Fix GPX provider is not thread safe!

qgis · Jul 30, 2021 · aa68824 · aa68824
1 parent 531428d
commit aa68824
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Showing 2 changed files with 32 additions and 13 deletions.
diff --git a/src/providers/gpx/gpsdata.cpp b/src/providers/gpx/gpsdata.cpp
@@ -24,6 +24,7 @@
 #include <QTextStream>
 #include <QObject>
 #include <QSet>
+#include <QMutexLocker>
 
 #include "gpsdata.h"
 #include "qgslogger.h"
@@ -140,6 +141,19 @@ void QgsTrack::writeXml( QTextStream &stream )
 }
 
 
+//
+// QgsGpsData
+//
+
+QgsGpsData::DataMap QgsGpsData::sDataObjects;
+
+
+#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
+QMutex QgsGpsData::sDataObjectsMutex { QMutex::Recursive };
+#else
+QRecursiveMutex QgsGpsData::sDataObjectsMutex;
+#endif
+
 QgsGpsData::QgsGpsData()
 {
   xMin = std::numeric_limits<double>::max();
@@ -369,7 +383,9 @@ void QgsGpsData::writeXml( QTextStream &stream )
 QgsGpsData *QgsGpsData::getData( const QString &fileName )
 {
   // if the data isn't there already, try to load it
-  if ( dataObjects.find( fileName ) == dataObjects.end() )
+  QMutexLocker lock( &sDataObjectsMutex );
+
+  if ( sDataObjects.find( fileName ) == sDataObjects.end() )
   {
     QFile file( fileName );
     if ( !file.open( QIODevice::ReadOnly ) )
@@ -411,45 +427,40 @@ QgsGpsData *QgsGpsData::getData( const QString &fileName )
 
     data->setNoDataExtent();
 
-    dataObjects[fileName] = qMakePair( data, 0 );
+    sDataObjects[fileName] = qMakePair( data, 0 );
   }
   else
   {
     QgsDebugMsg( fileName + " is already loaded" );
   }
 
   // return a pointer and increase the reference count for that file name
-  DataMap::iterator iter = dataObjects.find( fileName );
+  DataMap::iterator iter = sDataObjects.find( fileName );
   ++( iter.value().second );
   return ( QgsGpsData * )( iter.value().first );
 }
 
 
 void QgsGpsData::releaseData( const QString &fileName )
 {
+  QMutexLocker lock( &sDataObjectsMutex );
 
   /* decrease the reference count for the file name (if it is used), and erase
      it if the reference count becomes 0 */
-  DataMap::iterator iter = dataObjects.find( fileName );
-  if ( iter != dataObjects.end() )
+  DataMap::iterator iter = sDataObjects.find( fileName );
+  if ( iter != sDataObjects.end() )
   {
     QgsDebugMsg( "unrefing " + fileName );
     if ( --( iter.value().second ) == 0 )
     {
       QgsDebugMsg( "No one's using " + fileName + ", I'll erase it" );
       delete iter.value().first;
-      dataObjects.erase( iter );
+      sDataObjects.erase( iter );
     }
   }
 }
 
 
-// we have to initialize the static member
-QgsGpsData::DataMap QgsGpsData::dataObjects;
-
-
-
-
 bool QgsGPXHandler::startElement( const XML_Char *qName, const XML_Char **attr )
 {
 

diff --git a/src/providers/gpx/gpsdata.h b/src/providers/gpx/gpsdata.h
@@ -24,6 +24,7 @@
 #include <QString>
 #include <QTextStream>
 #include <QStack>
+#include <QMutex>
 
 #include "qgsrectangle.h"
 #include "qgsfeatureid.h"
@@ -280,7 +281,14 @@ class QgsGpsData
      * does reference counting, so several providers can use the same GPSData
      * object.
     */
-    static DataMap dataObjects;
+    static DataMap sDataObjects;
+
+    //! Mutex for sDataObjects
+#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
+    static QMutex sDataObjectsMutex;
+#else
+    static QRecursiveMutex sDataObjectsMutex;
+#endif
 
 };