Avoid thread violation warnings spamming console by limiting to one w…

…arning per code location

src/core/CMakeLists.txt

@@ -532,6 +532,7 @@ set(QGIS_CORE_SRCS
   qgstemporalrangeobject.cpp
   qgstemporalutils.cpp
   qgstessellator.cpp
+  qgsthreadingutils.cpp
   qgstilecache.cpp
   qgstiledownloadmanager.cpp
   qgstiles.cpp

src/core/qgsthreadingutils.cpp

@@ -0,0 +1,19 @@
+/***************************************************************************
+               qgsthreadingutils.cpp
+                     --------------------------------------
+               Date                 : April 2023
+               Copyright            : (C) 2023 by Nyall Dawson
+               email                : nyall dot dawson at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsthreadingutils.h"
+
+QSet< QString > QgsThreadingUtils::sEmittedWarnings;
+QMutex QgsThreadingUtils::sEmittedWarningMutex;

src/core/qgsthreadingutils.h

@@ -26,6 +26,7 @@
 #include <QThread>
 #if defined(QGISDEBUG) || defined(AGGRESSIVE_SAFE_MODE)
 #include <QDebug>
+#include <QMutex>
 #endif
 #include <QSemaphore>
 #include <QCoreApplication>
@@ -46,7 +47,7 @@
 #ifdef __clang_analyzer__
 #define QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL do {} while(false);
 #elif defined(QGISDEBUG)
-#define QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL if ( QThread::currentThread() != thread() ) {qWarning() << QStringLiteral("%2 (%1:%3) is run from a different thread than the object %4 lives in [0x%5 vs 0x%6]" ).arg( QString( __FILE__ ), QString( __FUNCTION__ ), QString::number( __LINE__  ), objectName() ).arg( reinterpret_cast< qint64 >( QThread::currentThread() ), 0, 16 ).arg( reinterpret_cast< qint64 >( thread() ), 0, 16 ).toLocal8Bit().constData(); }
+#define QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL if ( QThread::currentThread() != thread() ) { const QString location = QStringLiteral("%1 (%2:%3)").arg( QString( __FUNCTION__ ) ,QString( __FILE__ ), QString::number( __LINE__  ) ); QgsThreadingUtils::sEmittedWarningMutex.lock(); if ( !QgsThreadingUtils::sEmittedWarnings.contains( location ) ) { qWarning() << QStringLiteral("%1 is run from a different thread than the object %2 lives in [0x%3 vs 0x%4]" ).arg( location, objectName() ).arg( reinterpret_cast< qint64 >( QThread::currentThread() ), 0, 16 ).arg( reinterpret_cast< qint64 >( thread() ), 0, 16 ).toLocal8Bit().constData(); QgsThreadingUtils::sEmittedWarnings.insert( location ); } QgsThreadingUtils::sEmittedWarningMutex.unlock(); }
 #else
 #define QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL do {} while(false);
 #endif
@@ -153,6 +154,10 @@ class CORE_EXPORT QgsThreadingUtils
         return true;
       }
     }
+#if defined(QGISDEBUG)
+    static QSet< QString > sEmittedWarnings;
+    static QMutex sEmittedWarningMutex;
+#endif
 
 };