Busy animators: fix access to childContainerNode()

Accessing QQuickItemPrivate::childContainerNode() in updateCurrentTime(),
which is executed in render thread context, is not safe and may cause
random crashes.

Change-Id: Ibbdf387f7e8d593740452e56b819a6d7fd9341e6
Reviewed-by: Mitch Curtis <mitch.curtis@theqtcompany.com>

2 files changed, 34 insertions, 10 deletions

diff --git a/src/imports/controls/material/qquickmaterialprogressring.cpp b/src/imports/controls/material/qquickmaterialprogressring.cpp
index 7f7ed114..54728686 100644
--- a/src/imports/controls/material/qquickmaterialprogressring.cpp
+++ b/src/imports/controls/material/qquickmaterialprogressring.cpp
@@ -71,9 +71,10 @@ public:
     void updateCurrentTime(int time) Q_DECL_OVERRIDE;
     void writeBack() Q_DECL_OVERRIDE;
     void nodeWasDestroyed() Q_DECL_OVERRIDE;
+    void afterNodeSync() Q_DECL_OVERRIDE;
 
 private:
-    QSGNode *m_itemNode;
+    QSGNode *m_containerNode;
     QQuickWindow *m_window;
 };
 
@@ -164,7 +165,7 @@ QQuickAnimatorJob *QQuickMaterialRingAnimator::createJob() const
 }
 
 QQuickMaterialRingAnimatorJob::QQuickMaterialRingAnimatorJob() :
-    m_itemNode(Q_NULLPTR),
+    m_containerNode(Q_NULLPTR),
     m_window(Q_NULLPTR)
 {
 }
@@ -176,14 +177,16 @@ QQuickMaterialRingAnimatorJob::~QQuickMaterialRingAnimatorJob()
 void QQuickMaterialRingAnimatorJob::initialize(QQuickAnimatorController *controller)
 {
     QQuickAnimatorJob::initialize(controller);
-    m_itemNode = QQuickItemPrivate::get(m_target)->itemNode();
+    m_containerNode = QQuickItemPrivate::get(m_target)->childContainerNode();
     m_window = m_target->window();
 }
 
 void QQuickMaterialRingAnimatorJob::updateCurrentTime(int time)
 {
-    QSGNode *childContainerNode = QQuickItemPrivate::get(m_target)->childContainerNode();
-    QSGSimpleRectNode *rectNode = static_cast<QSGSimpleRectNode*>(childContainerNode->firstChild());
+    if (!m_containerNode)
+        return;
+
+    QSGSimpleRectNode *rectNode = static_cast<QSGSimpleRectNode*>(m_containerNode->firstChild());
     if (!rectNode)
         return;
 
@@ -252,10 +255,15 @@ void QQuickMaterialRingAnimatorJob::writeBack()
 
 void QQuickMaterialRingAnimatorJob::nodeWasDestroyed()
 {
-    m_itemNode = Q_NULLPTR;
+    m_containerNode = Q_NULLPTR;
     m_window = Q_NULLPTR;
 }
 
+void QQuickMaterialRingAnimatorJob::afterNodeSync()
+{
+    m_containerNode = QQuickItemPrivate::get(m_target)->childContainerNode();
+}
+
 QQuickMaterialRingTexture::QQuickMaterialRingTexture()
 {
 }
diff --git a/src/imports/controls/qquickbusyindicatorring.cpp b/src/imports/controls/qquickbusyindicatorring.cpp
index 4711ae1b..18413b73 100644
--- a/src/imports/controls/qquickbusyindicatorring.cpp
+++ b/src/imports/controls/qquickbusyindicatorring.cpp
@@ -50,9 +50,14 @@ public:
     QQuickBusyIndicatorAnimatorJob();
     ~QQuickBusyIndicatorAnimatorJob();
 
+    void initialize(QQuickAnimatorController *controller) Q_DECL_OVERRIDE;
     void updateCurrentTime(int time) Q_DECL_OVERRIDE;
     void writeBack() Q_DECL_OVERRIDE;
     void nodeWasDestroyed() Q_DECL_OVERRIDE;
+    void afterNodeSync() Q_DECL_OVERRIDE;
+
+private:
+    QSGNode *m_node;
 };
 
 static const int circles = 10;
@@ -153,7 +158,7 @@ QQuickAnimatorJob *QQuickBusyIndicatorAnimator::createJob() const
     return new QQuickBusyIndicatorAnimatorJob;
 }
 
-QQuickBusyIndicatorAnimatorJob::QQuickBusyIndicatorAnimatorJob()
+QQuickBusyIndicatorAnimatorJob::QQuickBusyIndicatorAnimatorJob() : m_node(Q_NULLPTR)
 {
 }
 
@@ -161,13 +166,18 @@ QQuickBusyIndicatorAnimatorJob::~QQuickBusyIndicatorAnimatorJob()
 {
 }
 
+void QQuickBusyIndicatorAnimatorJob::initialize(QQuickAnimatorController *controller)
+{
+    QQuickAnimatorJob::initialize(controller);
+    m_node = QQuickItemPrivate::get(m_target)->childContainerNode();
+}
+
 void QQuickBusyIndicatorAnimatorJob::updateCurrentTime(int time)
 {
-    if (!m_target)
+    if (!m_node)
         return;
 
-    QSGNode *childContainerNode = QQuickItemPrivate::get(m_target)->childContainerNode();
-    QSGSimpleRectNode *rootRectNode = static_cast<QSGSimpleRectNode*>(childContainerNode->firstChild());
+    QSGSimpleRectNode *rootRectNode = static_cast<QSGSimpleRectNode*>(m_node->firstChild());
     if (!rootRectNode)
         return;
 
@@ -204,6 +214,12 @@ void QQuickBusyIndicatorAnimatorJob::writeBack()
 
 void QQuickBusyIndicatorAnimatorJob::nodeWasDestroyed()
 {
+    m_node = Q_NULLPTR;
+}
+
+void QQuickBusyIndicatorAnimatorJob::afterNodeSync()
+{
+    m_node = QQuickItemPrivate::get(m_target)->childContainerNode();
 }
 
 QT_END_NAMESPACE