer::updateFields( QgsFields& fields )
 
 void QgsVectorLayerJoinBuffer::createJoinCaches()
 {
+  QMutexLocker locker( &mMutex );
   QList< QgsVectorJoinInfo >::iterator joinIt = mVectorJoins.begin();
   for ( ; joinIt != mVectorJoins.end(); ++joinIt )
   {

diff --git a/src/core/qgsvectorlayerjoinbuffer.h b/src/core/qgsvectorlayerjoinbuffer.h
@@ -101,6 +101,9 @@ class CORE_EXPORT QgsVectorLayerJoinBuffer : public QObject
 
     /** Caches attributes of join layer in memory if QgsVectorJoinInfo.memoryCache is true (and the cache is not already there)*/
     void cacheJoinLayer( QgsVectorJoinInfo& joinInfo );
+
+    /** Main mutex to protect most data members that can be modified concurrently */
+    QMutex mMutex;
 };
 
 #endif // QGSVECTORLAYERJOINBUFFER_H