fix: prevent null pointer dereference by disconnecting textureChanged signal#637
Conversation
signal 1. The crash occurred during scene graph cleanup when the textureChanged signal was triggered after preprocessNode had already been cleared 2. Added explicit disconnection of textureChanged signal connection in clearPreprocessNode to prevent accessing freed preprocessNode 3. This ensures the signal handler doesn't execute after node cleanup Influence: 1. Test scene graph cleanup by closing/quitting the application 2. Verify no crashes occur when transitioning between different viewport states 3. Test viewport rendering with dynamic content updates 4. Validate no memory leaks from dangling signal connections fix: 通过断开textureChanged信号连接防止空指针解引用 1. 崩溃发生在场景图清理过程中，textureChanged信号在preprocessNode被清除 后触发 2. 在clearPreprocessNode中添加显式的信号连接断开操作，防止访问已释放 的preprocessNode 3. 确保信号处理函数在节点清理后不会执行 Influence: 1. 通过关闭/退出应用测试场景图清理过程 2. 验证在不同视口状态切换时不会发生崩溃 3. 测试带动态内容更新的视口渲染 4. 验证没有因悬空信号连接导致的内存泄漏
![sourcery-ai[bot]](https://avatars.githubusercontent.com/in/48477?s=60&v=4){kind=small}
There was a problem hiding this comment.
Sorry @18202781743, you have reached your weekly rate limit of 500000 diff characters.
Please try again later or upgrade to continue using Sourcery
|
Thread 1 (Thread 0x7f921d2006c0 (LWP 3649)): |
deepin pr auto review你好！我是CodeGeeX，你的智能编程助手。我已仔细审查了你提供的 Git Diff 输入。 这次代码变更主要做了两件事：一是更新了版权声明的时间范围；二是针对 以下是我对该代码变更的详细审查意见： 1. 语法逻辑
2. 代码质量
3. 代码性能
4. 代码安全
💡 改进建议虽然当前的修复已经很好了，但在代码的健壮性和一致性方面，还有进一步优化的空间： 建议一：增加 建议二：确保“成对出现”的连接与断开逻辑 建议三：考虑使用 Lambda 捕获的上下文安全（如果槽函数是 Lambda） 优化后的代码示例（考虑了连接前的安全断开）： void DQuickItemViewportPrivate::clearPreprocessNode(PreprocessNode *oldNode)
{
Q_ASSERT(load(preprocessNode) == oldNode);
preprocessNode = nullptr;
// 断开 textureChanged 信号连接，避免在场景图清理过程中
// 信号触发时访问已清除的 preprocessNode 导致空指针解引用
if (textureChangedConnection) {
QObject::disconnect(textureChangedConnection);
textureChangedConnection = {};
}
}
// 假设这是建立连接的地方，建议保持对称逻辑
void DQuickItemViewportPrivate::setupPreprocessNode(PreprocessNode *newNode)
{
// 如果存在旧连接，先安全断开
if (textureChangedConnection) {
QObject::disconnect(textureChangedConnection);
textureChangedConnection = {};
}
preprocessNode = newNode;
// 建立新连接
if (newNode && textureProvider) { // 伪代码，视实际情况而定
textureChangedConnection = QObject::connect(textureProvider, &SomeClass::textureChanged,
this, &DQuickItemViewportPrivate::onTextureChanged);
}
}总结：这是一个质量很高的 Bug 修复提交，逻辑清晰，注释到位，安全性和代码质量都得到了提升。采纳上述建议可以让相关模块的代码更加稳健。 |
|
崩溃摘要 位置: src/dquickitemviewport.cpp:455-456 根本原因 这是一个竞态条件导致的空指针解引用：
崩溃堆栈 #0 operator() at ./src/dquickitemviewport.cpp:455 |
|
[APPROVALNOTIFIER] This PR is NOT APPROVED This pull-request has been approved by: 18202781743, BLumia The full list of commands accepted by this bot can be found here. DetailsNeeds approval from an approver in each of these files:Approvers can indicate their approval by writing |
3 participants
signal
was triggered after preprocessNode had already been cleared
clearPreprocessNode to prevent accessing freed preprocessNode
Influence:
states
fix: 通过断开textureChanged信号连接防止空指针解引用
后触发
的preprocessNode
Influence: