Merge pull request #46049 from mhugent/ogr_shared_ds_multithreading

Fix locking of ogr datasource in case the datasource is shared (trans…
qgis · Nov 18, 2021 · 345dbd6 · 345dbd6
2 parents 2bc3f51 + a1be5a9
commit 345dbd6
Showing 1 changed file with 10 additions and 7 deletions.
diff --git a/src/core/providers/ogr/qgsogrfeatureiterator.cpp b/src/core/providers/ogr/qgsogrfeatureiterator.cpp
@@ -53,6 +53,11 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrFeatureSource *source, bool
   , mSymbolType( QgsSymbol::symbolTypeForGeometryType( QgsWkbTypes::geometryType( source->mWkbType ) ) )
 {
 
+  if ( mSharedDS )
+  {
+    mSharedDS->mutex().lock();
+  }
+
   /* When inside a transaction for GPKG/SQLite and fetching fid(s) we might be nested inside an outer fetching loop,
    * (see GH #39178) so we need to skip all calls that might reset the reading (rewind) to avoid an endless loop in the
    * outer fetching iterator that uses the same connection.
@@ -124,7 +129,6 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrFeatureSource *source, bool
       }
     }
   }
-  QMutexLocker locker( mSharedDS ? &mSharedDS->mutex() : nullptr );
 
   if ( mRequest.destinationCrs().isValid() && mRequest.destinationCrs() != mSource->mCrs )
   {
@@ -372,8 +376,6 @@ void QgsOgrFeatureIterator::setInterruptionChecker( QgsFeedback *interruptionChe
 
 bool QgsOgrFeatureIterator::fetchFeature( QgsFeature &feature )
 {
-  QMutexLocker locker( mSharedDS ? &mSharedDS->mutex() : nullptr );
-
   QgsCPLHTTPFetchOverrider oCPLHTTPFetcher( mAuthCfg, mInterruptionChecker );
   QgsSetCPLHTTPFetchOverriderInitiatorClass( oCPLHTTPFetcher, QStringLiteral( "QgsOgrFeatureIterator" ) )
 
@@ -469,8 +471,6 @@ void QgsOgrFeatureIterator::resetReading()
 
 bool QgsOgrFeatureIterator::rewind()
 {
-  QMutexLocker locker( mSharedDS ? &mSharedDS->mutex() : nullptr );
-
   if ( mClosed || !mOgrLayer )
     return false;
 
@@ -487,10 +487,10 @@ bool QgsOgrFeatureIterator::close()
   if ( mSharedDS )
   {
     iteratorClosed();
-
     mOgrLayer = nullptr;
-    mSharedDS.reset();
     mClosed = true;
+    mSharedDS->mutex().unlock();
+    mSharedDS.reset();
     return true;
   }
 
@@ -525,6 +525,9 @@ bool QgsOgrFeatureIterator::close()
   mOgrLayer = nullptr;
 
   mClosed = true;
+
+
+
   return true;
 }