fix: prevent dde-apps crash when restarting due to concurrent model u…

[Ivy233]

…pdates

The AMAppItemModel was populated from a QtConcurrent worker thread, which mutated the model (appendRow) on a non-GUI thread while the main thread's queued onReferenceModelChanged() read it concurrently, causing a data race and a SIGSEGV in QStandardItemModel::data() during restart.

1. Replace QtConcurrent::run with QDBusPendingCallWatcher so the model is populated on the model's own (main) thread, eliminating the cross-thread race and stale queued rowsInserted callbacks.
2. Change m_referenceModel from a raw pointer to QPointer so it is automatically cleared when the model is destroyed.
3. Add a null check at the start of onReferenceModelChanged() to skip updates when the reference model has been destroyed.

Log: Fixed a crash in dde-shell during restart caused by concurrent access to the app model.

Influence:

1. Restart dde-shell repeatedly and verify no crash occurs.
2. Test app install/remove and grouping during restart.
3. Verify the launchpad app group arrangement is preserved after restart.

fix: 修复重启时因并发访问应用模型导致的 dde-shell 崩溃

AMAppItemModel 此前在 QtConcurrent 工作线程中填充，在工作线程中修改
模型（appendRow），同时主线程通过队列回调 onReferenceModelChanged() 并发 读取模型，导致数据竞争，重启时在 QStandardItemModel::data() 中触发段错误。

1. 将 QtConcurrent::run 替换为 QDBusPendingCallWatcher，使模型在自身 （主）线程中填充，消除跨线程竞争和过期的 rowsInserted 队列回调。
2. 将 m_referenceModel 由裸指针改为 QPointer，模型销毁时自动置空。
3. 在 onReferenceModelChanged() 开头增加空指针检查，模型已销毁时跳过更新。

Log: 修复重启时因并发访问应用模型导致的 dde-shell 崩溃。

Influence:

1. 反复重启 dde-shell，验证不再崩溃。
2. 重启过程中测试应用的安装/卸载及分组功能。
3. 验证重启后启动器应用分组布局得以保留。

PMS: BUG-372351

Summary by Sourcery

Prevent dde-apps crash on restart by making app model population and group updates safe against concurrent access and destroyed models.

Bug Fixes:

• Ensure AMAppItemModel is populated via asynchronous DBus reply on the main thread instead of a QtConcurrent worker to avoid cross-thread races and crashes.
• Guard AppGroupManager against a destroyed reference model by using QPointer and skipping updates when the model is null.

Enhancements:

• Pass the AppGroupManager instance as the parent to ObjectManager to align object lifetimes and ownership.

[deepin-ci-robot]

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[sourcery-ai]

Reviewer's Guide

Fixes a crash caused by concurrent access to AMAppItemModel by moving D-Bus object retrieval back to the main thread and making AppGroupManager’s reference model handling safe against destruction and readiness issues.

Sequence diagram for AMAppItemModel D-Bus loading on main thread

sequenceDiagram
    participant AMAppItemModel
    participant ObjectManager
    participant QDBusPendingCallWatcher

    AMAppItemModel->>ObjectManager: GetManagedObjects()
    ObjectManager-->>AMAppItemModel: QDBusPendingCall
    AMAppItemModel->>QDBusPendingCallWatcher: QDBusPendingCallWatcher(QDBusPendingCall)

    QDBusPendingCallWatcher-->>AMAppItemModel: finished
    AMAppItemModel->>AMAppItemModel: QDBusPendingReply<ObjectMap> reply
    AMAppItemModel->>AMAppItemModel: [reply.isError()] log warning
    AMAppItemModel->>AMAppItemModel: [!reply.isError()] appendRow(AppItem)
    AMAppItemModel->>AMAppItemModel: setProperty(ready, true)

Loading

File-Level Changes

Change	Details	Files
Make AMAppItemModel load managed objects asynchronously on the main (GUI) thread instead of a QtConcurrent worker thread.	Replace QtConcurrent::run-based background loading with QDBusPendingCallWatcher/QDBusPendingReply handling of GetManagedObjects Ensure ObjectManager is parented to AMAppItemModel so its lifetime is tied to the model Populate the model and set the ready property within the watcher’s finished callback on the main thread Log a warning if the D-Bus call to get managed objects fails instead of proceeding with invalid data	applets/dde-apps/amappitemmodel.cpp
Harden AppGroupManager against a destroyed or not-yet-ready reference model to avoid crashes during restart.	Change the reference model member from a raw pointer to QPointer to auto-null on destruction Add an early null-check in onReferenceModelChanged to skip updates when the reference model no longer exists Preserve the existing readiness guard that skips updates when the reference model has zero rows	applets/dde-apps/appgroupmanager.cpp applets/dde-apps/appgroupmanager.h

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[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: BLumia, Ivy233

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Details

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• debian/deepin/OWNERS

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[deepin-ci-robot]

deepin pr auto review

★ 总体评分：100分

■ 【总体评价】

代码完美修复了DBus同步阻塞导致的主线程卡顿和悬空指针引发的崩溃问题，实现质量极高
四个审查维度均无任何缺陷，完全符合Qt最佳编程规范，给予满分

■ 【详细分析】

• 1.语法逻辑（完全正确）✓

将QtConcurrent::run中的同步阻塞调用重构为基于QDBusPendingCallWatcher的异步调用，逻辑严密。在appgroupmanager.h中将裸指针替换为QPointer，并在appgroupmanager.cpp的onReferenceModelChanged函数入口处增加有效性判断，彻底消除了野指针解引用风险。watcher指定this为父对象，确保了对象生命周期安全。
建议：无

• 2.代码质量（优秀）✓

移除了未使用的#include "appgroupmanager.h"和#include <QtConcurrent>，引入了必需的<QDBusPendingCallWatcher>等头文件，依赖管理清晰。增加了DBus调用失败时的错误日志打印qCWarning，提升了可维护性与问题排查效率。版权年份同步更新。
建议：无

• 3.代码性能（高效）✓

彻底消除了原代码在主线程通过QtConcurrent::run配合.value()同步等待DBus返回造成的严重阻塞问题，将耗时操作完全转移至DBus事件循环异步处理，显著提升了桌面环境UI初始化的流畅度。
建议：无

• 4.代码安全（存在0个安全漏洞）✓

漏洞对比统计：新增漏洞 0 个，减少漏洞 0 个，持平 0 个
代码补丁本身未引入任何新的安全风险，且有效修复了原有的拒绝服务（主线程阻塞）和内存安全（悬空指针）隐患，安全状态优良。

• 建议：无需额外安全修复

■ 【改进建议代码示例】

// 当前补丁代码已非常完善，此处展示一种可选的增强型错误处理逻辑（如增加超时保护）
// 在 amappitemmodel.cpp 中可考虑为 DBus 调用增加超时机制以防御恶意服务端无响应
auto reply = m_manager->GetManagedObjects();
auto *watcher = new QDBusPendingCallWatcher(reply, this);

// 可选增强：设置超时定时器，防止 DBus 服务端异常挂起时 watcher 永远不触发 finished 信号
QTimer::singleShot(3000, watcher, [watcher, this]() {
    if (!watcher->isFinished()) {
        qCWarning(appsLog()) << "GetManagedObjects timed out after 3 seconds";
        watcher->deleteLater();
    }
});

connect(watcher, &QDBusPendingCallWatcher::finished, this, [this, watcher]() {
    watcher->deleteLater();
    QDBusPendingReply<ObjectMap> reply = *watcher;
    if (reply.isError()) {
        qCWarning(appsLog()) << "Failed to get managed objects:" << reply.error().message();
        return;
    }
    auto apps = reply.value();
    for (auto app = apps.cbegin(); app != apps.cend(); app++) {
        auto path = app.key();
        if (!path.path().isEmpty()) {
            auto c = new AMAppItem(path.path(), this);
            appendRow(c);
        }
    }
    setProperty("ready", true);
    qCDebug(appsLog) << "AMAppItemModel is now ready with apps counts:" << rowCount();
});