QmlProfiler: Avoid race conditions in QQmlTypeLoader

We have to make sure all profiler calls to one adapter are done from the
same thread.

It turns out that all the calls from QQmlTypeLoader are done from the
type loader thread. By using a separate adapter for that, we avoid any
extra locking.

Task-number: QTBUG-62987
Change-Id: I5cffcc30b84dd4154daa0c56312a1141ce2033e1
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 10 insertions, 4 deletions

diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index 84410875ab..9b7b970e56 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -700,8 +700,7 @@ void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
 {
     Q_ASSERT(m_waitingFor.contains(blob));
     Q_ASSERT(blob->status() == Error || blob->status() == Complete);
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(typeLoader()->engine())->profiler,
-                               blob);
+    QQmlCompilingProfiler prof(typeLoader()->profiler(), blob);
 
     m_inCallback = true;
 
@@ -1262,7 +1261,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QString &fileName)
 void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeData &d)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -1282,7 +1281,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeD
 void QQmlTypeLoader::setCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -1597,6 +1596,9 @@ Constructs a new type loader that uses the given \a engine.
 */
 QQmlTypeLoader::QQmlTypeLoader(QQmlEngine *engine)
     : m_engine(engine), m_thread(new QQmlTypeLoaderThread(this)),
+#ifndef QT_NO_QML_DEBUGGER
+      m_profiler(nullptr),
+#endif
       m_typeCacheTrimThreshold(TYPELOADER_MINIMUM_TRIM_THRESHOLD)
 {
 }
@@ -1613,6 +1615,10 @@ QQmlTypeLoader::~QQmlTypeLoader()
     clearCache();
 
     invalidate();
+
+#ifndef QT_NO_QML_DEBUGGER
+    delete m_profiler;
+#endif
 }
 
 QQmlImportDatabase *QQmlTypeLoader::importDatabase() const